Biotin, which is a water-soluble vitamin, is given in several genetic conditions and often used as a supportive treatment in mitochondrial disorders.  A recent report (S Kummer et al. 2016; 375: 704-6 Letter to Editor) noted six children ages 1 mo-9 yrs with markedly abnormal thyroid studies who were receiving biotin.  The results mimicked Graves’ disease with high free thyroxine levels, low thyrotropin levels, and elevated anti-thyrotropin receptor antibodies.

After stopping biotin, these biochemical abnormalities resolved in 48 hrs for free T4/TSH and 7 days for anti-thyrotropin receptor antibodies.

My take: High-dose biotin can create concerning laboratory profile of Graves’ disease. Awareness of this phenomenon is important for endocrinologists and pediatric gastroenterologists as well.

Glacier Nat’l Park