What You Need to Know Before Taking Biotin Supplements

Marketed for hair and nail growth, biotin supplements have also been shown to skew important medical test results.

Supplements for healthy hair, skin and nails seem to be everywhere on social media these days, including Instagram, where celebrities like the Kardashian-Jenners push certain brands of gummy vitamins (to the tune of a huge $1 million paycheque per post).

Despite the ubiquity of these supplements, there isn’t a ton of research to back up their health claims. Biotin, the main ingredient in a lot of these supplements, has not been proven to help nail or hair growth.

Possibly more alarming is the fact that high dosages of biotin might distort the results of certain medical tests. In 2017, the FDA in the U.S. issued a warning about biotin’s interference on troponin tests (which are used to diagnose heart attacks) after learning about a patient who died after showing artificially low levels of troponin.

We spoke to Dr. Sophia Park, one of the authors of a B.C. Medical Journal article exploring the effects of biotin on medical results, about what you need to know about biotin supplements.

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What is biotin?

Biotin, or Vitamin B7, is a key nutrient responsible for many metabolic processes in our body, including breaking down food into energy. “Biotin is what we call a water-soluble vitamin, meaning that your body doesn’t accumulate it,” says Park. This is different from fat-soluble vitamins (like vitamin D), which your body keeps, leading to potentially toxic levels if you take too much. “That’s why we don’t have a lot of warnings for biotin, because as long as your kidneys are functioning, you can pee out the excess.”  You can find biotin naturally in foods like eggs, fish and sweet potatoes.

Do biotin supplements really work?

Research suggests that biotin might not actually help with hair, nail, and skin growth. One study  found that “research demonstrating the efficacy of biotin is limited,” and “there is a lack of sufficient evidence for [biotin] supplementation in healthy individuals.” 

(Related: 15 Supplements Nutritionists Don’t Take—So You Shouldn’t Either)

How does biotin skew medical test results?

Without getting too technical, medical labs use biotin-streptavidin binding technology in a lot of different tests—including those for cardiac function and thyroid function. What’s supposed to happen is that the biotin-streptavidin technology helps detect specific proteins that signal different health problems (for example, it is used to detect the protein troponin, which aids in the diagnosis of heart attacks).

When there’s biotin in a patient’s blood, however, “the biotin may interfere with the measurement of [a target protein] so that the test can no longer accurately detect the protein,” says Park. This leads to erroneous test results which can lead to misdiagnosis and patient mismanagement.

What can you do?

The good news is that the problem can be mitigated if your doctor knows about it. So, if you’re taking biotin supplements, tell your doctor when they send you to a lab for testing. “A lot of times, doctors will ask patients what medications they’re taking, but they forget to ask what supplements and vitamins they’re taking,” says Park. “If you volunteer that information, and if you know the dosage you’re taking, that would be really helpful.”

Once doctors know there might be biotin in your system, they discuss your options with the lab and see if the tests you need would be affected (it all depends on which tests exactly you need done and what technology that specific lab uses).

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