Commonly used antacids may have an immediate effect on stomach acid, but new research suggests long-term use can be linked to a deficiency in vitamin B12.

According to Reuters, the study researchers determined that patients diagnosed with B12 deficiency were more likely to be on medications such as proton-pump inhibitors (PPIs) and histamine 2 receptor antagonists (H2RAs). Patients who were not were less likely to have a B12 deficiency.

"This doesn't mean people should stop their medications," study senior author Douglas Corley told Reuters. "People take these for good reasons. They improve quality of life and prevent disease."

Corley, a gastroenterologist and researcher at the Kaiser Permanente Division of Research in Oakland, California, added, "It does raise the question that people who are taking these medications should have their B12 levels checked."

For humans, B12 is commonly found in eating animal products, but it is also added to processed food and can be ingested as a dietary supplement pill. B12 is most associated with metabolism and a deficiency can result in being tired, weak, anemic and constipated. According to the U.S. National Institutes of Health, B12 deficiency can lead to nerve damage and dementia.

BBC News reported the study, published in the Journal of the American Medical Association, consisted of 200,000 people in the U.S. The deficiency is likely caused because acid is needed to absorb the B12 vitamins from foods like fish, meat and dairy in our stomachs.

Mark Pritchard, of the British Society of Gastroenterology, echoed Corley and said people should not be alarmed.

"Only patients who had taken these tablets for more than two years were at risk and only a minority of patients on long-term proton pump inhibitors showed evidence of vitamin B12 deficiency," he told BBC News.

Dr. Joel J. Heidelbaugh, an associate professor of family medicine at the University of Michigan, told the New York Times PPIs should not be considered the only like to a B12 deficiency. Other factors, primarily diet, are far more influential, especially when someone is not getting enough vitamin B12 in their daily diet.

"If you treat 67 people with PPIs for two years, one of them will have a vitamin B12 deficiency," he said. "Just because someone is deficient in B12, you don't know if they will develop a serious consequence."