Whole Blood Thiamine Levels in Extreme Anorexia Nervosa: A Pilot Study

Objective Risk for thiamine deficiency in individuals with anorexia nervosa (AN) remains uncertain due to significant heterogeneity in limited studies and given that current treatment recommendations are based on expert opinion and research in alcoholism. The purpose of this pilot study is to better understand thiamine deficiency in individuals with extreme AN. Method In this prospective, observational, pilot study, whole blood thiamine diphosphate (TDP) levels in 24 individuals with extreme AN, without nutritional rehabilitation or micronutrient supplementation for the preceding 30 days before admission, were compared to both a reference range and whole blood TDP levels in normal‐weighted individuals. Individuals in the AN cohort were also provided 200 mg of oral thiamine for the first 10 days of hospitalisation, to better understand the impact of supplementation during refeeding. Results Mean whole blood TDP levels were within the standard reference range and not statistically different from the control group. Whole blood TDP levels did not significantly increase after 10 days of oral thiamine supplementation. Conclusions Individuals with AN may not be at high risk for thiamine deficiency. A larger follow‐up study assessing whole blood TDP levels, without any recent thiamine supplementation, is required to fully understand the risk of thiamine deficiency.