The Effect of Laparoscopic Sleeve Gastrectomy on Serum Levels of Vitamin A, D and B12 and Iron Profile on Patients with Morbid Obesity.

Background: One of the concerns after bariatric surgery is the lack of nutrients and vitamins due to anatomical and physiological changes that occur after the surgery. The aim of the present study is to evaluate the effect of laparoscopic sleeve gastrectomy on these nutrients and vitamins.

Materials and methods: This prospective study was performed in Tehran and all the patients who met the inclusion criteria before the surgery were tested for serum levels of vitamins A, B12, D, ferritin, serum iron, and TIBC. The patients were tested once again for the same micronutrients, one year after surgery.

Results: A total of 120 patients had the inclusion criteria and all of them completed the follow-up period. Of the patients, 64.2% (77 patients) were female and 35.8% (43 patients) were male. The mean weight of the patients was 122.1 ± 14.8 kg and the mean BMI of patients before surgery was 43.6 ± 4.4 kg/m². Comparing these parameters before and after surgery showed that serum levels of vitamins A and B12, ferritin, and TIBC were not significantly different from before surgery. However, vitamin D levels after surgery were significantly higher than before (p < 0.001).

Conclusion: The result of the present study demonstrated that laparoscopic sleeve gastrectomy is one of the most effective surgical methods for obesity treatment and does not cause a lack of nutrients and vitamins in long term and does not require supplementation. In addition, it promotes serum levels of vitamin D, which is effective in preventing the effects of vitamin D deficiency in obese patients.