Can Vitamin B Ward off Mosquitoes?

THE BELIEF: Vitamin B can ward off mosquitoes.

THE FACTS: Mosquitoes are more attracted to some people than to others; that much is known from several studies.

But the Internet is full of advertisements for pills and supplements that are supposed to keep the pests away from walking mosquito magnets. One pervasive claim is that taking vitamin B, or wearing patches and other products that are infused with it, can do the trick. Studies dating to the 1960s suggest that taking small doses of the supplement three times a day during biting season helps to produce a skin odor that mosquitoes find repulsive.

But more recent studies have shown that assertion to be a myth. In a study published in 2005 in the Journal of the American Mosquito Control Association, scientists had a group of subjects take vitamin B supplements every day for eight weeks, while a second group took vitamin C and a third took no supplements. Once every two weeks, the scientists used swarms of mosquitoes to examine whether the supplements were having any effect. Although the subjects' attractiveness to the mosquitoes varied considerably, over all there was no evidence that vitamin B did anything to help.

Another study by scientists in Brazil tested it by administering vitamin B droplets to animals and exposing them to female mosquitoes (the only ones that bite). They found no difference in attractiveness between the vitamin B group and control groups.

THE BOTTOM LINE: Studies suggest that vitamin B is not an effective mosquito repellent.