Association of Biotin Ingestion With Performance of Hormone and Nonhormone Assays in Healthy Adults.
Level 3 - non-randomized controlled study
Nonrandomized crossover / before-after study in healthy volunteers
PubMed 28973622 · doi:10.1001/jama.2017.13705
What was done
Six healthy adults (2 women, 4 men; age range 31–45 years) took 10 mg/d of oral biotin for 7 days in a nonrandomized crossover study. Blood samples collected at baseline (day 0), day 7 (treatment end), and day 14 (7 days post-treatment) were tested across 37 immunoassays on 4 diagnostic systems. Evaluated analytes comprised 9 hormones (TSH, total T4, total T3, free T4, free T3, PTH, prolactin, NT-proBNP, 25-hydroxyvitamin D) and 2 nonhormones (PSA, ferritin), spanning 23 biotinylated assays and 14 nonbiotinylated negative controls.
What was found
Biotin-associated interference occurred in 9 of 23 (39%) biotinylated assays compared with 0 of 14 (0%) nonbiotinylated assays (P = .007). Among biotinylated platforms, 5 of 8 (63%) competitive immunoassays showed falsely elevated results, whereas 4 of 15 (27%) sandwich immunoassays showed falsely decreased results.
Why it matters
Over-the-counter biotin supplements at standard consumer doses (10 mg/d) can systematically distort routine laboratory hormone and protein panels, creating false-positive or false-negative diagnostic findings depending on assay design.
Limits
The study included only 6 healthy participants and evaluated a single dosage regimen (10 mg/d for 7 days). It did not test patients with underlying endocrine disorders or assess interference across all commercial diagnostic platforms.
Cited by
- supports Taking 300 micrograms or more of biotin supplementation for seven days interferes with laboratory assays for steroid and thyroid hormones, including estradiol, progesterone, hCG, TSH, and testosterone.