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.
Study Goal
The researchers aimed to investigate the combined and separate effects of high dairy protein intake and vitamin D supplementation on body composition and cardiometabolic markers in children.
Results Summary
High dairy protein intake reduced increases in fat mass index compared to normal protein intake, while vitamin D supplementation prevented winter declines in 25-hydroxyvitamin D and reduced LDL cholesterol. No significant combined effects were observed except for plasma glucose.
Population
200 white, Danish children aged 6-8 years.
Effective Dosage
260 g/d of high-protein (10 g/100 g) or normal-protein (3.5 g/100 g) yogurt, plus 20 µg/d vitamin D3 or placebo.
Duration
24 weeks.
Interactions
None mentioned.
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
high dairy protein intake | decrease | fat mass index | white, Danish, 6-8-y-old children | - | hampered an increase | #1 |
vitamin D supplementation | increase | 25-hydroxyvitamin D | white, Danish, 6-8-y-old children | - | counteracted the winter decline | #2 |
vitamin D supplementation | decrease | LDL cholesterol | white, Danish, 6-8-y-old children | - | counteracted the increase | #3 |
high dairy protein intake | decrease | fat mass index | white, Danish, 6-8-y-old children | - | smaller increases | #4 |
high dairy protein intake | decrease | insulin | white, Danish, 6-8-y-old children | - | the same pattern was seen | #5 |
high dairy protein intake | decrease | HOMA-IR | white, Danish, 6-8-y-old children | - | the same pattern was seen | #6 |
high dairy protein intake | decrease | C-peptide | white, Danish, 6-8-y-old children | - | the same pattern was seen | #7 |
vitamin D supplementation | decrease | LDL cholesterol | white, Danish, 6-8-y-old children | - | reduced | #8 |
high dairy protein intake | no change | fat-free mass | white, Danish, 6-8-y-old children | - | unaffected | #9 |
high dairy protein intake | no change | blood pressure | white, Danish, 6-8-y-old children | - | unaffected | #10 |
normal-protein yogurt with vitamin D | increase | plasma glucose | white, Danish, 6-8-y-old children | - | largest increase | #11 |
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 wk during winter. We measured body composition (by DXA), 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 median: 3.7 (25th-75th percentile: 2.5-5.1) energy percentage (E%) and increased to median: 7.2 (25th-75th percentile: 4.7-8.8) E% and median: 4.2 (25th-75th percentile: 3.1-5.3) E% with HP and NP. Mean ± SD serum 25-hydroxyvitamin D concentration changed from 81 ± 17 to 89 ± 18 nmol/L and 48 ± 13 nmol/L with vitamin D and placebo, respectively. 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 with 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 with placebo (P < 0.05). Fat-free mass and blood pressure were unaffected. CONCLUSIONS: High compared with 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. This trial was registered at clinicaltrials.gov as NCT03956732.