Thiamin Deficiency (Beriberi; Vitamin B1 Deficiency) By Larry E Johnson, MD, PhD, University of Arkansas for Medical Sciences Reviewed / Revised Nov 2022 View Patient Education Etiology Pathophysiology Symptoms and Signs Diagnosis Treatment Key Points Thiamin deficiency (causing beriberi) is most common among people subsisting on white rice or highly refined carbohydrates in countries with high rates of food insecurity and among people with alcohol use disorder.