Nikola Baumann, Ph.D., Director of the Central Clinical Laboratory and Central Processing Laboratory at Mayo Clinic, was recently featured in a CAP Today article about biotin interference. According to findings of a Mayo Clinic study published recently in Clinical Biochemistry, biotin use is not rare, and don’t count on it being listed in the patient’s electronic medical record.
The research analyzed several questions, including: How prevalent is biotin use, and who is taking it? In one week in July 2017, Dr. Baumann and colleagues surveyed 4,000 Mayo Clinic outpatients who presented for scheduled blood collections. Of those surveyed, 1,944 returned completed paper questionnaires (972 female, 963 male, 9 unspecified).
“I found it quite surprising that eight percent said, yes, they were taking biotin,” Dr. Baumann said. “And what was also interesting is that 5% didn’t know if they were taking biotin. So people are taking over-the-counter supplements and may not even be aware what they’re taking.” The study also found that an alarmingly high percentage of samples (7.4%) had biotin concentrations that fell at or above the lowest thresholds for assay interference (10 ng/mL), while nearly 2% of samples had biotin concentrations greater than or equal to 20 ng/mL.
The study also looked at what serum biotin concentrations laboratories and providers can expect to see in patients taking biotin supplements in the range of 1,000 to 10,000 mcg/day. According to Dr. Baumann, after five days of biotin supplementation, peak serum concentrations were comparable to those of day one, with levels decreasing by 12 hours but not returning to baseline.“What’s interesting here is that biotin is rapidly absorbed, and there is a broad distribution of concentrations following a single dose of biotin,” she said.
Mayo Clinic’s quest to understand and mitigate the impact of biotin interference began in July 2015, when a physician questioned a patient’s free T4 lab results. In September of the same year, biotin interference was confirmed as the reason for the discrepant results on that patient, and a month later Dr. Baumann and colleagues began retesting all samples with elevated free T4 to check for interference.
In using a new retesting protocol for two years, Mayo Clinic has found 17 confirmed cases of biotin interference. “What I think is striking is that 15 of those cases were found after we had implemented patient instructions that explicitly say to refrain from using biotin” before a draw, Dr. Baumann said.