February 21, 2018

FDA Safety Alert: Biotin Can Affect Medical Test Results

Make sure you’re not taking too much

Pills spilling out of a medication bottle

If you’re taking a multivitamin, there’s a good chance it contains biotin, a water-soluble B vitamin also known as B7. And, while biotin is known to support healthy hair, skin and nails, it may interfere with certain common lab test results if you’re taking too much. The Food and Drug Administration recently issued a safety alert on this topic.


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Family medicine practitioner Matthew Goldman, MD, explains what the alert means, and what you need to know about biotin use.

Which tests might biotin supplements affect?

Many labs use immunoassay-based screening methods. This testing method measures the presence and concentration of a small molecule in a solution. If you have too much biotin free-floating in your system, it can throw these tests off.

In other words, the biotin in your system can replace what tests are measuring for in the solution and create false readings, Dr. Goldman says.

High levels of biotin can impact tests used to diagnose conditions such as:

Results may appear falsely low or falsely high, depending on the specific testing method, Dr. Goldman says. And lab results influenced by biotin supplements are not always obvious to your healthcare provider or the lab conducting the test.


How much biotin is too much?

If you’re like most people, you can get all the biotin you need by eating a well-balanced diet, Dr. Goldman says. Daily biotin recommendations range from 5 to 35 micrograms, depending on your age and gender, and on whether you’re pregnant or lactating.

While most multivitamins contain about 30 micrograms of biotin, some supplements — especially those that promote hair, skin and nail health — may contain much higher doses, he says.

“Obtaining biotin naturally is much less likely to cause abnormal test results because you won’t get as high concentrations of biotin as supplements provide,” he says.

You can boost your biotin levels naturally by eating these biotin-rich foods:

  • Liver
  • Eggs
  • Soybeans
  • Yeast
  • Fish
  • Dairy
  • Almonds
  • Mushrooms
  • Sweet potatoes
  • Spinach

How can you keep yourself safe?

Check your supplements to find out how much biotin they contain and consider how much you are getting from your diet, Dr. Goldman advises. If you’re getting more than the recommended daily allowance, talk with your doctor or a nutritionist about whether you should continue taking a biotin supplement.


And, make sure your doctors and lab technicians know what you’re taking.

“If you’re concerned about how the supplements you’re taking might affect future or previous lab results, speak to your healthcare provider and the lab performing the test. Let them know about any medications and supplements you take,” he says.

Your doctor also can advise you on whether you should stop taking your supplement ahead of an upcoming lab test. Most water-soluble vitamins flush out of your body in 24 to 48 hours, but it might take longer depending on the dose you’re taking.

“Making sure we’re all on the same page can help ensure you are receiving accurate lab results, and the best care,” Dr. Goldman says.

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