Clinical Research: Vitamin D Supplementation for Children
Alan Gaby, MD
Author: Aglipay M, et al
Reference: Effect of high-dose vs standard-dose wintertime vitamin D supplementation on viral upper respiratory tract infections in young healthy children. JAMA 2017;318:245-254.
Design: Randomized, double-blind, placebo-controlled trial.
Participants: Seven hundred three healthy children (aged 1-5 years; mean, 2.7 years) in Toronto, Canada.
Study Medication and Dosage: A standard dose (400 IU per day) or a high dose (2,000 IU per day) of vitamin D for at least 4 months between September and May, 2015 (which included the winter months). The mean serum 25-hydroxyvitamin D level at baseline was 36.3 ng/ml, and 31.6% of the children had a level below 30 ng/ml.
Outcome Measures: The primary outcome measure was the number of laboratory-confirmed viral upper respiratory tract infections (URIs) based on parent-collected nasal swabs over the winter months. A secondary outcome measure was the number of parent-reported upper respiratory tract illnesses.
Key Findings: The mean number of laboratory-confirmed URIs per person per year was nonsignificantly lower by 3% in the high-dose group than in the standard-dose group (p = 0.71). The mean number of parent-reported upper respiratory tract illnesses was nonsignificantly higher by 1% in the high-dose group than in the standard-dose group.
Practice Implications: Some research has shown that vitamin D supplementation can prevent URIs in children, although other studies failed to find a benefit. The results of the present study indicate that a relatively high dose of vitamin D is not significantly more effective than a standard dose (400 IU per day) for preventing URIs in children with reasonably good baseline vitamin D status. A previous randomized controlled trial found that vitamin D in doses of 800 or 1,200 IU per day, as compared with 400 IU per day, resulted in subtle impairments in motor development in breastfed infants. It is generally agreed that many children can benefit from taking 400 IU per day of vitamin D. However, the available evidence does not support the routine use of larger doses for young children with normal or near-normal vitamin D status.
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2 Wicklow B, et al. Impact of vitamin D supplementation on gross motor development of healthy term infants: a randomized dose-response trial. Phys Occup Ther Pediatr 2016;36:300-342.