Cross-sectional Long-term Micronutrient Deficiencies After Sleeve Gastrectomy Versus Roux-en-Y Gastric Bypass: a Pilot Study

Background: Nutritional deficiencies are highly prevalent in obese patients. Bariatric surgery has been associated with adverse effects on homeostasis of significant vitamins and micronutrients, mainly after gastric bypass. The aim of the present study was to compare the extent of long-term postsurgical nutritional deficiencies between Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG).

Methods: This cross-sectional, pilot study included 95 patients who underwent RYGB or SG surgery with a mean follow-up of 4 years. Demographic, anthropometric, and biochemical parameters were compared according to the type of surgery.

Results: Both types of surgery were associated with significant nutritional deficiencies. Vitamin B12 deficiency was significantly higher in patients with RYGB compared with SG (42.1% versus 5%, P = .003). The type of surgery was associated neither with anemia nor with iron or folate deficiency (SG versus RYGB: anemia, 54.2% versus 64.3%, P = .418; folate deficiency, 20% versus 18.4%, P = .884; iron deficiency, 30% versus 36.4%, P = .635).

Conclusion: During a mean follow up period of 4 years postRYGB or SG, patients were identified with several micronutrient deficiencies, including vitamin D, folate, and vitamin B12. SG may have a more favorable effect on the metabolism of vitamin B12 compared with RYGB, being associated with less malabsorption. Adherence to supplemental iron and vitamin intake is of primary significance in all cases of bariatric surgery.