Biotin (Vitamin B7) Interferes with Lab Tests; Deadly Results

On November 28, 2017, the FDA alerted the public, health care providers, lab personnel, and lab test developers that biotin can significantly interfere with certain lab tests and cause incorrect test results which may go undetected.


Biotin in blood or other samples taken from patients who are ingesting high levels of biotin in dietary supplements can cause clinically significant incorrect lab test results. The FDA has seen an increase in the number of reported adverse events, including one death, related to biotin interference with lab tests.


Many lab tests use biotin technology due to its ability to bond with specific proteins which can be measured to detect certain health conditions. For example, biotin is used in hormone tests and tests for markers of cardiac health like troponin. Biotin, also known as vitamin B7, is a water-soluble vitamin often found in multi-vitamins, prenatal vitamins, and dietary supplements marketed for hair, skin, and nail growth.


Biotin in patient samples can cause falsely high or falsely low results, depending on the test. Incorrect test results may lead to inappropriate patient management or misdiagnosis. For example, a falsely low result for troponin, a clinically important biomarker to aid in the diagnosis of heart attacks, may lead to a missed diagnosis and potentially serious clinical implications. The FDA has received a report that one patient taking high levels of biotin died following falsely low troponin test results when a troponin test known to have biotin interference was used.


The FDA is aware of people taking high levels of biotin that would interfere with lab tests. The daily recommended allowance for biotin is 0.03 mg and these biotin levels do not typically cause significant interference. However, supplements containing high biotin levels including those marketed for hair, skin, and nail benefits, may contain up to 20 mg of biotin, and physicians may recommend up to 300 mg per day for conditions such as multiple sclerosis. Biotin levels higher than the recommended daily allowance may cause significant interference with affected lab tests.


Patients and physicians may be unaware of biotin interference in laboratory assays. Even physicians who are aware of this interference are likely unaware as to whether, and how much biotin, patients are taking. Because patients are unaware of biotin interference, patients may not report taking biotin supplements to their physicians, and may even be unware they are taking biotin (e.g., when taking products generally labeled for their benefits to hair and nails).


The FDA recommended that health care providers take a number of steps related to biotin and lab tests. First, health care providers should talk to their patients about any biotin supplements the patients may be taking, including supplements marketed for hair, skin, and nail growth. Second, health care providers should be aware that many lab tests, including but not limited to cardiovascular diagnostic tests and hormone tests that use biotin technology are potentially affected. Incorrect test results may be generated if there is biotin in the patient’s specimen. Health care providers should communicate to the lab conducting the testing if their patient is taking biotin. If a lab test result does not match the clinical presentation of the patient, health care providers should consider biotin interference as a possible source of error. Finally, health care providers should report to the lab test manufacturer and the FDA if they become aware of a patient experiencing an adverse event following potentially incorrect laboratory test results due to biotin interference.


The FDA recommended that laboratory personnel take a number of steps related to biotin and lab tests. If laboratory personnel use assays with biotin technology, they should be aware that it is difficult to identify samples that contain biotin; therefore, it is important to communicate with health care providers and patients to prevent incorrect test results. Second, if laboratory personnel are collecting samples in the lab, they should ask whether the patient is taking biotin. Third, laboratory personnel should be aware that specimens collected from patients taking high levels of biotin may contain more than 100 ng/mL biotin. Concentrations of biotin up to 1200 ng/mL may be present in specimens collected from patients taking up to 300 mg per day.


Currently available data is insufficient to support recommendations for safe testing using affected tests in patients taking high levels of biotin, including about the length of time for biotin clearance from the blood.


See the FDA Safety Alert


Also see the FDA Safety Communication


See also Medical Law Perspectives Report: Blood Draws, Testing, Transfusions: Venipuncture Injury, Inaccurate Results, Tainted Blood - The Liability Risks


See also Medical Law Perspectives Report: Drugs, Dosage, and Damage: Physician Liability for Prescribing or Administering Medication