What is Biotin and Does It Help Hair?

You may have heard that biotin can help hair, skin, and nails.  What exactly is it and does it work?

     Biotin is a vitamin; it is also known by the name Vitamin B7.  Like other B vitamins, it is water-soluble.  It is found in a variety of foods, including cooked eggs, avocados, salmon, nuts, and seeds [1].  Vitamin B7 plays a role in the metabolism of carbohydrates, fats, and proteins [2], as well as in cell signaling and gene expression [1].  Furthermore, biotin is a precursor to keratin, one of the main components of hair and nails [2].

     There is no recommended daily allowance for biotin, but nutritional adequacy is defined as 30 micrograms a day for men and women age 19 years and older; lactating women need 35 micrograms a day [2].   True deficiencies of B vitamins are rare in North America, but they can occur [1 and 2].  Foods with raw eggs may decrease the bioavailability of biotin.   Deficiencies of B7 can result in hair loss and may negatively impact skin or nail health; it can also lead to depression, anemia, and heart issues [2].

     There is no tolerable upper intake level for biotin and there is a paucity of evidence demonstrating adverse effects from high biotin intake levels.  However, high biotin levels may interfere with laboratory testing, including tests for thyroid disease.  (Thyroid testing may be performed as part of a work-up for hair loss).  There have been reports that this has occurred in people taking biotin supplements; their intake was higher than the 30 microgram adequate intake level [2].

     There is inconclusive evidence that supplementation of biotin improves the hair and nail growth [2].  However, it may prevent balding and hair loss; it may reduce inflammation.  Additionally, there are shampoos with biotin.  Research demonstrating the benefits of biotin-rich shampoo on hair growth is inconclusive [3].

     Before making any dietary changes or adding a supplement to your regimen, speak to your physician to ensure it is right for you.  When reporting medications to your physician, make sure you list dosages so your health status can be appropriately determined. 

Disclaimer: This information is for educational purposes only, and is not meant to be used for diagnosis, prognosis, or treatment purposes.  This is not medical advice.  Please see your physician or care provider with any questions or concerns.

Sources:

1.  (2023, March).  Biotin-Vitamin B7 [Online].  Available: https://www.hsph.harvard.edu/nutritionsource/biotin-vitamin-b7/#:~:text=You%20may%20recognize%20vitamin%20B7,carbohydrates%2C%20and%20proteins%20in%20food.

• Lykstad, J. and Sharma, Sandeep.  (2023, March 6).    Biochemistry, Water Soluble Vitamins [Online].  Available: https://www.ncbi.nlm.nih.gov/books/NBK538510/

• [2022, October 26].  Is biotin as good as advertised for your hair loss? [Online]: https://health.clevelandclinic.org/is-biotin-as-good-as-advertised-for-your-hair-loss/#:~:text=But%20biotin%20has%20been%20shown,and%20the%20nails%20all%20benefit.%E2%80%9D