Wellington : Vitamin D does not reduce the severity of colds, even for those who received a monthly dose of 100,000 units in a trial, says a study.
The association of Vitamin D deficit and susceptibility to viral respiratory tract infections has been unclear, said the University of Otago study.
David R. Murdoch, University of Otago, New Zealand, and colleagues conducted a randomized trial to examine the effect of Vitamin D supplementation on rate and severity of upper respiratory tract infections (URTIs) in healthy adults.
The study, conducted between February 2010 and November 2011, included 322 healthy adults in New Zealand, reported the Journal of American Medical Association.
Participants were randomly assigned to receive an initial dose of 200,000 units of oral Vitamin D3, then 200,000 units on month later, then 100,000 units monthly, or placebo administered in an identical dosing regimen, for a total of 18 months, according to an Otago statement.
Researchers found that there was no statistically significant differences in the number of URTIs per participant (average, 3.7 per person in the vitamin D group and 3.8 per person in the placebo group).
“The main finding from this study is that a monthly dose of 100,000 IU of Vitamin D3 in healthy adults did not significantly reduce the incidence or severity of URTIs,” the study authors wrote.