Biotin is a vitamin often recommended for hair health. Since biotin deficiency can lead to thinning of the hair, proponents claim that taking biotin supplements or washing your hair with biotin-enriched shampoo can thicken the hair and stimulate hair growth. However, there is very little evidence to support the claim that biotin can enhance hair health.

Biotin for Hair Loss

There isn't enough evidence to rate biotin's effectiveness in treatment of hair loss, according to the National Institutes of Health (NIH). However, there's some evidence that biotin may benefit children with alopecia areata. For instance, a 1999 study published in Pediatric Dermatology found that taking supplements containing both zinc and biotin while topically applying a cream made with clobetasol propionate (a synthetic steroid hormone) may help reduce the hair loss associated with childhood alopecia areata.

Biotin Shampoo for Hair Health

Manufacturers claim that shampoo containing biotin can thicken hair, increase fullness, and add shine. Despite these claims, there are no scientific studies to show that biotin shampoo can benefit the hair.

Recommended Dosage for Biotin and Hair Health

Although there is no recommended dietary allowance for biotin, proponents of biotin often recommend taking 5,000 mcg of biotin in supplement form daily in order to strengthen hair shafts. There is no evidence to support this recommendation.

Should You Take Biotin for Hair Growth?

Although biotin deficiency is uncommon, it may occur in people who drink alcohol excessively or consume a great deal of raw egg white (which contains a protein that blocks the absorption of biotin). Genetic disorder of biotin deficiency, infant seborrheic dermatitis, and surgical removal of the stomach may also increase your need for biotin.

If you notice any symptoms of biotin deficiency, consult your physician. Symptoms include thinning of the hair, a red scaly rash (especially around the eyes, nose, and mouth), depression, exhaustion, hallucinations, and tingling of the arms and legs.

Most people can meet their daily biotin needs by consuming biotin-rich foods like brewer's yeast, nutritional yeast, liver, cauliflower, salmon, bananas, carrots, egg yolks, sardines, legumes, and mushrooms. If you're considering the use of biotin for hair growth, talk to your doctor before starting your supplement regimen.

Although biotin deficiency is uncommon, it may occur in people who drink alcohol excessively or consume a great deal of raw egg white (which contains a protein that blocks the absorption of biotin). Genetic disorder of biotin deficiency, infant seborrheic dermatitis, and surgical removal of the stomach may also increase your need for biotin.

Symptoms of biotin deficiency include thinning of the hair, a red scaly rash (especially around the eyes, nose, and mouth), depression, exhaustion, hallucinations, and tingling of the arms and legs. Biotin deficiency may also lead to high cholesterol and heart problems.

To get your fill of biotin, make sure to include biotin-rich foods like brewer's yeast, nutritional yeast, liver, cauliflower, salmon, bananas, carrots, egg yolks, sardines, legumes, and mushrooms in your diet. If you're considering the use of biotin supplements for prevention or treatment of any health condition, talk to your doctor before starting your supplement regimen.

Biotin is widely distributed in most foods but at very low levels compared to other water-soluble vitamins. It is found in free and protein-bound forms in foods. Its richest sources are yeast, liver and kidney. Egg yolk, soybeans, nuts and cereals are also good sources. 100 g of liver contains approximately 100 µg biotin, whereas most other meats, vegetables and fruits only contain approximately 1 µg biotin /100 g. In animal experiments, biotin bioavailability has been shown to vary considerably (5%-62%), and in cereals it appears to be lower.

Biotin-producing microorganisms exist in the large intestine, but the extent and significance of this enteral synthesis in the overall biotin turnover is difficult to calculate and thus remains a subject of controversy.

Biotin plays a key role in the metabolism of lipids, proteins and carbohydrates. It acts as a critical coenzyme of four carboxylases (enzymes):

acetyl-CoA carboxylase (involved in the synthesis of fatty acids from acetate)

propionyl-CoA carboxylase (involved in gluconeogenesis, i.e. the generation of glucose from lactate, glycerol, and amino acids)

b-methylcrotonyl-CoA carboxylase (necessary for the metabolism of leucin, an essential amino acid)

pyruvate carboxylase (involved in energy metabolism, necessary for the metabolism of amino acids, cholesterol, and odd chain fatty acids)

Biotin also plays a special role in enabling the body to use blood glucose as a major source of energy for body fluids. Furthermore, biotin may have a role in DNA replication and transcription arising from its interaction with nuclear histone proteins. It owes its reputation as the “beauty vitamin” to the fact that it activates protein/amino acid metabolism in the hair roots and fingernail cells.