Risk assessment of vitamin A (retinol and retinyl
esters) in cosmetics

Opinion of the Panel on Food Additives, Flavourings, Processing Aids,
Materials in Contact with Food and Cosmetics of the Norwegian ScientificCommittee for Food Safety
Date:

22.08.12

Doc. no.:10-405-3 final

ISBN:

978-82-8259-059-4

VKM Report 2012: 25

VKM Report 2012: 25
Norwegian Scientific Committee for Food Safety (VKM)

10/405-3 final

Risk assessment of vitamin A (retinol and retinyl esters) incosmetics

Ragna Bogen Hetland (Chair)
Berit Granum
Claus Lützow-Holm
Jan Ludvig Lyche
Jan Erik Paulsen
Vibeke Thrane2Norwegian Scientific Committee for Food Safety (VKM)

10/405-3 final

Contributors
Persons working for VKM, either as appointed members of the Committee or as ad hoc
experts, do this by virtue of their scientific expertise, not as representatives for theiremployers. The Civil Services Act instructions on legal competence apply for all work
prepared by VKM.

Acknowledgements
The Norwegian Scientific Committee for Food Safety (Vitenskapskomiteen for mattrygghet,
VKM) has appointed a working group consisting of both VKM members and external experts
to answer the request from the Norwegian Food Safety Authority. The members of theworking group are acknowledged for their valuable work on this opinion.
The members of the working group are:
VKM members
Ragna Bogen Hetland, Panel on Food Additives, Flavourings, Processing Aids, Materials in
Contact with Food and Cosmetics (Chair)
Berit Granum, Panel on Food Additives, Flavourings, Processing Aids, Materials in Contact
with Food and Cosmetics
Jan Ludvig Lyche, Panel on Nutrition, Dietetic Products, Novel Food and Allergy
Jan Erik Paulsen, Panel on Food Additives, Flavourings, Processing Aids, Materials in
Contact with Food and Cosmetics
Vibeke Thrane, Panel on Food Additives, Flavourings, Processing Aids, Materials in Contact
with Food and Cosmetics
External experts
Claus Lützow-Holm, Huddoktoren, self-employed

Assessed by
The report from the working group has been evaluated and approved by the Panel on Food
Additives, Flavourings, Processing Aids, Materials in Contact with Food and Cosmetics of
VKM.
Panel on Food Additives, Flavourings, Processing Aids, Materials in Contact with Foodand Cosmetics:
Inger-Lise Steffensen (Chair), Jan Alexander, Mona-Lise Binderup, Knut Helkås Dahl, Berit
Granum, Ragna Bogen Hetland, Trine Husøy, Jan Erik Paulsen, Tore Sanner, Vibeke Thrane.
Scientific coordinators from the secretariat
Tor Øystein Fotland, Inger Therese Laugsand Lillegaard.

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Summary
The Norwegian Scientific Committee for Food Safety (Vitenskapskomiteen for mattrygghet,
VKM) has at the request of the Norwegian Food Safety Authority (Mattilsynet) conducted anassessment of the risk related to the use of retinol and retinyl esters in cosmetic products. VKM
was asked to assess both systemic and local effects of vitamin A for different age groups in the
Norwegian population. The total exposure to vitamin A for different age groups should be
estimated, taking into account both oral and dermal exposure routes, and include exposure
scenarios that illustrate the influence of changing maximum authorised concentration levels of theretinol and retinyl esters used in cosmetics. The assessment has been performed by the VKM
Panel on Food Additives, Flavourings, Processing Aids, Materials in Contact with Food andCosmetics.
Vitamin A constitutes a group of lipid-soluble compounds including retinyl esters, retinol andretinal. The main sources of dietary vitamin A are preformed vitamin A in the form of retinol andretinyl esters (from animal foods and supplements) and provitamin A carotenoids (from plants).
Vitamin A is essential throughout life as it is required in numerous physiological functions.
Retinol and retinyl esters are widely used ingredients in skin care products, such as anti-wrinkle
products, moisturisers and sunscreens, due to their effects on various biological processes in the
skin.
Both acute and chronic excessive intake of vitamin A may result in hypervitaminosis A which
includes a number of systemic adverse effects. The teratogenic potential, effects on bone and local
effects in the skin of vitamin A were considered as the most critical toxicological endpoints in thisopinion and have therefore been dealt with in more detail than other possible adverse effects.
The risk characterisation for all age groups in the present opinion is based on the tolerable upper
intake levels (UL) derived from earlier opinions from the Scientific Committee of Food (SCF)
and European Food Safety Authority (EFSA). In 2002, the SCF derived an UL of 3000 µg retinol
equivalents (RE)/day for all women of child-bearing age based on the teratogenic potential ofvitamin A. Although teratogenicity is only relevant to women of child-bearing age, SCF
considered that the upper level of 3000 µg RE/day is appropriate also for men and for infants andchildren after correction for differences in metabolic rate. In 2008, EFSA considered that amaximum intake of 1500 µg RE/day would serve as a guidance level (GL) for individuals atgreater risk of osteoporosis and bone fracture (particularly post-menopausal women).
Estimations of the intake of vitamin A from the diet and supplements were based on national foodconsumption surveys for children (1-, 2-, 4- and 9-year-olds), adolescents (13-year-olds) andadults (18-70-year-olds) (Spedkost 2006-2007, Småbarnskost 2007, Ungkost 2000 and Norkost
3).
The Scientific Committee for Consumer Safety’s (SCCS) Notes of Guidance for the Testing of
Cosmetic Ingredients was used to estimate the systemic exposure dose (SED) from dermal
absorption of retinol and retinyl esters. The study considered to best fulfil the SCCS’s criteria forin vitro absorption studies was Yourick et al. (2008). Based on this study, the value of dermallyabsorbed retinol was estimated by VKM to be 5.7%.
The use of retinol and retinyl esters in cosmetic product is restricted in the Norwegian cosmetics
regulations with maximum allowed concentrations of 0.3% retinol and 0.7% retinyl palmitate.
According to the cosmetic industry, retinol and retinyl esters are used in the following
concentrations: 0.01%-0.05% RE in body lotions and 0.01-0.3% retinol equivalents (RE) in faceand hand creams. Thus the standard exposure scenarios in this opinion are based on aconcentration of 0.05% RE in body lotions and 0.3% RE in face and hand creams. In the worst
case scenarios, a concentration of 0.3% RE in body lotions and 1% RE in face and hand creams
are used. These concentrations are based on maximum allowed concentration of retinol in Norway
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and on information from the Norwegian Medicines Agency that products intended for cosmetic
use may contain 1% retinol.
Application of vitamin A-containing baby skin care products such as body lotions and creams
were considered relevant for 1- and 2-year old children. Similarly, application of body lotion for
4- and 9-year old children, body lotion and hand cream for adolescents and body lotion, face andhand creams for adults were included in the exposure estimates.
Based upon these premises, previous international and national risk assessments, and publishedliterature, the following conclusions were drawn by VKM:
The critical adverse health effect of excess intake of vitamin A is teratogenicity. This effect is thebasis for the tolerable upper intake level (UL) of 3000 µg RE/day.
The most important source of vitamin A in the population is diet, followed by food supplements
and then cosmetics.
The dietary intake of preformed vitamin A is high in parts of the Norwegian population.
Consumption of food supplements contributes significantly to the total intake of preformed
vitamin A in all age groups and will increase the proportion of the population exceeding the UL.
Topical application of cosmetic products as estimated in the standard scenarios (0.05% in body
lotions and 0.3% in face and hand cream), increases the total exposure to vitamin A (retinol andretinyl esters) in all age groups. The estimated contribution of retinol and retinyl esters fromcosmetics is most prominent for 13-year-old adolescents (23% of UL) and adults (29% of UL).
In the worst case scenarios based on the assumed increased concentrations in cosmetics (0.3% inbody lotions and 1% in face and hand cream), the contribution from cosmetics would further
increase the total exposure to vitamin A (retinol and retinyl esters). The estimated contribution ofretinol and retinyl esters from cosmetics would reach 42-58% of the ULs for children, 98% of the
UL for 13-year-old adolescents and exceed the UL for adults (115%).
The contribution from cosmetics is of special concern for women of fertile age, and a total
exposure above the UL before and during pregnancy will increase the risk of birth defects.
For persons who are at higher risk for reduced bone mineral density, osteoporosis and fractures,
especially post-menopausal women, a lower guidance level (GL) than the UL has been set, i.e.
1500 µg RE/day. About 10% of adult women in Norway exceed this GL by intake of vitamin A
from food and food supplements alone. The additional contribution from cosmetics increases this
proportion to approximately 75%. An increased exposure due to higher concentrations of vitamin
A (retinol and retinyl esters) in cosmetic products would further augment the proportion of
women at risk of osteoporosis.
Impaired skin may result in increased absorption of cosmetic products. This can occur in persons
with diagnosed atopic dermatitis, in persons that suffer from dry skin and in small children withirritated skin in the nappy area.
Regarding local adverse effects in the skin, no information was found indicating that long-term
use of topical retinoids may induce other effects than irritation and erythema. A NTP study
indicates that retinol and retinyl palmitate may be photocarcinogenic in mice. However, these data
do not provide sufficient information for a risk assessment of this effect of retinol and retinyl
esters in cosmetics.

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Norsk sammendrag
Vitenskapskomiteen for mattrygghet (VKM) har på oppdrag fra Mattilsynet gjennomført en
risikovurdering forbundet med bruk av vitamin A (retinol og retinyl estere) i kosmetiske
produkter. VKM ble bedt om å vurdere både lokale og systemiske effekter av vitamin A. Videreskulle den totale eksponeringen for vitamin A i ulike aldersgrupper i den norske befolkningen
beregnes ved å ta hensyn til både oral og dermal eksponering, og gjennom å inkludereeksponeringsscenarioer som illustrerer betydningen av å endre den maksimalt tillatte
konsentrasjonen av retinol og retinyl estere i kosmetiske produkter. Vurderingen er gjennomført
av Faggruppen for tilsetningsstoffer, aroma, matemballasje og kosmetikk.
Vitamin A består av en gruppe fettløselige forbindelser inkludert retinyl estere, retinol og retinal.
Hovedkildene til inntak av vitamin A fra kosten er retinol og retinyl estere fra animalske matvarerog kosttilskudd og karotenoider fra frukt og grønnsaker. Inntak av vitamin A er nødvendig siden
det inngår i en rekke fysiologiske funksjoner i kroppen. På grunn av sine effekter i huden er
retinol og retinylestere mye brukt som ingredienser i kosmetiske produkter, for eksempel
antirynkekremer, fuktighetskremer og solkremer.
For høyt akutt eller kronisk inntak av vitamin A kan medføre hypervitaminose A som inkluderer
flere negative systemiske effekter. De mest kritiske endepunktene for vitamin A-toksisitet synes åvære risiko for teratogene effekter, effekter på beinbygningen og lokale effekter i huden. Disse
effektene har derfor blitt omtalt mer detaljert enn andre mulige negative effekter av vitamin A i
denne risikovurderingen.
Risikokarakteriseringen for de ulike aldersgruppene tar utgangspunkt i de øvre tolerable
inntaksnivåene (UL) for vitamin A som er fastsatt av EUs tidligere vitenskapskomité påmatområdet (SCF) og EUs mattrygghetsorgan (EFSA). Basert på risikoen for potensielle
teratogene effekter av vitamin A, fastsatte SCF i 2002 en UL-verdi på 3000 µg retinolekvivalenter(RE)/dag. Selv om teratogenisitet kun er relevant for kvinner i fertil alder, vurderte SCF at detøvre tolerable inntaksnivået på 3000 µg RE/dag også er passende for menn og for spedbarn og
barn etter at det er korrigert for forskjeller i metabolsk rate. I 2008 kom EFSA fram til at etmaksimalt inntak på 1500 µg RE/dag kan fungere som et veiledende inntaksnivå (GL) for
personer med høyere risiko for å utvikle osteoporose og beinskjørhet (spesielt kvinner ettermenopausen).
Inntaksberegningene for vitamin A fra mat og kosttilskudd i denne risikovurderingen er basert pådata fra de nasjonale kostholdsundersøkelsene for barn (1-, 2-, 4- og 9 åringer), ungdom (13åringer) og voksne (18-70-åringer) (Spedkost 2006-2007, Småbarnskost 2007, Ungkost 2000 og
Norkost 3).
EUs vitenskapelige komité for forbrukerprodukter (SCCS) sine retningslinjer for hvordan man
skal beregne eksponering fra kosmetiske produkter har blitt benyttet til å estimere den systemiske
eksponeringsdosen etter opptak av retinol og retinyl estere over huden. En studie publisert av
Yourick og medarbeidere i 2008 ble vurdert å være den studien som best oppfylte SCCS’s
kriterier for in vitro absorpsjonsstudier. Basert på opplysningene i denne studien, estimerte VKM
en verdi for dermal absorbsjon av retinol på 5.7 %.
I henhold til den norske kosmetikkforskriften er bruken av retinol og retinyl estere i kosmetiske
produkter regulert med en maksimalt tillatt konsentrasjon på 0,3 % retinol og 0,7 % retinyl
palmitat. Kosmetikkindustrien oppgir at det er vanlig å bruke følgende konsentrasjoner i aktuelle
produkter: 0,01-0,05 % RE i body lotion og 0,01-0,3 % RE i ansikts- og håndkremer. Standard
eksponerings-scenarioene for kosmetiske produkter i risikovurderingen tar derfor utgangspunkt i
at konsentrasjonene er 0,05 % RE i body lotions og 0,3 % RE i ansikts- og håndkremer. I verstefall-scenarioene er det benyttet konsentrasjoner på 0,3 % RE i body lotion og 1 % RE i ansikts- oghåndkremer. Disse konsentrasjonene er basert på den maksimalt tillatte konsentrasjonen av retinol
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i kosmetiske produkter i Norge og på informasjon fra Statens legemiddelverk som tilsier at
produkter ment for kosmetisk bruk kan inneholde 1 % retinol.
Bruk av vitamin A-holdige kremer og bodylotion ment for babyer og små barn ble ansett som
realistisk eksponering for 1- og 2 åringer. Tilsvarende ble bruk av body lotion for 4- og 9 åringer,
en kombinasjon av body lotion og håndkrem for ungdom og en kombinasjon av body lotion,ansiktskrem og håndkrem for voksne ansett å være relevant.
Basert på forutsetningene nevnt ovenfor, tidligere internasjonale og nasjonale risikovurderinger
samt publisert litteratur, har VKM trukket følgende konklusjoner:
Den avgjørende negative helseeffekten ved et for høyt inntak av vitamin A er teratogene effekter.
Disse er basis for fastsettelse av det øvre tolerable inntaksnivået (UL) på 3000 µg RE/dag.
Den viktigste kilden til eksponering for vitamin A i befolkningen er kostholdet etterfulgt av
kosttilskudd og deretter kosmetikk.
Inntaket av vitamin A er høyt for deler av den norske befolkningen. Inntak av kosttilskudd bidrar
signifikant til det totale inntaket av vitamin A for alle aldersgrupper og øker også andelen av
befolkningen som overskrider det øvre tolerable inntaksnivået.
Ved standard-scenarioene (0,05 % i bodylotion og 0,3 % i ansikts- og håndkremer) vil påføring av
kosmetiske produkter øke den totale eksponeringen for vitamin A (retinol og retinylestere) i allealdersgrupper. Det estimerte bidraget fra retinol og retinylestere fra kosmetikk er mest
fremtredende for 13 år gamle ungdommer og voksne (henholdsvis 23 og 29 % av UL).
I verste-fall-scenarioene basert på en økt brukskonsentrasjon av vitamin A i kosmetiske produkter(0,3 % i bodylotion og 1 % i ansikts- og håndkremer), vil bidraget fra kosmetikk kunne gi enytterligere økning av den totale eksponeringen for vitamin A (retinol og retinylestere). Det
estimerte bidraget av retinol og retinylestere fra kosmetikk kan komme opp mot 42-58 % av UL
for barn, 98 % for 13 år gamle ungdommer og kan overskride UL for voksne(115 %).
Bidraget fra kosmetikk er av spesiell bekymring for kvinner i fertil alder hvor total eksponeringover UL før og under graviditet vil kunne øke risikoen for medfødte skader hos barnet.
For personer som har en økt risiko for redusert beintetthet, osteoporose og beinbrudd (spesielt
kvinner etter menopausen) er det satt et veiledende inntaksnivå på 1500 µg RE/dag (GL) som daer lavere enn det øvre tolerable inntaksnivået (UL). For rundt 10 % av voksne kvinner i Norge vil
inntak av vitamin A gjennom kostholdet og kosttilskudd alene føre til en overskridelse av GL.
Bidraget fra bruk av retinol og retinyl estere i kosmetikk (som estimert i standard-scenarioene)øker denne andelen til rundt 75 %. Verste-fall-scenarioene vil gi en ytterligere økning i andelen
kvinner med en forhøyet risiko for å utvikle osteoporose.
Svekket/skadet hud kan føre til økt dermalt opptak av kosmetiske produkter. Dette gjelder spesielt
for personer diagnostisert med atopisk dermatitt, for personer med tørr hud og for små barn med
irritert/sår hud i bleieområdet.
Når det gjelder lokale effekter i huden, er det ikke funnet informasjon som tyder på at langsiktig
bruk av produkter som inneholder retinoider vil kunne indusere andre effekter enn irritasjon og
erytem. En studie fra National Toxicology Program (NTP) indikerer at retinol og retinyl palmitat
kan være fotokarsinogent i mus. Disse dataene bidrar imidlertid ikke med tilstrekkelig
informasjon for en risikovurdering av denne effekten av retinol og retinyl estere i kosmetiske
produkter.

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Abbreviations/Glossary
1,25(OH)2D – 1,25-dihydroxyvitamin D
25(OH)D – 25-hydroxyvitamin D
AFSSA – The French Food Safety Agency
AFSSAPS – The French Agency for the Safety of Health Products
BfR – Federal Institute for Risk Assessment
BMD – Bone mineral density
CNS – Central nervous system
CSF – Cerebro spinal fluid
EFSA – European Food Safety Authority
Erythema – Redness of the skin caused by any skin injury, infection or inflammation
FDA – Food and Drug Administration (US)FSA – Food Standards Agency (UK)GL – Guidance level
IU – International unit
LI – Lower level of intake
MMR – Matrix metalloproteinase
NNR – Nordic Nutrition Recommendations
NTP – National Toxicology Program
RAR – Retinoic acid receptor
RARE – Retinoid acid response element
RBP – Retinol-binding protein
RE – Retinol equivalent
Retinoids – all synthetic or natural compounds that have biological activity like that ofvitamin A
RI – Recommended intake
8Norwegian Scientific Committee for Food Safety (VKM)

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RXR – Retinoid X receptor
RXRE – Retinoid X responsive element
SACN – Scientific Advisory Committee on Nutrition
SCCS – Scientific Committee on Consumer Safety
SCF – Scientific Committee for Food (1974 - 1997)
SCF – Scientific Committee on Food (1997 - 2003)
SED – Systemic exposure dose
SSL – Simulated solar light
UL – Tolerable upper intake level
VDR – Vitamin D receptor
VKM – Norwegian Scientific Committee for Food Safety9Norwegian Scientific Committee for Food Safety (VKM)

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Contents
Contributors ............................................................................................................................. 3
Summary ................................................................................................................................... 4
Norsk sammendrag .................................................................................................................. 6
Abbreviations/Glossary ........................................................................................................... 8Contents................................................................................................................................... 10
Background ............................................................................................................................. 12
Terms of reference ................................................................................................................. 13
Assessment .............................................................................................................................. 13
1

Introduction ................................................................................................................ 14
1.1
1.1.1
1.1.2
1.2
1.2.1
1.2.2
1.2.3
1.2.4
1.3
1.3.1
1.3.1.1
1.3.1.2
1.3.1.3
1.3.2
1.3.2.1
1.3.2.2
1.3.2.3
1.3.2.4

2

Hazard identification and characterisation ............................................................. 23
2.1
2.1.1
2.2
2.2.1
2.2.2
2.2.2.1
2.2.2.2
2.3
2.3.1
2.3.2
2.3.3
2.3.3.1
2.3.3.2
2.3.4
2.3.5
2.4
2.4.1
2.4.2
2.4.3
2.5

3

Vitamin A – general background ....................................................................................................... 14
Recommended intake and tolerable upper intake level ...................................................................... 14
Retinol equivalents............................................................................................................................. 15
Vitamin A and the skin ...................................................................................................................... 15
Structure and physiology of the skin .................................................................................................. 16
Retinoid function in the skin .............................................................................................................. 17
Retinoids in cosmetics ....................................................................................................................... 18
Retinoids for medical use................................................................................................................... 19
Previous assessments of vitamin A (retinol and retinyl esters) .......................................................... 19
Cosmetics ........................................................................................................................................... 19
Norwegian Institute of Public Health/Ullevål University Hospital (Paulsen et al., 1997) ................. 19
Federal Institute for Risk Assessment (BfR) (2006, 2009 and 2010) ................................................ 20
The French Agency for the Safety of Health Products (AFSSAPS) (2011)....................................... 20
Food and food supplements ............................................................................................................... 21
Scientific Committee on Food (2002) ................................................................................................ 21
European Food Safety Authority (2008) ............................................................................................ 21
Nordic Council of Ministers (TemaNord 2003:502) (Blomhoff et al., 2003) .................................... 22
Nordic Nutrition Recommendations (2004) ....................................................................................... 23
Retinoid uptake and metabolism after oral intake .............................................................................. 23
Retinoid-dependent signalling ........................................................................................................... 24
Systemic adverse effects of retinoids (hypervitaminosis A) .............................................................. 25
Teratogenic effects ............................................................................................................................. 26
Osteoporosis....................................................................................................................................... 26
Skeletal effects of vitamin A .............................................................................................................. 26
Combined effects of vitamins A and D .............................................................................................. 28
Retinoid uptake and metabolism after topical application ................................................................. 29
In vivo absorption ............................................................................................................................... 29
In vitro absorption .............................................................................................................................. 29
Factors that may influence dermal absorption ................................................................................... 30
Vehicles ............................................................................................................................................. 30
Impaired skin ..................................................................................................................................... 31
Skin metabolism of retinol and retinyl esters ..................................................................................... 31
Dermal absorption and systemic availability of topical retinoids ...................................................... 32
Local adverse effects of retinoids ...................................................................................................... 34
Skin irritation ..................................................................................................................................... 34
Photocarcinogenesis ........................................................................................................................... 34
Other potential local biological adverse effects ................................................................................. 35
Critical effect and upper intake levels ................................................................................................ 36

Exposure characterisation ......................................................................................... 38
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3.1
Exposure to retinol and retinyl esters from the use of cosmetics ....................................................... 38
3.1.1
Estimated exposure to retinol and retinyl esters from the use of cosmetic products in different age
groups in Norway ............................................................................................................................................. 38
3.1.1.1 Daily exposure to skin care products used in the exposure scenarios ................................................ 39
3.1.1.2 Concentrations of retinol and retinyl esters in skin care products used in the exposure scenarios .... 39
3.1.1.3 Dermal absorption data used in the exposure scenarios ..................................................................... 40
3.1.2
Estimated exposure to retinol and retinyl esters from the use of cosmetic products for infants andchildren 40
3.1.3
Estimated exposure to retinol and retinyl esters from the use of cosmetic products for adolescents . 41
3.1.4
Estimated exposure to retinol and retinyl esters from the use of cosmetic products for adults .......... 42
3.2
Dietary intake from preformed vitamin A.......................................................................................... 44
3.2.1
Methodological considerations and description of the national consumption surveys ...................... 44
3.2.2
Contribution of major food sources to retinol intake in Norway ....................................................... 45
3.2.3
Estimated intake of preformed vitamin A in the Norwegian population ........................................... 46

4

Risk characterisation ................................................................................................. 47
4.1
4.1.1
4.1.2
4.1.3
4.1.4
4.2
4.3

5

Systemic effects of retinol and retinyl esters from food, food supplements and cosmetics ............... 47
Total exposure to retinol and retinyl esters in Norwegian children ................................................... 48
Total exposure to retinol and retinyl esters in Norwegian adolescents .............................................. 51
Total exposure to retinol and retinyl esters in Norwegian adults ....................................................... 52
Summary of total exposure scenarios ................................................................................................ 53
Local adverse effects of retinoids ...................................................................................................... 55
Vulnerable groups .............................................................................................................................. 55

Uncertainty ................................................................................................................. 56
5.1
5.2
5.3

Dermal absorption and systemic availability ..................................................................................... 56
Dietary exposure assessment ............................................................................................................. 57
Summary table of uncertainties.......................................................................................................... 58

Data gaps ................................................................................................................................. 60
Conclusions ............................................................................................................................. 61
References ............................................................................................................................... 62
Appendices .............................................................................................................................. 71

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Background
Vitamin A (retinol and retinyl esters, such as retinyl palmitate and retinyl acetate) are widelyused ingredients in cosmetics products, such as anti-aging creams and other skin care products
to generally improve the appearance of skin. Topical application of vitamin A in the form of
retinol and retinyl esters has been shown to have beneficial effects on the skin when applied at
low concentrations. Products which are marketed as especially suitable for making the skin ofchildren soft and smooth could also contain vitamin A.
Currently, according to the national regulations for cosmetic products in Norway the
maximum authorised concentrations of vitamin A are 0.3% in the form of retinol and 0.7% in
the form of retinyl palmitate (Norwegian Cosmetic Regulations, 1995). There are no suchspecific restrictions for the use of vitamin A in cosmetic products laid down in the European
Cosmetics Directive 76/768/EEC (EC, 1976).
Excessive intakes of vitamin A has been linked to increased risk for hypervitaminose A,
retinol-induced teratogenicity and bone health problems. Another debated question related tovitamin A is whether frequent application of skin care products containing retinol or retinyl
esters could result in long term effects in skin. Recently, some concerns were also raised
regarding the phototoxic potential of retinol and its esters (NTP, 2011).
Amendments in the Norwegian Medicines Agency’s procedures for classification of drugs
have made it necessary to assess the use of pharmacological active substances in foods andcosmetics sold on the Norwegian market. At present, cosmetic products containing more
vitamin A (retinol or retinyl esters) than the abovementioned maximum authorised
concentrations would be illegal.
The current national regulations for retinol and retinyl palmitate in cosmetic products are
based on an evaluation of retinol and retinol esters in cosmetic products, taking into accountintake from dietary vitamin A and vitamin A supplements, performed by the NorwegianInstitute of Public Health and the Ullevål University Hospital in 1997 (Paulsen et al., 1997).
This previous evaluation is 15 years old and did not include relevant endpoints, such as
osteoporosis. The Norwegian Food Safety Authority has therefore requested an updated risk
assessment of vitamin A (retinol and retinyl esters) in cosmetic products from VKM.
The Norwegian Food Safety Authority will use VKM’s risk assessment to consider if thenational restrictions on the use of vitamin A (retinol and retinyl esters) in cosmetics should bemaintained, and if so, aim for an amendment of the European Cosmetics Directive to have
harmonised maximum authorised concentrations for vitamin A in cosmetic products within
the European Union (EU).
The Norwegian Food Safety Authority has emphasized that the risk assessment from VKM
should be based on the total exposure to vitamin A from cosmetic products and foods,
including food supplements, in the Norwegian population.
This opinion has been performed and approved by the VKM Panel on Food Additives,
Flavourings, Processing Aids, Materials in Contact with Food and Cosmetics. As a basis forthe final and approved opinion from VKM, a draft opinion was prepared by a working groupconsisting of members of the VKM Panel on Food Additives, Flavourings, Processing Aids,
Materials in Contact with Food and Cosmetics, the VKM Panel on Nutrition, Dietetic
Products, Novel Food and Allergy, and one external expert.

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Terms of reference
The Norwegian Food Safety Authority requests the Norwegian Scientific Committee for Food
Safety to assess the risk related to use of retinol and retinyl esters in cosmetics. The following
aspects should be considered in the assessment:The risk assessment should consider both systemic and local effects of vitamin A for
children and adults in the Norwegian population.

The SCCS’s Notes of Guidance for the Testing of Cosmetic Ingredients and Their
Safety Evaluation should be used to estimate the exposure from dermal absorption ofretinol and retinyl esters from the use of cosmetics.



The total exposure to vitamin A, taking into account the intake from foods and foodsupplements and exposure to cosmetic products should be estimated for different age
groups in the Norwegian population.



The risk assessment should include exposure scenarios that illustrate the influence ofchanging the maximum authorised concentration levels of the different forms ofvitamin A used in cosmetics.

The risk assessment should be based on already existing national and international evaluations
and opinions of vitamin A and on relevant data from the national food consumption surveys,
including new results from Norkost 3 for adults.

Assessment
The risk assessment of vitamin A (retinol and retinyl esters) in cosmetics and theconsiderations of the total exposure to vitamin A in this opinion from VKM are based onearlier opinions from the Scientific Committee on Food (SCF) and the European Food Safety
Authority (EFSA) on the Tolerable Upper Intake Level (UL) of preformed vitamin A (retinol
and retinyl esters). The Scientific Committee on Consumer Product’s (SCCS’s) Notes of
Guidance for the Testing of Cosmetic Ingredients and Their Safety Evaluation (7th revision)and recent evaluations on the use of retinol and its esters in cosmetics from the Federal
Institute for Risk Assessment (BfR) in Germany have been considered for specific issues
related to exposure to cosmetic products in this opinion.
VKM has focused on possible excessive intakes of preformed vitamin A in this opinion, as
exposure to vitamin A (retinol and retinyl esters) from cosmetic products is considered an
additional contribution to a potentially high intake of the substance in the population via foodand food supplements. The teratogenic potential, effects on bone and local effects in the skinof vitamin A were considered as the most critical toxicological endpoints and have therefore
been dealt with in more detail than other possible adverse effects in this opinion. Possible
health effects of vitamin A deficiency are not relevant according to the terms of reference forthis assessment and are therefore not discussed.

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1 Introduction
1.1 Vitamin A – general background
Vitamin A is essential throughout life as it is required in numerous physiological functions
such as vision, growth, proliferation and differentiation of epithelial tissues, immune
functions, bone growth, reproduction and embryonic development. Vitamin A constitutes agroup of lipid-soluble compounds including retinyl esters, retinol and retinal (retinyl
aldehyde). The main sources of dietary vitamin A are preformed vitamin A in the form of
retinol and retinyl esters from animal foods (dairy products, liver and fish liver oil) andsupplements. The vitamin can also be derived from plants (dark green leefy vegetables,orange-yellow fruits and vegetables) in the form of provitamin A carotenoids which are
enzymatically converted to vitamin A in the intestine and other tissues. Provitamin A
carotenoids may also be a constituent of food supplements. Because of the well regulated
bioconversion of carotenoids to preformed vitamin A, only intake of preformed vitamin A isconsidered relevant for vitamin A toxicity (Blomhoff et al., 2003; EFSA, 2008).
In industrialized countries there could be a potential health risk associated with excessive
vitamin A intake from diet and food supplements (Blomhoff et al., 2003). Symptoms ofhypervitaminosis A may occur in skin, nervous system, musculo-skeletal system, internalorgans and embryo (EFSA, 2008). In contrast, in many developing countries, vitamin A
deficiency is highly prevalent among children and pregnant woman, causing serious healtheffects such as reduced resistance against infections, reduced growth, severe anaemia,
blindness and death (West et al., 2011). The foetal and postnatal life stages appear to be mostsensitive to inadequate doses of vitamin A and both low and excess intake have the potential
to induce birth defects as well as other serious developmental disorders.

1.1.1

Recommended intake and tolerable upper intake level

The recommended intake (RI) of a nutrient is the intake at which the risk of health effects due
to inadequacy would be very small. It is assumed that adverse events occur above a thresholdintake level, therefore the vitamin A intake which should not be exceeded because of safetyconcerns is defined as the tolerable upper intake level (UL). The UL states the maximum levelof total chronic daily intake of a nutrient (from all sources) judged to be unlikely to pose arisk of adverse health effects to humans (SCF, 2000).
The risk of developing health problems along the intake scale of vitamin A can be illustrated
by a U-shaped curve with a lower level of intake (LI) at 400 and 500 µg/day for women andmen, respectively. RI is set to be 700 and 900 µg/day for women and men, respectively(NNR, 2004). Among women consuming vitamin A in the lower dose-ranges, no increase in
the risk of vitamin A-associated birth defects has been observed at doses below 3000 µg/day
and this dose is set as the UL for adults (SCF, 2002; EFSA, 2006a; 2008). However, longterm intakes of preformed vitamin A in excess of 1500 µg/day have been associated withincreased risk of osteoporosis in older men and women. Therefore, this level serves as a
guidance level (GL) for individuals at greater risk of osteoporosis and bone fracture(particularly post-menopausal women). Provitamin A carotenoids are not known to cause
vitamin A toxicity; therefore ULs are expressed in terms of preformed vitamin A (EFSA,
2008). The UL for retinol applies to intakes from both foods and food supplement, whereas anadditional contribution from cosmetic products has not been included.
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Retinol equivalents

For nutritional purposes, the term “retinol equivalent” (RE) is used to convert all dietary
sources of preformed vitamin A (retinol and retinyl esters) and provitamin A (carotenoids)
into a single unit. Based on molecular weights, 1 RE is defined as 1 µg of all-trans-retinol.
For conversion of preformed vitamin A activity expressed in International Units (IU) to RE, 1
RE is equivalent to 3.33 IU (Table 1). 1 µg of retinol is estimated to be biologicallyequivalent to 12 µg of carotenoids. In this opinion, VKM has chosen to express vitamin A
activity in RE.
Table 1: Vitamin A activity1.
Vitamin A activity inInternational Units (IU)

Vitamin A activity in Retinol Equivalents(µg RE)

Retinol (1 mg)

3330

1000

Retinyl acetate (1 mg)

2900

870

Retinyl palmitat (1 mg)

1830

550

1

Modified from SCF 2002.

1.2 Vitamin A and the skin
The use of cosmetic products could be another important source of vitamin A exposure.
Retinol and its esters are widely used ingredients in skin care products, such as antiphotoaging products and moisturizers. Consequently, dermal absorption of these ingredients
could contribute to the total exposure of vitamin A in the population. Retinol toxicity has beenshown to be a matter of concern for the Nordic countries where the dietary intake of retinol isrelatively high (Blomhoff et al., 2003; NNR, 2004). It is therefore of special importance tomonitor the additional contribution from the use of cosmetics in populations with an alreadyhigh intake of vitamin A from food and food supplements.
The retinyl esters retinyl palmitate and retinyl acetate, and the retinol all-trans-retinol, are themain vitamin A forms used in cosmetics. Retinal is another ingredient which could be foundin some cosmetic products, while retinoic acid, the biological active metabolite, is not allowedin cosmetics (Figure 1) (EC, 1976; Norwegian Cosmetic Regulations, 1995). Retinoic acid is,
however, the active component in some drugs used in clinical dermatology (van de Kerkhof,
2006).

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Retinyl palmitate

Retinyl acetate

All-trans retinol

RetinalRetinoic acid

Figure 1: Structure formulas of retinyl palmitate, retinyl acetate, all-trans retinol, retinal and retinoic acid.

1.2.1

Structure and physiology of the skin

The skin is the largest organ of the human body, with a surface area of around 2 m2 and a
thickness between 0.5 and 4 mm. It is anatomically designed to exert a wide range ofphysiological functions as it is: a physical and chemical barrier between the external andinternal environment; a sensory organ of touch, pressure, vibration, tissue injury andtemperature; a termoregulating organ controlling heat loss from sweating and cutaneous blood
flow. The specialized functions of the skin are made possible by its unique structure (Figure2), which is primarily stratified into the epidermis, the dermis and the hypodermis.
The epidermis, the outermost layer, has a protective structure, which consists of distinct strata
that reflect different stages of keratinocyte maturation: corneum, lucidum (only palms ofhands and sole of feet), granulosum, spinosum and basale (Fu et al., 2007; NTP 2010). In
addition to keratinocytes, the epidermis contains melanocytes (produce the sunlight protecting
pigment melanin), Langerhans cells (immune function) and Merkel (sensory) cells.
The dermis is a fibrous layer that support and strengthens the epidermis. It interfaces with theepidermis through a system of upward protrusions of dermal papillae, which provide a firmanchor to physically stabilize and support the epidermis. This papillary dermis contains a
network of capillaries. Since the epidermis contains no blood vessels, the metabolic needs ofthe epidermis are met through diffusion exchange of nutrients and waste products between theepidermis and capillaries in the dermis. The deeper portion of dermis, the reticular region, islesser vascularized. In aging, the synthesis of matrix proteins decelerates, while expression of
matrix metalloproteinases (MMPs) which are essential for the turnover of extracellular matrix
proteins accelerates. Chronic exposure to sunlight can further exacerbate these biochemical
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changes (Darlenski et al., 2010). The dermis also contains hair follicles, sweat glands,
sebaceous glands, apocrine glands and lymphatic vessels.
The hypodermis is a subcutaneous layer of fat beneath the dermis that supplies nutrients to theother two layers and cushions and insulates the body.

Figure 2: Principal components of the skin.

1.2.2

Retinoid function in the skinVitamin A has long been known to play a critical role in homeostasis of various epithelia
including epidermis and is important for sustaining normal growth and differentiation. A diet
deficient in vitamin A was early known to cause abnormal keratinization of epithelia (Bloch,1921 cited in NTP, 2011). Even though epidermis is avascular it contains significant
quantities of retinoids (Randolf and Siegenthaler, 1999 cited in NTP, 2011). This
demonstrates that plasma retinol has access to and is taken up by the keratinocytes, but themode of uptake is not clear (NTP, 2011). When absorbed, retinol may be esterified with fatty
acids to form retinyl esters. Retinol may also be oxidized into retinal, which subsequently
may be oxidized to retinoic acid (Figure 3).
Skin may also be supplied with vitamin A via topical application of cosmetics and drugs.
External topical retinoids may reverse dermatological disorders most likely by interferingwith local retinoid functions. Hence, topical retinoids have been used for clinical treatment ofpsoriasis, hyperkeratosis, acne, early aging and photodamage (Orfanos et al., 1997). The
retinoids seem to play a role in the aging process of the skin, since many of the changes may
be reversed by topical application (Darlenski et al., 2010). In the dermis, topical retinoids may
increase synthesis and inhibit degradation of collagen, changes that are associated withimprovement of coarse wrinkling. In the epidermis, topical retinoids may cause hyperplasia,
compaction of the stratum corneum, thickening of the granular layer and increased
intercellular mucin deposition. These changes are associated with increased smoothness of the
skin.

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Apparently the anti-aging effect of topical retinoids is mainly linked to the receptor-mediatedgene activation induced by the ligand retinoic acid modulating epidermal cell proliferationand differentiation, extracellular matrix production, angiogenesis, oxidative stress andmelanocyte function (Sorg et al., 2006). According to the intracrine-proligand concept theother topical retinoids have to be metabolised to retinoic acid by the skin to exert theirgenomic effects (see Figure 3). This concept implies that topical application of any precursor
retinoids may result in biological effects. However, the potency of the retinoid is strongly
dependent on its metabolic distance to retinoic acid. Hence, the retinoid-like activity after
topical application is increasing in the following order: retinyl esters << retinol < retinal <retinoic acid.
Retinyl ester
Esterase

Retinol
Alcohol dehydrogenase

Retinaldehyde (Retinal)
Aldehyde dehydrogenase

Retinoic acid

Figure 3: Metabolism of retinyl esters to retinoic acid.

1.2.3

Retinoids in cosmetics

The retinoids retinyl esters, retinol and retinal are used in a large variety of cosmetic products
such as anti-wrinkle creams, body lotions, hand creams and sunscreens. As active ingredients
they are expected to provide the cosmetic product with a series of specific abilities to improveand counteract skin aging and photoaging, prevent oxidative stress, and control cutaneousbacterial flora (Serri and Iorizzo, 2008; Sorg et al., 2006).
Although retinyl esters did not show significant anti-aging activity, the retinyl ester retinyl
palmitate is widely used in cosmetics because of its stability (Mukherjee et al., 2006). With
respect to sunscreen products, retinyl palmitate is extensively used because of its antioxidant,
stabilizing properties. However, in Europe and USA retinyl palmitate is not allowed to be
added as UV-filter as such.
Several studies have demonstrated that topical retinol may induce the same cellular andmolecular changes as retinoic acid although a 20 times higher dose is needed and the local
irritation characteristics are less prominent. It has been shown that retinol could be effectivein the treatment of aging and photoaging, but the effect was dependent on the vehicle used, as
retinol is unstable and easily gets degraded to biological inactive forms when exposed to lightand air (reviewed in Mukherjee et al., 2006).
In several studies it has been demonstrated that retinal may be a useful topical agent in thetreatment of aged and photoaged skin (reviewed in Mukherjee et al., 2006). Various cosmetic
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products containing retinal, primarily anti-aging preparations are available on the European
market, although these products are rarely traded in Norway.

1.2.4

Retinoids for medical use

Retinoids have been used mainly for treating skin diseases. The first use of vitamin A was
published in 1943, but first by the work of Bollag et al. (1983), a wide range of retinoids weresynthesized and tested for clinical use. Isotretinoin (13-cis retinoic acid) has been a very
widespread and important drug for treating severe acne conditions, since the approval by the
US Food and Drug Administration (FDA) in 1982. The monoaromatic retinoid etretinate, later
replaced by acitretin, have also been widely used for treating severe psoriasis and otherkeratinisation conditions as ichtyosis. Recently also alitretinoin (9-cis retinoic acid) has been
introduced for treating chronic hand eczema. Since these drugs are exhibiting similar effects
and are highly teratogenic, they are under strict governmental and medical control forprescription. For local treatment the (polyaromatic) retinoids taxaroten and adapalen (differin)
are widely used. Bexarotene is an oral and local retinoid with limited use in clinicaldermatology, for the treatment of cutaneous T cell lymphoma. An imposing list of adverse
effects are to be considered in clinical use, but clinical significant adverse effects are highly
dose-related, and can be tolerated as the drugs are most often used for relatively short periodsof months (isotretinoin), or for months and eventually lifelong (acitretion). Alternatives tothese drugs do not exist for some dermatological conditions.

1.3 Previous assessments of vitamin A (retinol and retinyl esters)
1.3.1
1.3.1.1

Cosmetics
Norwegian Institute of Public Health/Ullevål University Hospital (Paulsen et al.,1997)

In 1997, the Norwegian Institute of Public Health/Ullevål University Hospital conducted anevaluation of retinol and retinyl esters in cosmetics. The objective of the evaluation, which
was requested by the Norwegian Food Control Authority (Statens næringsmiddeltilsyn), wasto assess if it was necessary to regulate the maximum permitted content of retinol and retinyl
palmitate in cosmetics. The evaluation focused on both systemic and local effects. Since no
relevant data on the systemic absorption of topical retinol and retinyl palmitate was available,
the Norwegian assessment was then based on data for all-trans-retinoic acid and a systemic
absorption rate of 7% (Nau, 1993).
The main conclusions in the evaluation was that the teratogenic risk of topical retinol andretinyl palmitate was low, and that a cream containing 0.3-0.6% retinol or 0.6-1.2% retinyl
palmitate can be considered as safe. The risk of local adverse effects of short-term topicaltreatment of retinol or retinyl palmitate was also found to be low and a cream with theabovementioned concentrations of retinol or retinyl palmitate was considered as safe.
Information on possible adverse effects of long-term topical treatment of retinol or retinyl
palmitate was not available.
It was further concluded that cellular and molecular changes after topical treatment of 0.3%
retinol was equivalent to changes observed with 0.03% retinoic acid, a dose used for clinicaltreatment. This indicates that the topical use of retinol and retinyl palmitate for treatment ofskin disorders should be assessed by the drug authorities.

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Federal Institute for Risk Assessment (BfR) (2006, 2009 and 2010)

The Committee for Cosmetics of the Federal Institute for Risk Assessment in Germany (BfR)
has in recent years discussed and assessed the use of vitamin A (retinol and retinyl esters) incosmetic products (BfR, 2004; 2008; 2009; 2010).
Relevant toxicological data from both animal and human studies, including pharmacologicalstudies with focus on the pharmacokinetics and skin penetration of retinol and retinyl esters
and their influence on plasma levels, were considered in the German assessment.
In its most recent statement (protocol from the meeting on 6th May 2010), the BfR Committee
for Cosmetics has looked into how high an additional exposure from vitamin A (retinol andretinyl esters) in cosmetics could be, on top of the dietary intake of vitamin A, withoutcausing any health risks for the consumer. Taking into account data on the dietary intakes ofretinol in the German population, the BfR Committee for Cosmetics has concluded that theadditional contribution from cosmetics should not exceed 10% of the UL (3000 µg RE/day).
The BfR Committee for Cosmetics estimated an additional contribution of retinol fromcosmetic products of approximately 7.5% of the UL taking into account assumptions of twice
daily application of a 0.3% vitamin A-containing oil/water emulsion to the face as well as aonce daily administered 0.05% vitamin A-containing oil/water body lotion. This estimate wasbased on in vitro penetration rate data for retinol and its esters between 1.24 and 4%. With
such conditions, the BfR Committee for Cosmetics is of the opinion that there are no concerns
over the use of vitamin A-containing cosmetics for persons with a healthy skin. However, it
should be noted that these considerations presume that no additional vitamin A-containing
products are used and that the penetration of retinol or its esters is not reinforced (e.g. throughpenetration enhancers). For persons with atopic eczema, higher penetration rates could be
expected (BfR, 2009). According to the BfR Committee for Cosmetics, a new risk assessment
should be performed in situations were additional vitamin A-containing cosmetic products are
used.
Based on its work on vitamin A, the BfR Committee for Cosmetics has proposed that the useof retinol and retinyl esters in cosmetic products should be restricted in the legislation forcosmetic products.

1.3.1.3

The French Agency for the Safety of Health Products (AFSSAPS) (2011)

The Norwegian Scientific Committee for Food Safety (VKM) is aware of a coming, but so far
not published, risk assessment on vitamin A in cosmetic products from the French Agency for
the Safety of Health Products. The Norwegian Food Safety Authority has, however,forwarded to VKM information received from AFSSAPS referring that skin irritation withface cream and body lotion at concentrations of 0.1% and 0.048% retinol, respectively, havebeen reported to the French cosmetovigilance system. Based on studies on potential
phototoxicity of retinol and retinyl palmitate, the Committee on Cosmetology within
AFSSAPS has suggested a maximum concentration corresponding to 0.15% retinol
equivalents in cosmetic products (AFSSAPS, 2011).

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1.3.2.1

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Food and food supplements
Scientific Committee on Food (2002)

The Scientific Committee on Food (SCF) expressed an opinion on the UL of preformed
vitamin A (retinol and retinyl esters) in 2002. SCF noted that determining an UL for
preformed vitamin A is difficult, as the margin between the population reference intake andthe intakes associated with adverse effects is narrow. The teratogenic risk, hepatotoxicity anda possible increase in risk of bone fracture were especially addressed in the derivation of an
upper level for the intake of vitamin A. SCF established an UL at 3000 µg RE/day of
preformed vitamin A for adults, based on the risk to women of child-bearing age. This value
was about 2.5-fold lower than the lowest daily intake associated with hepatotoxicity during
chronic intake. The tolerable intake levels for infants and children were based on the adultvalue with correction for differences in basal metabolic rate compared to adults (bodyweight0.75).
The SCF further considered that the tolerable upper intake level may not provide an adequate
margin of safety in relation to the possible decrease in bone density and the risk of bone
fracture, and that it would be advisable that postmenopausal women, who are at greater risk ofosteoporosis and bone fracture, should restrict their intake of preformed vitamin A to 1500 µg
RE/day.

1.3.2.2

European Food Safety Authority (2008)

The EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP)
published a scientific opinion on the consequences for the consumer of the use of vitamin A
in animal nutrition in 2008. The EFSA opinion reviewed two recent reports on the safety ofvitamin A performed by the UK Scientific Advisory Committee on Nutrition (SACN, 2005)
and the Agence Francaise de Securite Sanitaire des Aliments (AFSSA, 2005). The review of
Ribaya-Mercado and Blumberg (2007) on the potential risk of vitamin A on osteoporosis andbone fracture was also considered in this EFSA opinion.
The FEEDAP Panel was of the opinion that new available data published later than the SCF
opinion from 2002 would not substantially alter the risk assessment for preformed vitamin A.
Consequently, EFSA still considered the UL of 3000 µg RE/day from preformed vitamin A as
being appropriate. The FEEDAP Panel further referred to the advice from SCF that amaximum intake of 1500 µg RE/day from preformed vitamin A would serve as a guidancelevel (GL) for individuals at a greater risk of osteoporosis and bone fracture, until new data
indicates the necessity of a re-evaluation.
Both relevant national studies on the intake of vitamin A and data from the food consumption
survey within the European Prospective Investigation into Cancer and Nutrition (EPIC)
project were considered in the intake calculations presented in the EFSA opinion. The mean
intake of preformed vitamin A in the adult population in Europe was estimated between 400
and 1200 µg RE/day in men and between 350 and 1000 µg RE/day in women. A small
proportion of the European population had an intake of preformed vitamin A above the UL.
Consumption of liver was found to be the predominant source of preformed vitamin A (about
60-80%) in France, Greece, Italy and Spain. Milk, including butter and other dairy products
represented the highest proportion (45-60%) of preformed vitamin A in Germany, theNetherlands, Norway and Sweden. The FEEDAP Panel concluded that the risk of exceeding
the UL (and GL) for preformed vitamin A was predominantly related to the consumption ofliver, but also to the consumption of supplements containing vitamin A.
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It was further concluded that preformed vitamin A may raise safety concerns because of its
high levels in some foods of animal origin and of individual consumption patterns. Therefore,
feeding practice should seek to avoid any unnecessary high concentrations in those foods. As
a consumer protection measure, the FEEDAP Panel recommended a general introduction of
maximum contents of vitamin A in feed for food-producing animals.

1.3.2.3

Nordic Council of Ministers (TemaNord 2003:502) (Blomhoff et al., 2003)

A working group appointed by the Nordic Council of Ministers published in 2003 a scientificreport on the health risks related to high intake of preformed retinol (vitamin A) in the Nordic
countries (Blomhoff et al., 2003). As vitamin A (i.e. preformed retinol) intake in Denmark,Sweden, Norway, Finland and Iceland is known to be higher than in most other countries, theobjective of this work was to evaluate whether vitamin A toxicity could be a real threat to thehealth of people in the Nordic countries. The potential health risk related to dietary intake ofvitamin A and use of supplements containing retinol (i.e. retinol and retinyl esters) was
evaluated in the report.
The intake calculations presented in the Nordic report showed that men have a higher intakeof retinol than women in all countries. The mean intake varied from 990 to 3180 µg RE/day inmen, and from 560 to 2050 µg RE/day in women, with the highest intakes found among
Icelanders, followed by Norwegians. The daily dietary intake among high consumers (90percentile) in the Nordic countries was between 1800 and 6500 µg RE in men and between
1100 and 5000 µg RE in women.
There have been no reports in the Nordic countries describing neither chronic nor acute
hypervitaminosis A due to consumption of foods containing large amounts of retinol (except
Arctic explorers eating Polar bear liver). Furthermore, 17 suspected cases of chronic
hypervitaminosis A have been reported due to consumption of supplements containing retinol.
The Nordic report emphasized that it is important to note that intake of retinol in various
physical forms may have different thresholds for toxicity. Intake of retinol from non-fortified
foods is generally below the dosages where hypervitaminosis A may be induced, with apossible exception being consumption of liver where the retinol content in some cases may bevery high.
In vitamin A-fortified foods, water miscible/emulsified preparations of retinol are mainly
used. Such preparations of retinol are presumed to have higher toxicity than oily preparations,indicating that intake of vitamin A-fortified foods may increase the likelihood that the safe
upper intake could be exceeded. The Nordic experts therefore recommended that fortification
with water miscible/emulsified and solid preparations of retinol should be kept to a minimum
and that oil-based preparations of retinol, with a lower toxicity threshold, should be preferred
if fortification is needed. The same arguments were found relevant in connection with retinolinduced toxicity from supplements.
Several studies demonstrate teratogenicity of high doses of preformed retinol in various
experimental animals. However, due to the limited occurrence of scientific data in humans, it
was not possible to establish a threshold level of intake of retinol during pregnancy below
which there is no increased risk of giving birth to a malformed child. The Nordic working
group was of the opinion that available epidemiological data indicate that intakes up to 3000
µg RE (10000 IU) per day during pregnancy were not associated with increased risk formalformations. They found it prudent to continue to apply precautionary measures and torecommend that daily intake of retinol during pregnancy should not exceed 3000 µg RE.
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The Nordic report further stated that the evidence for lower bone mineral density andincreased risk of hip fracture after retinol intakes marginally above the recommended dietaryintake is limited and not consistent. Since there was evidence that links a high intake of
preformed retinol with negative effects on the skeleton, further studies addressing the issue
were warranted.

1.3.2.4

Nordic Nutrition Recommendations (2004)

The Nordic countries have for several decades collaborated in setting guidelines for dietarycomposition and recommended intakes of nutrients. The recent recommended intake ofvitamin A in the Nordic countries is described in the 4th edition of the Nordic Nutrition
Recommendations published in 2004 (NNR, 2004).
The Nordic recommendations have been based on estimated requirements that assure
adequate body stores of retinol where no clinical signs of deficiency are observed, adequate
plasma retinol levels are maintained and there is protection against vitamin A deficiency for
approximately 4 months on a vitamin A-deficient diet, as described by the U.S. Food andNutrition Board of the Institute of Medicine in 2001 (FNB, 2001). Using a factorial method
for Nordic reference subjects, the estimated average requirement for vitamin A was found tobe very similar as for U.S. reference subjects, i.e. close to 600 and 500 µg/day for men andwomen, respectively. Based on these considerations, the present Nordic recommended intakes
for adults were set to 900 µg RE/day for men and 700 µg RE/day for women. The
recommended intake for pregnancy has been set to 800 µg RE/day to cover individual
variation, while an additional intake of 400 µg RE/day is recommended during lactation tocounteract the loss of vitamin A through breast milk.
The recommended intakes for children and adolescents have been extrapolated from the adultvalues by using a scaling factor (body weight0.75). The following recommended intakes arevalid for Nordic children and adolescents: 2- to 5-year-olds (350 µg RE/day), 6- to 9-yearolds (400 µg RE/day) and 10- to 13-year-olds (600 µg RE/day).
The Nordic Nutrition Recommendations are currently under revision and the 5th edition is due
to be published in 2013.

2 Hazard identification and characterisation
2.1 Retinoid uptake and metabolism after oral intake
In food derived from animal products, the major forms of preformed vitamin A are longchained fatty acid esters of retinol (reviewed in Harrison, 2005). Prior to uptake essentially allof the esters are hydrolysed in the intestinal lumen into retinol. Free retinol is then taken up byintestinal cells where it is re-esterified with long-chained fatty acids before they areincorporated into chylomicrons. Studies using the human intestinal cell line, Caco-2, showthat retinol uptake is a rapid process with a half-life of minutes (Nayak, 2001). The absorption
efficiency of retinol is generally high, in the range of 70-90% (NNR, 2004). However, it may
be reduced if diets are low in fat or if individuals suffer from fat malabsorption syndrome(EVM, 2003).
The chylomicrons are released into the blood circulation via the lymph where they undergo a
remodelling process involving primarily the hydrolysis of triglyceride and acquisition of23

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apolipoprotein E from the circulation, resulting in the formation of chylomicron remnants.
The majority of the chylomicron remnants are taken up by the liver (66-75%). However
extrahepatitic uptake of remnants in tissues such as bone marrow, peripheral blood cells,
spleen, adipose tissue, skeletal muscle and kidney, do also occur (D’Ambrosio, 2011;
Blomhoff et al., 2003).
Although much of the absorbed retinol is secreted into lymph in esterified form, there isevidence that a significant amount is also secreted into portal circulation, probably as freeretinol (Harrison, 2005). This transport is expected to be physiologically significant inpathologic conditions that affect the secretion of chylomicrons, and thus may be an essential
back-up mechanism for the homeostasis of vitamin A under some conditions.
In liver parenchymal cells, the retinyl esters are hydrolysed and retinol may be transferred toretinol-binding proteins (RBP). The retinol-RBP complex can be secreted directly into thecirculation or they are transferred to the hepatic stellate cells and stored in the form of longchained fatty esters (Debier and Laronedelle, 2005; Harrison, 2005).
Before the release of retinyl esters from the stellate cells, the retinyl esters are hydrolysed andfree retinol binds to RBP and are secreted into the circulation (Harrison, 2005). The secreted
retinol-RBP forms a ternary complex with plasma transthyretin to prevent renal elimination(Tzimas and Nau, 2001). Circulating retinol-RBP can then enter the target cells, anddepending on the tissue type, retinol is either transformed into retinyl ester, retinal or retinoic
acid (Debier and Larondelle, 2005; Evira 2007; 2008) (Figure 3). The conversion of retinol
into active metabolites occurs usually in the target cells by complex metabolic pathways: 1)
esterifying within the tissue, 2) activation by oxidation of the side chain into retinal andretinoic acid, which can in turn be further oxidised into 4-hydroxy metabolites, or 3)
conjugation with glucuronic acid which leads to retinoyl- and retinyl glucuronides, which
results in their elimination in faeces and urine (reviewed in Blomhoff et al., 2003; EFSA,
2006a).
The release of retinol from the liver is tightly controlled, and in vitamin A-sufficientconditions, circulation levels of retinol-RBP are maintained at a constant level (1-3 mol/l)
The serum level of retinol is indicating the vitamin A storage in the liver only if there is anextreme depletion or over-consumption of vitamin A (EFSA, 2008; Evira 2007; 2008). If
hepatic storage capacity is exceeded, plasma levels of retinyl esters increase, but not retinol
itself (EVM, 2003).
Serum retinol concentrations have been extensively used to identify populations at risk ofvitamin A toxicity, but are not considered as an efficient biomarker of exposure in individual
patients because of the homeostatic regulation of vitamin A. Other factors may also affect theserum concentration without any changes in the total body stores. For example, retinolbinding protein (RBP) is a negative acute phase protein. Therefore, serum retinol and RBP
concentrations will fall during times of infection. The status of other nutrients, particularly
iron and zinc deficiency, may also negatively affect serum retinol concentrations without any
depletion of the liver store. However, studies in humans suggest that retinoic acid and its
metabolites instead of plasma retinol may be the biomarker of choice when evaluating the risk
for vitamin A toxicity (reviewed in Penniston and Tanumihardjo, 2006).
2.1.1

Retinoid-dependent signalling

The biological functions of vitamin A are mediated by the active metabolite retinoic acid
which acts as the natural ligand for two distinct nuclear receptors, the retinoic acid receptor(RAR) and the retinoid X receptor (RXR). While RARs bind the two physiological forms of24

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retinoic acid, all-trans retinoic acid and 9-cis retinoic acid, RXRs have been reported to onlybind 9-cis retinoic acid. The RAR-RXR heterodimer recognizes retinoic acid response
elements (RAREs) on the DNA whereas the RXR-RXR homodimer recognizes retinoid "X"
response elements (RXREs) in the promoter regions of target genes. This interaction with thetranscriptional machinery and regulation of gene expression indicates that the biologicaleffects of vitamin A are regulated at the gene level (reviewed in Blomhoff and Blomhoff,
2006; Theodosiou et al., 2010; Gutierrez-Mazariegos et al., 2011). Furthermore, there areindications that retinoic acid can serve as ligand for other nuclear receptors. Examples are theperoxisome proliferators-activated receptor (PPAR)which may be involved in regulationof skin integrity, and the retinoic acid receptor related orphan receptors (ROR). Effects ofretinoic acid that are independent of gene transcription have also been reported, both with andwithout the involvement of retinoid receptors. However, the relevance of these observations isstill unclear (Theodosiou et al., 2010).

2.2 Systemic adverse effects of retinoids (hypervitaminosis A)
It is well documented that both acute and chronic excessive intake of vitamin A may result ina number of adverse effects. Acute hypervitaminosis A, following the ingestion of a single
very high dose or several repetitive very high doses over a few days, is characterised byvarious symptoms such as nausea and vomiting, fatigue, abdominal pain and skin disorders.
In neonates and infants, one single or series of large doses of vitamin A may lead to thedevelopment of reversible bulging fontanelle. In adolescents and adults, headache and blurredvision is frequently reported during hypervitaminosis A. Both these symptoms, as well as
bulging fontanelle may possibly arise from increased cerebrospinal fluid (CSF) pressure.
Chronic hypervitaminosis A results from continued ingestion of high doses for months or
years and the clinical picture of symptoms are varied and non-specific. The onset and severityof the various toxic effects are also dependent on dose and duration of the exposure, as has
been clearly demonstrated for vitamin A-induced damage to the liver. The teratogenic
potential of retinoids is well documented and excessive exposure to retinol during embryonal
development may lead to congenital malformations in many different target organs. Other
symptoms of chronic vitamin A toxicity include increased CSF pressure and chronicheadache, various skin disorders and erythema, bone pain and reduced bone density(Blomhoff et al., 2003; FNB, 2001; SCF, 2002; EFSA, 2006a).
Based on the weight of evidence neither retinol nor retinyl esters are considered genotoxic(EVM, 2003). Retinoids seem not themselves to induce tumours in animals. However, studies
on the effects of retinoids on carcinogenesis in animals show contradictory results as somestudies show a protective effect and other an enhancing effect on tumour formation. In vitro
studies suggest that retinoids may inhibit certain steps of carcinogenesis and enhance othersteps (Rivedal and Sanner, 1992; Miller et al., 2000).
Among the adverse toxic reactions of vitamin A, the teratogenic effects of chronic excess
intake of vitamin A, as well as the effects on bone mineral density and osteoporosis arereferred more closely in the following paragraphs. Furthermore, local effects in the skin and apotential contribution to systemic effects of vitamin A from cosmetic products are discussed
in more details (see section 2.3 and 2.4).

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Teratogenic effects

Extensive research carried out over the last 100 years has established that vitamin A plays
crucial roles in embryonic development by regulating organogenesis, cell proliferation,differentiation and apoptosis. Because of the importance of vitamin A during development,
the transport via the placenta is tightly regulated and it is documented that both low andexcess dietary levels of vitamin A may induce malformations in experimental animals andhumans indicating that the concentration must be within a narrow range to avoid birth defects(SCF, 2002; Blomhoff et al., 2003; Gutierrez-Mazariegos et al., 2011).
Because vitamin A bioaccumulate in the human liver, intake of large doses in the months
before conception may lead to increased teratogenic risk. In a prospective study performed by
Rothman et al. (1995) which included 22748 pregnant women, it was concluded that intake ofmore than 10000 IU (3000 µg RE) of supplemental vitamin A per day was associated withincreased risk of birth defects. In this study, 1.3% of babies born to women who took 5000 IU(1500 µg RE) or less of vitamin A supplement had cleft lip, cleft palate, hydrocephalus or
major heart defects, while 3.2% of infants born to women who took over 10000 IU/day had
such defects (Rothman et al., 1995). One prospective study including exposures of more than
50000 (>15000 µg RE) and 100000 IU (>30000 µg RE) per day and available
epidemiological data on intake in the lower-dose ranges support the conclusion that daily
intake of 10000 IU (3000 µg RE) per day would be associated with a low or negligible risk ofteratogenicity (Mastroiacovo et al., 1999; SCF, 2002; Blomhoff et al., 2003).
Teratogenic effects after oral exposure to vitamin A in humans are best documented inchildren born to mothers treated with the pharmaceutical Accutane, 13-cis-retinoic acid(isotretionin) during pregnancy. Accutane entered the U.S. market in 1982 for the treatment ofsevere acne, and already 3 years later Lammer et al. (1985) reported high risk for spontaneousabortion, premature birth, perinatal mortality and major malformations associated with
exposure to the therapeutic dose. The pattern of malformations reflected the birth defects
observed in animal studies including craniofacial, cardiac, thymic, and CNS deformities. The
most frequently occurring category was CNS malformations (Lammer et al., 1985; 1988).
Furthermore, longitudinal follow-up of the children, both with and without major
malformations, indicated that 47% of the children had mental ability scores in the borderline
to the mentally retarded range (Adams and Lammer, 1993).
As opposed to oral intake, more than 25 years of topical use of RA for acne are without
evidence for increased teratogenicity. In a case control study of 215 mothers exposed totretinoin during pregnancy, the prevalence of major foetal malformations was 1.9 in thetreatment group versus 2.6 in the control group (Jick et al., 1993 cited in Mukherjee et al.,2006). However, it is still being warned against using the drug retinoic acid during pregnancy.

2.2.2
2.2.2.1

Osteoporosis
Skeletal effects of vitamin A

Osteoporosis is an age-related condition characterised by low bone mass and increased risk offracture. This is a major health problem among older adults, and especially among
postmenopausal white women (discussed in Ribaya-Mercado and Blumberg, 2007). It is welldescribed that large doses of retinol interfere with calcium and bone metabolism, as
demonstrated by abnormalities such as hypercalcemia, ligamentous calcification, bone pain,
demineralisation of bones or osteopososis (reviewed in NNR, 2004). However, association
between slightly greater than recommended intake level of retinol and poor bone mineraldensity or increased risk of hip fracture have also been demonstrated. The risk of both26

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reduced bone mineral density (BMD) and fracture was increased for retinol intake > 1500 g
RE/day (Melhus et al., 1998; Michaëlsson et al., 2003) and self-reported fractures wereincreased for total vitamin A intake  3000 g RE/day and retinol intake (food +supplements)  2000 g/day, respectively (Fescanich et al., 2002). Additional studies since
the SCF opinion from 2002 support the apparent increased risk of bone fracture over an intake
range similar to that normally consumed from food and supplements (SCF, 2002; SACN,
2005; AFSSA, 2005; EFSA, 2008). Several cases of skeletal problems have also beenreported in children with severe hypervitaminosis A or after treatment with synthetic
retionoids for several years. The symptoms involve abnormalities in ossification andcalcification, decreased cortical thickening and decreased bone density (SCF 2002; Ahmadiehand Arabi, 2011).
Among studies examining relationships of vitamin A intake and BMD or fractures in humans,
both low and high intakes of retinol were associated with low BMD in a study by Promislow
et al. (2002). In contrast, there are others that suggest a certain protective effect of vitamin A
against bone loss (reviewed in Ribaya-Mercado and Blumberg, 2007; Crandall, 2004; NNR,
2004) and also a few observational studies, and one small short-term clinical trial, where little
or no associations between vitamin A intake from food and supplements and bone health were
found. In studies where serum or plasma retinol or retinyl esters were measured as markers ofvitamin A status, increased risk of hip fracture was demonstrated for high serum retinol(Melhus et al., 1998; Michaëlsson et al., 2003) and for high as well as low serum retinol +retinyl esters combined (Opotowsky et al., 2004). Certain positive relations have also beenshown for plasma retinol and BMD, whereas no correlations were found for carotenoids(Maggio et al., 2003; Ribaya-Mercado and Blumberg, 2007; Crandall, 2004).
Previous studies with retinoids used as drugs have identified musculoskeletal symptoms thatmimic those of hypervitaminosis A, including cortical hyperostosis and changes in tendonsand ligaments. With respect to bone demineralisation, a number of human studies from the
1980s reported contradictory evidence. Retinoids have been shown to alter bone turnover anddecrease BMD in some smaller studies, whereas other studies have demonstrated no or minor
decrease in BMD (DiGiovanna, 2001; Blomhoff et al., 2003; DiGiovanna, 2010). In a recent
case-control study obtained from two nationwide registers in Denmark, it was concluded thatrisk of fractures is not associated with dose or duration of systemic retinoids (isotretinoin andacitretin) (Vestergaard et al., 2010).
Animal studies support the clinical findings that modest excesses of retinol is associated withincreased fracture risk and effects on bone growth and bone remodelling (reviewed in RibeyaMercado, 2007). In rats, it has been demonstrated that subclinical hypervitaminosis led toincreased bone fragility (Johansson et al., 2002), however, BMD measurements did not reveal
adverse skeletal changes in the same group (Lind et al., 2006). Excess retinoid treatment
induced bone thinning in both young and old rodents, and the measured BMD was decreased
in cortical but increased in trabecular bones (Kneissel et al., 2005). In a recent study in rats,
high doses of retinol for one week led to weakening and higher degree of mineralisation ofbones with little apparent effect on BMD. Furthermore, the findings indicated a reduced
endosteal/marrow blood flow leading to hypoxia and pathological mineralisation (Lind et al.,2011). In a long-term study, vitamin A supplementation induced a transient increase in
medullary and decrease in cortical thickness in young rats. Furthermore, no effects on
resistance to fracture or on bone mineral content were observed in old rats (Wray et al., 2011).
One of the major roles of retinol is regulation of differentiation and proliferation of various
cell types and both osteoblasts (bone formation) and osteoclasts (bone resorpsion) express
retinoid receptors. Retinoic acid has been shown to suppress osteblast activity and stimulate27

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osteoclast formation and activity, resulting in decreased bone formation and increased bone
resorption (Binkley and Kreuger, 2000; NNR, 2004; SCF, 2002).
In summary, the data on bone density and risk of fracture provides basis for concern sinceeffects are reported at lower daily intakes of vitamin A than for other adverse effects. The datais, however, not considered sufficient to establish causality and can therefore not be used toderive a tolerable upper intake level.

2.2.2.2

Combined effects of vitamins A and D

Vitamin D regulates normal serum calcium concentrations and an adequate serum level is ofgreat importance for bone health. Deficiency of vitamin D results in secondary
hyperparathyroidism, increased bone turn over and bone loss, and is therefore a main risk
factor in osteoporosis-related fractures (Holick et al., 2007; Lips P, 2001).
An antagonistic effect of vitamin D and retinol was previously found on serum calcium after
combined intake in humans (Johansson et al., 2001). The past high retinol concentration in
cod liver oil was also suggested as a possible explanation for the observed negative
association between childhood cod liver consumption and bone mineral density in a
population-based cohort of peri- and postmenopausal Norwegian women (Forsmo et al.,2008). In a recent study on postmenopausal Spanish women, it was concluded that highretinol levels together with vitamin D deficiency increase the risk of osteoporosis (MataGranados et al., 2010). Also among participants of the Women Health Initiative
Observational Study, a modest increase in total fracture risk with high vitamin A and retinol
intakes was observed in the low vitamin D-intake group (Caire-Juvera et al., 2009). In a metaanalysis of case-reports on toxicity induced by intakes of excessive amounts of dietary retinol,
it was observed that the mean dose retinol causing chronic hypervitaminosis A was higher
when retinol was taken together with vitamin D (Myhre et al., 2003). This may indicate thatthe antagonistic effects of vitamin A and vitamin D occur mainly at low dietary levels ofvitamin D. Furthermore, a possible effect of high intakes of retinol on serum levels of 25hydroxyvitamin D (25(OH)D) has also been demonstrated (Birgisdottir et al., 2011; MataGranados et al., 2008).
Several animal studies support an antagonism between retinol and vitamin D at high dietary
retinol intake (reviewed in Blomhoff et al., 2003). Also at physiological levels antagonism ofretinol on effects of vitamin D has been demonstrated in rats (Lind et al., 2006; Rohde et al.,1999). A potential antagonistic effect of retinol on vitamin D may also be illustrated by theobservation that high intake of retinol lowers vitamin D status in mice and rats (Hetland et al.,2009, Lind et al., 2006).
Various mechanisms may be involved in an antagonistic effect between retinol and vitamin D.
Competition between the active metabolites of retinol and vitamin D, retinoic acid and 1,25dihydroxyvitamin D (1,25(OH)2D), for the receptor RXR which forms heterodimers both with
RAR and the vitamin D receptor (VDR), has been suggested by several (NNR, 2004, Rohdeand DeLuca, 2005). However, retinol could also interfere with the absorption, transport andconversion to the active form or degradation of vitamin D. In male rats, however, results
suggests that retinol does not antagonise the action of calciferol (vitamin D3) by altering themetabolism of calciferol or its active metabolite 1,25(OH)2D (Rohde and De Luca, 2005).
In summary, both human and animal studies indicate an antagonistic effect of retinol on theeffects of vitamin D on serum calcium and bone metabolism. Furthermore, data indicate thathigh intake of retinol may affect the serum levels of vitamin D.
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2.3 Retinoid uptake and metabolism after topical application
One of the skin functions is to limit the chemical exchange between the body and theenvironment. The stratum corneum is a barrier to the absorption of most topically appliedchemicals (NTP, 2010). This layer, which is composed of approximately 40% lipids, 40%proteins and 20% water, is generally permeable only to small lipophilic molecules. Although
the thickness of the stratum corneum may modulate absorption, the major barrier to topicalabsorption of chemicals is the intercellular lipid channels. The barrier function may beaffected by lipid extraction, inhibition of lipid synthesis, and penetration enhancers thatbiochemically alter lipid composition. The skin of mouse, rat and guinea pig is more
permeable with respect to vitamin A than human skin. Thus absorption studies using theseanimals have not been included in the present opinion.
2.3.1

In vivo absorption

Topical application of a 0.05% retinal on 14 consecutive days (7 mg/day) covering around
40% of the body surface (back, chest, abdomen, external aspects of the arms) on malevolunteers did not induce an alteration of the plasma levels of retinoids (retinol, all-transretinoic acid, retinyl palmitate/oleate, 13-cis-retinoic acid and 4-oxo-13-cis-retinoic acid)during the treatment period. However, there was a slight, but not statistically significant,increase in the levels of all-trans-retinoic acid, retinol and retinyl palmitate/oleate until one
week after the end of the treatment (Sass et al., 1996).
In a study by Nohynek et al. (2006), two groups of female volunteers were treated topicallyfor 21 days with creams containing 0.3% retinol or 0.55% retinyl palmitate on about 3000
cm2 of their body surface (back, upper legs). Daily, 3.5 g of cream was applied comprising 9
mg of retinol or 16 mg of retinyl palmitate. Plasma levels of retinol, retinyl palmitate, retinyl
oleate, retinyl stearate, 9-cis-, 13-cis-, all-trans-, 13-cis-4-oxo- or all-trans-oxo-retinoic acids
were measured 0, 1, 2, 4, 6, 8, 12, 14-16 and 24 hours after each application. On day 21, nochanges in plasma retinoid levels were observed.
Franz and Lehman (1990) examined the absorption of [14C]retinoic acid in 8 male subjects
with mild to moderate facial acne. Four of the subjects had dermatitic skin (signs of mild
irritation induced by treatment with non-radioactive 0.05% Retin-A cream during the prior
two weeks). A commercial available 0.05% ATRA (all-trans-retinoic acid) cream containing
radioactive ATRA was applied on the forehead and neck (100 mg/50 cm2). The applicationsites were washed after 10 hours. There were no significant differences in the absorption of
ATRA through normal acne skin and dermatitic acne skin (urinary excretion of radioactivity:
1.1% (±0.2) and 1.5% (±0.4) through normal and dermatitic skin, respectively). Whencorrected for excretion by non-urinary routes (factor 0.21 obtained from experiments on
rhesus monkeys) total absorption was 5.3 and 7.2%, respectively, for the normal and thedermatitic skin. The rate of absorption continually increased until the time of the skin wash ofnormal skin, but peaked and started to decline prior to the wash in dermatitic skin (10 vs 5
hours).

2.3.2

In vitro absorption

In in vitro experiments, Boehnlein et al. (1994) applied 20 g/cm2 of radioactive retinyl
palmitate in an aceton vehicle on viable human skin obtained from two female donors (skinobtained from abdominoplasty and breast reduction). After incubation in a flow-through29

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diffusion cell for 24 hours under dark conditions, the skin surface was washed. Then the skin
was homogenised and radioactivity measured. In addition, aliquots of the receptor fluid(Hepes buffered Hanks’ balanced salt solution (HHBSS) w/4% bovine serum) fraction wereanalysed. Of the applied dose, 18% (±1) was absorbed in the skin (about 3.6 g/cm2). Only
0.2% (±0.01) of the absorbed material partitioned into the receptor fluid from the skin. The
authors suggest that this low amount may be caused by retinyl palmitate being insoluble inwater and thus not readily partition from skin into the diffusion cell receptor fluid.
An oil-in-water formulation containing 0.3% of retinyl palmitate was applied for 16 hours on
human abdominal tissue (2 mg/cm2, yellow light conditions, flow-trough diffusion cell).
Cutaneous absorption (epidermis + dermis + receptor fluid (HHBSS w/4% bovine serum
albumin)) was found to be about 4% (Leclerc, 1997).
Percutaneous absorption of retinol was studied by Yourick et al. (2008) using an in vitro
model with human skin (from abdominoplasty) in a flow-through diffusion cells. Two
vehicles were used: gel (hydroxypropylcellulose, butylhydroxytoluene, ethanol) and oil-inwater emulsion (polyglyceryl-3-distearate, cetyl stearyl alcohol, propylene glycol, lightmineral oil, methyl- and propyl-p-hydroxybenzoate, butylhydroxytoluene, distilled water).
Retinol (0.3%) formulations (gel or oil-in-water emulsion) containing 3H-retinol were appliedand absorption was measured at 24 and 72 hours. After 24 hours, unabsorbed retinol on the
top of the skin constituted 87.3% (±6.3) for gel and 94.8% (±2.6) for oil-in-water emulsion,
whereas 3.5% (±0.4) and 5.9% (±1.4) remained in the stratum corneum for gel and oil-inwater emulsion, respectively. In the viable skin (dermis/epidermis), 2.1% (±1.2) of the applied
doses for gel and 3.0% (±0.6) for oil-in-water emulsion were absorbed. Retinol was found in
the receptor fluid (HHBSS w/4% bovine serum albumine) at a concentration of 0.3% (±0.01)
and 1.3% (±0.1) after application of the gel and oil-in-water emulsion vehicles, respectively.
The levels of retinol increased over 72 hours in the receptor fluid (0.5% (±0.01) and 2.2%(±0.2) for gel and oil-in-water emulsion vehicles, respectively), but decreased or was
unchanged in the viable skin (1.0% (±0.1) for gel vehicles and 2.9% (±0.6) for oil-in-water
emulsion vehicles).

2.3.3
2.3.3.1

Factors that may influence dermal absorption
VehiclesBy using different vehicles, skin penetration enhancers and carrier systems the penetration or
deposition rate may be altered. An increase in the water content in stratum corneum may
result in increased transdermal delivery of both hydrophilic and lipophilic substances. Skin
hydration can be achieved by using both occlusion (ointments, water-in-oil emulsion) and byproviding water from the vehicle to stratum corneum (oil-in-water emulsions) (Otto et al.,2009). However, to further increase the dermal absorption, penetrations enhancers are often
used in cosmetic products. Chemical penetration enhancers act by lipid fluidisation and lipid
extraction. Surfactants may have different effects on the skin (inflammation, direct cytotoxic
effects, lipid extraction) that can impair the skin barrier function and thus increase dermal
penetration. In an in vitro study by Föster et al. (2011), three surfactants (esters ofpolyethyleneglycol) were used in preparing three oil-in-water emulsions and three surfactant
solutions all containing retinol (0.5 wt%). All the surfactant solutions showed higher
penetration rate compared with the corresponding emulsion, and the penetration behaviour
appeared to be dependent on the surfactant used in the formulation. In an in vivo study, twoskin penetration enhancers, Triton X 100 (octoxynol) and oleic acid were added to a cream(Myritol: caprylic/capric acid triglyceride), containing 0.3% all-trans-retinol (Mélot et al.,30

Norwegian Scientific Committee for Food Safety (VKM)

10/405-3 final2009). Myritol is a non skin penetration oil in which retinol is highly soluble. Solutions wereapplied once on the volar forearm on male voluntaries and dermal absorption of retinol wasmeasured up to 6 hours after treatment using Raman spectroscopy. After treatment withretinol and Myritol, retinol hardly penetrated the skin. When oleic acid or Triton X 100 was
added, retinol penetrated much more efficiently within the skin. Oleic acid, one of the mostcommonly used penetration enhancers in cosmetic products, resulted in a better penetration ofretinol compared to Triton X 100.
Carrier systems such as nanoparticles can be used to alter the dermal absorption.
Nanoparticles can be divided into soft and rigid particles where soft particles are made oforganic materials (e.g. lipids, proteins, polymers) and rigid particles are made of inorganic
materials (e.g. metals, metal oxides, ceramics). Particles penetrate preferentially into the hairfollicle canal, thus enabling high concentrations within the reservoir of the follicular
infundibulum (reviewed in Papakostas et al., 2011). In in vitro studies, skin permeability of
encapsulated retinoic acid was shown to be lower than for free retinoic acid. However, theencapsulated retinoic acid yielded a continuous increase in drug concentrations in the stratum
corneum and in the viable skin tissues (dermis/epidermis), whereas when applied as freeretinoic acid the concentration of retinoic acid decreased gradually in all skin layers. Thus, thehigher, sustained levels of retinoic acid may be due to retarded diffusion and not to enhanced
dermal absorption (Masini et al., 1993; Fresno Contreras et al., 2005). The same dermal
absorption pattern has been shown for retinol. Although the time needed to cross 20 µm ofepidermis was found to be 7 minutes for encapsulated retinol and 11 minutes for free retinol(in oil-in-water emulsion), the release was highest for free retinol. However, the encapsulated
retinol remained for a longer time in the skin than free retinol (Failloux et al., 2004). The useof nanoparticles may thus change both the penetration pathway and kinetics of topicallyapplied substances.
2.3.3.2

Impaired skin

Cosmetic products are meant to be used on normal skin, however, they may also be applied
on non-healthy skin. In these individuals, the barrier properties of the skin may be impaired.
The prevalence of dry and sensitive skin is very high in the population at all age groups.
Halvorsen et al. (2008) found that 34% of 2670 healthy adolescents in Norway had dry skin,and 13% dermatitis. The extent of dry skin varies, but dry skin is clearly related to reduced
barrier properties and increased penetration of cutaneously applied cosmetics. Similar highpercentages of dry and sensitive skin are reported from other studies in the USA (Misery etal., 2011).
In a study by García Ortiz et al. (2009), six adults with atopic dermatitis received one topicalapplication (4 mg/cm2; non-occluded) of metronidazole (1%) in a cream formulation on areas
on the forearm with active atopic dermatitis and on areas with uninvolved (normal) skin. The
cutaneous penetration of the metronidazole cream was 2.4-fold higher when applied on areas
with active atopic dermatitis compared to cream applied on uninvolved skin. In the study byFranz and Lehman (1990), the absorption of retinoic acid after topical application ondermatitic skin was found to be 7.2% as compared to 5.3% after application on normal skin.

2.3.4

Skin metabolism of retinol and retinyl esters

In the in vitro experiments by Boehnlein et al. (1994) where radioactive retinyl palmitate inan aceton vehicle was applied on viable human skin, about 44% of the absorbed dose was31

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metabolised to retinol. No other additional metabolites were observed indicating that topicallyapplied retinyl palmitate may deliver significant amounts of retinol into the skin.
Antille et al. (2004) applied oil-in-water creams containing 0.05% retinoids (retinoid acid,retinal, retinol or retinyl palmitate) onto fresh surgically excised human abdominal skin (25skin explants from 5 females aged 26-66 years). After 24 hours incubation at 37 °C (mounted
on Franz perfusion cells), all retinoids penetrated well into the epidermis. Retinal induced aslight increase in endogenous retinol and retinyl esters, and a small part was transformed into
retinoic acid. Retinol and its palmitic esters increased endogenous retinol and retinyl esters,
but no retinal or retinoic acid was found. Retinoic acid did not undergo metabolism.
In human volunteers, Kang et al. (1995) applied varying concentrations of retinol (up to1.6%), 0.025% retinoic acid and a vehicle (70% ethanol/30% propylene glycol) to buttock
skin (100 l/18 cm2). The sites were occluded under plastic wrap and covered with light-proof
dressing for four days. Biopsies were obtained on day 4. After removal of stratum corneum,
the epidermal content of retinyl ester and retinoic acid were measured (reverse-phase HPLC).
The four day occlusion with 0.4% retinol increased the skin content of retinol, 13-cis-retinol
and retinyl esters in comparison with vehicle. In another group of volunteers, biopsies were
performed after retinol (0.4%) occlusive patches had been in place for 0, 6, 24 and 96 hours.
At 24 hours, the levels of retinol had increased 70-fold, 13-cis-retinol 280-fold and retinyl
esters 260-fold. Retinoic acid was undetectable or found at trace levels only. In untreatedskin, retinyl ester was found in relatively small amounts compared to retinol (4127 vs30528 ng/g wet weight). Of the esters, retinyl linoleate was the predominant ester at all time
points examined. Other identified retinyl esters were oleate, palmitate, laurate and stearate(each made up less than 10% of the total).
Metabolisms of retinol into retinyl esters seem to be the primary route for disposition ofretinol in the skin, suggesting that retinol may be metabolised into retinyl ester to prevent
further conversion of retinol to retinoic acid (Figure 3). Retinol and retinyl esters account for
more than 99% of total epidermal retinoids (reviewed in Sorg et al., 2006). The lack ofdetectable increase in retinoic acid in the skin following application of retinol may be
explained by a tightly controlled, low-level conversion of retinol to retinoic acid at specificphysiologically relevant sites (Kang et al., 1995). Adequate retinol levels in the skin are
obtained by retrieval of retinyl esters from their storage sites in the skin followed byhydrolysis of the esters into retinol. The intracellular storage site is, however, not known.
Retinol is then oxidised to retinoic acid by a two-step pathway: i) Oxidation of retinol toretinal by a cytoplasmic alcohol/retinol dehydrogenase and a microsomal, short-chain retinol
dehydrogenase. Both unbound retinol and retinol-RBP can be oxidised. ii) Oxidation ofretinal to retinoic acid where aldehyde dehydrogenase may play an important role. The
formation of retinal is considered to be the rate-limiting step (Fu et al., 2007).

2.3.5

Dermal absorption and systemic availability of topical retinoids

In the in vivo studies cited in section 2.3.1, no significant increase in plasma levels of
retinoids could be detected after repeated applications of retinal, retinol or retinyl palmitate(Sass et al., 1996; Nohynek et al., 2006). This may be due to several factors such as dose andarea of application. In the study by Sass, the application area was about 40% of the total bodysurface area and the dose corresponded to 7 mg of retinal daily for 14 days. In the study byNohynek, around 19% (3000 cm2) of the total body surface area was covered daily by anamount of 3.5 g of cream for 21 days. This corresponds to a daily dose of 9 mg of retinol or
16 mg of retinyl palmitate. According to the SCCS’s Notes of Guidance (SCCS, 2010), 7.82 g
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10/405-3 finalof body lotion is the estimated daily exposure level. Furthermore, the mean exposed skinsurface area for body lotion is 15 670 cm2. Thus, both the doses applied and the application
area in the studies by Sass and Nohynek are much lower than recommended by SCCS. In
addition, serum retinol concentrations are not considered as an efficient biomarker of
exposure in individual patients because of the homeostatic regulation of vitamin A (Penniston
and Tanumihardjo, 2006). An increase in plasma levels of retinoids after topical application
may not be expected due to the storage capacity and the tightly controlled low-level
conversion of retinol to retinoic acid in the skin. However, both in vivo and in vitro studies
demonstrate that topical application is effective with respect to loading the skin with
substantial levels of retinoids. Furthermore, the topically applied retinol and retinol palmitate
has been shown to trigger biochemical (e.g. increased expression of retinol and retinoic acidbinding proteins, increased levels of enzymes that metabolise retinoic acid) and histological(e.g. epidermal hyperplasia, dermal collagen synthesis and degradation) changes in the skinthat might be expected from pertubation of previously established retinoid homeostasis (Kanget al., 1995; Duell et al., 1997; Fu et al., 2007).
SCCS has in the Notes of Guidance for the Testing of Cosmetic ingredients (SCCS, 2010)provided general guidelines to estimate the systemic availability (SED: systemic exposuredose) of a cosmetic ingredient by taking into account the daily amount of finished cosmetic
product applied, the concentration of the ingredient, the dermal absorption of that particularingredient and a mean human body weight value. Preferably, SED should be calculated basedon the absolute amount bioavailable (µg/cm2) after a certain time period, but calculations
based on the percentage dermally absorbed may also be used.
According to the SCCS’ Notes of Guidance for the Testing of Cosmetic ingredients, dermal
absorption is defined as the amount measured in the dermis, epidermis (without stratum
corneum) and the receptor fluid (SCCS, 2010). When studies fulfil the SCCS basic
requirements for in vitro dermal absorption studies (Appendix I), the mean + 1SD should be
used when calculating the margin of safety (MoS). However, in case of significant deviations
from the protocol and/or very high variability, the mean + 2SD should be used. None of the invitro studies assessed in the present opinion (Boehnlein et al., 1994; Leclerc, 1997; Yourick etal., 2008) fulfil the SCCS requirements. When it comes to the in vitro experimental
conditions (e.g. diffusion cell designs, receptor fluid, skin preparation, dose/volume/contacttime), they are comparable. The main differences between the studies are the choice ofvehicles and measurements of the test substance in the relevant compartments (excess on theskin (dislodgeable dose), stratum corneum, living epidermis (without stratum corneum),dermis, receptor fluid). In the study by Boehnlein et al. (1994), information on the absorption
in all relevant compartments is not available. The amount of absorbed retinyl palmitate isdefined as the sum of absorbed in skin and receptor fluid. However, there is no information onwhether the stratum corneum was removed before the homogenisation of the skin samples. In
addition, there is no information on the dislodgeable dose. Lerclerc et al. (1997) define theabsorbed amount as the sum of absorbed in epidermis, dermis and receptor fluid. The amountin the different compartments is shown, but only in three-dimensional figures making it
difficult to define the exact absorption rates. There is no information on the dislodgeable dose.
The study considered to best fulfil the SCCS’s criteria was Yourick et al. (2008) where theamount absorbed in all the different compartments were measured. However, the standard
error has been used when calculating dermal absorption due to lack of information on thestandard deviation. Data derived from the oil-in-water emulsion was chosen because it best
mimics the vehicle used in cosmetic products as moisturisers. The absorptions after 24 hours
were in viable skin 3.0%±0.6 and receptor fluid 1.3%±0.1. The value of dermally absorbed
retinol in agreement with the SCCS’s guideline (mean absorption in viable skin + receptor
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fluid + 2 SD) was estimated by VKM to be 5.7%. This value correspond well with theabsorption value of 5.3% calculated from the human in vivo study by Franz and Lehman(1990) after topical application of retinoic acid.

2.4 Local adverse effects of retinoids
2.4.1

Skin irritation

The main effect of topical retinoids is believed to be the receptor-mediated gene activationinduced by the ligand retinoic acid. Accordingly, retinoic acid is the most potent topicalretinoid and not allowed in cosmetics. Apparently, the other topical retinoids have to be
metabolised to retinoic acid by the skin to exert their genomic effects and their potency arestrongly dependent on their metabolic distance to retinoic acid. Hence, the retinoid-like
activity after topical application is increasing in the following order: retinyl esters << retinol <retinal < retinoic acid. Notably, the similar ranking is seen for their capacity to induce skinirritation, the most pronounced local adverse effects. Retinoic acid is the most toxic retinoid,
and the ability of a topical retinoid to enhance the local content of retinoic acid seems topredict its toxicity profile. For all topical retinoids the skin irritation effect is dose-dependent,
and the adverse effect may be avoided with a topical dose below 0.3% (retinol) or 0.55%(retinyl esters) (Nohynek et al., 2006).
Irritated skin is characterized by redness, dryness and flaking of the skin at the treated site
(Varani et al., 2008). Epidermal hyperplasia and features of abnormal differentiation are seenat the histological level. The molecular events that underlie retinoid-induced irritation are notclear.

2.4.2

Photocarcinogenesis

Experimental studies have indicated that topically applied retinoids can, under someconditions of testing, enhance photocarcinogenesis. In 2000, the Center for Food Safety andApplied Nutrition (CFSAN) within the FDA in USA nominated retinyl palmitate to National
Toxicology Program (NTP) for phototoxicity and photocarcinogenicity testing. The
nomination was based on the increasingly widespread use of this compound in cosmetic retailproducts for use on sun-exposed skin, the biochemical and histological cutaneous alterations
elicited by retinyl palmitate, and the association between topical application of retinoids andenhancement of photocarcinogenesis (FSA CFSAN, 2000). In 2003, NTP begun a one-year
photococarcinogenesis study to determine whether the topical application of creams
containing retinoic acid or retinyl palmitate would alter the process of photocarcinogenesis in
SKH-1 mice exposed to simulated solar light (SSL), UVA, or UVB. A draft report of thisstudy was available in 2010 (NTP, 2010).
In the Technical Reports Peer Review Meeting January 26, 2011 (NTP, 2011), the panel
agreed that under the conditions of these studies, the topical treatment of SKH-1 mice withthe control cream (vehicle without retinoids) resulted in earlier onsets of in-life skin lesions
and higher incidences and multiplicities of in-life skin lesions, when compared to untreatedcontrols, in the absence and presence of SSL. The control cream consisted of 85% base cream(EDTA, glycerin, carbopol981, mineral oil, BRIJ 721, stearic acid, cetearyl alcohol, octyl
palmitate, germaben, water) and 15% diisopropyl adipate. The topical treatment of SKH-1
mice with control cream resulted in higher incidences and multiplicities of squamous cell
neoplasms of the skin when compared to untreated controls in the absence and presence ofSSL. Compared to the control cream, retinoic acid and retinyl palmitate further enhanced the34Norwegian Scientific Committee for Food Safety (VKM)

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effects of SSL in SKH-1 mice based upon earlier onsets and increased multiplicities of in-lifeskin lesions. Compared to the control cream, retinyl palmitate further enhanced thephotocarcinogenic activity of SSL in SKH-1 mice based upon increased incidences andmultiplicities of squamous cell neoplasms of the skin.
In the same meeting, it was expressed some concern about the methodology used, thesignificant effect of the control cream, possible effects of animals scratching themselves as aresult of irritation from high doses of retinoids and exclusion of animals because of skincondition. It was also commented that the experimental protocol for the study wasappropriately chosen, the lines of evidence all point to the photocarcinogenic effect of retinyl
palmitate in combination with sunlight, and the findings of the NTP study are in agreementwith the research database on the phototoxicity and photococarcinogenicity of retinoid
compounds.
Although the causative mechanisms of photococarcinogenesis demonstrated in the NTP study
are not clear, one plausible mechanism may be related to the formation of free radicals andphotomutagenic effects observed in cells exposed to retinoids and UV light. It is reported that
retinyl palmitate in combination with UVA light produce genotoxic effects in mouse
lymphoma or human Jurkat T-cells via a photoclastogenic mechanism (Mei et al., 2005; 2006,
Yan et al., 2005). Other promotional mechanisms could also be involved, such as stimulationof cell proliferation, hyperplasia, irritation and erythema. These effects of topical retinoids arewell known in human skin (Sorg et al., 2006).
The NTP photocarcinogenesis study of retinyl palmitate and retinoic acid in hairless mouseskin has introduced safety concern about the use of topical retinoids in combination with sun
exposure. However, extrapolation of the NTP results from highly susceptible hairless mouseskin to human skin cannot be done directly. The mouse is a typical nocturnal animal with askin normally covered with fur, and it is not adapted to intense UV light. In contrast, thehuman skin is practically hairless and in general relatively well adapted to sunlight, but withsome variation because of different pigmentation. The function profile of the natural skinretinoids may be different in man and mouse. In humans, the local retinoids may in fact beinvolved in the protection system of various antioxidants in the skin. Wang et al. (2010) has
critically analysed the safety of retinyl palmitate in sunscreens with particular focus on the
NTP study. They point out two observations from clinical medicine that provide the strongest
challenges to the notion that topical retinoids may be photocarcinogenic in humans: after
more than 40 years use of topical retinoids and medical follow up there is no publishedevidence of increased risk of photocarcinogenesis, and oral and topical retinoids are in factused for chemoprevention of skin cancers in individuals at high risk.
In conclusion, VKM notes that the NTP data may indicate that retinol and retinyl palmitate
could be photocarcinogenic in mice. However, these results do not provide sufficient
information for a risk assessment of this effect of retinol and retinyl esters in cosmetics. Morestudies are needed to clarify mechanisms of possible retinoid photocarcinogenesis as well as
characteristics needed for the extrapolation from mouse skin to human skin.

2.4.3

Other potential local biological adverse effects

The retinoids retinyl esters, retinol and retinal are used in a large variety of cosmetic products,
such as anti-wrinkle creams, body lotions, hand creams and sunscreens. Topical retinoids
from cosmetics are absorbed and loaded in the skin, and they interfere with the normal
vitamin A function in a long-term perspective, for many users a life-long perspective.
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No published materials have indicated that long-term use of topical retinoids may induce local
biological adverse effects other than skin irritation, even though these retinoids have beenused in cosmetics and medical treatment for more than 30 years.

2.5 Critical effect and upper intake levels
It is considered difficult to determine a tolerable upper intake level for preformed vitamin A
due to the narrow margin between the RDI and intakes that are associated with adverse healtheffects. The teratogenic potential of vitamin A has received the most attention in setting an
UL for intake, and dose-response relationship has been demonstrated in several humanstudies. In 2002, the Scientific Committee on Food (SCF) derived an UL of 3000 µg RE/day
for all women of child-bearing age based on the teratogenic potential of vitamin A (SCF,
2002). The UL value is also lower than the daily intake that has been demonstrated to cause
hepatotoxicity (7500 µg RE/day). The lowest reported effect doses for selected adverse
effects are presented in Table 2 (adapted from SCF 2002; EFSA, 2006a).
Table 2: Reported lowest effect doses for a selection of adverse effects1.
EffectLowest reported effect dose

Teratogenesis>3000 µg RE/day (from Rothman et al., 1995)

Bone density/fracture1500 µg RE/day (trend analysis do not show a threshold)

Hepatotoxicity

7500 µg RE/day for 6 years

Bulging fontanelle

7500 µg RE/day (as a single dose in infants)

Lipid metabolism

7500 µg RE/day for 4 years (only a minor change)

1

Data from SCF, 2002.

The UL set by SCF is derived by fitting a curve to the dose response data from the large
number of subjects in the at risk group included in the study cohort (Rothman et al., 1995).
SCF acknowledged that a clear threshold for teratogenicity was difficult to establish, but it
was found appropriate to use the value of 3000 µg RE/day. Since data from other studies
indicated that the true threshold for an effect could be higher, SCF considered it not necessary
to use any uncertainty factor.
Although teratogenicity is only relevant to women of child-bearing age, SCF considered thatthe upper level of 3000 µg RE/day is appropriate for men and for infants and children after
correction for differences in metabolic rate, because it is 2.5-fold lower than the lowest daily
intake associated with other toxic effects such as hepatotoxicity during chronic intake. The
tolerable upper intake levels for different age groups presented in Table 3 is based on thevalue of 3000 µg RE/day for adults, with correction for differences in basal metabolic ratecompared to adults using a scaling factor (body weight0.75) (SCF, 2002; EFSA, 2008).

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Table 3: Tolerable Upper Intake Levels (UL) for preformed vitamin A (retinol and retinyl esters) for different age
groups (SCF, 2002; EFSA, 2008).

Age (years)

Tolerable Upper Intake Level (UL) for preformed vitamin A (retinol andretinyl esters) (µg RE/day)

1–3

800

4–6

1100

7–10

1500

11–14

2000

15–17

2600

Adults*3000* Women of child-bearing age and men

The UL derived by SCF may, however, not adequately address the possible risk of bone
fracture in particularly vulnerable groups, such as postmenopausal women. SCF therefore
recommended that it would be advisable for postmenopausal women, who are at greater riskof osteoporosis and fracture, to restrict their intake to 1500 µg RE/day (SCF, 2002).
In a more recent scientific opinion published by the EFSA FEEDAP Panel in 2008, the UL set
by SCF was considered as still being appropriate, taking into account new available data
published later than 2002 (SACN, 2005; AFSSA, 2005; Ribaya-Mercado and Blumberg,2007). EFSA further concluded that quantitative correlations between retinol intake and bonehealth risk could not justify the establishment of a lower UL for a specific population
subgroup (elderly people). Until new data indicates the necessity of a re-evaluation, EFSA
therefore considered that a maximum intake of 1500 µg RE/day would serve as a guidancelevel (GL) for individuals at greater risk of osteoporosis and bone fracture (particularly postmenopausal women) (EFSA, 2008).
The main contribution to vitamin A intake comes from food and food supplements. However,an additional source to the total vitamin A exposure is the use of cosmetic products containing
retinol, retinyl esters and retinal. Consequently, the assessments for the different age groupsof the population are based on the total estimated exposures from food, food supplements andcosmetics. For the risk characterisation in this opinion, VKM has chosen to use the agedifferentiated UL levels (Table 3) and the GL level for individuals at risk of osteoporosis andbone fracture established by SCF/EFSA (SCF, 2002; EFSA, 2008).

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3 Exposure characterisation
3.1 Exposure to retinol and retinyl esters from the use of cosmetics
Vitamin A, in the form of retinol and retinyl esters, is widely used in cosmetic products.
Retinol and its esters, such as retinyl palmitate or retinyl acetate are used to improve theappearance of skin by reducing fine lines and wrinkles and to generally improve theappearance of skin (Yourick et al., 2008). These ingredients are listed as skin conditioning
agents in the EU inventory list for cosmetic products and are mainly used in various facecreams with anti-photo aging purposes and in moisturizers.
According to Nohynek et al., (2006), retinol and retinyl esters are used in skin care products
and cosmetic preparations at concentrations of up to 0.3% (retinol) or 0.55% (retinyl
palmitate). Given that higher concentrations tend to be irritating to the skin, they are
considered to be unsuitable for cosmetic use (Ries and Hess, 1999; Fluhr et al., 1999). Recent
information from the cosmetic industry and the BfR refers to the following concentrations ofretinol and retinyl esters in different cosmetic products (personal communication G. Nohynek,
L’Oreal, October 2011; BfR, 2010):
Face and hand creams: 0.01-0.3% RE*Body lotions: 0.01-0.05% RE*



Rinse-off products: 0.01-0.3% RE**RE = retinol equivalents, i.e. retinyl palmitate and retinyl acetate at corresponding retinol concentrations (seesection 1.1.2).

The use of retinol and retinyl esters in cosmetic products is restricted in the Norwegiancosmetics regulations with maximum allowed concentrations of 0.3% (retinol) and 0.7%
(retinyl palmitate).

3.1.1

Estimated exposure to retinol and retinyl esters from the use of cosmetic
products in different age groups in Norway

In this opinion, VKM has estimated the systemic exposure dose (SED) to vitamin A (retinol
and retinyl esters) from topical application of cosmetic products in different age groups of theNorwegian population.
The different exposure scenarios presented in Table 4-6 are based on default values for
exposure to the relevant cosmetic products described in the SCCS’s Notes of Guidance for the
Testing of Cosmetic Ingredients and Their Safety Evaluation (SCCS, 2010). The SED has
been calculated as follows:
SED = Daily exposure to a cosmetic product (mg/kg bw/day) x concentration of theingredient (%)/100 x dermal absorption (%)/100
Various concentrations of vitamin A (retinol and its esters) in the products have been used toillustrate how the estimated SED could be altered in the different scenarios.

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Daily exposure to skin care products used in the exposure scenarios

In the new version of the Notes of Guidance (7th revision), more recent and robust cosmetic
exposure data, provided by the European Cosmetics Association (Colipa), have been
incorporated for 6 product types (body lotion, deodorant, facial moisturiser, shampoo, lipstickand toothpaste). The following default values for daily exposure to different skin careproducts (Table 3 in Notes of Guidance) are used in this opinion:Body lotion: 7.82 g/day, equivalent to 123.20 mg/kg bw/day
Face cream: 1.54 g/day, equivalent to 24.14 mg/kg bw/day
Hand cream: 2.16 g/day, equivalent to 32.70 mg/kg bw/day

The daily exposure values presented in Table 3 in the Notes of Guidance are valid for adults.
For the younger age groups, the daily amount applied has been adjusted to the difference inskin surface area over body weight ratio (SSA/BW) between adults and children. The
SSA/BW ratios for children from 0 to 10 years described in Notes of Guidance have beenused in the different exposure scenarios:

1.6 fold at 12 months (used for 1- and 2-year-olds)
1.5 fold at 5 years (used for 4-year-olds)
1.3 fold at 10 years (used for 9-year-olds)

The daily exposure to skin care products for 13-year-old adolescents has been assumed to be
similar to adults, as there is no correction factor for SSA/BW ratio above 10 years in theNotes of Guidance (SCCS, 2010).

3.1.1.2

Concentrations of retinol and retinyl esters in skin care products used in the
exposure scenarios

The exposure scenarios are based on different concentrations of retinol and retinyl esters in
the relevant cosmetic products. The maximum allowed concentrations for retinol and retinyl
esters in Norway, and the concentration levels referred to by the cosmetic industry and BfR
have been used in the estimates (Norwegian Cosmetic Regulations, 1995; BfR, 2010). In
addition, a scenario for cosmetic products containing as much as 1% retinol has been included(information in a letter from the Norwegian Medicines Agency (2009) regarding anapplication for classification of medicinal products).
The concentrations of retinol and retinyl esters in cosmetic products are apparently limited atconcentrations up to 0.3% retinol or 0.55% retinyl palmitate because higher concentrations
will irritate the skin (Nohynek et al., 2006). Since the effects of retinyl esters are related totheir retinol activity (i.e. 0.55% retinyl palmitate comprises 0.3% retinol), all concentrations
have been given in % or g RE (see also 1.1.2).
The following concentrations have been used for different cosmetic product types in the
exposure scenarios:Body lotion:o Standard scenario: 0.05% (BfR, 2010)o Worst case scenario: 0.3% (maximum allowed concentration in Norway)
Face cream:o Standard scenario: 0.3% (BfR, 2010; maximum allowed concentration in
Norway)o Worst case scenario: 1% (based on information from the Norwegian Medicines
Agency (2009) that products for cosmetic use contain such concentrations).
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Hand cream:o Standard scenario: 0.3% (BfR, 2010; maximum allowed concentration in
Norway)o Worst case scenario: 1% (based on information from the Norwegian Medicines
Agency (2009) that products for cosmetic use could contain suchconcentrations).

It should also be noted that the German database “Codecheck.info”(http://www.codecheck.info/kosmetische_mittel.kat), which contains around 40000 cosmetic
products offered for sale in German retailer outlets, gives information of cosmetic productswith even higher concentrations of retinol than 1%. These products are especially intended forthe niche market of anti-aging products/beauty saloons. However, products with retinol
concentrations above 1% have not been considered in this risk assessment.
3.1.1.3

Dermal absorption data used in the exposure scenarios

The dermal absorption rate for retinol and retinyl esters has been based on the data for oil-inwater emulsions in the study of Yourick et al. (2008). Taking into account the basic criteria
for dermal/percutaneous absorption studies described in SCCS’s Notes of Guidance (SCCS,
2010), a dermal absorption rate of 5.7% has been calculated and used in the exposure
scenarios in this opinion from VKM. For more details, see section 2.3.

3.1.2

Estimated exposure to retinol and retinyl esters from the use of cosmetic
products for infants and children

The estimated exposure to retinol and retinyl esters from topical application of cosmetic
products for 1-year old infants, 2-, 4- and 9-year-old children is shown in Table 4. Applicationof baby skin care products containing vitamin A, such as e.g. body lotions or creams is
considered relevant for 1 year-old infants and 2-year-old children. A similar exposure
situation from application of body lotions has been assumed for 4- and 9-year-old children.
Two different exposure scenarios for topical application of body lotions containing retinol andretinyl esters for different age groups of children are presented in Table 4; first a scenario
based on a concentration of 0.05% in body lotions referred to by the cosmetic industry and
BfR (standard scenario), and secondly a worst case scenario based on the maximum allowed
concentration of retinol and retinyl esters in cosmetic products in Norway (0.3%).
Table 4: Exposure scenarios for the application of skin care products containing retinol and retinyl esters for infants
and children.

Cosmetic
product type

Estimateddaily
amountapplied (g)1

Concentration ofretinol andretinyl esters(%2)3

Dermalabsorption(%)4

SSA/BW5

Systemic
exposure
dose (SED)(µg RE/day)UL

1-year-old infants
Body lotion

1.22

0.05

5.7

1.6

56

800

Body lotion

1.22

0.3

5.7

1.6

334

800

1.6

72

800

2-year-old children
Body lotion

1.58

0.05

5.7

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Norwegian Scientific Committee for Food Safety (VKM)

Body lotion

1.58

0.3

5.7

10/405-3 final

1.6

432

800

4-year-old children
Body lotion

2.22

0.05

5.7

1.5

95

1100

Body lotion

2.22

0.3

5.7

1.5

569

1100

9-year-old children
Body lotion

3.94

0.05

5.7

1.3

146

1500

Body lotion

3.94

0.3

5.7

1.3

876

1500

1

Based on default exposure levels from Table 3 in SCCS Notes of guidance and adjusted for the mean bodyweight of 1-year-old infants (9.9 kg), 2-year-old children (12.8 kg), 4-year-old children (18 kg) and 9-year-old
children (32 kg).
2
Retinyl palmitate and retinyl acetate at corresponding retinol concentrations.
3Standard scenario: 0.05% in body lotion, Worst case scenario: 0.3% in body lotion.
4
The different scenarios are based on a dermal absorption rate of 5.7% (Yourick et al., 1998; SCCS, 2010).
5
Factor for the difference in skin surface area (SSA) over body weight (BW) ratio between adults and children(SCCS, 2010).

From Table 4 it can be seen that the estimated SED from topical application of body lotions
containing 0.05% ranged from 56 µg RE/day in 1-year-old infants to 146 µg RE/day in 9year-olds.
In the worst case scenario that was based on the maximum allowed concentration of retinol incosmetic products in Norway (0.3%), the estimated exposure increased to 334 µg RE/day for
1-year-old infants. For 2-, 4- and 9-year-old children, the respective SED-values were
estimated to 432, 569 and 876 µg RE/day for topical application of body lotions containing
0.3%.

3.1.3

Estimated exposure to retinol and retinyl esters from the use of cosmetic
products for adolescentsThe estimated exposure to retinol and retinyl esters from topical application of cosmetic
products for 13-year-old adolescents is shown in Table 5. Application of skin care products
containing vitamin A, such as body lotions and hand creams, is considered a realistic
exposure for Norwegian adolescents.
Different exposure scenarios for adolescents, taking into account topical application of both
body lotions, hand creams and a combination of these two skin care products containing
retinol and retinyl esters are presented in Table 5. The two scenarios for body lotions are
based on the concentration levels of retinol or retinyl esters in such products (0.05%) referred
to by the cosmetic industry and BfR and on the maximum allowed concentration of retinol incosmetic products in Norway (0.3%). For hand creams, the first scenario is based on the
maximum allowed concentration in Norway (0.3%), whereas the second scenario is based on
information in a letter from the Norwegian Medicines Agency (2009) regarding an application
for classification of medicinal products showing that products for cosmetic use could contain
1% retinol.

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Table 5: Exposure scenarios for the application of skin care products containing retinol and retinyl esters for 13-yearold adolescents.

Cosmetic
product type

Estimateddaily
amountapplied (g)1

Concentration ofretinol andretinyl esters(%2)3

Dermalabsorption(%)4

SSA/BW5

Systemic
exposure
dose (SED)(µg RE/day)

UL

Body lotion

6.10

0.05

5.7

1

174

2000

Body lotion

6.10

0.3

5.7

1

1043

2000

Hand cream

1.62

0.3

5.7

1

277

2000

Hand cream

1.62

1.0

5.7

1

923

2000

Body lotion +hand cream

6.10
1.62

0.05
0.3

5.7

1

451

2000

Body lotion +hand cream

6.10
1.62

0.3
1.0

5.7

1

1967

2000

1

Based on default exposure levels from Table 3 in SCCS Notes of guidance and adjusted for the mean bodyweight of 13-year-old adolescents (49.5 kg).
2
Retinyl palmitate and retinyl acetate at corresponding retinol concentrations.
3Standard scenario: 0.05% in body lotion and 0.3% in hand cream, Worst case scenario: 0.3% in body lotion and
1.0% in hand cream.
4
The different scenarios are based on a dermal absorption rate of 5.7% (Yourick et al., 1998; SCCS, 2010).
5
Factor for the difference in skin surface area (SSA) over body weight (BW) ratio between adults and children(SCCS, 2010).

The results in Table 5 show that the SED from topical application of body lotions containing
retinol and retinyl esters in 13-year-old adolescents could be estimated to 174 and 1043 µg
RE/day for the standard scenario (0.05%) and the worst case scenario (0.3%), respectively.
For topical application of hand creams containing retinol and retinyl esters, the standard
scenario based on the maximum allowed concentration of retinol in cosmetic products in
Norway (0.3%) resulted in an estimated SED of 277 µg RE/day. In the worst case scenario(1%) (Norwegian Medicines Agency, 2009), a SED of 923 µg RE/day was calculated.
For topical application of both body lotions and hand creams daily, SED-values of 451 µg
RE/day and 1967 µg RE/day were estimated for the standard scenario and the worst casescenario, respectively.

3.1.4

Estimated exposure to retinol and retinyl esters from the use of cosmetic
products for adults

The estimated exposure to retinol and retinyl esters from topical application of cosmetic
products for adults is shown in Table 6. Application of various skin care products containing
vitamin A, such as body lotions, face creams and hand creams, is considered as a relevant andrealistic exposure for Norwegian adults of both gender.

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Norwegian Scientific Committee for Food Safety (VKM)

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Different exposure scenarios for adults, taking into account topical application of body
lotions, face creams and hand creams and a combination of all these three skin care products
containing retinol and retinyl esters are presented in Table 6. The two scenarios for body
lotions and hand creams are based on the same concentration levels of retinol or retinyl esters
as described in the exposure scenarios for adolescents (section 3.1.3). For face creams, thestandard scenario is based on the maximum allowed concentration of retinol in cosmetic
products in Norway (0.3%), whereas the worst case scenario is based on information in a
letter from the Norwegian Medicines Agency (2009) regarding an application forclassification of medicinal products showing that products for cosmetic use could contain 1%
retinol.
Table 6: Exposure scenarios for the application of skin care products containing retinol and retinyl esters for adults.

Cosmetic
product type

Estimateddaily
amountapplied (g)1

Concentration ofretinol andretinyl esters(%2)3

Dermalabsorption(%)4

SSA/BW5

Systemic
exposure
dose (SED)(µg RE/day)

UL

Body lotion

7.82

0.05

5.7

1

223

3000

Body lotion

7.82

0.3

5.7

1

1337

3000

Face cream

1.54

0.3

5.7

1

263

3000

Face cream

1.54

1.0

5.7

1

878

3000

Hand cream

2.16

0.3

5.7

1

369

3000

Hand cream

2.16

1.0

5.7

1

1231

3000

Body lotion +face cream +hand cream

7.82
1.54
2.16

0.05
0.3
0.3

5.7

1

856

3000

Body lotion +face cream +hand cream

7.82
1.54
2.16

0.3
1.0
1.0

5.7

1

3446

3000

1

Based on default exposure levels from Table 3 in SCCS Notes of guidance.
Retinyl palmitate and retinyl acetate at corresponding retinol concentrations.
3Standard scenario: 0.05% in body lotion and 0.3% in hand cream and face cream, Worst case scenario: 0.3% inbody lotion and 1.0% in hand cream and face cream.
4
The different scenarios are based on a dermal absorption rate of 5.7% (Yourick et al., 1998; SCCS, 2010).
5
Factor for the difference in skin surface area (SSA) over body weight (BW) ratio between adults and children(SCCS, 2010).
2

In Table 6, the SED from topical application of body lotions containing retinol and its esters
in adults has been estimated to 223 µg RE/day in the standard scenario (0.05%) and 1337 µg
RE/day in the worst case scenario (0.3%).

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The two exposure scenarios for face creams resulted in a SED of 263 µg RE/day for products
containing 0.3% and 878 µg RE/day for products containing 1.0% retinol. Slightly higher
exposures were found for the two scenarios for topical application of hand creams. The
standard scenario based on the maximum allowed concentration of retinol in cosmetic
products in Norway (0.3%) resulted in a SED of 369 µg RE/day. In the worst case scenario(1.0%) (Norwegian Medicines Agency, 2009), a SED of 1231 µg RE/day was calculated.
For a daily topical application of body lotions, face creams and hand creams, SED values of
856 µg RE/day and 3446 µg RE/day were estimated for the standard scenario and the worst
case scenario, respectively. Daily application of all the abovementioned vitamin A-containing
products should be considered more common for women than for men.

3.2 Dietary intake from preformed vitamin A
Vitamin A is present in the diet as preformed vitamin A in various animal sources such as
liver, milk, eggs, butter and fish liver oil or as provitamin A carotenoids (mainly ß-carotene)in dark green leafy vegetables, and in red or orange coloured fruits and vegetables such as
carrot, mango, papaya and sweet potato (Blomhoff et al., 2003; EFSA, 2008). In addition,
preformed vitamin A is also contained in a number of mono and multivitamin supplements.
The dietary intake from vitamin A calculated in this VKM opinion only consider the intake
from preformed vitamin A (retinol), as there is no evidence for vitamin A-related toxicity
from provitamin A carotenoids.
3.2.1

Methodological considerations and description of the national consumption
surveys

The dietary intake estimates from preformed vitamin A presented in this opinion are based ondata from the nationally food consumption surveys for infants, children, adolescents andadults. The food consumption data are the most complete and detailed currently available in
Norway. However, it should be pointed out that three different methodologies were used in
the different surveys and thus direct comparisons between different age groups (1-2-yearolds/ 4-13 year-olds/ adults) can be misleading.
A short description of the consumption surveys and the different methodologies used is given
below:


1-year-old infants; Spedkost 2006-2007 is based on a semi-quantitative foodfrequency questionnaire. In addition to predefined household units, food amounts werealso estimated from photographs. The study was conducted in 2007, and a total of
1635 1-year-old children participated (Øverby et al., 2009).
2-year-old children; Småbarnskost 2007 is based on a semi-quantitative foodfrequency questionnaire. In addition to predefined household units, food amounts werealso estimated from photographs. The study was conducted in 2007, and a total of
1674 2-year-olds participated (Kristiansen et al., 2009).
4-, 9-, and 13-year-old children/adolescents; Ungkost 2000 is based on a 4-day foodintake registration with a precoded food diary. Food amounts were presented inpredefined household units or as portions estimated from photographs. The study
among 4-year-olds was conducted in 2001, and 391 4-year-old children participated(Pollestad et al., 2002). The study among 9- and 13-year-olds was conducted in 2000
and 810 9-year-old children and 1005 13-year-old adolescents participated (Øverby
and Andersen, 2002).
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Adults; Norkost 3 is based on two 24-hour recalls by telephone at least one monthapart. Food amounts were presented in household measures or estimated fromphotographs (Totland et al., 2012). The study was conducted in 2010/2011 and 925
women and 862 men aged 18-70 years participated.

Daily intake of preformed vitamin A was computed by using food databases in the softwaresystem (KBS) developed at the Institute of Basic Medical Sciences, Department of Nutrition,at the University of Oslo. The food databases are mainly based on various versions of theofficial Norwegian food composition table (Rimestad et al., 2000, The Norwegian Food
Composition Table, 1995; 2006) and are continuously supplemented with data on new fooditems. The three dietary surveys that are the basis for this risk assessment were conducted atthree different time points, Ungkost-2000 in 2000-2001, Sped- and Småbarnskost in 2007 andthe data for Norkost 3 were collected in 2010-2011. The retinol calculations were conductedboth with and without vitamin supplements.
In the intake calculations each age group are divided in two, with one group consisting of
those taking retinol supplements and the other group consisting of those not taking retinol
supplements.
As retinol is found in relatively large quantities in a small number of foods, it is difficult toestimate the intake with few food registration days. To obtain an accurate estimate ofindividual retinol intakes a large number of repeated measurements are needed (Willett,1998).
3.2.2

Contribution of major food sources to retinol intake in Norway

The relative contribution of major food sources, including food supplements, to the intake ofretinol in different age groups is shown in Table 7. The table also shows the mean intake ofretinol for all participants in each age group. The figures presented are based on the intakes
reported by all participants in the consumption surveys.
Table 7: Relative contribution (%) of major food sources, including food supplements, to retinol intake based on datafrom all participants in the Norwegian consumption surveys. For reference, mean intake of retinol in each age groupis presented.

1-year-olds(n=1635)

2-year-olds(n=1674)

4-year-olds(n=391)9-year-olds(n=810)13-year-olds(n=1005)

Adults(n=1787)

467 µg705 µg848 µg

832 µg766 µg808 µgFood supplements

22

21

29

23

20

17

Meat, blood, offal(liver pâté)40 (40)32 (31)28 (24)27 (24)28 (16)22 (19)Butter, oil,margarine

18

21

17

19

16

22

Milk, cream, icecream

6

10

12

13

12

10

Cheese

5

8

5

7

8

11

Mean intake ofretinol

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Liver pâté is the single food item contributing most to retinol intake on group level in all age
groups (Table 7). Food supplements are also a major contributor of retinol with between 17%
and 29% relative to the intake in the different age groups. Milk and milk products, and butter,oil, and margarine with fortified retinol do also contribute to the overall intake.
Worth mentioning is that the retinol content of cod liver oil, decreased from 10000 µg/100 g
cod liver oil in year 2000 to 5000 µg/100 g cod liver oil in 2007. It is therefore likely that theretinol intake calculated from cod liver oil in Ungkost 2000 is an overestimation of the intake
compared with today’s retinol content in cod liver oil.
3.2.3

Estimated intake of preformed vitamin A in the Norwegian population

The estimated intakes (mean and 95 percentile) in different age groups in the Norwegian
population are shown in Table 8. The results are presented both for the selection ofparticipants with a reported consumption of vitamin A supplements and for those that did notconsume food supplements. For 1-year-old infants, the intakes have been estimated both forthe infants that were breastfed and those that were not breastfed at the age of 12 months.
Table 8: Mean and 95 percentile intakes for consumers of preformed vitamin A (retinol) in different age groups (µgRE/day).

Diet without food supplements

Diet including food supplements

Age group(number ofconsumers)

Mean intakeof retinol

95 percentile
intake of retinol

Age group(number ofconsumers)

Meamintake ofretinol

95 percentile
intake of retinol

1-year old infants(breastfed) (n=354)

315

737

1-year old infants(breastfed) (n=368)

521

1080

1-year old infants(non-breastfed)(n=485)394

1005

1-year old infants(non-breastfed)(n=396)644

1297

2-year-old children(n=775)563

1129

2-year-old children(n=899)827

1485

4-year-old children(n=156)592

1329

4-year-old children(n=235)

1019

1711

9-year-old children(n=450)651

1581

9-year-old children(n=360)

1060

2015

13-year-old
children (n=708)

631

1293

13-year-old children(n=297)

1087

2184

Adults (women)(n=629)544

1236

Adults (women)(n=296)983

1983

Adults (men)(n=587)751

1635

Adults (men) (n=275)

1349

2691

The intake of retinol varies between age groups. Those who take supplements have a higher
mean and 95 percentile intake compared with those not taking supplements in the same agegroup. Adult men taking supplements have the highest intake with 2691 µg retinol among the
95 percentile. The 13-year-old adolescents have the second highest intake with 2184 µg
retinol among the 95 percentile.
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4 Risk characterisation
4.1 Systemic effects of retinol and retinyl esters from food, foodsupplements and cosmetics
VKM has chosen to base this risk characterisation on the ULs derived by SCF/EFSA and theestimated total exposure from diet, supplements and cosmetics for different age groups in the
Norwegian population. For adult women, as considered at greater risk of osteoporosis andbone fracture, the estimated total intake is also discussed in relation to the GL level based on
retinol intake and effects on bone health. Diet is the dominating source, but the contribution
from supplements is substantial. In addition, dermal absorption of retinol and retinyl esters
increases the total exposure proportionately to the use of cosmetics. Dietary intake of
preformed vitamin A is estimated from national food consumption surveys for the various age
groups and the risk characterisation for this intake in the different age groups has been
demonstrated for two different groups of the population. One group is based on theindividuals not consuming supplements and where retinol intake from diet only is included.
The other group is based on the individuals that have consumed supplements with retinol, andwhere the intake of retinol from both diet and supplements are combined.
The estimated additional contribution from cosmetics is calculated according to the SCCS’s
Notes of Guidance for the Testing of Cosmetics Ingredients and Their Safety Evaluation(SCCS, 2010). The estimated values are based on default values for daily exposure to various
skin care products and a dermal absorption rate of skin products of 5.7% derived from thestudy of Yourick et al. (2008). The concentrations of vitamin A generally used (body lotion
0.05%, face and hand cream 0.3%) have been chosen for the standard exposure scenario in
this opinion. As a worst case scenario, the estimated contribution from cosmetics is based on
an assumed increase in the concentration of vitamin A as described in 3.1.1.2 (body lotion
0.3%, face and hand cream 1%). The estimated systemic exposure dose (SED) both for the
standard and the worst case scenarios, as well as the SEDs as percentage of the ULs for thedifferent age groups, are presented in Table 9. When exposure to retinol and retinyl esters
from cosmetics is calculated as percentage of UL, however, the values may represent anunderestimation relative to the contribution from consumption of food and food supplements.
This is because UL is based on dietary intake of preformed vitamin A and do not take into
account the 70 – 90% absorption rate in the intestine (NNR, 2004).
Table 9: Exposure scenarios for the application of skin care products containing retinol and retinyl esters comparedto the tolerable upper intake level (UL).

Cosmetic
product type

Concentration of retinol andretinyl esters (%1)2

Systemic exposure
dose (SED)(µg RE/day)

Percentage ofUL

1-year-old infants
Body lotion

0.05

56

7

Body lotion

0.3

334

42

72

9

2-year-old children
Body lotion

0.05

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Norwegian Scientific Committee for Food Safety (VKM)

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0.3

10/405-3 final

432

54

4-year-old children
Body lotion

0.05

95

9

Body lotion

0.3

569

52

9-year-old children
Body lotion

0.05

146

10

Body lotion

0.3

876

58

13-year-old adolescents
Body lotion + hand cream

0.05
0.3

451

23

Body lotion + hand cream

0.3
1.0

1967

98

AdultsBody lotion + face cream +hand cream

0.05
0.3
0.3

856

29

Body lotion + face cream +hand cream

0.3
1.0
1.0

3446

115

1

Retinyl palmitate and retinyl acetate at corresponding retinol concentrations.
Standard scenario: 0.05% in body lotion and 0.3% in hand cream and face cream, Worst case scenario: 0.3% inbody lotion and 1.0% in hand cream and face cream.
2

4.1.1

Total exposure to retinol and retinyl esters in Norwegian children

The total estimated exposures to vitamin A for the different age groups of the population, as
well as the ULs, are presented in Figures 4-11. The exposure scenarios presented in the
figures are all based on the chosen standard concentrations of vitamin A (retinol and retinyl
esters) in cosmetics (see section 3.1.1.2). Exposures are shown separately for the groups witha diet without food supplements and those who include supplements in their diet. The
additional exposure from cosmetics is illustrated in the figures for both groups. The
proportion of each age group that exceeds its respective UL is presented in Table 10. Values
are given as the closest 5%.
For all age groups of children (1-, 2-, 4- and 9-year-olds), daily exposure to vitamin A (retinol
and retinyl esters) from cosmetics is ascribed to the use of body lotion. The additional
contribution of vitamin A (retinol and retinyl esters) from cosmetics to the total intake fromdiet without and with supplement, based on the concentrations in the standard exposure
scenario (body lotion 0.05%, face and hand cream 0.3%) is illustrated in Figures 4 - 8.
In the standard scenario for 1-year-old breastfed infants (Figure 4B), 15% of those taking
supplements exceed the UL of 800 µg RE/day (Table 10). The children not using supplements
will not reach the UL even when cosmetics is added (Figure 4A and Table 10). The vitamin A
content in breast milk is not known and therefore not taken into account. When it comes to48

Norwegian Scientific Committee for Food Safety (VKM)

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non-breastfed children (Figure 5), the UL may be reached or exceeded by more than 10% if
supplements are not included in the diet (Figure 5A and Table 10) and by 30% among those
who receive food supplements (Figure 5B and Table 10). For 1-year-old infants, the exposure
from cosmetics in the standard scenario represents 7% of the UL (Table 9).
In a worst case scenario, based on an increase in the concentration of vitamin A in body
lotions from 0.05% to 0.3% (current maximum allowed concentration in Norway), theestimated proportion of breastfed children that would exceed the UL would be 20% for those
without and 50% for those with supplements in their diet. For non-breastfed, thecorresponding estimates are 30% and 65%, respectively. The estimated exposure fromcosmetics would constitute 42% of the UL (Table 9).

P r e fo r m e d v i t a m i n A (µ g R E/d a y )

1000
500

0
5

25

50

75

1500
1000

500
0
5

95

25

50

75

95

Percentiles of consumers

Percentiles of consumers
ULB

1‐year‐old infants, breastfed (n=368)
P r e fo r m e d v i t a m i n A (µ g R E /d a y )A

1‐year‐old infants, breastfed (n=354)
1500

Cosmetics+diet

UL

Diet

Cosmetics+diet+supplements

Diet+supplements

1500

1‐year‐old infants, non‐breastfed (n=485)

A

1‐year‐old infants, non‐breastfed (n=396)
P re fo rm e d v it am in A (µ g R E/d ay )P re fo rm e d vitam in A (µ g R E/d ay)

Figure 4: Additional contribution of preformed vitamin A from cosmetic products (body lotion 0.05%) to the intake
from diet only (A) and to the intake from diet and food supplements (B) in Norwegian 1-year-old children (breastfed)
compared to the UL of 800 µg RE/day.

1000

500

0
5

25

50

75

1500

1000

500

0

95

5

Percentiles of consumers
UL

Cosmetics+diet

B

25

50

75

95

Percentiles of consumers
Diet

UL

Cosmetics+diet+supplements

Diet+supplements

Figure 5: Additional contribution of preformed vitamin A from cosmetic products (body lotion 0.05%) to the intake
from diet only (A) and to the intake from diet and food supplements (B) in Norwegian 1-year-old children (nonbreastfed) compared to the UL of 800 µg RE/day.

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The total exposure to retinol and retinyl esters for 2-, 4- and 9-year old children, based on theconcentrations in the standard scenario for cosmetic products is presented in Figures 6 – 8.
Among 2- and 4-year-old children without supplements in their diet (Figures 6A and 7A), thedaily exposure reaches or exceeds the ULs of 800 µg RE/day and 1100 µg RE/day,
respectively, for 20% and 15% in these age groups (Table 10). For children in the same agegroups that use supplements (Figures 6B and 7B), 55% and 45% exceeds their ULs (Table
10). The total exposure for the 9-year-old children is shown in Figure 8, and it is estimatedthat 10% of those not using and 20% of those using supplements would exceed the UL of
1500 µg RE/day (Table 10). It should be mentioned, however, that the retinol level in cod
liver oil had been reduced by the time of the food consumption survey for 2-year-old children
compared to the survey for the 4- and 9-year old children. In this standard scenario, thecontribution from cosmetics to the total exposure represents 9% of the referred age-related
ULs for both 2- and 4-years old children and 10% of the UL for 9-year-old children (Table 9).
A worst case scenario based on an increase in concentration of retinol and retinyl esters inbody lotion from 0.05% to 0.3% would represent a 75% and 45% exceedance of therespective UL for 2- and 4-year-old children not using supplements and a 100% and 90%
exceedance for children in the same age groups who use supplements. For the 9-year oldchildren the estimated portions that exceed the UL would reach 35% for the group without
and 80% for the group with supplements in their diet. This worst case scenario would
correspond to an estimated increase in percentage of the age-related contribution fromcosmetics to the UL from 9% to 54 % and 52% for 2- and 4-year-old children, respectively(Table 9). For the 9-year-old children, the worst case scenario would represent an estimatedincrease from cosmetics to the UL from 10% to 58% (Table 9).

A

1500
1000
500
0
5

25

50

75

95

2000
1500
1000
500
0
5

Cosmetics+diet

25

50

75

95

Percentiles of consumers

Percentiles of consumers
UL

B

2‐year‐old children (n=899)
P r e fo rm e d v i t a m i n A (µ g R E/d a y )P r e fo rm e d v it am in A (µ g R E/d ay )2‐year‐old children (n=775)
2000

Diet

UL

Cosmetics+diet+supplements

Diet+supplements

Figure 6: Additional contribution of preformed vitamin A from cosmetic products (body lotion 0.05%) to the intake
from diet only (A) and to the intake from diet and food supplements (B) in Norwegian 2-year-old children comparedto the UL of 800 µg RE/day.

50

A

P r e fo rm e d v it am in A (µ g R E/d ay )4‐year‐old children (n=156)
2000
1500
1000
500

P re fo r m e d v i t am i n A (µ g R E/d ay )Norwegian Scientific Committee for Food Safety (VKM)

10/405-3 final

B

4‐year‐old children (n=235)
2000
1500
1000
500
0

0
5

25

50

75

5

95

25

UL

50

75

95

Percentiles of consumers

Percentiles of consumers
Cosmetics+diet

UL

Diet

Cosmetics+diet+supplements

Diet+supplements

Figure 7: Additional contribution of preformed vitamin A from cosmetic products (body lotion 0.05%) to the intake
from diet only (A) and to the intake from diet and food supplements (B) in Norwegian 4-year-old children comparedto the UL of 1100 µg RE/day.

P re fo r m e d v i t a m i n A (µ g R E/d a y )

2000
1500
1000
500

B

9‐year‐old children (n=360)
P r e fo r m e d v i t am i n A (µ g R E/d ay )A

9‐year‐old children (n=450)
2500

2500
2000
1500
1000
500
0

0
5

25

50

75

5

95

UL

Cosmetics+diet

25

50

75

95

Percentiles of consumers

Percentiles of consumers
Diet

UL

Cosmetics+diet+supplements

Diet+supplements

Figure 8: Additional contribution of preformed vitamin A from cosmetic products (body lotion 0.05%) to the intake
from diet only (A) and to the intake from diet and food supplements (B) in Norwegian 9-year-old children comparedto the UL of 1500 µg RE/day.

4.1.2

Total exposure to retinol and retinyl esters in Norwegian adolescents

The total exposure to retinol and retinyl esters in the standard scenario for 13-year-old
adolescents is shown in Figure 9. The total exposure will keep below the UL of 2000 µg
RE/day for those who do not use supplements, irrespective of the use of cosmetics (Figures
9A and Table 10). For the diet plus supplement group, however, the contribution fromcosmetics increases the proportion that exceeds the UL from 10% to 20% (Figures 9B and
Table 10). It should be noted that the retinol concentration in cod liver oil has been reduced
since the consumption survey was performed. The use of hand cream and body lotion with theconcentrations of retinol and retinyl esters in the standard scenario results in a contribution
from cosmetics of 23% of the UL for this age group (Table 9).
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Norwegian Scientific Committee for Food Safety (VKM)

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3000

A

13‐year‐old adolescents (n=708)

2500
2000
1500
1000
500
0

P r e fo r m e d v i t a m i n A (µ g R E/d a y )P r e fo r m e d v i t a m i n A (µ g R E/d a y )In a worst case scenario for the 13-year-old adolescents, the estimates represent a 100%exceedance of the UL both for the group without and with supplements in their diet. The
estimated contribution from cosmetics alone would correspond to an increase in percentage of
the UL from 23% to 98% (Table 9).

B

13‐year‐old adolescents (n=297)

3000
2500
2000
1500
1000
500
0

5

25

50

75

95

5

Percentiles
UL

Cosmetics+diet

25

50

75

95

Percentiles
Diet

UL

Cosmetics+diet+supplements

Diet+supplements

Figure 9: Additional contribution of preformed vitamin A from cosmetic products (body lotion 0.05%) to the intake
from diet only (A) and to the intake from diet and food supplements (B) in Norwegian 13-year-old adolescentscompared to the UL of 2000 µg RE/day.

4.1.3

Total exposure to retinol and retinyl esters in Norwegian adults

The total exposure to retinol and retinyl esters in the standard scenarios for adults is shown in
Figures 10 and 11. The exposure characterisation shows that both women and men who do
not use supplements will keep below the UL of 3000 µg RE/day (Figures 10A and 11A, Table
10). Among those who have an intake of preformed vitamin A from diet and supplements, anestimated portion of 10% of the men will exceed the UL when cosmetics are included,
whereas the women will keep below (Figures 10B and 11B, Table 10). The estimatedcontribution from cosmetics constitutes 29% of the UL for adult women and men with theretinol concentrations in the standard exposure scenario (Table 9). The relationship between
the total exposure to vitamin A and the GL for individuals at risk of osteoporosis and bone
fracture is discussed under vulnerable groups (section 4.3).
In a worst case scenario for adults, based on the assumed increase in retinol concentrations
described previously, the estimated contribution from cosmetics would correspond to anincrease in percentage of the UL from 29% to 115% (Table 9). Thus, this worst case estimate
for adult women and men represents a 100% exceedance of the UL both for the group without
and with supplements in their diet.

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Norwegian Scientific Committee for Food Safety (VKM)

P r e fo r m e d v i t a m i n A (µ g R E /d a y )

5

25

50

75

4000
3500
3000
2500
2000
1500
1000
500
0

95

5

25

Percentiles of consumers

UL

GL Osteoporosis

B

Adults, women (n=296)
P r e fo r m e d v i t a m i n A (µ g R E /d a y )AAdults, women (n=629)
4000
3500
3000
2500
2000
1500
1000
500
0

10/405-3 final

50

75

95

Percentiles of consumers

Cosmetics+diet

UL
Cosmetics+diet+supplements

Diet

GL Osteoporosis
Diet+supplementsA

P r e fo r m e d v i t a m i n A (µ g R E / d a y )Adults, men (n=587)
4000
3500
3000
2500
2000
1500
1000
500
0
5

25

50

75

95

P r e fo r m e d v i t a m i n A (µ g R E / d a y )Figure 10: Additional contribution of preformed vitamin A from cosmetic products (body lotion 0.05%, face cream
0.3% and hand cream 0.3%) to the intake from diet only (A) and to the intake from diet and food supplements (B) in
Norwegian adults (women) compared to the UL of 3000 µg RE/day and GL for osteoporosis of 1500 µg RE/day.

5

Cosmetics+diet

25

50

75

95

Percentiles of consumers

Percentiles of consumers

UL

B

Adults, men (n=275)
4000
3500
3000
2500
2000
1500
1000
500
0

Diet

UL

Cosmetics+diet+supplements

Diet+supplements

Figure 11: Additional contribution of preformed vitamin A from cosmetic products (body lotion 0.05%, face cream
0.3% and hand cream 0.3%) to the intake from diet only (A) and to the intake from diet and food supplements (B) in
Norwegian adults (men) compared to the UL of 3000 µg RE/day.

4.1.4

Summary of total exposure scenarios

Table 10 summarizes the estimated proportions within each age group that may exceed theirrespective age-related UL. The percentages are higher for the groups with a reported
consumption of supplements compared to the groups who do not use supplements. The
estimates also demonstrate that the contribution from cosmetics increases the proportion ofindividuals that exceeds the UL by up to 10% in the diet plus supplement groups (Table 10).

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Table 10: Estimated percentiles of consumers that reach or exceed their respective UL in different age groups basedon the concentrations of retinol and retinyl esters in the standard exposure scenario for cosmetics (body lotion 0.05%,
face and hand cream 0.3%).

Percentile of consumers exceeding
UL

Percentile of consumers exceeding UL

Age group(number ofconsumers)

Diet

Diet + cosmetics

Age group(number ofconsumers)

Diet + foodsupplements

Diet + foodsupplements +cosmetics

1-year old
infants(breastfed)(n=354)

Below UL

Below UL

1-year old
infants(breastfed)(n=368)10%15%

1-year old
infants (nonbreastfed)(n=485)10%10%

1-year old
infants (nonbreastfed)(n=396)25%

30%

2-year-old
children (n=775)

15%

20%

2-year-old
children (n=899)

45%

55%

4-year-old
children (n=156)

10%

15%

4-year-old
children (n=235)

35%

45%

9-year-old
children (n=450)

5%

10%

9-year-old
children (n=360)

15%

20%

13-year-old
adolescents(n=708)Below UL

Below UL

13-year-old
adolescents(n=297)10%20%Adults (women)(n=629)Below UL

5%Adults (women)(n=296)

Below UL

Below UL

Adults (men)(n=587)

Below UL

Below UL

Adults (men)(n=275)

Below UL10%

As demonstrated in the exposure characterisation, the total intake of vitamin A may be highin some groups of the Norwegian population. The use of food supplements contributes
significantly. The groups at highest risk of exceeding their respective UL are 1-year-old
infants (non-breastfed) and 2- and 4-year-old children who use food supplements (Table 10).
The additional contribution from cosmetics results in increased exposure to vitamin A(retinol and retinyl esters) and a further increase in the proportion of the population thatexceeds the UL. When the estimated exposures from cosmetics are related to the respective
age-related ULs, the contribution is most prominent for 13-year-old adolescents (23%) andadults (29%) (Table 9).
For other toxic effects than teratogenicity and bone health, e.g. liver toxicity, the reported
lowest effect dose is 7500 µg RE/day (Table 2). This value is 2 times higher than theestimated 95 percentile intake for adult men, which represents the highest intake within all
age groups (Table 8). Thus, the estimations presented in this opinion indicate that the intakesof preformed vitamin A should not pose a risk of other adverse health effects such as liver
toxicity for any of the age groups.
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4.2 Local adverse effects of retinoids
The retinoid effect in cosmetics is primarily against aging of the skin. In contrast to retinoic
acid, the weaker retinoids retinol and retinyl esters are not classified as drugs and are
currently used as active ingredients in various cosmetic products. Although not as potent as
retinoic acid, the retinoids used in cosmetics may also induce local irritation. The
concentrations of these retinoids in cosmetic products are to a high degree determined andlimited by these immediate adverse effects. On the other hand, as ingredients in cosmetics,
they may be used daily throughout the life without medical control and examination, also by
vulnerable groups, such as atopics. VKM has not found reported information indicating that
long-term use of topical retinoids may induce local adverse effects other than irritation anderythema.
A NTP study indicates that retinol and retinyl palmitate may be photocarcinogenic in mice.
However, VKM concludes that these data do not provide sufficient information for a risk
assessment of this effect of retinol and retinyl esters in cosmetics. More studies are needed toclarify mechanisms of possible retinoid photocarcinogenesis as well as characteristics needed
for the extrapolation from mouse skin to human skin.

4.3 Vulnerable groups
The UL is based on the teratogenic effects of vitamin A and is therefore of special
significance for women of fertile age. The contribution from supplements and cosmetics tothe total exposure should be given special attention in this group.
In addition to the UL, a guidance level (GL) of 1500 µg RE/day is established for groups withincreased risk of reduced BMD, osteoporosis and fractures. This is especially applicable forpostmenopausal women. The estimated contribution of vitamin A exposure from cosmetics
leads to an increase in exceedance of the GL from 0% to 25% for those who do not use
supplements and an increase in exceedance from 10% to 75% in the group where supplements
are included (Figures 10A and 10B). The estimated use of cosmetics in the standard exposure
scenario results in a substantial exposure to retinol and retinyl esters in postmenopausal
women with an increased risk of osteoporosis. A further increase in concentrations of retinol
and retinyl esters in cosmetic products would aggravate this situation.
The estimated exposures from cosmetics presented for the different age groups are based on
normal skin and healthy populations. There are, however, conditions in the skin that may leadto increased absorption of cosmetic products. In infants and small children the use of diapers
may often lead to sore and irritated skin. In order to rectify this, the use of cosmetic cream
may increase both in amount and number of applications per day. Assuming that the impaired
skin is more easily penetrated and the cream contains vitamin A, this will contribute to anincreased uptake and a subsequent increased exposure. Occlusion under the diaper is also
likely to further increase the absorption.
An increased dermal uptake and a subsequent increased exposure will also be the case forpeople with diagnosed skin disorders, such as atopic dermatitis which constitute a prevalenceof 10-12% of the schoolchildren, and 1-2% of the adult population in most western countries(Horii et al., 2007). These situations, in which the skin barrier is disrupted, lead to frequent
use of hand cream, and with a dysfunctional epithelial barrier the absorption through the skin
will increase.
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Large groups of the population in the Nordic countries suffer from dry skin due to air withvery low humidity during the winter season. A subsequent enhanced absorption and a more
frequent use of cosmetic products may result in increased dermal exposure.
Patients treated with oral drugs containing retinoids (isotretinoin etc.) receive contribution of
the more active forms of vitamin A. This additional exposure to retinoids increases the risk ofthese patients to reach or exceed the UL for vitamin A.

5 Uncertainty
5.1 Dermal absorption and systemic availability
VKM has used the SCCS’s Notes of Guidance for the Testing of Cosmetic ingredients(SCCS, 2010) when estimating the dermal absorption of retinol and the SED for the different
exposure scenarios. However, some human in vivo studies did not find any increase in plasma
levels of retinoids after daily applications to the skin. As discussed in 2.3.5, the lack of anincrease in plasma levels may be due to the small application areas and low doses in thesestudies. Short-term studies show that the metabolism of retinol into retinol esters is theprimary route for disposition of retinol in the skin. In addition, there is a tightly controlled
low-level conversion of retinol to retinoic acid. The tightly controlled levels of retinol andretinyl esters may result in an overestimation of the systemic exposure dose after topicalapplication.
The studies on skin metabolism of retinol and retinol esters are short-term studies. How longterm exposure by daily applications of retinol and retinyl esters affects the systemic or local
doses of retinoids are not known. Thus the estimated systemic exposure doses in the present
opinion may be either over- or underestimated.
In the different exposure scenarios presented in this opinion, VKM has assumed daily
applications of body lotion covering the entire body surface (except the face) for all age
groups. In addition, adolescents are also assumed to use hand cream and adults hand and facecream daily. Furthermore, it has been assumed that all product types contain retinol or retinyl
esters. In situations where fewer product types have been used or not all products containretinol or retinyl esters, the systemic exposure dose will be overestimated. Similarly,
application on a smaller surface area or a less frequent application of products containing
retinol or retinyl esters than used in the exposure scenarios, would result in a lower systemic
exposure dose from cosmetic products.
The contribution from cosmetics calculated as percentage of UL may be underestimatedrelative to the contribution from consumption of food and food supplements since the UL isbased on dietary intake of preformed vitamin A and do not take into account the 70 – 90%
absorption rate in the intestine (NNR, 2004).
There are products on the market containing higher concentrations of retinol and retinyl esters
than in the standard scenario used for estimations of the systemic exposure doses. However,VKM has in the worst case scenarios assumed daily applications of products containing 0.3%
(body lotion) and 1% (face and hand cream) retinol. The likelihood for daily use of products
containing these concentrations is however small. Thus, the systemic exposure doses in theworst case scenarios will be overestimated.

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5.2 Dietary exposure assessment
Every dietary assessment are connected with uncertainty. A description of the most important
uncertainties and assumptions in the dietary intake calculations is described below.
Three concepts are fundamental to understanding the limitations of dietary assessement:
habitual consumption, validity and precision (Livingstone and Black, 2003).
The habitual consumption of an individual is the person’s consumption averaged over a
prolonged period of time, such as weeks and months rather than days. However, this is alargely hypothetical concept; the consumption period covered in a dietary assessment is acompromise between desired goal and feasibility. In the Norwegian dietary surveys the time
period covered are 14 days among the 1- and 2-year olds (Sped- and småbarnskost 2007), four
consecutive days among the 4-, 9- and 13-year-olds (UNGKOST 2000) and 2 noneconsecutive days among the adults (Norkost 3). Both large within person and between person
variations in retinol intake are found in the consumption surveys. Retinol is found in a
relatively limited number of foods, and has large day-to-day variation (Willett, 1998). To
obtain an accurate estimate of individual retinol intakes a large number of repeatedmeasurements are needed (Willett, 1998). There is a higher uncertainty associated with the 95
percentile than the mean value, especially among the age groups with a low number ofparticipants.
The validity of a dietary assessment method refers to the degree to which the method actually
measures the aspect of diet that it was designed to measure (Nelson and Margetts, 1997).
Lack of validity is strongly associated with systematic errors (Burema et al., 1988). Withsystematic errors all respondents in a dietary study or each subgroup in a population produce
the same type of error, like systematic under- or overestimation of intake. All the threedifferent dietary assessment methods used in this opinion have limitations when it comes tovalidity. Results from validation studies among 9- and 13-year-olds indicate anunderestimation of energy intake of around 20% when the precoded food diary, used in
UNGKOST 2000, is compared with energy expenditure (Andersen et al., 2005; Lillegaard
and Andersen, 2005). The validation studies among 1- and 2-year-olds were performed on apreviously established questionnaire, but the results showed a significantly higher estimate ofvitamin A with the FFQ than with the weighed record reference method (Andersen et al.,
2003; Andersen et al., 2004; Andersen et al., 2009). The Norwegian 24-hour recall method
used among adults in Norkost 3 has not been validated. However, other similar 24-hour recall
methods have been validated and show an underestimation in energy intake of around 15%(Subar et al., 2003; Poslusna et al., 2009). Underestimation of energy intake indicates that not
all foods eaten are reported, but not which foods are underreported. It has been shown thatfoods perceived as unhealthy such as fats, sweets, desserts and snacks tend to beunderreported while foods perceived as healthy tend to be overreported (Olafsdottir et al.,2006). However, among children and adolescents there have been studies were this selective
underreporting was not shown (Sjøberg et al., 2003, Lillegaard and Andersen, 2005). As
shown in Table 7, consumption of supplements and liver pâte are the diet sources that
contribute most to the vitamin A intake. There are not specific studies on the reporting
accuracy for these food items, but they will, by most, be regarded as healthy rather thanunhealthy.
The precision of a technique is one that yields the same answer on repeat administrations(Livingstone and Black, 2003). Poor precision derives from large random errors in thetechniques of dietary assessment. The effect of random errors can be reduced by increasing
the number of observations, but cannot be entirely eliminated (Rothman, 2002).
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Among the 1-year-olds who still are breastfed it is important to notice that the vitamin A
contribution from breast milk is not included in the calculations. The vitamin A intake for thisage group is thereby underestimated.
In Norkost 3 the number of registration days is only two. The impact of the short registration
period is neither evaluated for single food items nor for nutrients yet.
The retinol content of cod liver oil were halved from year 2000 when the Ungkost 2000 study
was performed to the studies, Sped- and Småbarnskost and Norkost 3 conducted in 2006/2007
and 2010/2011. It is therefore likely that the retinol intake from cod liver oil in Ungkost 2000
is an overestimation of the intake compared with the retinol content in cod liver oil in studies
from 2006/2007 and 2010/2011.
Since retinol is present in large quantities in a few foods, a correct portion size assessment offor instance cod liver oil consumption is important. The size of the spoons used among theparticipants varies, and this will be a source of uncertainty in the retinol intake on individuallevel. The direction of the uncertainty is difficult to estimate without further studies.
The food data bases (KBS) used to calculate retinol have only one given value per food item.
There is a rather high variation in the retinol content in different food items. To take liver pâtéas example, the variation is in three levels. The first level is the variation in analysed liver,where the variation could be between 6700-29000 µg retinol/100 g in ox liver (Blaker, 1991).
The second level is that different brands use different recipes, and during the data collection
similar liver pâtés are aggregated into one food code in the food data base. Thirdly,
analysed/calculated retinol values for liver pâté will also differ between the databases used to
calculate the different diet surveys. A low fat liver pâté used in Ungkost 2000 have 4351 µg
retinol/100 g while in Norkost 3 a low fat liver pâté had 8200 µg retinol/100 g.
It is unclear to which extent a low participation rate will influence the assessment of retinol
intake. It has been shown is that health conscious people are more likely to participate in a
dietary survey. This can indicate a somewhat different dietary pattern and pattern ofsupplement use among the participants than among the whole population. The direction of theuncertainty is difficult to estimate.

5.3 Summary table of uncertainties
An evaluation of the overall effect of identified uncertainties is presented in Table 11,
highlighting the main sources of uncertainty and indicating whether the respective source of
uncertainty might have led to an over- or underestimation of the exposure and/or the resulting
risk (EFSA, 2006b).

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Table 11: Qualitative evaluation of influences of uncertainties on the assessment of vitamin A exposure.

Source of uncertainty

Direction andmagnitude

Dermal absorption and systemic availability
Dermal application of retinol and retinyl esters less than assumed in the exposure scenarios(i.e. smaller application area, less frequent applications, use of fewer products containing
retinol/retinyl esters)+Long term storage capacity of retinol and retinyl esters in the skin and conversion rate into
retinoic acid are not known+/-

Worst case scenario: small likelihood for all products, assumed to be used by the
consumers, to contain the chosen concentrations of retinol and retinyl esters+

Contribution from cosmetics calculated as percentage of UL may be underestimatedrelative to the contribution from consumption of food and food supplements-

Dietary exposure assessment
Analysed/calculated retinol values in the food data base+/-Retinol intake difficult to measure, and needs large number of days with repeated measures+/-

Different dietary assessment methods+/-

Portion size+/-

Sped- and småbarnskost 2006/2007
Use of 95 percentile+/-

FFQ time span is 14 days+/-

Retinol from breast milk not included-

Ungkost 2000
Retinol content in cod liver oil have decreased since 2000+

Use of 95 percentile- the number of participants among 4-year-olds is only 391+/-

Four registration days+/-

Norkost 3, Adults
Participation rate 37%+/(-)

Two registration days+/-

Use of 95 percentile- the number of men and women taking retinol supplements are only 275 and 296+/-

Qualitative evaluation of overall effect of identified uncertainties:++: uncertainty likely to cause over-estimation of exposure-: uncertainty likely to cause under-estimation of exposure59

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In spite of the limitations outlined above in evaluating the dermal application and systemic
availability and assessing the food consumption, leading to uncertainties related to estimating
the exposure to vitamin A, VKM conclude that the exposure to retinol and retinyl esters
presented in this report can be considered realistic for the different age groups. The risk
assessment of vitamin A according to the standard scenario is likely to be conservative, i.e.
more likely to overestimate than to underestimate the risk. The worst case scenario is anoverestimation of the exposure to vitamin A.

Data gaps
There are relatively few studies on absorption of vitamin A in human skin. In addition,none of the cited in vitro studies in the present opinion fulfilled the SCCS basic
requirements for in vitro dermal absorption. Studies on vitamin A fulfilling theserequirements are needed.

There are short-term studies on metabolism of topically applied retinol and retinyl
esters. However, information on storage and/or metabolism of retinol and retinyl
esters after long-term use of cosmetic products containing vitamin A is lacking.



There are data on local adverse effects after short-term use of vitamin A containing
cosmetic products, whereas information on local adverse effects after long-term use is
missing.



Data demonstrating if topically applied vitamin A can contribute to systemic adverse
effects is lacking.

Further research on the relationship between retinol and bone health is required inorder to reach clear conclusions.

More data is needed to understand the interaction between retinol and vitamin D withrespect to fracture risk.

More studies are needed to clarify mechanisms of possible retinoid
photocarcinogenesis as well as characteristics needed for the extrapolation frommouse skin to human skin.

More information on the frequency of use and concentrations of retinal in cosmetics isneeded.

More information on the frequency of use and concentrations of retinol and retinyl
esters in sun screen products on the European market is needed.

More data is needed to understand under-/over-reporting of food consumption in
dietary surveys.



Further research is needed to get more accurate portion size estimation in the dietary
surveys.

Further research is needed to evaluate the impact of variation in number of registration
days in the dietary surveys.

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Conclusions


The critical adverse health effect of excess intake of vitamin A is teratogenicity. Thiseffect is the basis for the tolerable upper intake level (UL) of 3000 µg RE/day.

The most important source of vitamin A in the population is diet, followed by foodsupplements and then cosmetics.



The dietary intake of preformed vitamin A is high in parts of the Norwegian
population. Consumption of food supplements contributes significantly to the total
intake of preformed vitamin A in all age groups and will increase the proportion of
the population exceeding the UL.

Topical application of cosmetic products, as estimated in the standard scenarios(0.05% in body lotions and 0.3% in face and hand cream), increases the total
exposure to vitamin A (retinol and retinyl esters) in all age groups.
o The estimated contribution of retinol and retinyl esters from cosmetics is mostprominent for 13-year-old adolescents (23% of UL) and adults (29% of UL).

In the worst case scenarios based on the assumed increased concentrations incosmetics (0.3% in body lotions and 1% in face and hand cream), the contribution
from cosmetics would further increase the total exposure to vitamin A (retinol andretinyl esters).
o The estimated contribution of retinol and retinyl esters from cosmetics would
reach 42-58% of the ULs for children, 98% of the UL for 13-year-old
adolescents and exceed the UL for adults (115%).

The contribution from cosmetics is of special concern for women of fertile age, andtotal exposure above the UL before and during pregnancy will increase the risk ofbirth defects.

For persons who are at higher risk for reduced bone mineral density, osteoporosis andfractures, especially post-menopausal women, a lower guidance level (GL) than the
UL has been set, i.e. 1500 µg RE/day. About 10% of adult women in Norway exceed
this GL by intake of vitamin A from food and food supplements alone. The additional
contribution from cosmetics increases this proportion to approximately 75%. An
increased exposure due to higher concentrations of vitamin A (retinol and retinyl
esters) in cosmetic products would further augment the proportion of women at riskof osteoporosis.

Impaired skin may result in increased absorption of cosmetic products. This can occur
in persons with diagnosed atopic dermatitis, in persons that suffer from dry skin andin small children with irritated skin in the nappy area.

Regarding local adverse effects in the skin, no information was found indicating that
long-term use of topical retinoids may induce other effects than irritation anderythema. A NTP study indicates that retinol and retinyl palmitate may be
photocarcinogenic in mice. However, these data do not provide sufficient information
for a risk assessment of this effect of retinol and retinyl esters in cosmetics.

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Appendices
Appendix I
The following information is based on the basic requirements for in vitro dermal absorption
studies described in the SCCS’ Notes of Guidance for the Testing of Cosmetic ingredients(SCCS, 2010).
Dermal/percutaneous absorptionA) Major guidelines for dermal/percutaneous absorption
Human exposure to cosmetic ingredients occurs mainly via the skin. In order to reach thecirculation (blood and lymph vessels) cosmetic ingredients must cross a number of cell layersof the skin, where the rate-determining layer is considered to be the stratum corneum (SC). A
number of factors play a key role in this process, including the lipophilicity of thecompounds, the thickness and composition of the SC (body site), the duration of exposure, theamount of topically applied product, the concentration of target compounds, occlusion, etc.
(for review see Schaefer et al., 1996; ECETOC, 1993; Howes et al., 1996). The
dermal/percutaneous absorption has been described by several international bodies(ECETOC, 1993, US EPA, 1996a, OECD, 2004) using a wide variety of terms and it isrecognised that confusion is possible. Therefore, it seems appropriate to define some
important terms in this particular field (SCCS/1358/10).
The dermal/percutaneous absorption process is a global term which describes the passage ofcompounds across the skin. This process can be divided into three steps:-

penetration is the entry of a substance into a particular layer or structure such as theentrance of a compound into the stratum corneum;
permeation is the penetration through one layer into another, which is both
functionally and structurally different from the first layer;
resorption is the uptake of a substance into the vascular system (lymph and/or bloodvessel), which acts as the central compartment.

Dermal/percutaneous absorption studies can be performed in vivo or in vitro. Today, however,in vivo dermal/percutaneous absorption testing is not an option any more for cosmetic
ingredients in the European context, as the animal testing deadline of 11 March 2009 has
passed (2003/15/EC).
Both in vivo and in vitro testing protocols form part of the lists of official EU and OECD test
methods (EC B.44, 45; OECD 427, 428), accompanied by more detailed guidance on theirperformance (DG SANCO, 2004; OECD, 2004). Whereas the first version of abovementioned OECD Guideline 428 was issued in 2000, the SCCNFP already adopted its first setof basic criteria for the in vitro assessment of dermal absorption of cosmetic ingredients in1999 (SCCNFP/0167/99). This opinion, most recently updated in 2010 (SCCS/1358/10),
focuses on the in vitro testing of cosmetic ingredients, whereas the general EU and OECD
Guidance (DG SANCO, 2004; OECD, 2004) addresses percutaneous absorption from a muchbroader point of view by mentioning in vivo methods besides in vitro testing and by providing
specifications for agricultural products and industrial chemicals besides cosmetics.

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As a result, the SCC(NF)P/SCCS has always considered a combination of the EU/OECD
Guidelines and its own "Basic criteria” as essential for dermal/percutaneous absorption
studies.
B) The SCCS “Basic criteria”
The purpose of in vitro dermal absorption studies of cosmetic ingredients is to obtain
qualitative and/or quantitative information on the substances that may enter, under in-use
conditions, into the systemic compartment of the human body. The quantities can then be
taken into consideration to calculate the margin of safety (MOS) using the no observed
adverse effect level (NOAEL) of an appropriate repeated dose toxicity study with therespective substance.
In these relatively complex in vitro studies, there are a number of points that require special
attention:
1) The design of the diffusion cell (technicalities and choice between static and flow
through system).
2) The choice of the receptor fluid (physiological pH, solubility and stability of chemical
in receptor fluid should be demonstrated, no interference with skin/membrane
integrity, analytical method, etc.).
3) The skin preparations should be chosen and treated with care (human skin from anappropriate site remains the gold standard).
4) Skin integrity is of key importance and should be verified.
5) Skin temperature has to be ascertained at normal human skin temperature.
6) The test substance has to be rigorously characterised and should correspond to thesubstance that is intended to be used in the finished cosmetic products.
7) Dose and vehicle/formulation should be representative for the in-use conditions of theintended cosmetic product. Several concentrations, including the highest concentrationof the test substance in a typical formulation, should be included.
8) Dose, volume and contact time with the skin have to mimic in-use conditions.
9) Regular sampling is required over the whole exposure period.
10) Appropriate analytical techniques should be used. Their validity, sensitivity anddetection limits should be documented in the report.
11) The test compound is to be determined in all relevant compartments:- product excess on the skin surface (dislodgeable dose),- stratum corneum (e.g. adhesive tape strips),- living epidermis (without stratum corneum),- dermis,- receptor fluid.
12) Mass balance analysis and recovery data are to be provided. The overall recovery oftest substance (including metabolites) should be within the range of 85-115%.
13) Variability/validity/reproducibility of the method should be discussed. The SCCS
considers that for a reliable dermal absorption study, eight skin samples from at least
four donors should be used.
The amounts measured in the dermis, epidermis (without stratum corneum) and the receptor
fluid will be considered as dermally absorbed and taken into account for further calculations.
When studies correspond to all of the basic requirements of the SCCS, the mean + 1SD will
be used for the calculation of the MOS. The reason for not using the mean per se is thefrequently observed high variability in the in vitro dermal absorption assays. In case of72

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significant deviations from the protocol and/or very high variability, the mean + 2SD will be
used as dermal absorption for the MOS calculation. In case the results are derived from aninadequate in vitro study, 100% dermal absorption is used. However, in case MW > 500 Da
and log Pow is smaller than -1 or higher than 4, the value of 10% dermal absorption isconsidered.

Appendix - references
2003/15/EC – Directive 2003/15/EC of the European Parliament and of the Council of 27
February 2003 ammending Council Directive 76/768/EEC on the approximation of the lawsof the Member States relating to cosmetic products. Official journal L66, 11/03/2003 p.26.
DG SANCO. Sanco/222/2000: Guidance document on dermal absorption,. European
Commission, Health and Comsumer Protection Directorate-General, Doc. Sanco/222/2000
revision 7 of 19 March 2004.
EC B.44 – Skin absorption: In vitro method. Council Regulation (EC) No 440/2008 of 30
May 2008 laying down test methods pursuant to Regulation (EC) No 1907/2006 of theEuropean Parliament and of the Council on the Registration, Evaluation, Authorisation andRestriction of Chemicals (REACH). Official Journal L142, 31/05/2008, p. 432.
EC B.45 – Skin absorption: In vitro method. Council Regulation (EC) No 440/2008 of 30
May 2008 laying down test methods pursuant to Regulation (EC) No 1907/2006 of theEuropean Parliament and of the Council on the Registration, Evaluation, Authorisation andRestriction of Chemicals (REACH). Official Journal L142, 31/05/2008, p. 438.
ECETOC. Percutanous absorption. European centre for ecotoxicology and toxicology ofchemicals, Monograph No 20, Brussels, 1993.
Howes D, Guy R, Hadgraft J, Heylings J, Hoeck U, Kemper F, Maibach H, Marty J-P, Merk
H, Perra J, REkkas D, Rondelli I, Schaefer H, Täuber U, Verbiese N. Methods for assessing
percutaneous absorption, ECVAM Workshop Report n. 13. Alternatives to laboratory
animals, 1996;24:81-106.
OECD 427 – OECD Guideline for testing of chemicals – Guideline 427: Skin absorption: In
vivo method, Organization for Economic Cooperation and Development, Paris, adopted 13
April 2004
OECD 428 – OECD Guideline for testing of chemicals – Guideline 428: Skin absorption: In
vitro method, Organization for Economic Cooperation and Development, Paris, adopted 13
April 2004
OECD. Guidance Document for the conduct of skin absorption studies. Document number
ENV/JM/MONO(2004)2. Organization for Economic Cooperation and Development(OECD), Environment Directorate, OECD Environmental Health and Safety Publications,
Series on testing and assessment No. 28, Paris, 5 March 2004.
SCCNFP/0167/99: Basic criteria for the in vitro assessment of percutaneous absorption of
cosmetic ingredients, adopted by the SCCNFP during the 8th plenary meeting of 23 June
1999.
SCCS/1358/10: Basic criteria for the in vitro assessment of dermal absorption of cosmetic
ingredients, adopted by the SCCS during the 7th plenary meeting on 22 June 2010.

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SCCS (Scientific Committee on Consumer Safety) (2010). The SCCS’s notes of guidance forthe testing of cosmetics ingredients and theis safety evaluation, 7th revision, adopted by SCCS
during the 9th plenary meeting of 14 December 2010, SCCS/1416/11.
Schaefer H, Redelmeier TE. Skin barrier, principles of percutaneous absorption, Karger,
Basel, 1996.
US EPA. Health effect test guidelines. Dermal penetration. US Environmental Protection
Agency (EPA). Doc EPA 712-C-96-350, Washington DC, 1996.

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