Old Remedy Uses Vitamin Power to Repel Mosquitoes


Mosquitoes have been biting humans for thousands of years, and for almost that long people have been trying to ward them off.

Native Americans are said to have used rancid bear grease. At Walden Pond, Henry David Thoreau tried a concoction of camphor, turpentine and oil of spearmint. (He eventually decided the smell was worse than the itch.) Marines have extolled the virtues of Avon Skin-So-Soft bath oil.

The trouble is, most of these folk remedies have not been proven effective.

One indisputably effective repellent was originally developed for the military. DEET is unrivaled in its ability to keep mosquitoes from biting. But there are concerns about toxicity, especially for young children. The American Academy of Pediatrics recommends against using insect repellents with more than 10 percent DEET on little children. There have been a few reports of headaches, behavioral changes, disorientation and seizures.

Another approach to repelling mosquitoes is to take 100 milligrams of vitamin B-1 (thiamine). The original research on this was done in the 1940s and doesn't meet today's standards. But we recently heard from a reader who found it very effective:

"Twenty years ago, my husband and I went backpacking in the High Sierras with three friends. It was an extremely wet year with a lot of snow melting.

"On the east side, we had many good places to camp. But on the west side, there wasn't a dry spot to be found. Where there wasn't snow, there were soggy marshes, ponds and swollen streams. It was mosquito heaven!

"Anticipating such conditions, my husband and I began taking a daily vitamin B-1 supplement two weeks before the trip. No one else in our group believed in this advice, and they all stuck with conventional insect repellent.

"Never in my life (and I grew up in New Jersey) had I seen so many mosquitoes. They hovered in thick black blankets over every square inch of our bodies. They tried to enter every available orifice, making it unpleasant to eat, drink water or go to the bathroom. It was so horrible that after two days on that side of the mountain, we gave up and retreated to the east side.

"My husband and I had only seven mosquito bites between us after those two nightmarish days. Our three friends, however, were literally covered with bites. One woman had more than 50 bites on a small section of her shoulder. There was a solid row of bites along the part in her hair. Each of the three was similarly blanketed with bites.

"The evidence I've provided is purely anecdotal, not scientific, but it was enough to prove to me the value of vitamin B-1 for keeping mosquitoes from thinking you're a good target."

The theory is that oral doses of vitamin B-1 create a smell at the level of the skin that mosquitoes don't like. But some people report that what once worked well is less effective against some species of mosquito. Personal body chemistry might also have something to do with effectiveness.

Editor's Note: This sounds remarkably like the stories in "Secrets of the Soil" where plants that received everything that they required for perfect health, never got any insect or other pests on them. I know that when I am next travelling overseas - where they have malaria - that I will certainly be taking oral doses of vitamin B1!