June 26, 2014
Popular drugs for heartburn may lead to deficiencies in vitamin B12, a vitamin critical for brain and nervous system health. People who used the drugs for two years or longer were at increased risk of low vitamin B12 levels, which could lead to dementia and other serious symptoms.
“Vitamin B12 deficiency is relatively common, especially among older adults; it has potentially serious medical complications if undiagnosed,” wrote the authors. “Left untreated, vitamin B12 deficiency can lead to dementia, neurologic damage, anemia and other complications, which may be irreversible.” The findings appeared in JAMA, from the American Medical Association.
The drugs in question suppress stomach acids and are known as proton pump inhibitors (PPI’s) and histamine 2 receptor antagonists (H2RA’s). They are commonly used to treat acid reflux, or gastroesophageal reflux disease, and stomach and intestinal ulcers. They are available by prescription as well as over-the-counter and sold under such brand names as Prilosec and Nexium.
The findings are important because as many as four in 10 Americans have symptoms of acid reflux, and many depend on such drugs to control symptoms, putting them at risk of vitamin B12 deficiency. The problem may be particularly acute in seniors, who typically have a harder time absorbing the vitamin even without taking the drugs than younger patients.
In the study, doctors at Kaiser Permanente in Oakland, Calif., looked at 25,956 patients who were newly diagnosed with vitamin B12 deficiency. Twelve percent of those patients had been taking PPI’s for at least two years, compared with 7.2 percent of patients who weren’t taking the drugs. B12 deficiency was present in 4.2 percent of those taking H2RA’s, compared with 3.2 percent of nonusers.
The higher the dose of acid-suppressing drugs that someone was taking, the greater the risk of vitamin B12 deficiency. The link to B12 deficiency decreased after people stopped taking the drugs.
“At minimum, the use of these medications identifies a population at higher risk of B12 deficiency, independent of additional risk factors,” the authors wrote. “These findings do not recommend against acid suppression for persons with clear indications for treatment, but clinicians should exercise appropriate vigilance when prescribing these medications and use the lowest possible effective dose.”
The researchers encourage patients who are taking or considering taking acid reflux drugs to discuss the risks and benefits with their doctors. Patients should also be monitored for levels of vitamin B12.
Other studies have shown that B12 and other B vitamins may be good for the brain and help to keep memory sharp in old age. One report noted that supplements of three B vitamins – folic acid, vitamin B6 and vitamin B12 – appear to help to keep brain areas critical for memory and thinking in good health in seniors with mild cognitive impairment, a form of memory loss that can lead to Alzheimer’s disease. Another study found that B12 supplements can help to prevent brain shrinkage, a sign of possible Alzheimer’s disease and poor brain function.
Vitamin B12 is found in high amounts in meats, seafood and dairy foods. After age 50, some people have trouble absorbing B vitamins from foods, particularly vitamin B12, and supplements are recommended. Those taking acid-suppressing drugs long-term will want to stay particularly vigilant in having their doctors monitor their B12 levels to help stave off possible memory problems and other symptoms like anemia and neurological problems.
Source: Jameson R. Lam, MPH; Jennifer L. Schneider, MPH; Wei Zhao, MPH; Douglas A. Corley, MD, PhD: “Proton Pump Inhibitor and Histamine 2 Receptor Antagonist Use and Vitamin B12 Deficiency.” JAMA Vol 310. No. 22, December 11, 2013.