SUMMARY OF THE STUDY
The goal of this study was to determine how common biotin consumption was in a population using a questionnaire and also measuring biotin levels in samples collected from patients presenting to the emergency department at Mayo Clinic. A total of 4000 questionnaires were distributed to patients scheduled for blood work during a period of one week ( July 10-14, 2017), and 1944 patients returned completed questionnaires. There was a very similar number of male and female responders.
A total of 812 ( 41.8%) of patients reported taking multivitamins and 149 patients (7.7%) reported taking biotin supplements. Of these, 29.5% did not know what dose they were taking, 8.1% reported taking 10,000 mcgs, 14.8% reported 5,000mcgs, 18.1% reported 1,000 mcg and 47% reported taking less than 1000 mcgs.
Biotin was measured in residual plasma samples from specimens of patients presenting to the emergency department over a two week period representing 1442 unique blood samples. Biotin levels were unmeasurable in 737 samples, > 5ng/mL in 705 samples and >10 ng/mL in 107 (7.4%) of samples. Of these 107 patients, only 2 had biotin reported in their electronic medical records. A total of 14 patients had biotin concentrations >30 mg/mL.
The lowest concentration at which biotin has been reported to interfere in a commonly used assay is 10 ng/ mL, however the concentration at which it may interfere with other assays may be different ( higher or lower).
WHAT ARE THE IMPLICATIONS OF THIS STUDY?
This study showed that >7% of patients seen in the emergency department at Mayo Clinic had biotin levels sufficient to cause false lab results with commonly used laboratory assays that measure thyroid hormone. Further, only ~30% of those reported taking biotin or multivitamins. This study is important for patients because it shows the magnitude at which a commonly used supplement can cause false laboratory test results that can lead to misdiagnosis and wrong treatments.
— Jessie Block-Galarza, MD