Biotin (vitamin H)

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Biotin is an essential water-soluble B vitamin, also known as vitamin B7. Biotin binds to a number of enzymes and other proteins. Without biotin, these enzymes do not function properly. Biotin is available in a wide variety of plant- and animal-based foods. Among the richest sources are milk and liver. Biotin can also be obtained from bananas, brewer's yeast, cauliflower, cooked eggs, legumes, nuts and nut butters, sardines, and whole grains.
Biotin deficiency is rare. This is because daily biotin requirements are relatively small. Biotin is found in many foods, bacteria in the intestine also make biotin, and the body is able to recycle much of the biotin it has already used. Reports of significant toxicity with biotin are lacking, even with doses 600 times greater than the estimated daily intake of approximately 30 micrograms in a healthy adult.
Some populations are at greater risk of developing biotin deficiency. These include malnourished children in developing countries, those taking anticonvulsants or broad-spectrum antibiotics (such as sulfa drugs), and those who consume large amounts of raw egg white over months or years. Raw egg white contains the protein avidin. Avidin binds biotin very tightly and prevents its absorption in the digestive system. Marginal biotin deficiency, which is not severe enough to cause classic symptoms, may develop in up to 50% of women during normal pregnancies.
Biotin deficiency can be the result of inborn errors of metabolism, such as defects in any of the enzymes that bind to or process biotin in the body. The symptoms of biotin deficiency are similar, regardless of the underlying cause. Symptoms include conjunctivitis, developmental delay in infants and children, hair loss, low muscle tone, metabolic changes (such as impaired glucose tolerance), skin lesions around the mouth and other body openings, seizures, and uncoordinated body movements. Biotin deficiency due to inborn errors of metabolism can generally be treated with very high doses of biotin without adverse effects.

Related Terms

ARP [N-(aminooxyacetyl)-N-(D-biotinoyl) hydrazine], B vitamins, biocytin, bioepiderm, bios II, biotín, biotin cadaverine, biotin nitrilotriacetic acid, biotin NTA, biotina, biotină, biotin-alkaline phosphate, biotin-PEO2-PPO2-amine, biotin-PEO3-maleimide, biotin-PEO4-amine, biotin-PEO4-propionate succinimidyl ester, biotinidase, biotyna, biyotin, carboxylic acids, cis-hexahydro-2-oxo-1H-thieno[3,4-d]-imidazole-4-valeric acid, coenzyme R, cofactors, D-biotin, cis-hexahydro-2-oxo-1H-thieno[3,4-d]-imidazole-4-valeric acid, Diachrome®, dUTP biotin, factor alpha, shēngwù sù (Chinese), tripotassium salt (BNTA), vitamin B7, vitamin H, W factor.
Note: This monograph does not include the use of biotin as a laboratory or diagnostic reagent. The monograph does not discuss analytical methods for measuring biotin, e.g., in biological fluids.

evidence table

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 (Grade: A)
Biotin deficiency is rare in developed countries. The symptoms of biotin deficiency are similar, regardless of the underlying cause. Symptoms include conjunctivitis, developmental delay in infants and children, hair loss, low muscle tone, metabolic changes, skin lesions around the mouth and other body openings, seizures, and uncoordinated body movements. Biotin deficiency may generally be treated by biotin supplementation without adverse effects.
Biotin-responsive inborn errors of metabolism (Grade: A)
Inborn errors of metabolism, such as defects in any of the enzymes that bind to biotin, can cause functional biotin deficiency. Biotin-responsive basal ganglia disease has been reported. Biotin deficiency due to inborn errors of metabolism can generally be treated with very high doses of biotin without adverse effects.
Total parenteral nutrition (TPN) (Grade: B)
Biotin has been routinely included in parenteral nutrition for over 25 years. Biotin deficiency associated with parenteral nutrition has not been reported since this practice was adopted.
Brittle fingernails (Grade: C)
Biotin has been used as a treatment for brittle fingernails. Additional studies are needed before a conclusion can be made.
Cardiovascular disease risk (in diabetics) (Grade: C)
Treatment with biotin and the nutritional supplement chromium picolinate reduced cholesterol and blood lipids in patients with diabetes mellitus type 2 who were also taking standard blood sugar-lowering agents by mouth. Additional research on the effect of biotin alone is needed.
Diabetes mellitus (type 2) (Grade: C)
Biotin may play a role in maintenance of glucose tolerance. Treatment with biotin and the nutritional supplement chromium picolinate improved glycemic control in overweight and obese individuals with diabetes mellitus type 2 who were also taking standard blood sugar-lowering agents by mouth. Additional research on the effect of biotin alone is needed.
Epilepsy (in infants) (Grade: C)
Biotin has been included in a therapeutic treatment plan for newborn infants with convulsions and epileptic syndromes. Additional research is required.