How does zinc supplementation benefit anorexia nervosa?

BACKGROUND

A randomized controlled trial of zinc supplementation in anorexia nervosa (AN) reported a two-fold increase of the rate of increase of body mass index (BMI) in the zinc group. Zinc is inexpensive, readily available and free of significant side effects. However, oral zinc supplementation is infrequently prescribed as an adjunctive treatment for AN. Understanding the mechanism of action of zinc may increase its use.

HYPOTHESIS

Low zinc intake, which is very common in AN, adversely affects neurotransmitters in various parts of the brain, including gamma-amino butyric acid (GABA) and the amygdala, which are abnormal in AN. Zinc supplementation corrects these abnormalities, resulting in clinical benefit in AN.

CONCLUSIONS

Oral administration of 14 mg of elemental zinc daily for 2 months in all patients with AN should be routine.