Which surgical intervention might lead to a greater risk of developing B12 deficiency?

Sleeve gastrectomy has specific physiological implications that can lead to an increased risk of developing vitamin B12 deficiency. This surgical procedure involves the removal of a significant portion of the stomach, which reduces gastric surface area and alters the anatomy of the gastrointestinal tract. One critical aspect of vitamin B12 absorption is intrinsic factor, a protein produced in the stomach that binds to vitamin B12 and is necessary for its absorption in the intestines.

While the sleeve gastrectomy does not directly affect intrinsic factor production as extensively as other procedures, the reduced stomach volume may lead to decreased acid production and altered gut flora, which can indirectly affect absorption of vitamin B12 later in the gastrointestinal tract. Additionally, the malabsorptive nature of smaller gastric capacity may contribute over time to nutritional deficiencies if monitoring and supplementation are not adequately addressed post-surgery.

In comparison, gastric banding and adjustable gastric bands are primarily restrictive procedures that do not typically impact nutrient absorption significantly. Roux-en-Y gastric bypass does have a stronger association with B12 deficiency due to its bypassing of the duodenum, where intrinsic factor is released, but the sleeve still presents a notable risk because of its reduction in stomach size and potential effects on nutrient absorption. Therefore, the sleeve gastrectomy carries