Analysis of vitamin levels and deficiencies in bariatric surgery patients: a single-institutional analysis

Background: Bariatric surgery patients are at risk for vitamin deficiencies. Objectives: Investigate the prevalence of deficiencies of vitamins A, B1, B12, D, and folate in sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB) patients in a single institution. Setting: An academic medical center. Methods: Retrospective chart reviews of 468 bariatric surgery patients (358 SG and 110 RYGB) were analyzed for vitamin levels, calcium, and parathyroid hormone. Both preoperative and postoperative measurements were obtained. Results: Deficiency of vitamin D was the most common, seen in 27% preoperatively. Postoperatively, RYGB patients had a higher prevalence of vitamin D deficiency than SG patients (11.5% RYGB versus 5.2% SG within the first postoperative year, and 20.3% RYGB versus 13.4% SG after 1 year). Elevated parathyroid hormone was observed in 45% of RYGB patients after 1 year postoperatively. Vitamin A deficiency was uncommon preoperatively (2.7% SG versus 1.7% RYGB), but increased after surgery (9.4% SG versus 15.9% RYGB within 1 year postoperatively, and 5.2% SG versus 7.7% RYGB after 1 year). Vitamin B1 deficiency was observed in 8.1% SG versus 1.7% RYGB patients preoperatively and increased during the first year postoperatively (SG 10.5% and RYGB 13.7%), but improved after 1 year (7.2% SG versus 5.9% RYGB). Less than 2% of Vitamin B12 deficiencies and no folate deficiencies occurred in both SG and RYGB patients. Conclusions: The highest prevalence of vitamin B1 and A deficiencies were seen in the first year postoperatively. Vitamin B12 and folate deficiency were uncommon in our patients. Vitamin D deficiency improved after surgery, but elevated parathyroid hormone was common after RYGB.