Association of Biotin Ingestion With Performance of Hormone and Nonhormone Assays in Healthy Adults

Abstract

Inaccuracy of laboratory medicine diagnostic tests may be associated with ingestion of over-the-counter vitamin and herbal supplements.^1,2 One such example is interference associated with biotin. Biotin (vitamin B7), a water-soluble vitamin found in meat, fish, eggs, and dairy,³ serves as a catalyst for carboxylase enzymes important in macronutrient metabolism.⁴ Biotin supplements, especially very large doses (eg, 10-15 mg/d, or 333-fold greater than the dietary recommendation of 30 µg/d)⁵ have become popular for presumptive health benefits such as stimulating hair growth and treating certain medical conditions including biotinidase deficiency, diabetes, lipid disorders, and diabetic peripheral neuropathy.^6-9 Ingestion of up to 300 mg/d may be beneficial for multiple sclerosis.^10,11 Taking high-doses of biotin may result in inaccurate laboratory results because biotin is commonly used, in the form of biotinylated antibodies or analogues, as a critical component in immunoassays. These assays exploit the strong, stable, and specific binding between biotin and streptavidin to amplify the assay sensitivity for detecting low analyte levels.^12,13 Excessive biotin in a blood sample can compete with biotinylated components in the assay, potentially falsely decreasing results in sandwich immunoassays or falsely increasing results in competitive immunoassays (eFigures 1 and 2 in the Supplement).¹⁴