Summary
Highlights
Dr. Mohan, a practicing endocrinologist, introduces his series 'Dr. Mohan Explains' and explains why he frequently asks thyroid patients about biotin supplementation. He highlights that biotin, a common supplement, can influence thyroid and other blood tests, and this video will explain why and what to do about it.
Biotin, also known as vitamin B7 or H, is an essential coenzyme crucial for metabolizing fats, carbohydrates, and proteins. It's found in various foods like liver, egg yolk, fish, meat, seeds, sweet potatoes, nuts, and vegetables. Raw egg whites contain avidin, which blocks biotin absorption, but cooking them inactivates avidin. Biotin deficiency is rare as only 30 micrograms are needed daily, and most diets provide more. Severe deficiency symptoms include dermatitis, muscle weakness, and neurological issues, while mild deficiency can cause hair loss and brittle nails.
Biotin supplementation has significantly increased, with 30 times more Americans taking it now compared to the 1990s, especially women and older age groups. Doses in supplements are often over a thousand times the adequate daily intake. This rise is driven by consumer desire for healthy hair and nails, and even dermatologists recommend it despite limited scientific data supporting its effectiveness for these purposes in individuals without a true deficiency.
The problem with biotin arises when individuals taking the supplement undergo blood tests. Dr. Mohan explains the mechanism of interference in the laboratory, using the example of a TSH test. He illustrates how biotin in the patient's blood competes with biotin used in laboratory reagents, leading to inaccurate results, specifically a falsely low TSH level.
Biotin can affect many lab tests. It tends to lower TSH values while increasing T4 and T3 levels, which can mimic hyperthyroidism. Other affected tests include parathyroid hormone (PTH), which can appear falsely low, and troponin (a heart attack marker) and hCG (pregnancy hormone), both of which can show falsely low levels, leading to dangerous misdiagnoses. Biotin does not interfere with the actual hormones or organ function but causes laboratory errors.
Dr. Mohan shares a case study where a patient's thyroid labs initially suggested hyperthyroidism due to high-dose biotin. After discontinuing biotin, the labs normalized within six days, preventing unnecessary testing and treatment. He advises patients to stop biotin for at least three to five days before blood draws to ensure it's cleared from the system, as typical doses clear within 8 hours, but very high doses can take up to 72 hours.
Biotin is an essential vitamin needed in small quantities, and true deficiency is rare. Despite a lack of strong scientific data, its use for hair, skin, and nails has skyrocketed. High doses can interfere with thyroid, parathyroid, and cardiac blood tests, leading to laboratory errors, not actual hormonal or organ dysfunction. Patients should inform their physician about biotin use and discontinue it for at least three days before any lab testing. It's crucial for patients to spread this awareness, as many physicians may not be informed about this interference.