WASHINGTON, D.C. (WUSA) -- As the cold and flu season is underway, a new study shows that Vitamin D supplementation may not be a go-to cold remedy, after all. The study, released in Wednesday's issue of the Journal of the American Medical Association, finds that taking Vitamin D supplements does not reduce the intensity or the occurrence of colds.
The study, headed by David R. Murdoch, M.D., of the University of Otago, Christchurch, New Zealand, found that taking Vitamin D supplements do not help with fighting upper respiratory tract infections, or URTIs.
The randomized study included 322 healthy adults who were either given doses of Vitamin D or a placebo over the course of a year and a half. The participants receiving Vitamin D supplements were given progressively smaller doses as the study went on, starting with 200,000 IU (international units) for two months, then were given 100,000 IU each month after.
After the 18 months were over, researchers found no substantial difference in the amount of incepted colds per person: on average, 3.7 per person in the Vitamin D supplement group, and 3.8 per person in the placebo group. The duration of cold symptoms remained identical in both groups, with an average of 12 days.
"Further research is required to clarify whether there is benefit from supplementation in other populations and with other dosing regimens," said the authors of the study.