Women with moderate to severe depression had substantial improvement in their symptoms of depression after they received treatment for their vitamin D deficiency, a new study finds. The case report series was presented June 23 at The Endocrine Society’s 94th Annual Meeting in Houston. Because the women did not change their antidepressant medications or other environmental factors that relate to depression, the authors concluded that correction of the patients’ underlying shortage of vitamin D might be responsible for the beneficial effect on depression