Currently, while there is no evidence to suggest that biotin intake at levels well above the adequate intake levels of 5–35 mcg/day is toxic in humans, there are other risks to consider.[1][2] For one, excessive biotin intake can imitate some of the signs and symptoms of diabetes, such as excessive thirst and urination.[2] Further, biotin supplementation can cause inaccurate results on multiple categories of medical lab tests.
Case studies and comparative tests have shown that biotin may cause inaccurate lab results in, for example, immunoassays that use biotin-streptavidin technology.
[3][4][5][6][7][8] Abnormally high or low readings as a result of biotin supplementation of as little as 10 mg/day could lead to misdiagnosis of pregnancy,[7] thyrotoxicosis,[8] Graves’ Disease,[9] and even heart attack.[6] Biotin concentrations are detectable in blood samples, which may help clinicians to assess whether biotin has affected a particular test result. Detectable levels of biotin have also resulted in false labs for serum tests including CK-MB, human chorionic gonadotropin (HCG, a hormone produced in pregnancy and some cancers), troponin, cortisol, ferritin, TSH, T3, T4, PTH, 25OHD, and prolactin; biotin may affect children’s and adults’ tests differently, and its effects on serum labs can also depend on intake levels.[5][6][7][8][10]