B12 Deficiency

 Patients with Roux-en-Y gastric bypass surgery can develop B12 deficiency and concomitant iron deficiency anemia.

Vitamin B12 (cobalamin) is a water-soluble vitamin, necessary for neurologic functioning, hematopoiesis, and DNA synthesis. It is obtained exclusively from animal proteins and absorbed in the ileum, facilitated by intrinsic Lack of intrinsic factor in gastric bypass patients make them appropriate candidate for lifelong replacement of B12.

Serum B12 less than 400 pg/mL is considered suboptimal because 5% to 10% of patients with neurologic symptoms related to B12 insufficiency present with levels from 200 to 400 pg/mL

Vitamin B12: 200-910 pg/mL ( reference range)