Biotin

Biotin: How it works in the body?

• There are biotin-dependent carboxylases that biotin acts as a coenzyme for.

• These carboxylases act in essential processes such as gluconeogenesis, amino acid metabolism, ATP production, regulation of oxidative stress, regulation of immunologic and inflammatory function, and fatty acid synthesis.

What is it used for and at what dosage?

• A major claim biotin supplementation can help with is to have longer and

  healthier nails and hair.

• This supplementation can range up to 500–1000 μg in dosage daily. The Food and Nutrition Board of the Institute of Medicine recommends a daily dietary intake of 30 mcg/day to maintain health.

• The average dietary intake of biotin in the western population is 35–70 mcg/day.

• Foods rich in biotin include egg yolk, liver, cereals containing wheat and oats, spinach, mushrooms, rice, breast milk, and dairy items contain biotin.

• Typically, patients can obtain biotin through diet alone, but if deficiency is present, oral supplementation has high bioavailability and is given starting at 5 mg/day.

Evidence for or against its different uses:

• A recent study in 2017 reviewed 18 reported cases of use of biotin for hair and nail changes. The overall results show that 10 of the 18 cases had patients with inherited enzyme deficiencies that utilize biotin as a cofactor.

• All patients reported some underlying pathology for poor hair and poor nail growth.

• All cases reported clinical improvement of hair and nail growth after receiving biotin.

• However, none of the studies included any information regarding efficacy of hair and nail growth in healthy individuals.

• The author’s conclusion was that there is no evidence for biotin supplementation outside of known biotin deficiencies.

• There has not been any reported injuries from taking too much biotin.

Safety concerns, side effects, and precautions:

• Per the FDA in 2017, there was a potential complication of biotin interference to cause inaccurate laboratory results, including falsely low troponin that could result in missed or delayed myocardial infarction diagnosis.

• Another study investigated the prevalence of biotin supplementation use in the general population (surveying the outpatient population) and corresponded these results with quantifying biotin in plasma samples collected from patients presenting to the emergency department.

• These results revealed that among completed surveys, 7.7% indicated biotin use (of 1944 patients surveyed). Of the samples collected in the ED (n = 1442), 7.4% had concentrations of biotin at or above the biotin level in plasma that would qualify for biotin interference in immunoassay tests. This finding was concerning as this identifies a population at risk for potential harm such as falsely low troponins as mentioned above.

Interactions with medications:

• Taking anticonvulsants such as carbamazepine or phenobarbital can increase requirements for biotin due to inhibiting uptake of biotin into brush borders of membrane vesicles.

• Smoking and pregnancy can also metabolize biotin quickly, therefore biotin supplementation may be indicated; however, this is controversial with conflicting studies.

• Biotin can interfere with hormone assays such as thyroid functions, gonadotrophins, and Vitamin D.

Key Web Sources

• Saleem F, Soos MP. Biotin deficiency. In: StatPearls. Treasure Island, FL: StatPearls

  Publishing; 2021.

• Patel DP, Swink SM, Castelo-Soccio L. A review of the use of biotin for hair loss. Skin Appendage Disord. 2017;3:166–9. https://doi.org/10.1159/000462981.

• Bistas KG, Tadi P. Biotin [updated 29 Sep 2021]. In: StatPearls. Treasure Island, FL: StatPearls

  Publishing; 2022. Available from: https://www.ncbi.nlm.nih.gov/books/NBK554493/.

• The FDA warns that biotin may interfere with lab tests: FDA safety communication.

  Published 28 Nov 2017. Updated 5 Nov 2019.

• Katzman BM, Lueke AJ, Donato LJ, Jaffe AS, Baumann NA. Prevalence of biotin supple-

  ment usage in outpatients and plasma biotin concentrations in patients presenting to the emer-

  gency department. Clin Biochem. 2018;60:11–6. ISSN: 0009-9120. https://doi.org/10.1016/j.

  clinbiochem.2018.07.004.

• Piketty ML, Polak M, Flechtner I, Gonzales-Briceño L, Souberbielle JC. False biochemical diagnosis of hyperthyroidism in streptavidin-biotin-based immunoassays: the problem of

  biotin intake and related interferences. Clin Chem Lab Med. 2017;55(6):780–8.