People who use certain acid-suppressing drugs for two years or longer are at increased risk of vitamin B12 deficiency, which can lead to anemia, neurological problems or dementia, researchers reported last week.
The drugs in question are called proton-pump inhibitors, or PPIs, and histamine 2 receptor antagonists, and they are available by prescription and over the counter under brand names such as Prevacid, Prilosec and Nexium.
Nearly 157 million prescriptions were written for PPIs alone last year.
“People who are taking these medications are more likely than the average person to be vitamin B12 deficient, and it’s a potentially serious problem,” said Dr. Douglas A. Corley, senior author of the study published in The Journal of the American Medical Association.
“This raises the question of whether people taking these medications for long periods should be screened for vitamin B12 deficiency,” he said.
Corley has received funding from Pfizer, which makes a PPI called Protonix.
He and his colleagues at Kaiser Permanente in Oakland, Calif., examined the medical records of 25,956 adults who received vitamin B12 deficiency diagnoses between 1997 and 2011.
They compared them with 184,199 patients without B12 deficiency during that period.
Patients who took PPIs for more than two years were 65 percent more likely to have a vitamin B12 deficiency, the researchers found.
Higher doses of PPIs were more strongly associated with the vitamin deficiency, as well.
Twelve percent of patients deficient in vitamin B12 had used PPIs for two years or more, compared with 7.2 percent of control patients.
The risk of deficiency was less pronounced among patients using H2RAs long term: 4.2 percent, compared with 3.2 percent of nonusers.
Acid suppressants are used to treat gastroesophageal reflux disease, or GERD, and ulcers in the stomach or duodenum.
The authors of the new research do not recommended stopping PPIs or H2RAs in people with clear indications for treatment. But studies have found the drugs are often overused or used for longer than necessary.
Factors other than PPI use might explain the link to vitamin B12 deficiency. One is diet: Vitamin B12 is found in meat, seafood and dairy products, so it matters whether patients taking a PPI might also be vegetarian or vegan, said Dr. T.S. Dharmarajan, the vice chairman of medicine at the Wakefield campus of Montefiore Medical Center in New York, who was not involved in the research.
The report did not address this question.
