Patients on acid suppressive therapy should take supplemental vitamin B12.
Gastric acid is needed to release food-bound vitamin B12 from protein for absorption. By inhibiting gastric acid secretion, PPIs and H2 blockers may impair the absorption of dietary vitamin B12.
Vitamin B12 deficiency is a common cause of anemia and can also lead to neurological changes. Symptoms of deficiency can include fatigue, numbness and tingling in the extremities, depression, and confusion.
There are studies that show PPIs and H2 blockers can lower serum vitamin B12 levels. But, these were studies in people who were using acid suppressive therapy chronically for many years.