From the Guidelines
Omeprazole may not directly cause vitamin B12 deficiency, but long-term use can interfere with the body's ability to absorb dietary vitamin B12. The relationship between omeprazole and vitamin B12 deficiency is complex, and the evidence is not conclusive. According to a study published in the Annual Review of Nutrition in 2021 1, the American Gastroenterological Association does not currently recommend screening for vitamin B12 deficiency in individuals taking proton pump inhibitors (PPIs) like omeprazole, due to the lack of causal evidence and heterogeneous findings. However, the study suggests that well-controlled, long-term trials are needed to determine the effects of PPIs on nutritional parameters. Some key points to consider:
- Omeprazole reduces stomach acid production, which is necessary for B12 absorption.
- Long-term use of omeprazole may interfere with the body's ability to absorb dietary vitamin B12.
- The risk of vitamin B12 deficiency is particularly significant for elderly patients, vegetarians, or those with limited dietary B12 intake.
- Periodic measurement of vitamin B12 levels may be considered in patients taking omeprazole long-term, especially if symptoms of deficiency appear. It is essential to weigh the benefits and risks of omeprazole treatment and consider alternative therapies or supplementation if necessary, to minimize the potential risk of vitamin B12 deficiency.
From the FDA Drug Label
Daily treatment with any acid-suppressing medications over a long period of time (e.g., longer than 3 years) may lead to malabsorption of cyanocobalamin (vitamin B-12) caused by hypo- or achlorhydria. Vitamin B-12 deficiency. Omeprazole delayed-release capsules reduce the amount of acid in your stomach. Stomach acid is needed to absorb vitamin B-12 properly. Talk with your doctor about the possibility of vitamin B-12 deficiency if you have been on omeprazole delayed-release capsules for a long time (more than 3 years).
Omeprazole may cause vitamin B-12 deficiency due to malabsorption caused by long-term use of acid-suppressing medications. This is because stomach acid is necessary for proper absorption of vitamin B-12. Patients taking omeprazole for more than 3 years should discuss the possibility of vitamin B-12 deficiency with their doctor 2, 2.
- Key points:
- Long-term use of omeprazole (more than 3 years) may lead to vitamin B-12 deficiency
- Stomach acid is necessary for proper absorption of vitamin B-12
- Patients should discuss the possibility of vitamin B-12 deficiency with their doctor if taking omeprazole for an extended period.
From the Research
Omeprazole and Vitamin B12 Deficiency
- Omeprazole therapy can decrease the absorption of vitamin B12 by preventing its cleavage from dietary proteins 3.
- Studies have shown that omeprazole therapy acutely decreases cyanocobalamin absorption in a dose-dependent manner 4.
- The absorption of protein-bound, but not unbound, cyanocobalamin is decreased during treatment with omeprazole 5.
- Long-term use of omeprazole is linked to an increased risk of vitamin B12 insufficiency, specifically in men falling under the ages of 18 and 40 6.
Mechanism of Deficiency
- Omeprazole prevents the cleavage of vitamin B12 from dietary proteins, leading to decreased absorption 3.
- The decreased absorption of protein-bound cyanocobalamin can lead to vitamin B12 deficiency over time 4, 5.
- The use of acidic drinks, such as juices, may increase cobalamin absorption and mitigate the risk of deficiency 3.
Clinical Significance
- Vitamin B12 deficiency can lead to various clinical complications, including cognitive decline and neurotoxicity 7.
- Healthcare workers should be aware of the potential clinical complications of omeprazole-associated vitamin B12 deficiency, particularly in elderly patients with poor dietary intake of vitamin B12 3.
- Patients on long-term omeprazole treatment should be monitored for signs and symptoms of vitamin B12 deficiency 3, 6.