Further assessment of the prevalence of biotin supplementation and its impact on risk.

•Awareness of biotin interference has been heightened requiring assessment of the prevalence of high dose supplementation.•The only previously published study indicated 7% prevalence of biotin levels over 10 μg/L in the USA.•Our emergency department study finds <1% over 10 μg/L in Australia.•The mitigation of biotin risk depends on understanding the population as well as the specific vulnerability of each assay.