Effect of Laparoscopic Sleeve Gastrectomy on Calcium Homeostasis: A Single-Center Study

Background: Treatment of obesity includes medical and surgical options.Bariatric surgery is a relatively new and successful therapy for obesity.The laparoscopic sleeve gastrectomy (LSG) is one of the most common operations done to manage obesity.Objective: This study aimed to assess calcium, phosphorus, and vitamin D levels in patients who performed LSG.Subjects and method: This retrospective study included 64 cases.The cases were divided into two major groups.Group 1 included obese patients who underwent LSG and took vitamin D and calcium supplements and group 2 that included obese patients who underwent LSG and did not take supplements.Anthropometric measures were performed for all participants.Routine lab investigations and calcium and phosphorus levels were determined by spectrophotometry. Results:In group 1, there were highly significant increases in calcium and vitamin D levels at 3 months after LSG when compared to before LSG (P<0.001).However, phosphorus levels showed no significant differences (P=0.242).In group 2, there were highly significant decreases in the levels of serum calcium, and vitamin D at 3 months after LSG when compared to before LSG (P<0.001, for each).Additionally, phosphorus levels showed a significant decrease (P=0.006). Conclusion:The anthropometric measures, lipid profile, and fasting and two hours post-prandial blood glucose levels showed marked decreases mediated by weight loss by LSG.In addition, calcium, phosphorus, and vitamin D showed a marked decline after LSG by 3 months, which was compensated by supplementation.