Safe addition of vitamins and minerals to foods : setting maximum levels for fortification in the Netherlands Background In 2004 , the European Court of Justice decided that the prohibition of fortification with vitamin A , vitamin D , folic acid , selenium , copper , and zinc in the Netherlands conflicts with the principle of free movement of goods in the European Union . This decision led to a change in the Dutch policy , resulting in a more flexible handling of requests for exemption from this prohibition to fortify . Therefore , an investigation was proposed in which it would be determined whether a general exemption could be granted for food fortification with a certain maximum safe amount per micronutrient . Introduction Foods are fortified with micronutrients and other bioactive compounds to prevent deficiencies or to provide additional health effects . Furthermore , the use of health claims on products after fortification is thought to result in better marketing . As fortification with micronutrients should be safe for the whole population , unacceptably large intakes of micronutrients from all sources should be prevented . For this purpose , tolerable upper intake levels -LRB- ULs -RRB- are established -LSB- 28 -RSB- . Because of the small range between recommended daily intakes and ULs and the lack of proof of a nutritional need , fortification with vitamin A , vitamin D , folic acid , selenium , copper , and zinc is prohibited in the Netherlands -LSB- 1 -RSB- . Addition of these six micronutrients was only allowed in the case of substitution -LRB- e.g. , vitamins A and D in margarine as a substitute for butter -RRB- or restoration -LRB- for instance , because of losses during processing -RRB- -LSB- 1 -RSB- . In December 2004 , the Court of Justice of the European Communities decided that the prohibition of fortification with these six micronutrients contradicted the free movement of goods , a fundamental principle in the Treaty Establishing the European Community -LSB- 5 -RSB- . This decision means that market introduction of fortified foods can only be prohibited if it can be proved that the degree of fortification -LRB- e.g. , level of fortification or quantity of foods fortified -RRB- may harm public health . This decision led to a change of Dutch policy , resulting in a more flexible handling of requests for exemption from the Dutch Commodity Act that prohibits fortification with these six micronutrients -LSB- 6 -RSB- . Exemption will only be granted if there is no harm to public health , based on the results of the most recent international scientific research . Because of this court decision , each request for individual exemption had to be evaluated for the risk of exceeding the UL . At first , requests for individual exemption were evaluated in order of receiving . To evaluate the risk of exceeding the UL , consumption of the new fortified product by the Dutch population was simulated by replacing the unfortified food products with the new fortified product within the Dutch National Food Consumption Survey -LRB- DNFCS -RRB- -LRB- e.g. , the consumption of all kinds of breakfast cereals as monitored within the DNFCS was replaced by the new fortified breakfast cereals -RRB- . The resulting habitual daily intake -LRB- P95 -RRB- of the micronutrient was compared with the UL . If the UL was not exceeded , the exemption was granted . This approach resulted in the exemption of very few products and turned out to be an unrealistic worst-case approach . Furthermore , the procedure resulted in an administrative overload and long waiting periods for the industry . Therefore , and in anticipation of upcoming European legislation -LSB- 11 -RSB- , an investigation was proposed in which it would be determined whether a general exemption could be granted for food fortification with a certain maximum safe amount per micronutrient . A model was needed to calculate the national maximum level of a specific micronutrient that can safely be added to foods . Several such models have recently been developed -LSB- 11 -- 14 , 25 -RSB- . First , an International Life Science Institute -LRB- ILSI -RRB- Europe model -LRB- 2002 -RRB- -LSB- 14 -RSB- , which was followed by models by Domke et al. -LSB- 12 , 13 -RSB- and Rasmussen et al. -LSB- 25 -RSB- . The latter is an adapted version of the ILSI Europe model -LSB- 14 -RSB- . These models were developed for the purpose of calculating the maximum amount of micronutrients that can be added to each 100 kcal of a given food -LSB- 14 , 25 -RSB- or each food portion -LSB- 12 -RSB- . The intake of micronutrients from nonfortified foods and dietary supplements must be taken into account for this calculation . Domke et al. also estimate the maximum amount of micronutrients in dietary supplements by dividing the space between the UL and the level of intake from nonfortified foods . Most models are theoretical approaches , and data regarding their practical use in decision - or policy-making have not yet been published , although the published acceptable levels of addition per 100 kcal by Rasmussen et al. have been implemented as the Danish maximum levels for fortification -LRB- Rasmussen , personal communication , 2006 -RRB- . Besides these models that calculate a maximum fortification level , models that calculate the optimal intake for the population -LRB- taking into account both too low and too high intakes -RRB- are also being developed -LSB- 15 , 26 -RSB- . In view of the present application , the derivation of maximum safe fortification levels -LRB- MSFLs -RRB- , these models on optimal intake were not taken into account . The question how to create an optimal micronutrient intake is outside the scope of this paper . On the basis of the existing models to calculate a maximum fortification level , a model adapted to the Dutch practical situation was developed for the Dutch authorities to derive for the fortification with micronutrients . This article first describes the model for the derivation of maximum amounts of micronutrient fortification in the Netherlands , and then it illustrates the use of the micronutrient specific data and assumptions in the calculation of the MSFLs for folic acid , vitamin A , and vitamin D . The article concludes with the considerations and the final allowed fortification level -LRB- AFL -RRB- of the risk management . Methods Models to calculate safe maximum levels of addition of micronutrients are published , among others , by ILSI , Rasmussen and Domke -LSB- 12 -- 14 , 25 -RSB- . We developed a model for the Dutch situation , based on -LRB- elements of -RRB- the models of ILSI , Rasmussen and Domke . Below , we will amplify on the main differences between the models and our filling-in for the Dutch model . The ILSI Europe and Rasmussen et al. models differ in several aspects from Domke et al. 's model . Instead of the calculation per portion size as applied by Domke et al. , both ILSI Europe and Rasmussen et al. calculate the maximum fortification level per 100 kcal . For our Dutch model , we also calculate with 100 kcal portions because the variation in mean daily energy intake is low compared to for instance the variation in micronutrient or carbohydrate intake -LSB- 29 -RSB- . Moreover , there is no univocal definition of portion size in the Netherlands . Another important difference is that Domke et al. not only establish maximum fortification levels , but they also establish maximum levels for dietary supplements . Because maximum safe addition levels of vitamins and minerals in dietary supplements will be regulated via European Union legislation , we did not determine them in our model -LSB- 11 -RSB- . Similarly to ILSI Europe and Rasmussen et al. , we estimated the current intake of micronutrients from dietary supplements and took them into account . Our Dutch model is principally based on the ILSI Europe model -LSB- 14 -RSB- and Rasmussen et al. 's extended model -LSB- 25 -RSB- , with adaptations to the Dutch practical situation . The formula is equal to the one used by Rasmussen et al. , however some of the factors are differently derived -LRB- see below -RRB- . Our model calculates the maximum safe level for fortification with a micronutrient per 100 kcal of the food -LRB- MSFL -RRB- for various age groups with the mathematical formula presented in Box 1 . The lowest MSFL , i.e. , the MSFL for the most sensitive group , is then advised to be the overall maximum acceptable fortification , as is common practice in toxicological risk assessment . Tolerable upper intake level -LRB- UL -RRB- The UL is the maximum level of total chronic daily intake of a nutrient that is unlikely to pose a risk of adverse health effects to humans . In general , the UL is related to total daily intake from all sources including nonfortified foods as well as fortified foods and dietary supplements . In Europe , the Scientific Committee on Food -LRB- SCF -RRB- and the Scientific Panel on Dietetic Products , Nutrition and Allergies -LRB- NDA -RRB- set age-specific ULs -LSB- 28 -RSB- . Due to lack of data , the ULs for children are usually extrapolated from the ULs for adults based on bodyweight . In anticipation of future European policy -LSB- 11 -RSB- , these age-specific European ULs were used as model input rather than the national ULs , which is similar to the model of Rasmussen et al. -LSB- 25 -RSB- . ILSI Europe has also used European ULs , although only the values for men -LSB- 14 -RSB- . Box 1 . Formula for the calculation of the maximum safe fortification level with micronutrients per 100 kcal food -LRB- MSFL -RRB- -LSB- 25 -RSB- . Current intake of energy and micronutrients from nonfortified foods -LRB- EI95 & CI95 -RRB- Micronutrients are naturally present in the diet -LRB- further referred to as ` background diet ' -RRB- . Because it is important to consider the intake from all possible sources to assess the risk , the intake from the background diet has to be included in the calculations . To estimate the intake of energy and micronutrients from the background diet , it is important to use the most up-to-date country - and age-specific data available . In view of the precautionary principle -LSB- 3 , 10 -RSB- , we calculated the age-specific habitual intake -LRB- also referred to as usual intake -RRB- at the 95th percentile of the distribution of energy and the specific micronutrients from the background diet on the basis of data from the most recent Dutch National Food Consumption Surveys -LRB- DNFCS -RRB- : DNFCS-3 and DNFCS-2003 . The DNFCS-3 was carried out in 1997 -- 1998 for the whole population -LRB- 1 -- 97 years -RRB- and the DNFCS-2003 was carried out in 2003 for young adults -LRB- 19 -- 30 years -RRB- -LSB- 16 , 23 -RSB- . In the DNFCS-3 , a 2-day dietary record method was used to collect data on two consecutive days . In the DNFCS-2003 , data were collected with a 2-day , 24-hour recall method using EPIC-SOFT , a computer-assisted interview method . We estimated the habitual intake of both micronutrients and energy with statistical correction for the within-person variation using the Iowa State University method -LRB- C-SIDE software -RRB- -LSB- 18 , 20 -RSB- . Rasmussen et al. 's model uses results from the Danish dietary survey in which a 7-day prospective food recall method was used to calculate the daily intake of micronutrients from nonfortified foods -LRB- 95th percentile -RRB- and energy intake -LRB- 95th percentile -RRB- -LSB- 25 -RSB- . ILSI Europe used pan-European estimates of the 95th percentile of intake of micronutrients based on seven national surveys . Some of these surveys already include voluntary fortification of foods with micronutrients and the intake of dietary supplements -LSB- 14 -RSB- . Furthermore , the pan-European 95th percentile of energy intake was estimated from five national surveys . Current intake of micronutrients from dietary supplements -LRB- SI -RRB- In addition to the intake from the background diet , the micronutrient intake from dietary supplements -LRB- SI -RRB- has to be taken into account in order to get a good estimate of the total intake from all sources . In the Netherlands , similar to other Western countries , the use of dietary supplements has increased and takes a more important place in the total micronutrient intake -LSB- 22 -RSB- . Preferably , the habitual micronutrient intakes of nonfortified foods and dietary supplements are calculated together . This method takes into account the facts that not everybody uses dietary supplements , not all supplement users use the supplements daily , and supplement users and nonusers may have different eating habits -LSB- 19 -RSB- . However , due to lack of information about supplement use , a calculation of combined habitual intake is not possible at this time . Therefore , we used two realistic high-intake scenarios of dietary supplements based on the limited Dutch dietary supplement data available : one for adults -LRB- ≥ 18 years old -RRB- and one for children -LRB- 1 -- 17 years old -RRB- . The scenario for adults was based on the P90-P95 of both the intake of micronutrients from dietary supplements in young adults -LRB- 19 -- 30 years -RRB- reported by the DNFCS-2003 -LSB- 22 -RSB- and the levels of micronutrients present in dietary supplements -LRB- for adults -RRB- available in the Netherlands -LSB- 4 -RSB- . The scenario for children was based on P90 -- P95 of the infants ' intake of dietary supplements -LSB- 9 -RSB- and the levels of micronutrients present in dietary supplements for children , that are available in the Netherlands -LSB- 4 -RSB- . We determined the SI differently than Rasmussen et al. and ILSI Europe did . Rasmussen et al. chose to set the SI at 100 % of the reference values for the recommended daily intake of vitamins and minerals because this is the content of the most used multi-vitamin -- mineral supplement in Denmark -LSB- 25 -RSB- . The ILSI Europe model does not include the intake from dietary supplements because only a minority of the population is expected to use them -LSB- 11 , 14 -RSB- . Fraction of energy intake that can and will be fortified -LRB- PFFn -RRB- Not all foods on the market can or will be fortified . The fraction of total energy intake that will finally be fortified consists of two parts : -LRB- 1 -RRB- the proportion of total energy intake that can be fortified ; for example , it is unlikely that fresh products such as vegetables , fruits and meat will be fortified ; and -LRB- 2 -RRB- the proportion of the energy intake of foods available for fortification that actually will be fortified . Due to practical constraints such as costs and processing , not all foods available for fortification will be fortified with a particular micronutrient . The first part of the fraction was set at 30 % , which is lower than the 50 % set by both ILSI Europe and Rasmussen et al. . Main argument for the lower percentage was that the large part of the energy intake in the Dutch population is delivered by the traditional dinner , which consists in general of fresh products like meat , vegetables , and potatoes . The second part of the fraction was equal to the one ILSI Europe and Rasmussen et al. set at 50 % -LRB- worst case -RRB- . This resulted in a fraction of the energy intake available for fortification -LRB- PFFn -RRB- of 15 % -LRB- i.e. , 30 % * 50 % -RRB- . Results Risk assessment : deriving MSFLs We illustrate the applicability of the Dutch model by deriving MSFLs of folic acid , vitamin A , and vitamin D. Tables 1 , 2 , 3 present the factors used for the calculation of the MSFLs for folic acid , vitamin A , and vitamin D . The classification into age groups is based on the age categories used by NDA/SCF to define the ULs -LSB- 28 -RSB- and is different for folic acid , vitamin A , and vitamin D . We calculated the 95th percentile of habitual energy intake for each age group . The habitual energy intake of children increases with age -LRB- Tables 1 -- 3 -RRB- . The 95th percentile of the habitual energy intake for men is greater than that for women ; there is a small decline of habitual energy intake with age for both genders . Table 1Maximum safe fortification levels and allowed fortification level of folic acid based on Dutch consumption data and European tolerable upper levels of intake for specific age groupsAge groupnUL -LRB- µg/day -RRB- CI95a -LRB- µg/day -RRB- SI -LRB- µg/day -RRB- EI95 -LRB- SE -RRB- -LRB- kcal/day -RRB- Max safe fortification level -LRB- MSFL -RRB- -LRB- µg/100 Kcal -RRB- Allowed fortification level -LRB- AFL -RRB- -LRB- µg/100 kcal -RRB- PFFn = 0.15 PFFn = 0.10 bChildren1 -- 3c25420003001 ,890 -LRB- 67 -RRB- 0Children4 -- 6c27630003001 ,995 -LRB- 56 -RRB- 0Children7 -- 10c31240003002 ,456 -LRB- 63 -RRB- 27Children11 -- 14c33660003003 ,154 -LRB- 117 -RRB- 63Adolescents15 -- 17c28080003003 ,518 -LRB- 150 -RRB- 95Men18 -- 30c5251 ,00006004,010 -LRB-112-RRB-67100100 Women18 -- 30c5791 ,00006002,867 -LRB- 62 -RRB- 93140Men19 -- 30d3521 ,00006003,751 -LRB-130-RRB-71106100 Women19 -- 30d3981 ,00006002,581 -LRB-76-RRB-103155 Men31 -- 50c9501 ,00006003,529 -LRB- 64 -RRB- 76113Women31 -- 50c1 ,1001,00006002,721 -LRB- 48 -RRB- 98147Men51 -- 65c4201 ,00006003,427 -LRB- 109 -RRB- 78117Women51 -- 65c4791 ,00006002,647 -LRB-74-RRB-101151 Men > 65c2601 ,00006003,106 -LRB- 119 -RRB- 86129Women > 65c4101 ,00006002,432 -LRB-65-RRB-110164 aDietary intake of folic acid only , folate is not taken into account because the UL is based on folic acid onlybAdditional calculation with exactly the same results as for PFFn = 0.15 in combination with a scenario of low dietary supplement intake -LRB- i.e. , 400 µg -RRB- , only calculated for adultscBased on consumption data from the DNFCS-3 -LRB- 1997 -- 1998 -RRB- -LSB- 2 -RSB- dBased on consumption data from the DNFCS 2003 -LSB- 17 , 21 -RSB- The most sensitive age groups are bolded ; CI95 , 95th percentile of habitual dietary folic acid intake ; EI95 , 95th percentile of habitual energy intake ; SI , supplement intake ; PFFn , proportion of energy intake that can and will be fortified ; UL , tolerable upper intake levelTable 2Maximum safe fortification levels of vitamin Aa based on Dutch consumption data and the European upper levels of intake for specific age groupsAge groupNUL -LRB- µg / day -RRB- CI95 -LRB- SE -RRB- -LRB- µg / day -RRB- SI -LRB- µg / day -RRB- EI95 -LRB- SE -RRB- -LRB- kcal/day -RRB- Max safe fortification level -LRB- MSFL -RRB- -LRB- µg / 100 kcal -RRB- PFFnb = 0.15 Children1 -- 3c2548001 ,057 -LRB-167-RRB-8001890 -LRB- 67 -RRB- 0Children4 -- 6c2761 ,1001,553 -LRB-262-RRB-8001995 -LRB- 56 -RRB- 0Children7 -- 10c3121 ,5001,055 -LRB-116-RRB-8002456 -LRB- 63 -RRB- 0Children11 -- 14c3362 ,0001,153 -LRB-131-RRB-8003154 -LRB- 117 -RRB- 10Adolescents15 -- 17c2802 ,6001,429 -LRB-205-RRB-8003518 -LRB- 150 -RRB- 70Men19 -- 30b3523 ,0001,886 -LRB- 261 -RRB- 1,2003751 -LRB- 130 -RRB- 0Women19 -- 30b3983 ,0001,203 -LRB- 162 -RRB- 1,2002581 -LRB- 76 -RRB- 154Men ≥ 18c2 ,1553,0002,363 -LRB- 132 -RRB- 1,2003642 -LRB- 50 -RRB- 0Women18 -- 50c1 ,6793,0001,350 -LRB- 83 -RRB- 1,2002785 -LRB- 39 -RRB- 108Women > 50c8891 ,5001,441 -LRB- 108 -RRB- 1,2002555 -LRB- 53 -RRB- 0aNot including provitamin AbBased on consumption data the DNFCS 2003 -LSB- 17 , 21 -RSB- cBased on consumption data from the DNFCS-3 -LRB- 1997 -- 1998 -RRB- -LSB- 2 -RSB- The most sensitive age groups are bolded ; CI95 , 95th percentile of habitual dietary vitamin A intake ; EI95 , 95th percentile of habitual energy intake ; SI , supplement intake ; SE , standard error ; PFFn , proportion of energy intake that can and will be fortified ; UL , tolerable upper intake levelTable 3Maximum fortification levels and allowed fortification level of vitamin D based on Dutch consumption data and European tolerable upper levels of intake for specific age groupsAge groupnUL -LRB- µg/day -RRB- CI95 -LRB- SE -RRB- -LRB- µg/day -RRB- SI -LRB- µg/day -RRB- EI95 -LRB- SE -RRB- -LRB- kcal/day -RRB- Max safe fortification level -LRB- MSFL -RRB- -LRB- µg/100 Kcal -RRB- Allowed fortification level -LRB- AFL -RRB- -LRB- µg/100 kcal -RRB- PFFn = 0.15 PFFn = 0.10 aChildren1 -- 3b254254 .8 -LRB- 0.6 -RRB- 101,890 -LRB- 67 -RRB- 3.65.4 Children4 -- 10b276254 .4 -LRB- 0.2 -RRB- 102,334 -LRB- 50 -RRB- 3.04.54.5 Children11 -- 13b312506 .5 -LRB- 0.6 -RRB- 102,935 -LRB- 100 -RRB- 7.611.4 Adolescents14 -- 18b336507 .6 -LRB- 0.5 -RRB- 103,509 -LRB- 116 -RRB- 6.29.2 Men19 -- 30c352506 .5 -LRB- 0.4 -RRB- 103,751 -LRB- 130 -RRB- 6.08.9 Women19 -- 30c398505 .2 -LRB- 0.4 -RRB- 102,581 -LRB- 76 -RRB- 9.013.5 Men31 -- 50b950508 .9 -LRB- 0.4 -RRB- 103,529 -LRB- 64 -RRB- 5.98.8 Women31 -- 50b1 ,100506.4 -LRB- 0.3 -RRB- 102,721 -LRB- 48 -RRB- 8.212.3 Men51 -- 60b3145011 .3 -LRB- 1.2 -RRB- 103,410 -LRB- 128 -RRB- 5.68.4 Women51 -- 60b332506 .7 -LRB- 0.6 -RRB- 102,623 -LRB- 90 -RRB- 8.512.7 Men61 -- 70b197509 .8 -LRB- 1.0 -RRB- 103,315 -LRB- 124 -RRB- 6.19.1 Women61 -- 70b270506 .6 -LRB- 0.6 -RRB- 102,528 -LRB- 87 -RRB- 8.813.2 Men > 70b1695012 .2 -LRB- 1.8 -RRB- 103,067 -LRB- 141 -RRB- 6.09.1 Women > 70b287508 .6 -LRB- 0.8 -RRB- 102,487 -LRB- 86 -RRB- 8.412.6 aAdditional calculation with exactly the same results as for PFFn = 0.15 in combination with low scenario of dietary supplement intake -LRB- i.e. , 5 µg -RRB- bBased on consumption data from the DNFCS-3 -LRB- 1997 -- 1998 -RRB- -LSB- 2 -RSB- cBased on consumption data from the DNFCS 2003 -LSB- 21 -RSB- The most sensitive age groups are bolded ; CI95 , 95th percentile of habitual dietary vitamin D intake ; EI95 , 95th percentile of habitual energy intake ; SI , supplement intake ; SE , standard error ; PFFn , proportion of energy intake that can and will be fortified ; UL , tolerable upper intake level Folic acid Folic acid is the synthetic form of folate , a natural component in the diet . An UL has been established only for folic acid and not for folate . For this reason , the calculation does not consider the intake of folate from the background diet . At the time the food consumption surveys were conducted , fortification with folic acid was not permitted in the Netherlands , which results in an intake from the background diet -LRB- CI95 -RRB- of 0 µg/day . The SI of folic acid was estimated to be 300 µg/day for children and adolescents and 600 µg/day for adults . Filling in these factors in the formula of Box 1 resulted in a maximum fortification level for folic acid of 0 µg/100 kcal for children 1 -- 6 years old to 110 µg/100 kcal for women older than 65 years -LRB- Table 1 -RRB- . For children and adolescents , the MSFL for folic acid fortification increased with age because of an increase in UL over the age groups . For adults , men generally had lower MSFLs than women due to a higher energy intake . Based on the most sensitive age group -LRB- i.e. , children 1 -- 6 years -RRB- the MSFL is 0 µg/100 kcal . For the most sensitive adult group -LRB- i.e. , men 18 -- 30 years old -RRB- the MSFL is 67 -- 71 µg/100 kcal . Our calculated MSFL for the most sensitive group is lower for folic acid than the acceptable level of addition of Rasmussen et al. , 23 µg/100 kcal for the most sensitive group -LRB- 1 -- 3 years old -RRB- , while we calculated 0 µg/100 kcal for children 1 -- 6 years old . This difference is mainly caused by a lower estimation of the SI by Rasmussen et al. , which was based on Danish legislation . In our calculations , the current intakes from dietary supplements were estimated based on the amount of folic acid available in dietary supplements on the Dutch market . Vitamin A Part of the vitamin A is consumed as provitamin A -LRB- for instance , carotenoids -RRB- . However , the UL is defined for the intake of vitamin A as pure retinol and retinyl esters only because it is thought that the intake of provitamin A will not significantly contribute to the toxicity of high intakes of vitamin A -LSB- 28 -RSB- . When we use the term ` vitamin A ' , we refer to pure retinol and retinyl esters . Due to the risk of osteoporosis , the UL for postmenopausal women is much lower than that for other women -LSB- 28 -RSB- . In our study population , the distinction between premenopausal and postmenopausal women could not be made exactly ; therefore , it was assumed that women older than 50 years are representative for the group of postmenopausal women . When the food consumption surveys were carried out , vitamin A addition was only allowed for margarine and low-fat margarine as a substitute for butter . This substitution will continue in the Netherlands , and therefore the fortification of -LRB- low-fat -RRB- margarine with vitamin A was included in the calculation of the CI95 . The SI was estimated to be 800 µg vitamin A/day for children and adolescents and 1,200 µg vitamin A/day for adults . The habitual dietary vitamin A intake varied from 1,055 µg/day to 2,363 µg/day . For children , the age group 4 -- 6 years had the greatest vitamin A intake -LRB- 1,553 µg/day -RRB- . Men had a larger intake than women . The vitamin A intake of premenopausal and postmenopausal women -LRB- i.e. , older than 50 years -RRB- was comparable -LRB- Table 2 -RRB- . Filling in these factors in the formula -LRB- Box 1 -RRB- resulted in a MSFL for vitamin A of 0 µg vitamin A/100 kcal for children 1 -- 10 years old , men and post-menopausal women , 154 µg vitamin A/100 kcal for women 19 -- 30 years old and for older children and adolescents , the MSFL is 10 -- 70 µg vitamin A/day . In conclusion , the MSFL for vitamin A will be 0 µg vitamin A/100 kcal on the basis of the most sensitive groups -LRB- i.e. , children 1 -- 10 years , men 18 years old or more , and postmenopausal women -RRB- . Our results for vitamin A were the same as Rasmussen et al. 's , i.e. , 0 µg vitamin A/100 kcal . Vitamin D At the time when the DNFCS-3 and the DNFCS-2003 were carried out , addition of vitamin D was only allowed for margarine and low-fat margarine as a substitute for butter . Because this substitution is expected to continue in the Netherlands , this fortification practice was included in the calculation of the CI95 . The 95th percentile of habitual dietary vitamin D intake varied from 4.4 µg/day to 12.2 µg/day -LRB- CI95 -RRB- . Vitamin D intake increased with age for children , although children 1 -- 3 years old had a slightly greater intake than children 4 -- 10 years old . For men , the 95th percentile of habitual vitamin D intake lies between 6.5 µg/day and 12.2 µg/day and for women , between 5.2 µg/day and 8.6 µg / day -LRB- Table 3 -RRB- . The SI was estimated to be 10 µg vitamin D/day for children , adolescents , and adults . Entering these factors into the formula -LRB- Box 1 -RRB- resulted in a MSFL for vitamin D of 3.0 µg/100 kcal for children 4 -- 10 years old to 9.0 µg/100 kcal for women 19 -- 30 years old . The MSFL increased with age for children , although children 4 -- 10 years old had a slightly lower MSFL than children 1 -- 3 years old . Due to a smaller habitual energy and vitamin D intake , the MSFL for women is greater than that for men . In conclusion , the MSFL of vitamin D is 3.0 µg/100 kcal based on the most sensitive group -LRB- i.e. , children 4 -- 10 years -RRB- . For the most sensitive adult group -LRB- men 51 -- 60 years old -RRB- , the MSFL is 5.6 µg/100 kcal . Our MSFL for vitamin D -LRB- 3.0 µg/100 kcal for children 4 -- 10 years old -RRB- is greater than Rasmussen et al. 's acceptable level of addition : 1 µg/100 kcal for children 7 -- 10 years old . This is mainly due to the difference in PFFn . Rasmussen et al. used a more strict PFFn of 25 % whereas we used a PFFn of 15 % . Risk-management : setting AFLs for general exemption After the risk was assessed , a risk manager considered all the important issues and decided what maximum level of fortification will be allowed and included in a general exemption . In the Netherlands , proposed changes and additions to the Dutch Commodity Act are discussed with stakeholders -LRB- e.g. , organizations of trade and industry , consumers organizations , authorities -RRB- in a Regular Consultation on the Commodity Act . Representatives of individual companies can not participate in the Regular Consultation on the Commodity Act . Several consultations regarding the results -LRB- Tables 1 -- 3 -RRB- of the risk assessment for fortification with folic acid , vitamin A , and vitamin D resulted in a general exemption for folic acid of 100 µg/100 kcal and for vitamin D of 4.5 µg/100 kcal . No general exemption was given for vitamin A . A main general consideration is that this national policy will be temporary , as European legislation is expected to come into effect within a few years -LSB- 11 -RSB- . Folic acid The UL of folic acid for adults is based on the risk of masking vitamin B12 deficiency , for children an UL is extrapolated from this adult value based on bodyweight . Because of an ongoing discussion about the value of the UL for children extrapolated from the UL for adults , the risk manager decided to focus on the results of the risk assessment for adults only . It was thought that such an extrapolation would be conservative because the risk of vitamin B12 deficiency for children was thought to be low . Furthermore , at that time , exemptions had been requested for only a few product types and some specific brands . Therefore , the risk manager expected that the chance of children consuming all available folic-acid-fortified products was small . In discussions with the stakeholders , which considered the temporary character of this national policy and the number of requests for exemption , the PFFn of 15 % was judged to be rather conservative . Using the dietary intake at the 95th percentile of the distribution -LRB- CI95 -RRB- and the 90 -- 95th percentile of intake from dietary supplements -LRB- SI -RRB- was also judged to be quite conservative . Therefore , two additional calculations were done , one with a PFFn of 10 % and the other with a low intake scenario of dietary supplements -LRB- i.e. , 400 µg for adults -RRB- . Both scenarios resulted in a maximum level for fortification in the most sensitive adult group -LRB- men aged 18 -- 30 years -RRB- of 100 -- 106 µg/100 kcal -LRB- Table 1 -RRB- . For practical reasons , the risk manager rounded this value off to an AFL of 100 µg folic acid/100 kcal . Because of this relatively liberal AFL and the fact that the value was based on the MLF of adults , it was decided to monitor the intake of folic acid from fortified foods . If the results of the monitoring show that the long-term intake exceeds the UL in specific population groups , appropriate measures can be taken . Vitamin D For vitamin D the derivation of the UL for children is based on critical effects observed in children , whereas for folic acid UL-values for children were established by extrapolation only -LSB- 28 -RSB- . Therefore , the maximum fortification levels for children from the risk assessment were considered . As for folic acid , this will be a temporary policy for only a couple of years and it was thought that the PFFn of 15 % and the high-intake scenario from dietary supplements are rather conservative estimates . In addition , only one request for exemption was received at that time for vitamin D fortification , and the risk manager did not expect more exemption requests . Thus , similar additional calculations with a PFFn of 10 % or a scenario of smaller intakes from dietary supplements -LRB- i.e. , 5 µg -RRB- were done for vitamin D . The calculations resulted in a MSFL of 4.5 µg vitamin D/100 kcal for the most sensitive group -LRB- children aged 4 -- 10 years -RRB- -LRB- Table 3 -RRB- . The risk manager adopted this MSFL and set the AFL at 4.5 µg/100 kcal . Again , the risk manager desires monitoring of vitamin D and energy intake for insight into current intakes and proportions of energy intake fortified . If long-term intakes exceed the ULs , appropriate measures can be taken . Vitamin A In contrast to the liberalization for folic acid and vitamin D , the risk manager did not liberalize the results from the risk assessments for vitamin A. To the opinion of the risk manager , exceeding the UL of vitamin A has more serious consequences for public health than exceeding the ULs for folic acid and vitamin D . In addition , the 95th percentile of habitual dietary vitamin A intake of several age groups already exceeded the UL , even without considering the vitamin A intake from dietary supplements . Furthermore , at this time no request for exemption has been received , although one product for which an exemption for folic acid was requested also contained vitamin A . So the AFL was set at 0 µg/100 kcal . The stakeholders in the consultation agreed with this decision . Exception for low-energy products An exception was made for light variants of products -LRB- low-energy products -RRB- . According to the model , products low in energy may be fortified with smaller amounts of the micronutrient than the more energy-dense counterparts . In view of the obesity trend and the healthy image of light products , this was considered undesirable . Therefore , light products may be fortified with amounts similar to the amounts approved for their more energy-dense counterparts . Discussion We presented a model for the derivation of maximum amounts of micronutrient fortification in the Netherlands . A novelty of this publication is that besides the theoretical model , the practical applicability for the Netherlands is shown including both the risk-assessment and risk-management aspects . The model has already contributed to new Dutch policy-making , as the allowed level for fortification for folic acid and vitamin D are applied as a general exemption in 2007 -LSB- 8 -RSB- . Applicability of the model Although the model can already be applied with the available data in the Netherlands , it is recommended to improve the monitoring of consumption of fortified foods and dietary supplements within the Netherlands . Such data are very useful to check the model parameters and to keep them up-to date . If necessary , AFLs can be adjusted . It is recommended to monitor the intake of fortified foods and dietary supplements as part of the national food consumption survey -LSB- 7 , 27 -RSB- . Food frequency questionnaires specifically for fortified functional foods and dietary supplements in a representative sample of the population would be a useful tool . In addition composition databases of fortified foods and dietary supplements are recommended -LSB- 27 -RSB- . Risk management The discussions about the risk-assessment results with the different stakeholders worked well for the risk manager . This resulted in broad insight into the various points of view of the stakeholders . Ultimately the risk manager took the final decision , and in all these cases the stakeholders agreed with the final outcome . The risk assessment was based on the precautionary principle . However , with a view to the fact that this will be a temporary policy , the outcome of the risk assessment was judged to be rather conservative for folic acid and vitamin D . In contrast , the market may change , the date the European legislation will come into effect can be later than expected , and people may consume more fortified foods than estimated . Therefore , monitoring the intake of micronutrients from fortified foods is a very important tool for warranting the safety of the population . If monitoring shows that some groups within the population have habitual intakes that exceed the ULs , adaptations should be made . Especially children may be vulnerable . A food consumption survey is currently being conducted among children in the Netherlands . These data will provide insight into the micronutrient intake from natural foods , fortified foods and dietary supplements during 2005/2006 . Additional considerations Some factors that were not taken into account in MSFL risk assessment are worth considering , and they can be implemented in the model or taken into account in the risk management if necessary . First , we made an exception for the fortification level of ` light ' products in our risk management . This exception was not considered in the calculation and can therefore theoretically lead to micronutrient intakes that are too large even if the energy intakes are not exceptionally high . Monitoring the use of fortified ` light ' products will be necessary to avoid frequent users exceeding the UL . Second , some products are intended for a specific population or target group only . If there is little risk that the product will be used by nontarget groups , the risk manager can make an exception to the model . Instead of using the calculated MSFL for the most vulnerable group , the MSFL for the specific target group can be used as a maximum for this specific product . Again , monitoring of the use of these products is important , and mentioning the target groups , as well as nontarget groups , on the product package might be considered . The vitamin levels in products may decrease over time . Therefore , it is possible that the amount of vitamin added by manufacturers is greater than the amount declared on the packages -LSB- 24 -RSB- . To be able to protect all consumers and avoid underestimation of the intake , this so-called overage should be integrated into the MSFL in the model . Rasmussen et al. also noted this problem . In Denmark the currently accepted practice is to add up to 150 % of the declared amount . Our calculated MSFL includes overage . International applicability of the risk-assessment model Currently , the European Commission is preparing to set maximum and minimum amounts for vitamins and minerals in both foods and dietary supplements -LSB- 11 -RSB- . The simultaneously setting of both the maximum levels for dietary supplements and for foodstuffs can result in a well based division of micronutrients over dietary supplements and fortified foods . Once the choice has been made which micronutrient is allowed to be added to dietary supplements and/or fortified foods , models like the one presented can be helpful to set the MSFL and AFL for micronutrients in food products . The applicability of the model for this purpose depends on the availability of the input data . When calculating MSFLs valid for Europe as a whole , the availability of European data is necessary . However , data from a food consumption survey that cover all Member States of the European Union representatively are not available . Such data are not even available for all Member States individually . Furthermore , consumption data available in various Member States are often collected with different methods , in a different time frame , and for different specific population groups and the fraction of energy intake that can be fortified may differ greatly from country to country because of the various traditional diets . This makes it difficult to estimate the total habitual intake for each micronutrient and energy type at a European level . To overcome these problems , MSFLs in Europe can be set by using the available country-specific calculations and to select the most sensitive country -LRB- i.e. , the country with the lowest MSFL -RRB- . The maximum safe level for fortification for this country can then be applied in all Member States . Conclusion As this paper illustrates , our model for risk assessment can be used in the Netherlands to help risk managers to set maximum levels for safe addition of vitamins to foods . This has resulted in two general exemptions , one for folic acid at 100 µg/100 kcal and one for vitamin D at 4.5 µg/100 kcal . The model is flexible and can be adapted to new insights . For example , aspects concerning overage and ` light ' products can be included with minor changes in the formula . Monitoring of the total micronutrient intake after applying a general exemption , as well as monitoring of the fortified fraction of the energy intake and the effect of the exception for light products , is recommended for evaluating the model parameters and AFLs and for making adjustments when needed .

B I O B O B O O O O O O O B O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B B O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O B O B O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O 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O O O O O O O B O B O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O B I O O B O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O B I I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O 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O O O O O O O B O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O 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O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O 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The Treatment of Pulmonary Diseases and Respiratory-Related Conditions with Inhaled -LRB- Nebulized or Aerosolized -RRB- Glutathione Reduced glutathione or simply glutathione -LRB- γ-glutamylcysteinylglycine ; GSH -RRB- is found in the cytosol of most cells of the body . GSH in the epithelial lining fluid -LRB- ELF -RRB- of the lower respiratory tract is thought to be the first line of defense against oxidative stress . Inhalation -LRB- nebulized or aerosolized -RRB- is the only known method that increases GSH 's levels in the ELF . A review of the literature was conducted to examine the clinical effectiveness of inhaled GSH as a treatment for various pulmonary diseases and respiratory-related conditions . This report also discusses clinical and theoretical indications for GSH inhalation , potential concerns with this treatment , its presumed mechanisms of action , optimal doses to be administered and other important details . Reasons for inhaled GSH 's effectiveness include its role as a potent antioxidant , and possibly improved oxygenation and host defenses . Theoretical uses of this treatment include Farmer 's lung , pre - and postexercise , multiple chemical sensitivity disorder and cigarette smoking . GSH inhalation should not be used as a treatment for primary lung cancer . Testing for sulfites in the urine is recommended prior to GSH inhalation . Minor side effects such as transient coughing and an unpleasant odor are common with this treatment . Major side effects such as bronchoconstriction have only occurred among asthma patients presumed to be sulfite-sensitive . The potential applications of inhaled GSH are numerous when one considers just how many pulmonary diseases and respiratory-related conditions are affected by deficient antioxidant status or an over production of oxidants , poor oxygenation and/or impaired host defenses . More studies are clearly warranted . Introduction Reduced glutathione or simply glutathione -LRB- γ-glutamylcysteinylglycine ; GSH -RRB- is found in the cytosol of most cells of the body -LRB- 1 -RRB- . It is a tripeptide consisting of glycine , cysteine and glutamate . GSH functions in several enzyme systems within the body that assist with the quenching of free radicals and the detoxification of fat-soluble compounds -LRB- Table 1 -RRB- -LRB- 2 -- 5 -RRB- . It also plays a significant metabolic role in supporting many different biochemical processes -LRB- e.g. amino acid transport , deoxyribonucleic acid synthesis and immune system augmentation -RRB- considered to be important mediators of health status -LRB- 6 -RRB- . Table 1 . Enzyme systems involving glutathioneEnzyme systemFunctionGlutathione synthetaseGamma-glutamyl cycle.Riboflavin-containing glutathione reductaseCatalyzes the conversion of oxidized glutathione -LRB- glutathione disulfide ; GSSG -RRB- to its reduced form.GSH transferase isoenzymesConjugation of GSH with fat-soluble substances for liver detoxification and the detoxification of environmental carcinogens , such as those found in tobacco smoke.Selenium-containing glutathione peroxidase -LRB- GPX -RRB- Protects cells from hydrogen peroxides and lipid hydroperoxides . If not neutralized , these peroxides will damage cellular membranes and other vital cellular components.Leukotriene C4 synthaseConjugation of leukotriene A4 with GSH , resulting in the generation of leukotrienes C4 . Gamma-glutamyl transpeptidase then metabolizes leukotrienes C4 to leukotrienes D4 . Glutathione in the epithelial lining fluid -LRB- ELF -RRB- of the lower respiratory tract is thought to be the first line of defense against oxidative stress -LRB- 6 -RRB- . The ELF concentration of GSH is 140 times that of serum concentrations with a redox ratio of > 9 : 1 -LRB- 7 -RRB- . In fact , alternations in alveolar and lung GSH metabolism are widely recognized as a central feature among many inflammatory lung diseases -LRB- 8 -- 14 -RRB- . In healthy lungs , the oxidant burden is balanced by local antioxidant defenses . However , in lung diseases cellular damage and injury is mediated by an increased oxidant burden and/or decreased antioxidant defenses . In inflammatory lung diseases , supplementation with exogenous sources of GSH would be necessary to reduce the oxidant load and/or correct for antioxidant deficiencies within the lungs . A few published clinical studies have shown the oral administration of GSH to be ineffective at increasing plasma levels when given to healthy subjects -LRB- 15 -RRB- , or when used for the treatment of hepatic cirrhosis -LRB- 16 -RRB- . If the oral administration of GSH can not raise plasma levels in healthy and diseased patients , it is doubtful that this method of delivery would have any appreciable effects at increasing GSH concentrations within the lungs . Intravenous administration might be effective since it bypasses the gastrointestinal tract , immediately enters the blood stream , and presumably would saturate body tissues such as the lungs . Unfortunately , the results of a study did not show intravenous administration to be effective at increasing GSH levels within the ELF -LRB- 17 -RRB- . When 600 mg of GSH was delivered intravenously to sheep , the levels in the venous plasma , lung lymph and ELF increased only for a very brief period of time . However , when the same amount of GSH was delivered through inhalation -LRB- nebulized or aerosolized -RRB- , the baseline GSH level in the ELF -LRB- 45.7 ± 10 μM -RRB- increased 7-fold at 30-min -LRB- 337 ± 64 μM -RRB- , remained above the baseline level 1 h later -LRB- P < 0.001 -RRB- and returned toward baseline levels by 2 h. Despite this short-term increase in GSH concentrations within the ELF , the inhalation method did not significantly increase the amount of GSH in the lung lymph , venous plasma and urine during the 2 h study period . The authors of this report concluded that inhalation specifically increased GSH levels at the lung epithelial surface . Given that inhalation is the only known method that increases GSH levels in the ELF for a significant duration , a review of the literature was conducted to examine the clinical effectiveness of inhaled GSH as a treatment for various pulmonary diseases and respiratory-related conditions . Only reports involving human subjects were included in the analysis . The clinical and theoretical indications for GSH inhalation were summarized and potential concerns with this treatment reported . Other pertinent details such as its presumed mechanisms of action and optimal doses to be administered were compiled and evaluated . Methods Literature Search Computer searches were conducted of English and non-English language articles in the Biomedical Reference Collection -LRB- 1984 to August 2006 -RRB- , CINAHL -LRB- 1982 to August 2006 -RRB- , MEDLINE -LRB- 1965 to August 2006 -RRB- and Nursing and Allied Health Collection -LRB- 1985 to August 2006 -RRB- databases . Articles were searched with the key search terms ` Nebulized Glutathione , ' and ` Glutathione ' in combination with ` Aerosol ' OR ` Inhalation . ' These keywords were also searched with words related to pulmonary and/or respiratory disease . To supplement the search , references of the articles found from the initial search were reviewed . Hand searching of relevant journals was also completed as part of the search . Selection of Articles To be included in the final review , articles had to report on the use and administration of inhaled GSH for pulmonary diseases and respiratory-related conditions in human subjects . Only peer-reviewed articles were reviewed . Quality Assessment An evidence grade was determined for each article . These evidence grades were adapted from the hierarchy of evidence developed by the Oxford Centre of Evidence Based Medicine -LRB- Table 2 -RRB- -LRB- 18 -RRB- . Table 2 . Grades of evidenceASystematic reviews of randomized controlled trials and/or randomized controlled trials with or without double-blind placebo control.BSystematic reviews of observational studies and/or high-quality observational studies including cohort and case-control studies and/or cohort ` outcomes ' research and/or nonrandomized controlled trials.CCase-series , case-reports , and/or poor-quality cohort and case-control studies.DExpert opinion without explicit critical appraisal or based on physiology , bench research or ` first principles . ' Results A total of 12 reports were screened -LRB- 9 , 10 , 17 , 19 -- 27 -RRB- . Only one report was excluded because it involved the use of inhaled GSH in sheep -LRB- 17 -RRB- . In total , 11 articles were found to meet the inclusion criteria and were included in this review -LRB- 9 , 10 , 19 -- 27 -RRB- . Table 3 displays the characteristics of the studies included in this review . Table 3 . Summary of articles demonstrating the effectiveness of inhaled glutathione for the treatment of pulmonary diseases and respiratory-related conditionsReferenceConditionNDosages of inhaled GSHOutcomeEvidence grade -LRB- 21 -RRB- AsthmaEight asthma patients -LSB- mean age , 29 ± 7 -LRB- standard deviation ; SD -RRB- years -RSB- 600 mg once weekly for 3 monthsA subset of patients with clinically stable mild asthma experienced a bronchoconstrictor effect when treated with inhaled GSH.A : Randomized placebo-controlled trial -LRB- 23 -RRB- Chronic otitis media with effusion -LRB- chronic OME -RRB- 30 patients -LRB- 3 -- 12 years of age ; mean age , 5.8 years -RRB- and 30 controls -LRB- 3 -- 12 years of age ; mean age , 6.1 years -RRB- 600 mg of GSH in 4 ml of saline subdivided into five 2-min sessions by nasal aerosol every 3 -- 4 waking h for 2 weeksGSH should be considered for the nonsurgical management of chronic OME.A : Randomized placebo-controlled trial -LRB- 24 -RRB- Cystic fibrosis -LRB- CF -RRB- Nine patients -LSB- mean age , 16.1 ± 1.44 -LRB- SD -RRB- years -RSB- received the S-nitrosoglutathione -LRB- GSNO -RRB- and 11 patients -LSB- mean age , 19.9 ± 3.45 -LRB- SD -RRB- years -RSB- received the phosphate - buffered saline -LRB- PBS -RRB- solution0 .05 ml/kg of 10 mM GSNOThe treatment group showed a modest improvement in oxygenation that was thought to be independent of the physiological effects of nitric oxide.A : Randomized placebo-controlled trial -LRB- 27 -RRB- CF19 patients -LRB- 6 -- 19 years of age -RRB- were randomized to treatment -LSB- mean age , 13.3 ± 4.1 -LRB- SD -RRB- years -RSB- or placebo groups -LSB- mean age , 12.9 ± 4.9 -LRB- SD -RRB- years -RSB- Total daily dose administered to the patients in the treatment group was 66 mg/kg of body weightGSH can improve clinical parameters in CF patients , and that effective treatment should include the correction of GSH deficiency.A : Randomized placebo-controlled trial -LRB- 9 -RRB- Idiopathic pulmonary fibrosis -LRB- IPF -RRB- 10 patients with IPF -LSB- mean age , 46 ± 3 -LRB- SD -RRB- years -RSB- and 19 normal nonsmokers -LSB- mean age , 36 ± 3 -LRB- SD -RRB- years -RSB- 600 mg twice daily for 3 daysInhaled GSH might be beneficial among IPF patients by reversing the oxidant -- antioxidant imbalance.B : Nonrandomized controlled trial -LRB- 19 -RRB- Human immunodeficiency virus -LRB- HIV -RRB- seropositive individuals14 HIV seropositive individuals -LSB- mean age , 32 ± 2 -LRB- SD -RRB- years -RSB- 600 mg twice daily for 3 daysIt is a reasonable therapeutic strategy to augment the deficient GSH levels of the lower respiratory tracts of HIV seropositive individuals.B : Cohort ` outcomes ' research -LRB- 20 -RRB- Chronic rhinitis13 patients with chronic rhinitis and 13 healthy subjects -LRB- 4 -- 15 years of age for all subjects ; mean age , 8.2 years -RRB- 600 mg daily for 14 daysStatistically significant improvement in nasal obstruction , rhinorrhea and ear fullness.B : Nonrandomized controlled trial -LRB- 10 -RRB- CFSeven CF patients -LSB- mean age , 25 ± 1 -LRB- SD -RRB- years -RSB- 600 mg of GSH for 3 daysInhalation therapy with GSH does normalize the respiratory epithelial surface oxidant -- antioxidant balance in CF patients.B : Cohort ` outcomes ' research -LRB- 25 -RRB- CF21 patients with CF -LRB- 16 -- 37 years of age for all subjects -RRB- 300 or 450 mg three times daily for 14 daysInhaled GSH can permeate the lower airways of the lungs and improve important parameters of lung function in CF patients despite not having any effect upon markers of oxidative injury.B : Cohort ` outcomes ' research -LRB- 26 -RRB- CF17 patients with CF -LRB- 18 -- 29 years of age for all subjects ; mean age , 24 years -RRB- 450 mg three times daily for 14 daysInhaled GSH did not affect the oxidative status of the patients who were tested , but it did favorably modulate their immune responses.B : Cohort ` outcomes ' research -LRB- 22 -RRB- EmphysemaOne -LRB- 95 year-old male -RRB- 120 mg of GSH in office , then 120 mg twice daily for 3 days , and continuation of treatment -LRB- dose unknown -RRB- for 2 yearsWhen the patient returned for a follow-up visit , he no longer required the use of his wheelchair and oxygen . The striking results were unexpected and unlikely to be due to placebo alone.C : Case report Discussion Based exclusively on the published evidence included in this review , inhaled GSH is potentially indicated for the following clinical conditions : cystic fibrosis -LRB- CF -RRB- , chronic otitis media with effusion -LRB- OME -RRB- , HIV seropositive individuals , idiopathic pulmonary fibrosis -LRB- IPF -RRB- and chronic rhinitis . These conditions were chosen since the published studies were of good quality , received A and B evidence grades , and their respective results demonstrated benefits from the use of GSH inhalation . Inhaled GSH can not be recommended as a potential treatment for emphysema since the quality of evidence is lacking at the present time . The emphysema case report had notable limitations since serial spirometry was not documented , and the placebo effect could not be ruled-out -LRB- 22 -RRB- . However , this does not necessarily indicate that GSH inhalation would be of no benefit for emphysema patients . There is experimental and human data demonstrating a link between GSH , oxidant-derived damage and possible protection against the development of emphysema . An in vitro study demonstrated that GSH could retard the oxidant-mediated down-regulation of α-1-proteinase inhibitor activity in smokers ' emphysema -LRB- 28 -RRB- . This finding is important since one of the principal pathophysiological mechanisms of emphysema is the down-regulation of this enzyme by means of oxidative damage -LRB- 29 -RRB- . Moreover , in a recent review of lung GSH and cigarette smoke-induced airway disease , increased GSH in the ELF of chronic smokers was presumed to be a protective adaptive mechanism against the development of chronic obstructive pulmonary disease -LRB- COPD -RRB- -LRB- 30 -RRB- . Considering that not all chronic smokers go on to develop COPD , the authors in that review pointed out that genetic variations in the molecular mechanisms that regulate GSH metabolism might explain why some individuals are better protected against the development of COPD . It thus appears that emphysema patients are subjected to progressive tissue damage due , in part , to the consequences of GSH deficiency and/or genetic variations in GSH metabolism . Since GSH inhalation would presumably offer both antioxidant protection and GSH replenishment , this method of treatment would potentially benefit emphysema patients . Asthma is another condition where inhaled GSH can not be recommended since this treatment caused notable side effects -LRB- e.g. breathlessness , bronchoconstriction and cough -RRB- in the cited study -LRB- 21 -RRB- . These side effects were linked primarily to the production of sulfites that occurred when GSH was in solution . GSH inhalation should continue to be explored as a potential treatment for asthma . None of the asthma patients in the study had their urine tested for sulfites . A positive test for sulfites would have eliminated these patients from entering the study . Accordingly , the results might have been much more favorable if patients without sulfite sensitivities were included . This issue of asthma and sulfite sensitivities is an important one for clinicians to be mindful of . Sulfites are found in beer , wine , restaurant salad bars , seafood , potatoes , processed foods and many pharmaceuticals -LRB- 31 -RRB- . Many asthma patients report being sensitive to sulfites . In an Australian study , ∼ 30 % of asthmatic patients reported being sensitive to sulfites in wine -LRB- 32 -RRB- . A more recent and rigorous scientific study , however , demonstrated that asthma patients can tolerate varying amounts of sulfites in wines ranging from 20 , 75 or 150 parts per million -LRB- ppm -RRB- -LRB- 33 -RRB- . Only a small minority of patients in this study -LRB- 4 of 24 self-reported wine-sensitive asthmatics -RRB- exhibited reactions when challenged with 300 ppm of sulfites . One report indicated that 4 -- 8 % of asthmatics are sensitive to sulfites -LRB- 34 -RRB- . Other reports have estimated the incidence of sulfite sensitivity to be around 5 -- 11 % -LRB- 35,36 -RRB- . Even though the exact percentage of sulfite-sensitive asthmatics is difficult to ascertain , sulfite sensitivity is an important factor to assess when using or evaluating research done on inhaled GSH . Future Research Directions There are additional clinical conditions that might benefit from this type of treatment , but further studies are necessary . One such condition is Farmer 's lung -LRB- FL -RRB- , which is a hypersensitivity pneumonitis caused by the inhalation of thermophilic actinomycetes and spores of Aspergillus specie -LRB- 11 -RRB- . A study was undertaken to investigate the effect of pulmonary GSH levels after hay exposure in patients with FL and in asymptomatic farmers -LRB- AF -RRB- -LRB- 11 -RRB- . Fifteen symptomatic patients with FL -LSB- mean age , 42 ± 1 -LRB- SD -RRB- year -RSB- were compared with 10 AF -LSB- mean age , 43 ± 1 -LRB- SD -RRB- year -RSB- serving as the control group . All patients had baseline lung function testing and testing at various time intervals following hay exposures . The authors of this study concluded that FL and AF patients have characteristically different intrapulmonary levels of GSH , and that the pathogenesis of FL is likely related to GSH regulatory mechanisms . They also speculated that AF patients have a better ability to upregulate their pulmonary GSH levels , which would protect them against active disease . Clinical testing of inhaled GSH in patients with FL is warranted . The administration of GSH inhalation before and/or immediately following exercise is another potential application of this novel treatment . Exercise is a known inducer of oxidative stress leading to free radical production , which can encourage lipid peroxidation and tissue damage among individuals with deficient and/or impaired antioxidant systems . As stated in the beginning of this report , selenium is a cofactor in the GPX enzyme that protects cells from hydrogen peroxides and lipid hydroperoxides . When under situations of oxidative stress , the GPX enzyme will markedly increase in the lungs as an antioxidant adaptive response -LRB- 37 -RRB- . By supplying more GSH to the lung tissues , more of this enzyme might be available to help reduce the production of free radicals associated with exercise . Although these assumptions are very speculative , it does seem possible and even logical that GSH inhalation would benefit those who regularly exercise by increasing exercise tolerance , and by maintaining and/or replenishing the antioxidant systems within the lungs . Multiple chemical sensitivity disorder -LRB- MCSD -RRB- is another condition that might be clinically responsive to this treatment . Patients with this disorder are known to have bronchial hyperreactivity and even exhibit asthma-like symptoms -LRB- 38 -RRB- . Unlike asthma , MCSD is not associated with atopy and immunoglobulin E -LRB- IgE -RRB- - mediated allergic mechanisms -LRB- 39 -RRB- . The prevailing theory explaining the cause of MCSD is a fusion between two separate theories -- the neural sensitization and nitric oxide/peroxynitrite theories -LRB- 40 -RRB- . This fusion theory , proposed by Pall , links long term potentiation of N-methyl-d-aspartate -LRB- NMDA -RRB- receptors at the synapses of nerve cells by glutamate and aspartate to an increased production of nitric oxide and its oxidant product , peroxynitrite -LRB- 40,41 -RRB- . Treatment with antioxidants may improve symptoms of MCSD by reducing the peroxynitrite elevations and other biochemical dysfunctions that are associated with such elevations -LRB- 40,41 -RRB- . Glutathione inhalation may be ideal since the primary route by which patients with MCSD get triggered is through smelling and breathing . Sulfite sensitivity would have to be considered since inhaled GSH could provoke adverse events . This treatment might be capable of providing antioxidant protection to both the upper and lower respiratory airways , which would theoretically help to reduce the symptoms of MCSD and the production of peroxynitrite . More research studies are necessary . Two final conditions , cigarette smoking and lung cancer , are worth mentioning since they are intimately related to each other and are affected by GSH and its related enzymes . These conditions are influenced by the glutathione S-transferase -LRB- GST -RRB- group of enzymes that are found in significant quantities in the bronchioles and alveoli of the lungs -LRB- 42 -RRB- , and in very high concentrations in the bronchial epithelium -LRB- 43 -RRB- . Among smokers , a lack of the GST mu enzyme was thought to be associated with a greater risk of lung cancer , especially if there was a cancer and/or lung cancer history among the relatives of the patients in this study -LRB- 44 -RRB- . Since the GST mu enzyme detoxify carcinogens in tobacco , any deficiency of this enzyme was presumed to be associated with an increased risk of lung cancer . However , a more recent study pertaining to the GST group of enzymes found no such association -LRB- 45 -RRB- . In this meta-analysis , polymorphisms in the GST genes had no associations or weakly positive associations with risk factors for lung cancer . Despite the need for more research , GSH inhalation might be beneficial for smokers to augment their GST enzymes , which would help facilitate the detoxification of carcinogens . Even though the best intervention for these patients would be smoking cessation , many patients lack the necessary willpower to quit . For these patients , regular GSH inhalation might reduce oxidants generated from cigarette smoke -LRB- ∼ 1014 free radicals/puff -RRB- -LRB- 46 -RRB- , and the epithelial lung injury associated with smoking -LRB- 47 -RRB- . For lung cancer patients , the use of GSH inhalation is not recommended . Cancer cells use multiple mechanisms -LRB- e.g. altered transport of a drug , inhibition of drug-induced apoptosis and elevation of cellular GSH -RRB- to circumvent the cytotoxic effects of chemotherapeutic agents -LRB- 48 -RRB- . Early research studies showed that GSH was able to reduce cytotoxicity to chemotherapeutic compounds by boosting the metabolism of drugs to less active compounds , or by the detoxification of free radicals -LRB- 49,50 -RRB- . More recently , research has revealed that the levels of a specific GST enzyme increases among cancer cells with higher differentiation grades , and that these drug-resistant gene products are found in lung carcinomas at the time of surgical resection -LRB- 51 -RRB- . There is also speculation that GSH might be capable of repairing drug-induced injury at the DNA level -LRB- 48 -RRB- . A recent review article has described the involvement of glutathione in the detoxification or inactivation of platinum drugs -- the most commonly employed drugs for the treatment of advanced stage lung cancer patients -LRB- 52 -RRB- . Based on this information , it would be unwise and illogical to use GSH inhalation while lung cancer patients are undergoing active chemotherapy treatment . Mechanism of Action Inhalation of GSH results in a mechanism of action confined to the upper airways and lungs -LRB- Fig. 1 -RRB- , and will not influence plasma levels to a significant degree . In the studies that measured both lung and plasma levels of GSH , the plasma levels remained essentially unchanged following GSH inhalation . Seven of the studies included in this review demonstrated that GSH inhalation exerts its effects upon the lower respiratory tract -LRB- 9 , 10 , 19 , 24 -- 27 -RRB- . The upper respiratory tract also appears to benefit from GSH augmentation . Two studies involving patients with upper respiratory tract diseases showed clinical benefits from GSH inhalation treatment -LRB- 20,23 -RRB- . The predominant mechanism responsible for GSH 's therapeutic effects are probably related to its antioxidant properties that offer protection against oxidative injury , and/or assist with the normalization of the oxidant -- antioxidant balance within the upper and lower respiratory tract . Even though the majority of these studies suggested that antioxidant protection was the principal reason for the favorable treatment responses , some of the studies were unable to demonstrate a change in markers of oxidation from this treatment . More data is necessary to confirm the precise nature of GSH 's antioxidant properties within the upper and lower respiratory tract . Additional explanations for GSH 's therapeutic effects might include an improvement in host defenses -LRB- e.g. increased cytotoxic lymphocytes -RRB- , and better oxygenation -LRB- e.g. an increase in oxygen saturation -RRB- . GSH inhalation produced clinically meaningful results in the majority of diseases that were studied . Specifically , GSH inhalation was shown to improve clinical markers of respiratory function that inevitably impact upon quality of life and disease progression . These improvements were the most important outcomes and features of this novel treatment . Figure 1 . Inhaled GSH 's mechanism of action . GSH , reduced glutathione ; FEV1 , forced expiratory volume in 1 s ; FVC , forced vital capacity . Considerations Prior to Initiating GSH Inhalation The urine should be tested for sulfite sensitivity . A special test strip can be dipped in the urine , and is known as the ` EM-Quant 10013 Sulfite Test . ' It can be easily located through any search engine on the Internet -LRB- 53 -RRB- . Even though instructions for sulfite testing have been published elsewhere -LRB- 54 -RRB- , a brief description of the procedure is outlined below : A random -LRB- fresh -RRB- urine sample is suitable , but a first morning void may be preferable due to its higher concentration . Once the test strip is dipped in the urine -LRB- for 1 s -RRB- , the reaction zone changes color to indicate the concentration of sulfites present . After 30 s , the color on the test strip is compared to a color scale on the bottle indicating the concentrations of sulfites in the urine -LRB- can detect 10 , 40 , 80 , 180 and 400 ppm of sulfites -RRB- . The resultant concentration should be multiplied by a factor of 1.5 to provide the amount of free sulfites in mg/l -LRB- ppm -RRB- . The strip will not detect below 10 ppm . The urine samples should be preservative free , and the urinary pH should also be tested with pH paper . If the urine pH is below 6 , then the amount of sulfites might be underestimated by the test . In such cases , consider adding sodium acetate or sodium hydroxide to raise the pH to at least 7 -- 10 -LRB- should not exceed a pH of 12 -RRB- , and then repeat with a new test strip . If the urine test were positive for sulfites -LRB- normally they are absent -RRB- , the use of inhaled GSH would be strictly contraindicated . Method of Delivery , Recommended Daily Dosages and Side Effects With a nebulizer , a solution of GSH is made into an aerosol and is delivered to the upper respiratory tract and the lungs through a mask that covers the nose and mouth , or is delivered directly into the lungs via a mouthpiece . Any compounding pharmacist would be able to prepare the solution of GSH at the desired concentrations . The typical dosages used in the studies cited in Table 3 were 600 mg once daily , 600 mg twice daily , 900 mg daily , 1350 mg daily or a daily dose of 66 mg/kg of body weight . Better results are more likely to be achieved with doses of at least 600 mg or more each day . One of the studies used much larger doses -LRB- 66 mg/kg of body weight -RRB- since the authors speculated that these would be necessary to replace half of the amount of GSH that is produced each day -LRB- e.g. a 150 lb male synthesizes 10 g daily and would need 5 g as a replacement dose -RRB- -LRB- 27 -RRB- . When patients are unresponsive to doses in the range of 600 -- 1350 mg per day , it might be suitable to try doses that would replace half the estimated amount of GSH that is synthesized each day . These gram doses might yield better clinical results . In terms of side effects , GSH inhalation is very safe . Minor side effects such as mild coughing and an unpleasant odor were reported in some of the studies included in this review . These minor side effects , better described as mild nuisance problems , were not severe enough to cause any of the study participants to discontinue treatment with inhaled GSH . The only worrisome or potentially life-threatening side effect to note is bronchoconstriction , which would be more likely to occur among sulfite-sensitive asthma and MCSD patients . However , if proper precautions such as sulfite testing are done prior to treatment , this serious side effect should be avoidable . Monitoring the Clinical Response to Inhaled GSH For pulmonary diseases or respiratory-related conditions , baseline pulmonary function testing with a spirometer or a simple peak flow meter is recommended prior to the first treatment . After a prescribed period of treatment time , pulmonary function tests should be repeated . This will help to establish if there are any clinical improvements from regular GSH inhalation . Conclusions GSH inhalation is an effective treatment for a variety of pulmonary diseases and respiratory-related conditions . Even very serious and difficult-to-treat diseases -LRB- e.g. , CF , IPF -RRB- yielded benefits from this novel treatment . GSH inhalation is very safe , and rarely causes major or life-threatening side effects . The potential applications are numerous when one considers just how many pulmonary diseases and respiratory-related conditions are affected by deficient antioxidant status , poor oxygenation and/or impaired host defenses . More studies are clearly warranted .

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O 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O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O 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O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O

aerosolized glutathione (gsh)
nebulized gsh
reduced gsh