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).