Biotin (also known as vitamin B7 or vitamin H), is one of the water-soluble B-vitamins, necessary for a number of functions, including cell growth, keeping skin, hair and nails healthy, as well as maintaining a well-functioning neuromuscular system. It is also involved in the metabolism of amino acids, carbohydrates and fats so they can be converted into energy.
One of the greatest advantages of biotin is that it has been shown to increase glucose tolerance and reduce insulin resistance, which is helpful for those with Type 2 diabetes. In studies performed on adults with Type 2 diabetes, it was found that supplementation with biotin reduced their blood sugar levels by half.
Though biotin can't be absorbed topically through either the hair or skin (making shampoos and cosmetics that contain it a waste of money), taking biotin supplements internally is often advised for those who are suffering from brittle nails and hair breakage.
Biotin is a vitamin produced naturally by your body's own intestinal bacteria, so a deficiency is not common, apart from those who drink alcohol excessively or eat raw eggs on a regular basis. One of the best sources of biotin is egg yolks, however, it is important to note that the body may not be able to absorb the biotin in an egg yolk if it is eaten with the white of the egg. Raw egg whites contain the glycoprotein avidin, which binds to biotin, preventing absorption. The prolonged consumption of raw or undercooked egg whites can lead to a biotin deficiency, but by cooking egg whites thoroughly the avidin is deactivated, leaving the biotin intact. Other good dietary sources of biotin are Swiss chard, liver, tomatoes, carrots, yeast and soy.
Some symptoms of biotin deficiency are skin problems, such as seborrheic dermatitis or cradle cap in infants (a relatively common problem in which they develop a pale yellow or white crusty growth on the scalp), hair loss, brittle nails, depression, lethargy, lack of muscle tone and coordination, and muscle pain. Biotin has also been used to help treat peripheral neuropathy and Parkinson's disease.
It is especially important that pregnant women get sufficient amounts of biotin, as it breaks down more quickly during pregnancy, and a deficiency in the first and third trimesters was found to be relatively common. Taking biotin supplements can alleviate this problem.
The recommended daily allowance for biotin in adults is 300 mcg per day, which will keep you from a deficiency and will provide you with healthy skin, hair and nails, in addition to helping prevent diabetes.