Vitamin D status before and after bariatric surgery during 4 years of follow-up

Background: Bariatric surgery for severe obesity can lead to micronutrient/vitamin deficiencies. Aim: To study baseline and post-surgical prevalence of vitamin D deficiency in patients undergoing bariatric surgery. Setting: University teaching hospital in North-West England. Methods: We performed an observational cohort analysis of longitudinal data on vitamin D and related parameters in patients who underwent bariatric surgery. Patients were routinely recommended daily combined calcium and vitamin D supplementation post-surgery. Results: We studied 480 patients with a median age of 48.8 years, weight 139.3 kg and body mass index 49.3 kg/m2 who underwent gastric bypass (277; 58.9%), sleeve gastrectomy (168; 35.7%) or other primary bariatric surgery (25 patients; 5.3%). Median vitamin D level was significantly lower at baseline and improved with supplementation post-surgery (Table 1). Whereas 52.8% had vitamin D deficiency (<30.0 nmol/l) and 25.1% insufficiency (≥30.0 <50.0 nmol/l) preoperatively, 13.3 and 23.0% had deficiency and insufficiency, respectively, at 12 months with similar trends up to 4 years of follow-up. Conclusion: Vitamin D deficiency and insufficiency were commonly prevalent pre-surgery, which reduced significantly with routine supplementation post-surgery.