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Original Investigation
September 26, 2017

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

Author Affiliations
  • 1Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis
  • 2Department of Medicine, Division of Diabetes, Endocrinology and Metabolism, University of Minnesota, Minneapolis
  • 3School of Medicine, University of Minnesota, Minneapolis
  • 4School of Public Health, Division of Biostatistics, University of Minnesota, Minneapolis
  • 5Department of Pathology and Laboratory Medicine, Boston Medical Center, Boston, Massachusetts
  • 6Department of Pathology and Laboratory Medicine, Children’s Mercy Hospitals, Kansas City, Missouri
  • 7Department of Pathology, Johns Hopkins Medical Institutions, Baltimore, Maryland
JAMA. 2017;318(12):1150-1160. doi:10.1001/jama.2017.13705
Key Points

Question  Does oral biotin supplementation interfere with hormone and nonhormone assays that use biotinylation in their design?

Findings  In this nonrandomized crossover study of 6 healthy adults (2 women, 4 men), 10 mg/d of biotin ingested for 1 week was associated with potentially clinically important assay interferences in some but not all biotinylated hormone and nonhormone assays studied.

Meaning  Oral biotin use may be associated with false hormone and nonhormone assay results.


Importance  Biotinylated antibodies and analogues, with their strong binding to streptavidin, are used in many clinical laboratory tests. Excess biotin in blood due to supplemental biotin ingestion may affect biotin-streptavidin binding, leading to potential clinical misinterpretation. However, the degree of interference remains undefined in healthy adults.

Objective  To assess performance of specific biotinylated immunoassays after 7 days of ingesting 10 mg/d of biotin, a dose common in over-the-counter supplements for healthy adults.

Design, Setting, and Participants  Nonrandomized crossover trial involving 6 healthy adults who were treated at an academic medical center research laboratory

Exposure  Administration of 10 mg/d of biotin supplementation for 7 days.

Main Outcomes and Measures  Analyte concentrations were compared with baseline (day 0) measures on the seventh day of biotin treatment and 7 days after treatment had stopped (day 14). The 11 analytes included 9 hormones (ie, thyroid-stimulating hormone, total thyroxine, total triiodothyronine, free thyroxine, free triiodothyronine, parathyroid hormone, prolactin, N-terminal pro-brain natriuretic peptide, 25-hydroxyvitamin D) and 2 nonhormones (prostate-specific antigen and ferritin). A total of 37 immunoassays for the 11 analytes were evaluated on 4 diagnostic systems, including 23 assays that incorporated biotin and streptavidin components and 14 assays that did not include biotin and streptavidin components and served as negative controls.

Results  Among the 2 women and 4 men (mean age, 38 years [range, 31-45 years]) who took 10 mg/d of biotin for 7 days, biotin ingestion–associated interference was found in 9 of the 23 (39%) biotinylated assays compared with none of the 14 nonbiotinylated assays (P = .007). Results from 5 of 8 biotinylated (63%) competitive immunoassays tested falsely high and results from 4 out of 15 (27%) biotinylated sandwich immunoassays tested falsely low.

Conclusions and Relevance  In this preliminary study of 6 healthy adult participants and 11 hormone and nonhormone analytes measured by 37 immunoassays, ingesting 10 mg/d of biotin for 1 week was associated with potentially clinically important assay interference in some but not all biotinylated assays studied. These findings should be considered for patients taking biotin supplements before ordering blood tests or when interpreting results.

Trial Registration  clinicaltrials.gov Identifier: NCT03034707