Bariatric surgery is becoming an increasingly common procedure performed to achieve long-term weight loss in morbidly obese patients. Bariatric surgery may cause long-term morbidity because of vitamin and mineral deficiencies. This review synthesizes the research on vitamin D and calcium status in obese patients before and after bariatric surgery. The literature shows that morbidly obese patients are likely deficient in vitamin D prior to surgery because of poor sunlight exposure, less bioavailability of the vitamin when sequestered in fat cells, and inhibited hepatic vitamin activation. Gastric bypass surgery may further exacerbate vitamin D and calcium deficiencies secondary to poor compliance, loss to follow-up, reduced food intake, and malabsorption. It is imperative that research be conducted to determine adequate supplementation regimens for vitamin D and calcium in bariatric surgery patients.