High-Dose Biotin Supplements Can Cause Inaccurate Laboratory Test Results

Biotin, also known as vitamin B7, is an essential water-soluble nutrient that is naturally present in many foods, including meats (particularly organ meats), eggs, fish, nuts, seeds and certain vegetables (such as sweet potatoes).[1] The recommended daily intake for biotin is quite small: 30 micrograms (mcg) for adults, with a slight increase for lactating women.

Although biotin deficiency is rare, this vitamin is available, often in high doses, in dietary supplements containing biotin only and in multivitamins and other supplements marketed for hair, skin and nail growth, as well as certain diseases, such as multiple sclerosis.[2] As of 2016, nearly 1% of adult Americans reported consuming 5 milligrams (mg) per day (167 times the recommended daily intake) of over-the-counter biotin-containing supplements.[3]

It has been discovered in recent years that supplements that contain more than the recommended daily intake of biotin can significantly interfere with many important clinical laboratory blood tests (including those for heart disease and thyroid problems), falsely altering their results. Incorrect test results can lead to misdiagnosis and inappropriate treatment of health conditions, which may have serious or even deadly consequences.

The Food and Drug Administration (FDA) has posted on its website warnings for the public and health care professionals, as well as laboratory personnel and manufacturers, about biotin interference with laboratory tests. Learn about this issue to protect yourself and your loved ones because the agency has not required supplement manufacturers to include test interference information on their product labeling.

About biotin interference

Generally, the amounts of biotin absorbed from natural foods do not result in biotin concentrations that could interfere with clinical laboratory tests.[4] However, consuming biotin supplements, particularly in high doses, can cause falsely low or high results for many immunoassays (laboratory tests that measure specific proteins or other substances) in which biotin is used as part of the test technology.

Examples of immunoassays that have been shown to yield dangerous, falsely low results due to high biotin in blood samples include tests for troponin (a substance that is elevated in patients having heart attacks) and N-terminal pro-brain natriuretic peptide (a hormone that is elevated in patients suffering heart failure).[5] Examples of immunoassays that have been found to yield falsely high results due to high biotin in blood samples include tests for thyroid hormones and the adrenal gland hormone cortisol. High blood biotin also can lead to false-negative tests for hepatitis B and HIV infection.

If not detected, inaccurate test results can lead to missed or delayed diagnoses or treatments, which can have serious outcomes.

FDA warnings

In 2017, the FDA issued its first biotin-related warning cautioning that many hair, skin and nail dietary supplements contain biotin levels of up to 650 times the recommended daily intake of biotin.[6] The agency noted that it has received a report that a patient had died due to a falsely low troponin test result caused by biotin interference, which presumably resulted in a failure to diagnose and treat a heart attack. Therefore, the FDA recommended that health care professionals routinely ask their patients about any supplements they may be taking that contain biotin and to consider biotin interference as a possible source of error if laboratory test results do not match disease signs and symptoms of their patients. It also asked laboratory manufacturers to contact the agency if their tests use biotin-based technology.

In an updated 2019 warning, the FDA noted that although some manufacturers have mitigated biotin interference in their tests successfully, others (particularly several that make troponin test devices) have not yet addressed this problem.[7] Importantly, the agency noted that it was still receiving adverse-event reports indicating biotin interference leading to falsely low troponin results. Therefore, it released a list of manufacturers with possibly inaccurate troponin tests to alert the public.[8]

In October 2020, the FDA published final guidance with recommendations for laboratory test manufacturers about how to evaluate biotin interference with their clinical tests and how the results of those evaluations should be communicated to laboratories and health care professionals who use the tests.[9] However, these recommendations are nonbinding given that the agency lacks the legal authority to enforce them.

What You Can Do

If you are a healthy adult consuming a balanced, nutrient-dense diet — a mix of colorful vegetables (especially leafy greens [including spinach and kale] as well as red and orange vegetables [including carrots and sweet potatoes]) — every day, you do not need to take a supplement for biotin or any other nutrient because such a diet easily meets your daily requirements of nutrients.[10],[11] However, if you have a risk factor for biotin deficiency — such as Crohn’s disease or taking certain epilepsy drugs, including carbamazepine (CARBATROL, EPITOL, EQUETRO, TEGRETOL, TERIL) and phenytoin (DILANTIN, PHENYTEK) — consult your doctor about getting an appropriate biotin supplement.[12]

Talk to your doctor if you are currently taking or have recently taken a supplement that contains more than the daily recommended amount of biotin, especially before you undergo any laboratory tests. Your doctor may need to communicate this information to the laboratory to mitigate the risk of biotin interference or ask you to repeat the test after stopping biotin supplements for some time, if possible.

If you had one of the aforementioned laboratory tests done recently and are concerned about the results, talk to your doctor about the possibility of biotin interference.
 

References

[1] National Institutes of Health, Office of Dietary Supplements. Biotin fact sheet for health professionals. June 3, 2020. https://ods.od.nih.gov/factsheets/Biotin-HealthProfessional/. Accessed December 3, 2020.

[2] Food and Drug Administration. Update: The FDA warns that biotin may interfere with lab tests: FDA safety communication. November 5, 2019. https://www.fda.gov/medical-devices/safety-communications/update-fda-warns-biotin-may-interfere-lab-tests-fda-safety-communication. Accessed December 3, 2020.

[3] Li D, Rooney MR, Burmeister LA, et al. Trends in daily use of biotin supplements among US adults, 1999-2016. JAMA. 2020;324(6):605-607.

[4] Johnson L, Li D. Strategies to investigate biotin interference in light of the FDA safety communication. J Appl Lab Med. 2019;3(5):914-915.

[5] Avery G. Biotin interference in immunoassay: a review for the laboratory scientist. Ann Clin Biochem. 2019;56(4):424-430.

[6] Food and Drug Administration. The FDA warns that biotin may interfere with lab tests: FDA safety communication. November 28, 2017. https://www.fda.gov/medical-devices/safety-communications/fda-warns-biotin-may-interfere-lab-tests-fda-safety-communication. Accessed December 3, 2020.

[7] Food and Drug Administration. Update: The FDA warns that biotin may interfere with lab tests: FDA safety communication. November 5, 2019. https://www.fda.gov/medical-devices/safety-communications/update-fda-warns-biotin-may-interfere-lab-tests-fda-safety-communication. Accessed December 3, 2020.

[8] Food and Drug Administration. Biotin interference with troponin lab tests - assays subject to biotin interference. November 5, 2019. https://www.fda.gov/medical-devices/vitro-diagnostics/biotin-interference-troponin-lab-tests-assays-subject-biotin-interference. Accessed December 3, 2020.

[9] Food and Drug Administration. Testing for biotin interference in in vitro diagnostic devices. Guidance for industry. October 2020. https://www.fda.gov/media/127915/download. Accessed December 3, 2020.

[10] National Institutes of Health, Office of Dietary Supplements. Biotin fact sheet for health professionals. June 3, 2020. https://ods.od.nih.gov/factsheets/Biotin-HealthProfessional/. Accessed December 3, 2020.

[11] National Institute of Health, National Institute of Diabetes and Digestive Diseases. Health tips for adults. September 2020. https://www.niddk.nih.gov/health-information/weight-management/healthy-eating-physical-activity-for-life/health-tips-for-adults. Accessed December 3, 2020.

[12] Avery G. Biotin interference in immunoassay: a review for the laboratory scientist. Ann Clin Biochem. 2019;56(4):424-430.