Vitamin D and hypophosphatemia in patients with anorexia nervosa and avoidant/restrictive food intake disorder: a case control study.

Refeeding hypophosphatemia (RH) is a common and potentially serious complication of nutrition restoration, yet its risk is not fully understood. Vitamin D is an important part of phosphorus absorption in the gut. We examined 25-hydroxy vitamin D levels on admission and the relationship with RH in individuals with avoidant/restrictive food intake disorder (ARFID) and anorexia nervosa (AN). Results showed individuals with ARFID had significantly lower vitamin D levels than individuals with restrictive type AN, but not individuals with binge/purge type AN. Additionally, analyses showed that higher levels of vitamin D may play a role in the association between RH and weight on admission. Better understanding of RH risk may improve care.