What is Biotin?

Biotin, also known as vitamin B or vitamin H, is a dietary supplement that is often taken for hair, skin, and nail health. It is marketed under various names, including vitamin B7, vitamin H, and coenzyme R. Recent studies have shown the benefit of biotin for medical conditions such as hair and nail problems, diabetes mellitus, peripheral neuropathy, and multiple sclerosis. Biotin supplements taken at common over-the-counter doses can interfere with the results of certain hormone assays, giving falsely high or low results that could lead to a misdiagnosis, researchers reported. Biotin deficiency, while unusual in modern times, can still occur and may lead to various health issues. Biotin supplements in very large amounts (10–15 mg) (333 times the daily recommended amount) have become popular because they are thought to help with hair growth, diabetes, lipid disorders, and diabetic peripheral neuropathy. They are also thought to help with treatment of mitochondrial energy metabolism disorders, lipid disorders, and diabetic peripheral neuropathy. The Mayo Clinic has also reported on the potential interference of biotin with hormone tests.

Biotin At A Glance

  • Many patients are taking megadoses of biotin that can cause falsely high and falsely low results in a variety of laboratory tests, including thyroid tests. Biotin has no impact on hormone tests used with liquid chromatography or mass spectrometry.
  • Patients are taking these supplements mainly to improve their hair, skin, and nails and might not consider them medications to report on their list. Most multivitamins do not have enough biotin for concern, however.
  • Biotin interference with lab tests could be causing misdiagnoses — and even mistreatment — in an unknown number of patients.

Biotin Affects Blood Tests Performed with Immunoassays

High doses of biotin may interfere with lab tests because biotin is a common component of many immunoassays in the form of biotinylated antibodies or analogs. If you are taking a biotin supplement, please stop it at least 4 days before getting your blood drawn. Biotin supplements taken at common over-the-counter doses can interfere with the results of certain hormone assays, giving falsely high or low results that could lead to a misdiagnosis and mimic the typical biochemical picture of Grave's disease. Biotin supplements, at very large doses of 10–15 mg (333-fold greater than the dietary recommendation), have become popular for the presumptive benefits of stimulating hair growth, diabetes, lipid disorders, and diabetic peripheral neuropathy. Biotin interference is particularly prominent in competitive immunoassays, which are commonly used for low-molecular-weight targets such as T4, T3, and cortisol. Therefore, it is important to stop taking biotin supplements before undergoing any blood tests performed with competitive immunoassays to avoid misleading results. Biotin interference causes inaccurate results, highlighting the importance of avoiding biotin supplements before blood tests, particularly those involving parathyroid hormone levels.

What Are the Typical Tests That Higher-Dose Biotin May Affect?

Biotin can affect a wide variety of laboratory tests. Examples include tests for:

  • Troponin—a test used to help diagnose heart attacks
  • Thyroid hormone tests, such as thyroid stimulating hormone (TSH), thyroxine (T4), and triiodothyronine (T3) tests
  • Other hormones, such as parathyroid hormone (PTH), cortfollicle-stimulating hormone (FSH) and luteinizing hormone (LH),
  • Vitamin D levels

How Much Does Taking Biotin Actually Affect TSH Results?

  1. Based on the search results, taking high doses of biotin (vitamin B7) can significantly interfere with thyroid function tests, including TSH (thyroid stimulating hormone), and lead to inaccurate results. The key points regarding biotin's effect on TSH are:When using immunoassays that use the biotin-streptavidin binding mechanism [1, 3, 6, 7, 9], biotin interference often leads to TSH levels that are too low. This is because too much biotin makes it harder for the TSH-antibody complex to bind to the streptavidin-coated solid phase in these "sandwich" immunoassays.
  2. The degree of TSH suppression depends on the dose of biotin and the specific assay method used by the laboratory [1, 3, 6, 7]. Higher biotin doses generally cause more suppression of the measured TSH level.
  3. One study found that taking 10 mg of biotin daily for 7 days caused TSH levels to be falsely low for up to 8 hours after the last biotin dose when measured on certain assay platforms like Roche Cobas and Beckman UniCel. With a 10 mg biotin dose, TSH remained falsely low for 1-2 days.
  4. Another study showed that taking 10,000 mcg (10 mg) of biotin daily caused TSH levels to be falsely low, mimicking hyperthyroidism, even though the patient was clinically euthyroid.
  5. Biotin interference can lead to misdiagnosis of hyperthyroidism or mismanagement of thyroid disorders like thyroid cancer if TSH is being used to monitor suppressive levothyroxine therapy [4, 7].

To sum up, high-dose biotin supplements, which are often used to treat hair, skin, and nails, can significantly lower measured TSH levels through assay interference. This could lead to a wrong diagnosis and bad treatment changes if biotin intake is not taken into account. The effect is dose-dependent and can last for 1-2 days after stopping high biotin doses. [1,3,6,7,9,12] Discussion - Our patient, who was taking 10000 mg/day of biotin for multiple sclerosis, showed lab results of falsely elevated free T3 and T4 and falsely low TSH, mimicking symptoms of hyperthyroidism. His thyroid function report returned to normal when he stopped taking biotin for five days, showing no signs of hyperthyroidism.

When to Stop Biotin Before Thyroid or OTher Hormone Tests

High doses of biotin can interfere with certain thyroid tests and other hormone tests, leading to inaccurate results. It is recommended to stop taking biotin at least 2 days before undergoing any thyroid function tests to ensure the most accurate readings. This precaution is essential as biotin ingestion can skew thyroid hormone levels in blood tests, potentially causing misdiagnosis or inappropriate treatment. The American Thyroid Association (ATA) has recommended stopping biotin at least 2 days prior to lab testing, specifically thyroid labs, to avoid spurious results, especially for free thyroxine (FT4) and thyroid stimulating hormone (TSH) levels. Always consult with your healthcare provider for specific guidance on when to discontinue biotin before thyroid testing.

The FDA Stance on Biotin

The FDA has said these about biotin's potential interference with lab tests:

  • Know that biotin is found in multivitamins, including prenatal multivitamins, biotin supplements, and supplements for hair, skin, and nail growth in levels that may interfere with laboratory tests. However, the amount of biotin can vary significantly among different products. Consider that the daily recommended allowance for biotin is 0.03 mg (300 mcg) and that amount does not typically cause interference in lab tests

Biotin Can Interfere with Certain Blood Tests: Physicians Should Warn Patients

Clinicians are cautioned to act decisively given the risk of inaccurate or missed diagnosis and in light of the urgency that prompted a Food and Drug Administration (FDA) Safety Communication on this very topic.

The FDA recommends that clinicians take the following precautions:

  • Talk to your patients about any biotin supplements they may be taking, including supplements marketed for hair, skin, and nail growth
  • Be aware that many lab tests, including but not limited to cardiovascular diagnostic tests and hormone tests, that use biotin technology are potentially affected, and incorrect test results may be generated if there is biotin in the patient’s specimen
  • Communicate to the lab conducting the testing if your patient is taking biotin
  • If a lab test result doesn’t match the clinical presentation of your patient, consider biotin interference as a possible source of error
  • Know that biotin is found in multivitamins, including prenatal multivitamins, biotin supplements, and dietary supplements for hair, skin, and nail growth in levels that may interfere with lab tests
  • Report to the lab test manufacturer and the FDA if you become aware of a patient experiencing an adverse event following potentially incorrect laboratory test results due to biotin interference.

Common Questions and Answers:

Does biotin interfere with TPO antibodies on a thyroid test?

Biotin can interfere with TPO (Thyroid Peroxidase) antibody test results, leading to falsely elevated or decreased levels. If you are taking biotin supplements and are scheduled for a thyroid test, it is recommended to inform your healthcare provider about your biotin use. This will allow them to provide guidance on whether you need to stop taking biotin before the test to ensure accurate results. It's important for healthcare professionals to have all the necessary information to interpret your test results correctly and make appropriate recommendations based on accurate data.

How does biotin interact with thyroid medication?

Biotin, also known as vitamin B7, is a water-soluble vitamin that is often included in multivitamin supplements and promoted for its potential benefits for hair, skin, and nails. However, recent literature suggests that high doses of biotin can interfere with certain thyroid function tests, leading to inaccurate results. The American Association of Clinical Endocrinology advises discussing biotin therapy with your healthcare provider, especially if you are taking thyroid medication, because this interference is more common in people who take biotin supplements at levels much higher than the recommended daily intake.

If you are taking thyroid medication and considering adding a biotin supplement to your routine, it is important to discuss this with your healthcare provider. They can provide guidance on the appropriate dosage of biotin and how it may interact with your thyroid medication. In some cases, they may recommend temporarily stopping the biotin supplement before thyroid function tests to ensure accurate results. It is always best to consult with a healthcare professional when making changes to your medication or supplement regimen to avoid any potential interactions or adverse effects.

Can biotin affect thyroid function?

Biotin can interfere with some thyroid function tests, leading to inaccurate results. If you are undergoing thyroid function testing, it is recommended to inform your healthcare provider if you are taking biotin supplements, as they may advise you to discontinue them temporarily before the test. It's important to follow your healthcare provider's guidance to ensure accurate test results and proper interpretation.

Click here for other FACTORS THAT CAN AFFECT THE ACCURACY OF YOUR BLOOD TEST RESULTS 

References

  1. "Thyroid hormone interference caused by biotin: review and case illustration" - PMC
  2. "Assessment of Biotin Interference in Thyroid Function Tests" (MD Journal)
  3. "The effect of biotin on thyroid function tests: A synthetic overview" (PMC)
  4. "Case of a misdiagnosed thyroid disorder due to biotin interference" - Journal of Medical Case Reports
  5. "Biotin Interference with Thyroid Function Tests - Safety Alert" (Health Sciences Authority)
  6. "Biotin supplementation and its impact on thyroid function testing: Analysis of a community population" (PMC)
  7. "Review on the interference of dietary supplements on clinical laboratory tests: Biotin and its effect on thyroid function testing" (International Journal of Thyroidology)
  8. "Biotin Supplementation: Implications for Thyroid Testing" - Thyroid.org
  9. "January 2016 - Thyroid Month: Beware of Biotin" (Endocrine News)
  10. "Understanding Biotin Interference in Thyroid Tests" (Medscape)
  11. "Biotin and Thyroid Testing: A Quantitative Review" (Journal of Endocrine Society)
  12. "New Insights into Biotin Interference with Thyroid Tests" (Thyroid.org)
  13. FDA In Brief: FDA provides draft recommendations to diagnostic manufacturers to help reduce risks of biotin interference with certain lab tests
  14. The FDA Warns that Biotin May Interfere with Lab Tests: FDA Safety Communication