Vitamin D status and functional health outcomes in children aged 2–8 y: a 6-mo vitamin D randomized controlled trial
The American Journal of Clinical Nutrition, Volume 107, Issue 3, 1 March 2018, Pages 355–364, https://doi.org/10.1093/ajcn/nqx062
Neil R Brett Colleen A Parks Paula Lavery Sherry Agellon Catherine A Vanstone Martin Kaufmann Glenville Jones Jonathon L Maguire Frank Rauch Hope A Weiler
It is extremely rare to find a study which finds a benefit from as little of 400 IU of Vitamin D
Here are some successful trials which used more Vitamin D
- Half the risk of Influenza -A in infants taking 1200 IU of vitamin D for 4 months – RCT Jan 2018
- Vitamin D needed to get children to just 20 ng in winter 800 IU white skin, 1100 IU dark (Sweden) – RCT June 2017
- Third study found that Infants needed 1600 IU of vitamin D – JAMA RCT May 2013
Which is 4X more than was used by the sutdy on this page - Childhood Respiratory Health hardly improved with 600 IU of vitamin D (need much more) – May 2018
 Download the PDF from Vitamin D Life
Background: Most Canadian children do not meet the recommended dietary intake for vitamin D.
Objectives: The aims were to test how much vitamin D from food is needed to maintain a healthy serum 25-hydroxyvitamin D3 [25(OH)D3] status from fall to spring in young children and to examine musculoskeletal outcomes.
Design
Healthy children aged 2–8 y (n = 51) living in Montreal, Canada, were randomly assigned to 1 of 2 dietary vitamin D groups (control or intervention to reach 400 IU/d by using vitamin D–fortified foods) for 6 mo, starting October 2014. At baseline and at 3 and 6 mo, anthropometric characteristics, vitamin D metabolites (liquid chromatography–tandem mass spectrometry), and bone biomarkers (IDS-iSYS, Immunodiagnositc Systems; Liaison; Diasorin) were measured and physical activity and food intakes surveyed. At baseline and at 6 mo, bone outcomes and body composition (dual-energy X-ray absorptiometry) were measured. Cross-sectional images of distal tibia geometry and muscle density were conducted with the use of peripheral quantitative computed tomography scans at 6 mo.
Results
At baseline, participants were aged 5.2 ± 1.9 (mean ± SD) y and had a body mass index z score of 0.65 ± 0.12; 53% of participants were boys. There were no differences between groups in baseline serum 25(OH)D3 (66.4 ± 13.6 nmol/L) or vitamin D intake (225 ± 74 IU/d). Median (IQR) compliance was 96% (89–99%) for yogurt and 84% (71–97%) for cheese. At 3 mo, serum 25(OH)D3 was higher in the intervention group (P < 0.05) but was not different between groups by 6 mo. Although lean mass accretion was higher in the intervention group (P < 0.05), no differences in muscle density or bone outcomes were observed.
Conclusions
The consumption of 400 IU vitamin D/d from fall to spring did not maintain serum 25(OH)D3 concentration or improve bone outcomes. Further work with lean mass accretion as the primary outcome is needed to confirm if vitamin D enhances lean accretion in healthy young children.
This trial was registered at www.clinicaltrials.gov as NCT02387892.