Getting bit by mosquitoes while out camping or hiking is no fun whatsoever. Sometimes it's more than just annoying. Some people even wind up with so many bites that it appears as if they have a really bad case of acne. There are a number of repellants available that keep the skeeters away, but some people insist that taking vitamin B12 can provide protection from the little pests. In fact, I recall taking vitamin B12 daily for a couple weeks before going on a ten-day hiking trip back when I was a scout in the 1970s. Whether it was the B12 or whether I was just lucky is impossible to determine, but I didn't wind up with many bites, despite the presence of the bloodsucking insects.