Note: This review does not cover the use of biotin in radioimmunotherapy (radioactive therapy) or radio-labeling for diagnostic procedures.
Biotin is an essential water-soluble B vitamin. The name biotin is taken from the Greek word bios meaning "life." Without biotin, certain enzymes do not work properly and various complications can occur involving the skin, intestinal tract, and nervous system. Metabolic problems including very low blood sugars between meals, high blood ammonia, or acidic blood (acidosis) can occur. Death is theoretically possible, although no clear cases have been reported. Recent studies suggest that biotin is also necessary for processes on the genetic level in cells (DNA replication and gene expression).
Biotin deficiency is extremely rare. This is because daily biotin requirements are relatively small, biotin is found in many foods, and the body is able to recycle much of the biotin it has already used. Significant toxicity has not been reported in the available literature with biotin intake.
These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.
Biotin deficiency is extremely rare. Some potential causes of biotin deficiency are: long-term use of certain anti-seizure medications; prolonged oral antibiotic use; intestinal malabsorption (for example short gut syndrome); intravenous feeding (total parenteral nutrition/TPN) without added biotin; and eating raw egg whites on a regular basis. Supplementing with biotin appears helpful for the treatment of this deficiency.
Biotin-responsive inborn errors of metabolism:
Disorders such as multiple carboxylase deficiency can cause inborn errors of metabolism that cause a "functional" biotin deficiency. High-dose biotin is used to treat these disorders. Management should be under strict medical supervision.
Biotin has been suggested as a treatment for brittle fingernails, particularly in women. There is not sufficient scientific evidence to form a clear conclusion.
Diabetes mellitus (type 2):
In early research, biotin has been reported to decrease insulin resistance and improve glucose tolerance, which are both properties that may be beneficial in patients with types 2 (adult-onset) diabetes. Other research suggests that a combination of biotin and chromium may help improve blood sugar control. However, there is not enough human evidence to form a clear conclusion in this area.
Marginal biotin deficiency has been found to commonly occur during pregnancy. Biotin supplementation during pregnancy is not currently standard practice, and prenatal vitamins generally do not contain biotin. However, individual patients may be considered for biotin supplementation by healthcare practitioners on a case-by-case basis. Additional study is needed in this area.
Total parenteral nutrition (TPN):
Intravenous feeding solutions (TPN) should contain biotin, in order to avoid biotin deficiency in recipient patients. This applies for patients in whom TPN is the sole source of nutrition. More study is needed in this area to make a firm recommendation.