Individuals with hypersensitivity to constituents of biotin supplements should avoid these products.

No significant toxicity has been reported with biotin intake, and very high doses have been used in patients with inborn errors of metabolism without reported toxicity. However, doses higher than the U.S. Food and Nutrition Board's recommended daily Adequate Intake (AI) should not be exceeded in healthy individuals unless under medical supervision.

Pregnancy: Marginal biotin deficiency has been found to commonly occur during pregnancy. Serious concern has been focused on this finding, because biotin deficiency is teratogenic (causes birth defects) in many animals. It has been suggested by some experts that biotin supplements should be considered for widespread use in pregnant women, although there is not enough available scientific information to make this recommendation.

Breastfeeding: The recommended daily adequate intake (AI) by the U.S. Food and Nutrition Board should not be exceeded unless under medical supervision.

The U.S. Food and Nutrition Board of the National Academy of Science's Institute of Medicine recommends a daily Adequate Intake (AI) of 30 micrograms in adults 19 years and older (a daily AI of 25 micrograms is recommended in those ages 14-18 years-old). In pregnant women older than 14 years, an AI of 30 micrograms is recommended. During breastfeeding, a daily AI of 35 micrograms is recommended. Most healthy non-pregnant individuals with regular diets obtain these amounts of biotin through dietary consumption.

The U.S. Recommended Daily Allowance (RDA) for biotin is 300 micrograms daily. This is the dose used in many dietary supplements. No toxicity has been reported with biotin intake, and doses as high as 200 milligrams daily have been used in patients with inborn errors of metabolism without significant reported toxicity.

Biotin is available as capsules and tablets in various doses, and as lozenges. Biotin deficiency should be under strict medical supervision. There is disagreement among experts about the proper dose. In adults, intramuscular (injected into the muscle) doses as low as 150-300 micrograms daily have been suggested. Higher doses between 10-40 milligrams of biotin daily have also been recommended (given by mouth, injected into the muscle, or injected into the veins).

The U.S. Food and Nutrition Board of the National Academy of Science's Institute of Medicine recommends a daily Adequate Intake (AI) of 5 micrograms daily (~0.7 micrograms per kilogram) in infants ages 0-6 months-old; 6 micrograms daily (~0.7 micrograms per kilogram) in infants ages 7-12 months-old; 8 micrograms daily in children ages 1-3 years-old; 12 micrograms daily in children ages 4-8 years-old; 20 micrograms daily in children ages 9-13 years-old; and 25 micrograms in adolescents ages 14-18 years-old.

Biotin deficiency and biotin-responsive inborn errors of metabolism should be under strict medical supervision. There is disagreement among experts about the proper dose.

Anti-seizure medications such as phenytoin (Dilantin®), primidone (Mysoline®), carbamazepine (Tegretol®), phenobarbital (Solfoton®), and possibly valproic acid have been associated with reduced blood levels of biotin. Patients using these medications should consult with a qualified healthcare professional, including a pharmacist, to see is biotin supplementation may be necessary.

Broad-spectrum antibiotics such as sulfa drugs can alter the normal intestinal bacteria (flora) which make biotin. Biotin supplementation may be necessary if deficiency is found.

Isotretinoin (Accutane®) may reduce biotinidase activity. It is not clear if biotin supplementation may be warranted during long-term use.

High-doses of pantothenic acid can lead to malabsorption of biotin in the gut, and can lower levels of biotin in the body. Caution is advised.