Written by Olivia Farrow, RD, MHSc
Reviewed by Krista Kolodziejzyk, RD, MPH, MBA
In this guide, we explore the role of biotin in the body, supplementation and precautions.
Biotin, also known as vitamin B7, may not be as widely recognized as some other vitamins, but plays an essential role in our body’s metabolic processes (1). Due to its role in the production of keratin, a protein involved in the formation of nails, skin, and hair, it has become popularized as a supplement, touted for beauty uses (1).
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The Functions of Biotin
Biotin aids enzymes in breaking down fats, glucose, and amino acids, contributing to energy production and maintaining a healthy metabolism (1,2). Additionally, biotin plays a crucial role in gene regulation, histone modifications, and cell signaling, making it a vital player in maintaining overall cellular health (1,2).
Recommended Daily Intake
There is no RDA for biotin because there is not enough research to suggest that daily intake is required in certain amounts (2). The Adequate Intake (AI) for biotin was extrapolated to various average body weights based on biotin quantities in human milk. Thus the AI amount varies depending on life stage (2):
|
Age/Stage |
AI |
|
|
0-6 months |
5 µg/d |
|
|
7-12 months |
6 µg/d |
|
|
1-3 years |
8 µg/d |
|
|
4-8 years |
12 µg/d |
|
|
9-13 years |
20 µg/d |
|
|
14-18 years |
25 µg/d |
|
|
19+ years |
30 µg/d |
|
|
Pregnancy (14+ years) |
30 µg/d |
|
|
Lactation (14+ years) |
35 µg/d |
|
Dietary Sources
Biotin is found in small amounts in many foods, but the highest quantities are found in (1):
Organ meats – 30.8 µg / 3 oz in beef liver
Eggs – 10 µg / egg
Fish – 5 µg / 3 oz in salmon
Other meats – 3.8 µg / 3 oz pork chop, hamburger patty
Sunflower seeds – 2.6 µg / ¼ cup
Biotin deficiency is rare but may require supplementation to correct (1,2). However, supplements are most commonly taken for potential health and beauty benefits, rather than for correcting a deficiency (1).
Biotin Supplements
Biotin supplements have gained popularity, particularly for their potential benefits in improving hair, skin, and nails (1). However, scientific evidence supporting these claims is limited and primarily based on small and often low-quality studies (1,3). While some research suggests improvements in nail thickness, larger, more rigorous studies are needed to confirm these findings (1,3). Despite the scarcity of scientific evidence, many individuals choose to take biotin supplements (1).
Biotin Supplements May Impact Lab Values
While biotin supplementation is generally considered safe, individuals taking supplements should be aware of potential interactions with laboratory tests (4). High-dose biotin supplementation, typically exceeding 10 mg/day for a week, can affect test accuracy in some medical assessments, including (1,4,5):
- Falsely low laboratory test results for troponin (used for measuring damage to the heart), which could lead to missed or delayed diagnosis of heart attack (4,5).
- Falsely normal or elevated thyroid hormone blood values leading to a false indication of hyperthyroidism in patients with normal thyroid levels (1,4).
The dosage in supplements marketed for skin, nail, and hair health is often 5 mg/day or higher (5).
Key Takeaways
- Biotin is an essential vitamin that is found in the highest quantities in meat and fish.
- Though biotin plays an important role in the body’s processes, evidence is lacking to support the use of biotin supplements for beauty purposes.
- High-dose biotin supplementation may affect the accuracy of lab tests for heart damage and thyroid function.
References
1. National Institutes of Health; Office of Dietary Supplements. Biotin: Fact Sheet for Health Professionals. https://ods.od.nih.gov/factsheets/Biotin-HealthProfessional/
2. Institute of Medicine. 2006. Dietary Reference Intakes: The Essential Guide to Nutrient Requirements. Washington, DC: The National Academies Press. https://doi.org/10.17226/11537
3. Patel DP, Swink SM, Castelo-Soccio L. A Review of the Use of Biotin for Hair Loss. Skin Appendage Disord. 2017 Aug;3(3):166-169. doi: 10.1159/000462981. Epub 2017 Apr 27. PMID: 28879195; PMCID: PMC5582478
4. Li D, Radulescu A, Shrestha RT, Root M, Karger AB, Killeen AA, Hodges JS, Fan SL, Ferguson A, Garg U, Sokoll LJ, Burmeister LA. Association of Biotin Ingestion With Performance of Hormone and Nonhormone Assays in Healthy Adults. JAMA. 2017 Sep 26;318(12):1150-1160. doi: 10.1001/jama.2017.13705. PMID: 28973622; PMCID: PMC5818818.
5. Li D, Rooney MR, Burmeister LA, Basta NE, Lutsey PL. Trends in Daily Use of Biotin Supplements Among US Adults, 1999-2016. JAMA. 2020 Aug 11;324(6):605-607. doi: 10.1001/jama.2020.8144. PMID: 32780133; PMCID: PMC7420177.
