Mosquitoes can put a real damper on enjoying the outdoors. When we were on our honeymoon, many years ago, we were camping in Grand Teton National Park. Even before we opened the car doors to set up our tent and camp stove, there were enormous mosquitoes hovering in large numbers to get a bite of our blood. There seem to be significant differences among individuals with respect to how attractive mosquitoes find them. Some people start slapping biting mosquitoes the second they step outside, while others are rarely troubled at all. suggests several factors that may help explain this curious phenomenon. It turns out that blood type matters, and so does body temperature and the amount of carbon dioxide a person exhales. The microbial ecology of the skin may also have an effect on mosquitoes and their likelihood of taking a taste. Be wary at the backyard cookout: people drinking beer appear to be especially appealing to mosquitoes. Q. I am a gardener and have always been a mosquito magnet.
I read about vitamin B1 and have been taking it for several days. I just went outside this evening and didn’t get one bite! Usually they are all over me. I will continue to take B1 until cold weather. A. There is almost no scientific research to support vitamin B1 (thiamine) against mosquitoes. That said, some readers report similar success. It may well be that thiamine works in conjunction with some of the other individual factors to make certain individuals less appealing. We heard before from an individual who had good luck like you do: Q. I have found vitamin B1 to be an effective deterrent for mosquito bites. I was recently in an area where I got multiple mosquito bites daily that itched unbearably. I developed open sores from scratching in my sleep, even when I used Benadryl or hydrocortisone cream. In less than a week of taking vitamin B1 (500 mg per day), I have not had any more bites. I know there are studies that say vitamin B1 has no value for deterring insect bites, but my experience convinces me otherwise.
A. Thank you for sharing your testimonial. Some other readers have also found taking vitamin B1 (thiamine) helpful against mosquitoes. The research we have found, however, indicates that this vitamin is not effective as a systemic mosquito repellent (Journal of the American Mosquito Control Association, June, 2005). We could find no more recent research on the effects of thiamine against mosquito bites. Another reader used B vitamins as a repellent in quite a different way: Q. I was hiking high in the Canadian Rockies and the black flies were voracious. I didn’t have insect repellent with me because mosquitoes, fleas and other critters never bite me. I think that’s because I take B-complex and garlic, among other supplements, and they don’t like that. Increasingly vexed by the black flies, I finally appropriated a B-complex 100 mg tablet I had with me. I smushed it up with some creek water, and then rubbed the bright yellow liquid all over myself. I admit, though, that I did look a bit jaundiced.
What do you think about the efficacy of B-complex or other supplements in repelling bugs? A. We love your story, but we’ve never heard of anyone else using vitamin B pills topically. With no studies, we wouldn’t dare venture a guess about effectiveness. There was some preliminary research on thiamine, a B vitamin, taken orally to repel mosquitoes. Since it was conducted many decades ago, however, it would not meet today’s scientific standards and newer research has not confirmed the benefit. Nevertheless, some readers swear that this nutrient keeps mosquitoes from biting them. Individual body chemistry seems to have an important effect on whether and how well this remedy works. Most people need to apply a proven mosquito repellent such as DEET, picaridin or lemon eucalyptus oil. That is particularly true in places where mosquitoes may be transmitting malaria, Zika virus or West Nile virus. Although DEET sets the standard for repellents and has for decades, there are concerns about toxicity, especially if it is being used for extended periods or at high concentrations.
We have written here about mosquito repellents. It turns out that different species are more sensitive to one repellent than another (Travel Medicine and Infectious Diseases, Nov-Dec., 2013). That might explain why some people find taking thiamine helps, at least under certain conditions. Adding vanillin to mosquito repellents can extend the amount of time they are effective by about two hours.Ideal ingredient calling card: Vitamin B12 (cobalamins) Vitamin B12 refers to a group of water-soluble cobalt-containing vitamer compounds called cobalamins Also known as “Red Vitamin,” it is the largest and structurally most complicated vitamin Cobalamins include: Cyanocobalamin (with trace cyanide from processing), Hydroxocobalamin (medicinal form produced by bacteria), Methylcobalamin and Adenosylcobalamin—two naturally occurring forms of B12 in the human body Vitamin B12 is a cofactor essential in DNA and methylation cycles; it is involved in the metabolism of every cell in the human body and has a key role in brain and nervous system functioning and the formation of blood
Found in virtually all types of meat, fish and dairy products; neither plants nor animals can make B12 The pseudo B12 forms found in Spirulina and algae test as B12 but do not have B12 biological activity in humans Only bacteria can synthesize B12; industrial production is through fermentation Leading suppliers: Sanofi-Aventis, BASF, and three Chinese companies manufacture most of the world’s B12 Essential as part of the diet for healthy nervous system and blood B12 deficiency generally presents in infants, the elderly, and vegans/vegetarians Adults require 2-3 mcg/day; Recommended Daily Allowance for pregnant women = 2.6 mcg/day (2.8 mcg during lactation) Majority of the world’s Vitamin B12 production goes into animal feed Manufacturing pluses and minuses (-) + Cyanocobalamin—synthetic form—is cheap and stable and hence, used in pharmaceuticals, supplements, and foods + Only traces needed for fortification so does not impact taste of food or beverage negatively
+ Fortified breakfast cereals are the most widely bioavailable processed food source of vitamin B12 for vegetarians - Vitamin B12 injection clinics—a recent trend in the commercial weight loss scene—despite lack of solid evidence that vitamin B12 in any form, including vitamin B12 injections, improves weight loss + Popularly used in energy products and diet supplements Marginal cobalamin status of infants, the elderly and vegetarians/vegans Growing popularity of foods, beverages, and supplements to boost energy HCG (human chorionic gonadotropin) Diets and Very Low Calorie Diet (VLCD) use Vitamin B12 and growing market belief that Vitamin B12 can help with weight loss Meat, poultry, and seafood production—all use Vitamin B12 as feed additive Strong evidence: May protect against brain atrophy or shrinkage, associated with Alzheimer’s disease and impaired cognitive function Decreases homocysteine levels to help people with vascular disease or diabetes