Aberrant Thyroid Function Tests in a Patient Taking Biotin Supplements

Abstract

Biotin is a component of the B-complex vitamins that has been widely used in over-thecounter supplements. The effects of biotin on thyroid function tests (TFTs) have been recently reported by multiple authors. We report here a case of a patient who presented with TFTs consistent with hyperthyroidism and a positive radioactive iodine uptake (RAIU) scan while taking biotin supplements. The TFTs normalized almost a month later and continued to be normal even after resumption of biotin supplements. Interpreting TFTs while patients are taking biotin could pose a diagnostic challenge, so we suggest more frequent monitoring for those patients before starting them on long-term anti-thyroid medications.

Novel mutation causing propionic acidemia associated with unexplained autoimmune thyrotoxicosis

“…In fact, the manufacturers of a widely used thyroid function assay, Roche Cobas TM,specifically advise an interval of at least 8 h after last biotin ingestion prior to thyroid function testing [ 21 ]. Moreover, one anecdotal case reported presence of TPO antibodies in an adult on Biotin supplementation while another article reported presence of TRAB antibodies in their patient [ 21 , 22 ]. In both these cases, FT3 and FT4 levels was elevated while TSH levels were suppressed because of biotin immune assay interference [ 21 ].…”

Biotin-induced thyroid stimulating hormone aberrations in the setting of immunotherapy

“…Biologically, it has importance as an essential enzyme cofactor for normal metabolism. 1 While the recommended daily allowance (RDA) of biotin is approximately 30 micrograms per day for adults, some products may contain up to 100 milligrams per dose. The Food and Drug Administration (FDA) has recently issued statements regarding the interference of biotin with thyroid function tests (TFT).…”