Acid Inhibition Associated with B12 Deficiency

By Joe Elia

Use of acid-suppressing drugs for more than 2 years is associated with a greater risk for vitamin B12 deficiency, according to a JAMA study. Gastric acid plays a key role in extracting B12 from dietary proteins.

Using Kaiser Permanente health records, researchers identified 26,000 cases of incident B12 deficiency, comparing their medication histories with those of 185,000 controls without the condition.

Incident B12 deficiency was more likely among those who'd received 2 years or more of proton pump inhibitors than among nonusers (odds ratio, 1.65). The effect was more pronounced in those taking 1.5 PPI pills a day or more; similar dose-dependent effects occurred with histamine-2 receptor antagonists. The association weakened with time after discontinuation of drug use.

The authors write that their findings don't argue against acid suppression, but instead advise that "clinicians should exercise appropriate vigilance" when prescribing the drugs.