Impact of Preoperative Serum Vitamin D Level on Postoperative Complications and Excess Weight Loss After Gastric Bypass

Introduction The aim of this study was to determine the impact of hypovitaminosis D on Gastric Bypass outcomes. Methods We retrospectively reviewed all patients who underwent primary intention Gastric Bypass in our center between January 2012 and December 2013. Postoperative complications, 1 and 2-year excess weight loss were compared between patients with and without hypovitaminosis D. Results Among 258 patients who met inclusion criteria, 56 (21.7%) presented with vitamin D deficiency. Mean age was 41.73 ± 12.95 years. Mean BMI was 40.90 kg/m 2 (34–58 kg/m 2 ). No statistically significant difference in postoperative complication rate was found between patients with and without hypovitaminosis D. Mean 1-year excess weight loss was 75.24%. In patients with vitamin D deficiency mean 1-year excess weight loss was 71.90 versus 76.15% in patients with optimal serum vitamin D level ( p = 0.17). No significant difference was found after a 2-year follow-up. In patients presenting with vitamin D insufficiency, 1-year excess weight loss was 75.64 versus 79.34% in patients with optimal serum vitamin D level ( p = 0.53). After a 2-year follow-up, there was a significant difference between patients presenting with and without vitamin D insufficiency (79.45 versus 91.71%; p = 0.01) and between patients presenting with and without hypovitaminosis D (80.50 versus 91.71%; p = 0.01). Conclusion In our study, hypovitaminosis D seemed to have a negative impact on long term excess weight loss, but not on short-term outcome or postoperative complications. The role of systematic supplementation before bariatric surgery has to be explored in prospective studies.