Nutritional iodine intake in patients with anorexia nervosa

Iodine deficiency (ID) causes a wide range of health issues, from endemic goiter to more subtle effects resulting from reduced thyroid hormone production. The recommended daily iodine intake for adolescents and adults is 150 μg, which corresponds to a median urinary iodine concentration (UIC) of 100-299 μg/L at the population level. Individuals with anorexia nervosa typically suffer from deficiencies in micronutrients and vitamins, but there is little data on iodine status. This study assessed UIC and associated factors in a cohort of patients with anorexia nervosa.

This was a prospective monocentric exploratory observational study performed at the Centre Vaudois anorexie boulimie (abC) and the Division interdisciplinaire de santé des adolescents (DISA) of the Centre Hospitalier Universitaire Vaudois, University of Lausanne, Switzerland. The study included 39 patients with anorexia nervosa, aged ≥14 years, recruited between May and August 2022. After obtaining informed consent, anthropometric data were extracted from the electronic medical record and random spot urine samples were collected. The UIC was determined by ion-chromatography mass spectrometry.

Median age (IQR) was 18 (14-62) years and median body mass index (BMI) was 17.72 (14.86-23.54) kg/m2. Median UIC was 67.7 μg/L, and 22/39 individuals had a UIC <100 μg/L. There was a positive correlation between BMI and UIC (P = 0.047).

The findings suggest that patients with anorexia nervosa are at risk of ID, and lower BMI predicts lower UIC. Although these data need to be corroborated in a larger cohort, clinicians caring for patients with anorexia should consider recommending an iodine-containing multivitamin.