Can Vitamin D fight off the flu?
There is some initial research that says vitamin D boosts immunity by stimulating production of cathelicidin, an antimicrobial protein that serves as a “natural antibiotic” in the body. Vitamin D may ward off some types of flu, at least in children. Researchers in Japan randomly assigned 334 schoolchildren aged 6 to 15 to take either vitamin D (1,200 IU/day) or a placebo starting in December. By March, 11% of the children taking the vitamin D and 19% of the children taking the placebo were diagnosed with influenza A, which include H1N1. Vitamin D had no effect on influenza B, which is less common than influenza A. Among the children who had also been diagnosed with asthma, only 2 attacks occurred in vitamin D takers, while 12 attacks occurred in placebo takers.
More studies are needed to know if vitamin D can prevent the flu in children or adults. However, it’s worth taking 700 to 1,000 IU/day for overall health.
