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Can Prilosec Interfere With Vitamin B12 Injections?

Vitamin B12 injections are a common treatment for pernicious anemia. Injections are not affected by acid-suppressing medicines.
Can Prilosec Interfere With Vitamin B12 Injections?
Vitamin B12 (cobalamin) in a syringe ready for injection with vials in the background; Vitamin B12 injections

Have you ever heard of pernicious anemia? This rare condition is an autoimmune disorder in which the immune system attacks parietal cells in the stomach. These cells secrete a substance, mysteriously known as “intrinsic factor,” that promotes vitamin B12 absorption from the digestive tract. Without intrinsic factor, people develop vitamin B12 deficiency, with symptoms such as fatigue, a distinctive change in red blood cells, nausea, indigestion and other digestive problems, weakness, headaches and weight loss. Doctors treat this problem by providing vitamin B12 (Medical Laboratory Observer, Feb. 2007). In Canada and Sweden, they prescribe high-dose B12 pills. In the US, however, most physicians give vitamin B12 injections. These need to be provided on a regular basis throughout the patient’s life.

Do Heartburn Medicines Block the Benefits of Vitamin B12 Injections?

Q. I was diagnosed a decade ago with pernicious anemia. Since that time, I have been getting regular injections of vitamin B12.

In the meantime, I began taking Prilosec to control nightly acid reflux due to a hiatal hernia. I understand that Prilosec can block absorption of vitamin B12 from food. Is this acid blocker a problem for my injections?

A. Pernicious anemia is a serious condition that prevents people from absorbing vitamin B12 normally from the digestive tract. Drugs that reduce stomach acid, as omeprazole does, also make it harder to absorb this nutrient from food. That holds even for people who would not otherwise have difficulties.

Can You Take Pills Instead of Injections?

Several studies demonstrate that oral vitamin B12 at a dose of 1000 micrograms daily replaces vitamin B12 levels even for people with pernicious anemia (Frontiers in Medicine, Aug. 23, 2016). Surprisingly, although scientists started documenting its efficacy before 1960, relatively few physicians in the US prescribe pills. Instead, they prefer injections. In your case, however, this might be a good thing. You don’t need to worry about interference from your heartburn pill.

Vitamin B12 injections bypass the stomach and should not be affected by a medication like omeprazole (Prilosec). Have your doctor monitor your B12 levels to make sure you are getting enough.

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About the Author
Terry Graedon, PhD, is a medical anthropologist and co-host of The People’s Pharmacy radio show, co-author of The People’s Pharmacy syndicated newspaper columns and numerous books, and co-founder of The People’s Pharmacy website. Terry taught in the Duke University School of Nursing and was an adjunct assistant professor in the Department of Anthropology. She is a Fellow of the Society of Applied Anthropology. Terry is one of the country's leading authorities on the science behind folk remedies. .
  • Kumar V, "Pernicious anemia." Medical Laboratory Observer, Feb. 2007.
  • Chan CQH et al, "Oral vitamin B12 replacement for the treatment of pernicious anemia." Frontiers in Medicine, Aug. 23, 2016. DOI: 10.3389/fmed.2016.00038
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