High-dose vs. standard-dose vitamin D supplementation for viral upper respiratory tract infections in healthy children

The results of a new study do not support the routine use of high-dose vitamin D supplementation for the prevention of viral upper respiratory tract infections in children, Canadian researchers report.

The results of a new study do not support the routine use of high-dose vitamin D supplementation for the prevention of viral upper respiratory tract infections in children, Canadian researchers report. The randomized clinical trial, conducted in the winter months between September 2011 and June 2015, included healthy children aged 1–5 years enrolled in a multisite primary care practice-based research network in Toronto. In all, 349 children were randomized to receive 2000 IU/d of vitamin D oral supplementation (high-dose group), while 354 were randomized to receive 400 IU/d (standard-dose group) for a minimum of 4 months between September and May. According to the data, the mean number of lab-confirmed upper respiratory tract infections per child was 1.05 in the high-dose group and 1.03 for the standard-dose group. There was no statistically significant difference in the number of lab-confirmed infections between groups, nor was there a significant difference in the median time to the first lab-confirmed infection or parent-reported upper respiratory tract illnesses. At the study termination, serum 25-hydroxyvitamin D levels were 48.7 ng/mL in the high-dose group, compared with 36.8 ng/mL in the standard-dose group.