You may recognize vitamin B7 by its popular name of biotin. It is a water-soluble B vitamin found naturally in some foods and also in supplements. Biotin plays a vital role in assisting enzymes to break down fats, carbohydrates, and proteins in food. It also helps to regulate signals sent by cells and the activity of genes.
Biotin supplements are often glamorized as a treatment for hair loss and to promote healthy hair, skin, and nails. Although a deficiency of biotin can certainly lead to hair loss and skin or nail problems, evidence showing a benefit of supplementation is inconclusive. A handful of case reports and small trials have shown a benefit, but the study designs had weaknesses: The diagnoses of the type of hair conditions varied or were not cited at all.
Researchers have also noted that certain hair loss conditions like alopecia can resolve spontaneously without treatment, so it is not clear that biotin supplements specifically caused the regrowth.
- hair loss
- brittle nails
- seborrheic dermatitis, a skin condition that affects infants
- mild depression
Those with biotinidase deficiency usually start with a dose of 5 to 10 mg a day. Those without this genetic condition should first try to get enough biotin from the diet, as dietary biotin also enhances the intake of other beneficial nutrients that work alongside it. It is always best to get nutrients from dietary sources first, and then from supplements, if necessary, as a backup.