Biotin (vitamin H)

 
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Biotin
Biotin

Background

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. No significant toxicity has been reported with biotin intake.

 

Synonyms

ARP [N-(Aminooxyacetyl)-N¡-(D-biotinoyl) hydrazine], biocytin, biotin-alkaline phosphate, biotin cadaverine, biotin NTA (nitrilotriacetic acid), biotin-PEO4-amine, Biotin-PEO2-PPO2-amine, biotin-PEO3-maleimide, biotin-PEO4-propionate succinimidyl ester, biotinidase, coenzyme R, D-biotincis-hexahydro-2-oxo-1H-thieno[3,4-d]-imidazole-4-valeric acid, dUTP biotin, factor alpha, tripotassium salt (BNTA), vitamin Bw, vitamin H, W factor.

 

Note: This review does not cover the use of biotin in radioimmunotherapy (radioactive therapy), or radio-labeling for diagnostic procedures.

 

Evidence

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.

Uses based on scientific evidence Grade*
Biotin deficiency

Biotin deficiency is extremely rare. 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 are some potential causes of biotin deficiency. Supplementing with biotin appears helpful for the treatment of this deficiency.

A
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.

A
Brittle fingernails

Biotin has been suggested as a treatment for brittle fingernails, particularly in women. There is not sufficient scientific evidence to form a clear conclusion.

C
Diabetes mellitus (type 2)

In preliminary research, biotin has been reported to decrease insulin resistance and improve glucose tolerance - both properties which may be beneficial in patients with types 2 (adult-onset) diabetes. However, there is not sufficient human evidence to form a clear conclusion in this area.

C
Pregnancy supplementation

Marginal biotin deficiency has been found to commonly occur during pregnancy. Biotin supplementation during pregnancy in not currently standard practice, and prenatal vitamins generally do not contain biotin. However, individual patients may be considered for biotin supplementation by health care practitioners on a case-by-case basis. Additional study is needed in this area.

C
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.

C

 

*Key to grades
A: Strong scientific evidence for this use;
B: Good scientific evidence for this use;
C: Unclear scientific evidence for this use;
D: Fair scientific evidence against this use;
F: Strong scientific evidence against this use.

 

Grading rationale

Uses based on tradition or theory
The below uses are based on tradition or scientific theories. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

Alopecia areata (hair loss), antioxidant, basal ganglia disease, cancer, Crohn's disease, exercise capacity improvement, glucose intolerance, gray hair, hair loss, hyperlipidemia, Parkinson's disease, peripheral neuropathy, Rett syndrome, seborrheic dermatitis, uncombable hair syndrome, vaginal candidiasis, wound healing (periodontal).

Dosing

The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.

Adults (18 years and older)
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).

 

Children (younger than 18 years)
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.

 

Safety

The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.

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

 

Side Effects and Warnings
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 and Breastfeeding
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.

 

Interactions

Most herbs and supplements have not been thoroughly tested for interactions with other herbs, supplements, drugs, or foods. The interactions listed below are based on reports in scientific publications, laboratory experiments, or traditional use. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy.

Interactions with Drugs
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.

 

Interactions with Herbs/Supplements
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.