Clinical trial NCT03956732: Effects of Milk Protein and Vitamin D on Children's Growth and Health
Official title: Effects of Milk Protein and Vitamin D on Children's Growth and Health (D-pro)
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Bone Health
Muscle Function
Cardiometabolic Health
Appetite Regulation
Keywords: Child Nutrition
Dietary recommendations
Milk protein
Vitamin D
Bone mineral density
Muscle strength
Immune defence
Lead sponsor: University of Copenhagen
Sponsor class: OTHER
Collaborators: name: University of Aarhus
name: Arla Foods
name: Arla Foods Ingredients
First posted: 2019-05-21
Enrollment: 200
Sex: ALL
Minimum age (years): 6
Maximum age (years): 8
Standard ages: CHILD
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: FACTORIAL
Primary purpose: PREVENTION

Brief summary: The purpose of D-pro is to investigate the combined and separate effects of milk protein and vitamin D on bone health, growth, muscle function, body composition and cardiometabolic health in 6-8-year-old children.

Detailed description: The D-pro study investigates the effects of high or medium intakes of milk protein, and vitamin D supplements or placebo, in healthy 6-8 year-old Danish children. The study is a 2×2-factorial randomized controlled trial with 4 study arms. The subjects will be randomly allocated to receive yoghurt products with either high or medium protein content (300g/day, 6 days/week) and to receive tablets with either vitamin D (20 μg/day) or placebo for 24 weeks. Measurements and biological sampling will be performed at baseline and at the end of the intervention.

The primary outcome will be bone mineral density (BMD). The investigators will also measure effects on children's muscle function, cardiometabolic health, body composition, growth and growth factors, nutrient status, immune defence and risk of acute respiratory tract infections, as well as appetite hormones. The investigators will also assess potential sex-specific effects and the potential modifying effect of genotype.

Eligibility criteria: Inclusion Criteria:

Children must:

* Be 6-8 years of age at the start of the intervention
* Be healthy
* Have a frequent intake of milk and yoghurt products, corresponding to at least ¼ liter a day
* Like yoghurt and high protein yoghurt ("skyr")
* Be of white, Danish or European origin

Moreover:

* The family must not be planning a winter vacation south of a latitude of 50° North
* The child must speak and understand Danish in order to understand the study procedures
* At least one parent must read, speak and write Danish

Exclusion Criteria:

* Known or suspected allergy or intolerance to milk or milk components
* Chronic illness or disease that may affect study outcomes
* Chronic intake of medicine that may affect study outcomes
* Use of vitamin D-containing supplements \>3 days/week the 2 last months and use of any vitamin D-containing supplements the last 1 month before intervention start
* Concomitant participation in other studies involving dietary supplements or blood sampling
* Living in a household with another participating child

Primary outcomes:
measure: Bone Mineral Density (BMD)
timeFrame: 24 weeks
Secondary outcomes:
measure: Bone Mineral Content (BMC)
timeFrame: 24 weeks
measure: Fat mass index
timeFrame: 24 weeks
measure: Fat free mass index
timeFrame: 24 weeks
measure: Bone area
timeFrame: 24 weeks
measure: Height
timeFrame: 24 weeks
measure: Waist circumference
timeFrame: 24 weeks
measure: Insulin-like Growth Factor 1 (IGF-1)
timeFrame: 24 weeks
measure: Insulin-like growth factor-binding protein 3 (IGFBP-3)
timeFrame: 24 weeks
measure: Serum calcium
timeFrame: 24 weeks
measure: Osteocalcin
timeFrame: 24 weeks
measure: Parathyroid hormone (PTH)
timeFrame: 24 weeks
measure: Bone-specific alkaline phosphatase
timeFrame: 24 weeks
measure: C-terminal telopeptide of type 1 collagen in serum (s-CTX)
timeFrame: 24 weeks
measure: Maximal leg press strength
timeFrame: 24 weeks
measure: Maximal jumping height
timeFrame: 24 weeks
measure: Maximal jumping length
timeFrame: 24 weeks
measure: Maximal grip strength
timeFrame: 24 weeks
measure: Muscle endurance
timeFrame: 24 weeks
measure: Blood pressure
timeFrame: 24 weeks
measure: Hemoglobin A1c (HbA1c)
timeFrame: 24 weeks
measure: Glucose
timeFrame: 24 weeks
measure: Insulin
timeFrame: 24 weeks
measure: Total cholesterol
timeFrame: 24 weeks
measure: High density lipoprotein cholesterol (HDL cholesterol)
timeFrame: 24 weeks
measure: Low density lipoprotein cholesterol (LDL cholesterol)
timeFrame: 24 weeks
measure: Triacylglycerol (TG)
timeFrame: 24 weeks
Other outcomes:
measure: Physical activity
timeFrame: 24 weeks
measure: C-peptide
timeFrame: 24 weeks
measure: Vitamin D binding protein
timeFrame: 24 weeks
measure: Serum 25(OH) vitamin D
timeFrame: 24 weeks
measure: 1,25(OH)2vitamin D
timeFrame: 24 weeks
measure: Urea
timeFrame: 24 weeks
measure: Interleukin-6 (IL-6)
timeFrame: 24 weeks
measure: Interleukin-1β (IL-1β)
timeFrame: 24 weeks
measure: Tumor necrosis factor a (TNF-a)
timeFrame: 24 weeks
measure: Leptin
timeFrame: 24 weeks
measure: Adiponectin
timeFrame: 24 weeks
measure: High sensitivity C-reactive protein (hsCRP)
timeFrame: 24 weeks
measure: Immune cell counts
timeFrame: 24 weeks
measure: Immuno-active peptides in nasal fluid
timeFrame: 24 weeks
measure: Immuno-active peptides in blood
timeFrame: 24 weeks
measure: Respiratory tract infections
timeFrame: 24 weeks
measure: Dietary intake
timeFrame: 24 weeks
measure: Vitamin D and calcium intake
timeFrame: 24 weeks
Locations:
city: Frederiksberg
country: Denmark
facility: Department of Nutrition, Exercise and Sports, University of Copenhagen
Study officials:
affiliation: Department of Nutrition, Exercise and sports, University of Copenhagen
name: Camilla T Damsgaard, Assoc Prof
role: PRINCIPAL_INVESTIGATOR
affiliation: Department of Nutrition, Exercise and sports, University of Copenhagen
name: Christian Mølgaard, Prof
role: STUDY_CHAIR
affiliation: Institute of Public Health, Aarhus University, Denmark
name: Mette Hansen, Assoc Prof
role: STUDY_CHAIR
References:
citation: Thams L, Hvid LG, Stounbjerg NG, Brond JC, Molgaard C, Damsgaard CT, Hansen M. Vitamin D supplementation and increased dairy protein intake do not affect muscle strength or physical function in healthy 6-8-year-old children: the D-pro randomized trial. Eur J Nutr. 2022 Oct;61(7):3613-3623. doi: 10.1007/s00394-022-02912-0. Epub 2022 May 28.
citation: Thams L, Stounbjerg NG, Hvid LG, Molgaard C, Hansen M, Damsgaard CT. Effects of high dairy protein intake and vitamin D supplementation on body composition and cardiometabolic markers in 6-8-y-old children-the D-pro trial. Am J Clin Nutr. 2022 Apr 1;115(4):1080-1091. doi: 10.1093/ajcn/nqab424.
citation: Stounbjerg NG, Thams L, Hansen M, Larnkjaer A, Clerico JW, Cashman KD, Molgaard C, Damsgaard CT. Effects of vitamin D and high dairy protein intake on bone mineralization and linear growth in 6- to 8-year-old children: the D-pro randomized trial. Am J Clin Nutr. 2021 Dec 1;114(6):1971-1985. doi: 10.1093/ajcn/nqab286.