Biotin is a water-soluble B vitamin that plays an important role in metabolizing the energy we get from food. Biotin assists four essential enzymes that break down fats, carbohydrates, and proteins.
Biotin deficiency is rare, except, possibly, among pregnant women. All proposed therapeutic uses of biotin supplements are highly speculative.
Although biotin is a necessary nutrient, we usually get enough from bacteria living in the digestive tract. Severe biotin deficiency has been seen in people who frequently eat large quantities of raw egg white. Raw egg white contains a protein that blocks the absorption of biotin. Fortunately, cooked egg white does not present this problem.
The official US and Canadian recommendations for daily intake of biotin are as follows:
Good dietary sources of biotin include brewer's yeast, nutritional (torula) yeast, whole grains, nuts, egg yolks, sardines, legumes, liver, cauliflower, bananas, and mushrooms.
There is some evidence that slight biotin deficiency may tend to occur during normal pregnancy.9 For this reason, pregnant women are advised to take a prenatal vitamin that contains the recommended amount of biotin.
For people with diabetes, the usual recommended dosage of biotin is 7,000 to 15,000 mcg daily.
For treating "cradle cap" (a scaly head rash often found in infants), the usual dosage of biotin is 6,000 mcg daily, given to the nursing mother (not the child). A lower dosage of 3,000 mcg daily is used to treat brittle fingernails and toenails.
All the proposed uses of biotin discussed here are speculative, based on highly incomplete evidence.
Preliminary research suggests that supplemental biotin might help reduce blood sugar levels in people with either type 1 (childhood onset) or type 2 (adult onset) diabetes,1,2 and possibly reduce the symptoms of diabetic neuropathy.3 However, no double-blind, placebo-controlled studies have been reported on these potential uses of biotin. (For why double-blind trials are so important, see Why Does This Database Rely on Double-blind Studies?) Two double-blind studies have found benefit for diabetes with a mixture of biotin and chromium10,11; however, it is not clear how much the biotin in this combination contributed.
On the basis of virtually no evidence at all, biotin has been proposed for treating cradle cap in infants.
There are indirect indications that individuals taking antiseizure medications might benefit from biotin supplementation at nutritional doses.7,8 However, it has been suggested that biotin should be taken at least 2 hours before or after the medication dose, to avoid potential interference with the medication's absorption. In addition, excessive biotin supplementation (above nutritional needs) should be avoided, because it might possibly interfere with seizure control. Note: All these proposed interactions are quite speculative, and even if they do exist, may not be important enough to make a difference in real life.
Biotin appears to be quite safe. However, maximum safe dosages for young children, pregnant or nursing women, or those with severe liver or kidney disease have not been established.
1. Maebashi M, Makino Y, Furukawa Y, et al. Therapeutic evaluation of the effect of biotin on hyperglycemia in patients with non-insulin dependent diabetes mellitus. J Clin Biochem Nutr. 1993;14:211-218.
2. Coggeshall JC, Heggers JP, Robson MC, et al. Biotin status and plasma glucose in diabetics. Ann N Y Acad Sci. 1985;447:389-392.
3. Koutsikos D, Agroyannis B, Tzanatos-Exarchou H. Biotin for diabetic peripheral neuropathy. Biomed Pharmacother. 1990;44:511-514.
4. Floersheim GL. Treatment of brittle finger nails with biotin [in German; English abstract]. Z Hautkr. 1989;64:41-48.
5. Colombo VE, Gerber F, Bronhofer M, et al. Treatment of brittle fingernails and onychoschizia with biotin: scanning electron microscopy. J Am Acad Dermatol. 1990;23:1127-1132.
6. Hochman LG, Scher RK, Meyerson MS. Brittle nails: response to daily biotin supplementation. Cutis. 1993;51:303-305.
7. Krause K-H, Bonjour JP, Berlit P, et al. Biotin status of epileptics. Ann N Y Acad Sci. 1985;447:297-313.
8. Said HM, Redha R, Nylander W. Biotin transport in the human intestine: inhibition by anticonvulsant drugs. Am J Clin Nutr. 1989;49:127-131.
9. Mock DM, Quirk JG, Mock NI. Marginal biotin deficiency during normal pregnancy. Am J Clin Nutr. 2002;75:295-299.
10. Singer GM, Geohas J. The effect of chromium picolinate and biotin supplementation on glycemic control in poorly controlled patients with type 2 diabetes mellitus: a placebo-controlled, double-blinded, randomized trial. Diabetes Technol Ther. 2006;8:636-43.
11. Albarracin CA, Fuqua BC, Evans JL, et al. Chromium picolinate and biotin combination improves glucose metabolism in treated, uncontrolled overweight to obese patients with type 2 diabetes. Diabetes Metab Res Rev. 2007 May 16. [Epub ahead of print]
Last reviewed December 2015 by EBSCO CAM Review Board Last Updated: 12/15/2015