A letter to the editor in the November 2017 issue (Holmes EW, Samarasinghe S, Emanuele MA, Meah F. Biotin Interference in Clinical Immunoassays: A Cause for Concern. Arch Pathol Lab Med. 2017;141[11]:1459-1460) incorrectly lists an oral dose of biotin as 10-mg in the first sentence of the third paragraph. The correct dose is 100-mg. The sentence should have read, “Healthy subjects who take a single 1-mg or 100-mg oral dose of biotin have mean peak serum biotin concentrations of 8.64 and 4955 ng/mL, respectively, occurring between 1 and 3 hours post dose and declining with half-lives of 8 to 19 hours.”