FDA recently issued an alert cautioning that biotin can significantly interfere with certain lab tests and cause incorrect test results that 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. According to FDA, the agency 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 that 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 multivitamins, 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. 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 agency states it is aware of people taking high levels of biotin that would interfere with lab tests. Many dietary supplements promoted for hair, skin, and nail benefits contain biotin levels up to 650 times the recommended daily intake of biotin. Physicians may also be recommending high levels of biotin for patients with such conditions as multiple sclerosis. Biotin levels higher than the recommended daily allowance may cause interference with lab tests.

FDA points out that physicians and patients may be unaware of biotin interference in laboratory assays. Furthermore, even physicians who are aware of this interference are likely unaware about whether their patients are taking biotin—and how much. Since patients are unaware of biotin interference, they may not report taking biotin supplements to their physicians, and may even be unaware they are taking biotin (eg, when taking products generally labeled for their benefits to hair and nails).

FDA is working with stakeholders to better understand biotin interference with laboratory tests, and to develop recommendations for safe testing among patients who have taken high levels of biotin when using laboratory tests that employ biotin technology.

Healthcare professionals and patients are encouraged to report adverse events or side effects related to the use of these products to FDA’s MedWatch safety information and adverse event reporting program. Reports can be submitted online at www.fda.gov/medwatch/report.

Individuals can also download the report form or call (800) 332-1088 to request a form, then complete and return it to the address on the preaddressed form, or submit by fax to (800) 332-0178.

The agency issued the following specific recommendations for lab personnel:

  • If a laboratorian uses assays with biotin technology, be aware that it is difficult to identify samples that contain biotin; therefore, it is important to communicate with healthcare providers and patients to prevent incorrect test results.
  • If a laboratorian is collecting samples in the lab, ask whether the patient is taking biotin.
  • Educate healthcare providers about biotin interference with certain lab tests used in one’s lab.
  • Consider that 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.
  • 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 are insufficient to support recommendations for safe testing using affected tests among patients taking high levels of biotin, including recommendations about the length of time for biotin clearance from the blood.
  • Communicate with the lab test manufacturer if an individual has questions about biotin interference.