Spurious Thyroid Function Test Results due to Biotin Interference: a Report of Three Cases and a Literature Review

Biotin (vitamin B7) is a water-soluble vitamin used as co-enzyme for carboxylases essential human metabolism. The high affinity to streptavidin makes biotin an important substance in immunoassays. Excessive intake due over-the counter supplements has become problematic because of the effects on laboratory test results. There have been no reports biotin-induced thyroid immunoassay interference Korea. We report three patients with papillary cancer who showed false thyrotoxicosis follow-up examinations literature review. patients’ medical history should be thoroughly questioned and informed curtail consuming before tests avoid assay interference. Non-biotinylated assays can considered if it impossible withhold supplements. These methods will prevent physicians from making incorrect decisions that could result inappropriate treatment their patients.