Many people with hair loss or thinning hair try a vitamin B7, or biotin, supplement in hopes of promoting hair and nail growth.
Hair loss and brittle nails are an especially common but upsetting side effect of cancer treatments, so many people who have cancer or are recovering from cancer give biotin supplements a try.
But dermatology and oncology experts hope to raise awareness that there’s little scientific evidence that these supplements can improve hair loss symptoms for these patients, and biotin supplements can actually cause inaccurate lab results, leading to delayed or incorrect treatment.
What is biotin?
Vitamin B7, or biotin, is an essential, water-soluble vitamin that helps us build the keratin that’s a foundational element of hair, skin and nails. It’s rare to be deficient in biotin, because it’s so available in common foods we eat.
Examples of foods containing biotin include:
- Eggs
- Fish
- Meats (beef liver has an especially high biotin content)
- Certain vegetables, such as sweet potatoes
- Nuts
- Seeds
- Some fruits
Risks of taking biotin supplements
There’s a misconception that biotin supplements are harmless and there’s no reason not to take them, says Brittany Dulmage, MD, an oncodermatologist at The Ohio State University Comprehensive Cancer Center – Arthur G. James Cancer Hospital and Richard J. Solove Research Institute (OSUCCC – James).
“The reality is that the supplements may cause inaccurate lab results, resulting in a delay or change in patients’ treatment plans,” she says.
Dr. Dulmage is the senior author of a recent article in JCO Oncology Practice that urges cancer doctors to talk with their patients about hair loss and educate them about how biotin could affect their test results.
“More than half the patients who come to see me with a problem related to hair loss are on a supplement that they’ve started on their own after learning about it online, by word of mouth and sometimes even at the advice of their doctor,” says Dr. Dulmage, associate director of dermatology at The Ohio State University College of Medicine and director of Ohio State’s Oncodermatology Clinic, which addresses side effects some cancer treatment can cause in hair, skin or nails.
Biotin can mask changes in breast, ovarian, prostate and thyroid cancers — some of the lab tests for these cancers look for a chemical reaction involving biotin, so biotin supplements can lead to false lab results.
The biotin isn’t actually changing the levels of hormones that the lab tests are looking for, Dr. Dulmage says, but it can interfere in the way those hormones’ levels can show up in blood work.
Dr. Dulmage says biotin can also affect levels of troponin, which are a marker for whether someone is having a heart attack. This can influence treatment plans in a cardiac event.
What to do if you’re taking a biotin supplement
Dr. Dulmage says that, if you’re getting blood work like this done and want to continue taking biotin supplements, you can stop taking them 72 hours before the blood work.
The trouble, though, is that not every lab test is planned 72 hours in advance — you might not know far enough ahead of time that you should stop taking it temporarily. This can be especially true for tests in a suspected heart attack scenario. No one’s planning to have a heart attack, Dr. Dulmage points out, so you can’t pause your biotin supplement before troponin levels are checked.
“This is why I recommend to patients that they think about not taking biotin at all, especially since very few people are biotin deficient,” says Dr. Dulmage.
What to try for hair loss instead of biotin
Over-the-counter minoxidil is FDA-approved for hair loss, and you can access it in multiple forms, from lotions to foams.
Dr. Dulmage typically tells her patients with hair loss to take minoxidil instead of biotin, because it’s been shown as both effective and safe for people who aren’t pregnant or breastfeeding.
“If you have been trying minoxidil for several months and not seeing any improvement or want to know about other options, see a dermatologist,” she says. “There are many other types of treatments that may be an option.”
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