Vitamin D Deficiency in Patients with Morbid Obesity before and after Metabolic Bariatric Surgery

Background: Metabolic bariatric surgery (MBS) is the most effective treatment for severe obesity. Vitamin D deficiency is a common complication encountered both during preoperative workup and follow-up. Aim: To estimate the prevalence of vitamin D deficiency in patients undergoing MBS. Methods: Prospectively maintained database of our university MBS center was searched to assess the rate of preoperative and postoperative vitamin D deficiency or insufficiency in patients undergoing MBS over a one-year period. Results: In total, 184 patients were included, 85 cases of Sleeve Gastrectomy (SG), 99 Gastric Bypass (GB; 91 One Anastomosis and 8 Roux-en-Y). Preoperative vitamin D deficiency and insufficiency were respectively found in 61% and 29% of patients, with no significant difference between SG and GB. After six months, 15% of patients had vitamin D deficiency, and 34% had vitamin D insufficiency. There was no significant difference in the rate of vitamin D deficiency or insufficiency and the percentage of total weight loss (%TWL) at 1, 3, and 6 postoperative months between SG and GB. Conclusions: Preoperative vitamin D deficiency or insufficiency is common in MBS candidates. Regular follow-up with correct supplementation is recommended when undergoing MBS. Early postoperative values of vitamin D were comparable between SG and OAGB.