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

Research output: Contribution to journalJournal articleResearchpeer-review


Background: Increasing evidence suggests that prevention of lifestyle diseases should begin early. Dairy protein and vitamin D can affect body composition and cardiometabolic markers, yet evidence among well-nourished children is sparse.

Objectives: We investigated combined and separate effects of high dairy protein intake and vitamin D on body composition and cardiometabolic markers in children.

Methods: In a 2 × 2-factorial, randomized trial, 200 white, Danish, 6-8-y-old children substituted 260 g/d dairy in their diet with high-protein (HP, 10 g protein/100 g) or normal-protein (NP, 3.5 g protein/100 g) yogurt and received blinded tablets with 20 µg/d vitamin D3 or placebo for 24 weeks during winter. We measured body composition by dual-energy X-ray absorptiometry, blood pressure, and fasting blood glucose, insulin, C-peptide, and lipids.

Results: In total, 184 children (92%) completed the study. Baseline median [25th-75th percentile] dairy protein intake was 3.7 [2.5-5.1] E% and increased to 7.2 [4.7-8.8] E% and 4.2 [3.1-5.3] E% with HP and NP. Mean ± SD serum 25-hydroxyvitamin D changed from 81±17 nmol/L to 89±18 nmol/L and 48±13 nmol/L with vitamin D and placebo. There were no combined effects of dairy protein and vitamin D, except for plasma glucose, with the largest increase in the NP-vitamin D group (Pinteraction = 0.005). There were smaller increases in fat mass index (P = 0.04) with HP than NP, and the same pattern was seen for insulin, HOMA-IR, and C-peptide (all P = 0.06). LDL cholesterol was reduced with vitamin D compared to placebo (P < 0.05). Fat free mass and blood pressure were unaffected.

Conclusions: High compared to normal dairy protein intake hampered an increase in fat mass index. Vitamin D supplementation counteracted the winter decline in 25-hydroxyvitamin D and the increase in LDL cholesterol observed with placebo. This study adds to the sparse evidence on dairy protein in well-nourished children and supports a vitamin D intake of ∼20 µg/d during winter.

Original languageEnglish
JournalAmerican Journal of Clinical Nutrition
Issue number4
Pages (from-to)1080-1091
Number of pages12
Publication statusPublished - 2022

Bibliographical note

© The Author(s) 2022. Published by Oxford University Press on behalf of the American Society for Nutrition.

    Research areas

  • Faculty of Science - Pediatric, Cholecalciferol, DXA, BMI, FMI, FFMI, Cholesterol, Blood lipids, Cardiovascular, Milk protein

Number of downloads are based on statistics from Google Scholar and www.ku.dk

No data available

ID: 289308914