Biotin-Related Lab Interference: The Prevalence of Excessive Biotin Use in Rural Michigan

Objective : Excessive intake of Biotin (Vitamin B7) can interfere with numerous lab tests that are analyzed via Striptavidin-Biotin immunoassays. Increased Biotin use in recent years, for skin-hair-nail health and as energy boosts and nutritional supplements, has lead to a parallel increase in lab interference in several commonly used lab tests, leading to misdiagnosis and unnecessary work up and treatment. Biotin intake of > 5 mg per day can cause such lab interference. A common misdiagnosis in numerous case reports and case series has been Graves' disease (falsely elevated thyroid hormones, coupled with suppressed TSH and positive TSI and TRAB). There is a paucity of literature on the prevalence of excessive Biotin use. A recent study from Mayo Clinic reported a prevalence of 7.7% in an outpatient setting.
The objective of this study is to evaluate the prevalence of clinically significant Biotin intake in a rural community.

Methods: Surveys were distributed to patients attending a family medicine rural health clinic in Alma, Michigan, to collect data on patient-reported Biotin use. The surveys collected data on the total daily doses in Biotin users. Additional demographic data were collected in the surveys.

Results: Between March 2021 and January 2022, a total of 264 patients completed the surveys. Incomplete data were found in 15 surveys, which were excluded from analysis. Of the remaining 249 study participants, 54 reported using Biotin (21.7%). Of these Biotin users, 87% of whom were females, 18 participants (7.2% of study participants) reported daily doses > 5 mg.

Discussion/Conclusion: The prevalence of clinically significant Biotin use in our rural cohort, 7.2%, is comparable to the prevalence reported in the Mayo Clinic's study. This implies that Biotin use is common across communities, urban and rural, alike. While excessive intake of Biotin is not toxic per se, adverse effects may result from erroneous diagnoses or missed diagnoses. The FDA issued a warning to the public about these adverse effects, citing a fatal case of myocardial infarction that was missed in the emergency department due to a falsely normal troponin level due to Biotin interference. Therefore, we recommend that clinicians be cautious in interpreting labs that appear inappropriate in the clinical context and to be attentive to the possibility of Biotin interference.