Long-term use of common anti-acids could increase risk of vitamin B12 deficiency, a new study has found.

Vitamin B-12 is required for red blood cell formation, neurological function and even DNA synthesis. A recent study had shown that even mild vitamin B12 deficiency could lead to cognitive decline in older adults.

The vitamin is water soluble and can be found in clams, liver and fortified cereals. Stomach acids help absorb the vitamin, which is why suppressing these acids eventually leads to lower levels of vitamin B12. The latest study was conducted by Jameson R. Lam from Kaiser Permanente, Oakland, Calif., and colleagues.

In the current study, researchers wanted to investigate whether the use of common anti-acids such as proton pump inhibitors (PPIs) and histamine 2 receptors for two years led to vitamin B12 deficiency.  PPIs are quite common in the U.S. with 15 million people using them in 2012 alone.

"Patients who took PPI medications for more than two years had a 65 percent increase in their risk of B12 deficiency," said Douglas A. Corley, MD, PhD, a gastroenterologist and research scientist with the Kaiser Permanente Division of Research, according to a news release. "Higher doses also were associated with an increased risk, compared with lower doses."

Data for the study came from the Kaiser Permanente Northern California population. Researchers looked at the medical records of 25,956 patients diagnosed with vitamin B12 deficiency between January 1997 and June 2011 and compared them with data obtained from 184,199 patients who had no such clinical history.

Researchers also found women and youngsters using more potent antacids were more likely to be suffering from some level of vitamin deficiency.

The study is published in the Journal of the American Medical Association.