Biotin, or vitamin B7, is part of a group of vitamins called B vitamins. It is used to metabolize fats, carbs and proteins so that they can be used for energy. Biotin also plays a role in the productions of hormones and cholesterol.
Limited data is available regarding the biotin content of foods, but it is found in most foods that are good sources of other B vitamins. Liver contains high concentrations of biotin, where as fruits and most meats contain low concentrations.
Other sources of biotin include cereal, nuts, yeast, legumes, organ meats, milk, egg yolk and chocolate. Raw egg whites contain a protein that inhibits biotin absorption, but the protein is deactivated by cooking the egg white.
The recommended daily intake of biotin (vitamin B7) is as follows:
Adult Men = 30 micrograms
Adult Women = 30 micrograms
Note: Population groups such as infants, the elderly and pregnant women have different daily nutrient requirements.
Deficiency / Toxicity
As mentioned above, raw egg whites can impair biotin absorption. Prolonged consumption of raw egg whites can lead to biotin deficiency, but most people easily avoid deficiency since biotin is a common nutrient. Symptoms of biotin deficiency include skin disorders, depression, hallucinations, tingling / numbness, and weakness.
There are no known toxic symptoms from consuming excess biotin.