Vitamin D Supplementation Tied to Slightly Lower Risk for Acute Respiratory Illness

By Kelly Young

Edited by Richard Saitz, MD, MPH, FACP, DFASAM

Vitamin D supplementation is associated with a slightly reduced risk for developing acute respiratory tract infections, according to a meta-analysis in The BMJ. But editorialists contend that most people shouldn't start supplementing.

Researchers analyzed individual participant data from 25 randomized, placebo-controlled trials of vitamin D3 or D2 supplementation in 11,000 patients.

The incidence of acute respiratory tract infection was significantly lower with supplementation than with placebo (40.3% vs. 42.2%). Benefits were limited to participants with baseline 25-hydroxyvitamin D levels below 25 nmol/L, as well as those who received daily and weekly doses (vs. large boluses). The researchers say their findings support "a major new indication for vitamin D supplementation."

However, editorialists say the results aren't "sufficiently applicable to the general population." They conclude: "We consider that current evidence does not support the use of vitamin D supplementation to prevent disease, except for those at high risk of osteomalacia, currently defined as 25-hydroxyvitamin D levels less than 25 nmol/L."