Omeprazole and Vitamin B₁₂ Deficiency

Abstract

The mainstay for cobalamin deficiency is correction of the underlying disorder and replacement therapy. Because the defect is often one of absorption, parenteral or intranasal routes are recommended. In most cases, replacement therapy is all that is needed. The vitamin preparation most commonly used is cyanocobalamin (also called vitamin B12), which has no known physiologic role but instead is converted to a biologically active form before it can be used by tissues. The studies reviewed in this article clearly show that omeprazole therapy will decrease the absorption of vitamin B12 by preventing its cleavage from dietary proteins. However, these data are insufficient to infer that clinically significant deficiency will occur over time. In fact, some of the studies suggest that the simple addition of juices or other acidic drinks into the diet may dramatically increase cobalamin absorption. Clearly, well-designed clinical trials are needed to evaluate this theory over an extended follow-up period to determine the clinical significance of omeprazole-associated vitamin B12 deficiency and possibly identify patients at risk for deficiency. In conclusion, the possibility of dietary vitamin B12 malabsorption should be considered in patients receiving chronic omeprazole treatment and presenting with signs and symptoms of deficiency. All healthcare workers should be made aware of the potential clinical complications of omeprazole-associated vitamin B12 deficiency since it may go unrecognized and is easily corrected. This is particularly relevant for elderly patients with poor dietary intake of vitamin B12, impaired vitamin B12 stores, and certain gastrointestinal disorders.

The Pathogenesis of Gastrointestinal Bacterial Overgrowth

“…Most studies have been negative [32,76,78,87], but recent data [66,72,74,77,91] may indicate otherwise, at least for bile acids. Gastric overgrowth by URT flora, the ultimate result of elevated gastric pH, may thus not be as harmless as currently thought [52,81,83,84]. Further studies are required [92] to clarify this important issue regarding the safety of pharmacological acid suppression in clinical practice.…”

“…Accordingly, omeprazole interferes with the absorption of vitamin B 12 [80][81][82][83] and protein assimilation [84]. The mechanism for altered vitamin B 12 absorption is prevention of its cleavage from dietary protein [83], for which the importance of the concurrent bacterial overgrowth has not yet been ruled out.…”

Long‐term use of proton pump inhibitors and vitamin B12 status in elderly individuals

“…In many reviews on the aetiology and diagnosis of vitamin B12 deficiency, it is stated that PPI use is a cause of vitamin B12 deficiency 7–11 . Screening for vitamin B12 deficiency in patients on long‐term treatment with PPIs has even been recommended 8, 12–14 . Short‐term studies have shown that PPI use indeed decreases the absorption of protein‐bound vitamin B12 15–17 .…”

Micronutrients and Older Adults

“…PPI medications can interfere with vitamin B 12 absorption from food by slowing the release of hydrochloric acid into the stomach. [124][125][126][127] This is a concern because acid is needed to release vitamin B 12 from food prior to absorption. Several recent studies found that vitamin B 12 status declined over time with use of acid-suppressing agents, thereby increasing the risk for B 12 deficiency.…”