Biotin May Affect Some Lab Results

 

I started taking biotin (Vitamin B7) last year at the recommendation of a pharmacist because my hair was falling out. I was experiencing a lot of low thyroid symptoms. The biotin helps with my hair health, but, it wasn’t until I was seen by a doctor at the University of Iowa’s Complementary and Alternative Clinic , that I found out that the biotin I was taking could affect my labs. I keep a list of my medications, allergies, and health history on a Microsoft Word document file and update it before each doctor visit. The doctor I saw at the Complementary and Alternative advised me to avoid taking biotin for a day or so before any blood work. As I always do when I find out new information, I researched the affects of biotin on labs and found the Food and Drug Administration had published a warning:

“In late November 2017, the Food and Drug Administration (FDA) published a safety alert to make the public and healthcare practitioners more aware that biotin can ‘significantly interfere with certain lab tests and cause incorrect test results…”‘

The FDA has warned that the B vitamin, biotin, may affect some lab results. Especially prone to skewed results are thyroid tests and certain cardiac tests:

“Most of the published research on biotin interference covers hormone tests, such as parathyroid hormone (PTH), thyroid stimulating hormone (TSH), T4 and T3 tests, as well as tests for troponin. However, because biotin is used in so many immunoassays, scientists say it could interfere with many others.

In its Safety Communication, the FDA advises healthcare practitioners to ask their patients if they are taking any biotin supplements and inform the testing laboratory if interference from biotin is a possibility. They should also consider biotin interference as a potential reason for lab results not matching with a patient’s signs and symptoms and/or suspected health condition.“

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My TSH levels continued an upward curve from early in 2018 through January of 2019; the increasing number matched increasingly intense symptoms of fatigue, skin infections, facial and ankle and feet swelling, hair loss, weight gain, and feet pain–to name a few of my symptoms. I saw an endocrinologist in January who said it was possibly hypothyroidism due to lack of iodine (this after seeing an endocrinologist in the fall who just looked at my lab numbers and said they “look great” and that she’d see me in a year). Years ago, I posted a blog post on my Be Well & B12 site about the need for iodine in the diet for the health, but failed to follow my own advice. I could have sworn I had iodized salt in my salt shaker, but when I went to refill it, it was non-iodized salt: the label looked very similar to the label of popular brand of salt with iodine added. I was hoping my low thyroid symptoms were just a matter of lack of iodine. I have Celiac Disease and do most of my own cooking and eat out rarely–so I was not getting iodine from fast food or restaurant food. But even with adding iodized salt to my diet, my low thyroid symptoms persisted. Interestingly, Isabella Wentz, in her book, Hashimoto’s Protocol, says too much iodine can worsen hypothyroidism if it is low thyroid due to an autoimmune process.

As my TSH numbers rose, the number and severity of low thyroid symptoms intensified. When I ran across this PDF checklist of thyroid-related symptoms , I was surprised to see that foot pain was on the list. I was diagnosed with plantar fasciitis in both feet years ago. I am on thyroid replacement now and some of my symptoms are improving, including the pain in my feet. I had thyroid labs drawn recently and was careful to abstain from biotin (and my other B vitamins to be on the safe side!) for two days before the test. I’m curious to see if the lab results. I’ve also cut back on the amount of biotin I’m taking. There are reports of deleterious side effects from too much biotin.

If you have any of these symptoms of low thyroid function, be sure to get them checked out. And if your doctor orders blood work for thyroid-related issues or any other condition, abstaining from taking a biotin supplement or anything containing biotin for at least a day before the blood work might lead to more accurate results.