More is masked with biotin

In the 1994 Jim Carrey film “The Mask,” timid bank clerk Stanley Ipkiss discovers a magical mask that transforms him into a manic, confident (and green) playboy with supernatural powers.

As the movie showed, masking can cause a lot of trouble. A few months ago we told you about a medical masking: the Food and Drug Administration warned that too much biotin (vitamin B-7) can mask test results for a clinical biomarker (troponin) that helps docs diagnose a heart attack. High doses of biotin can skew test results for thyroid hormones, which can lead to an overdiagnosis of Graves’ disease or hyperthyroidism.

But biotin can cause even more masking trouble. A case report in the Journal of the Endocrine Society reveals that someone taking 5,000 micrograms of biotin daily (a common dosage sold over the counter, even though 30 micrograms is adequate for good skin, nail and liver health) seemed to test positive for hypercortisolemia, believed to be caused by a testosterone-producing tumour. That, the report says, “led to weeks of psychological distress ... nearly resulting in an unnecessary invasive procedure.”

Now, moms-to-be and breastfeeding moms may need to take B-7 (ask your doc; the dose in a prenatal multivitamin usually suffices) to assure proper fetal development and infant health. But the rest of you: if you have two to three daily servings of 100 per cent whole grains; eat walnuts, pecans and almonds; get half a multivitamin twice a day; and have at least a couple servings of wild salmon and trout each week, you don’t need biotin supplements.

Mehmet Oz, M.D. is host of “The Dr. Oz Show,” and Mike Roizen, M.D. is Chief Wellness Officer and Chair of Wellness Institute at Cleveland Clinic. To live your healthiest, tune into “The Dr. Oz Show” or visit www.sharecare.com.