Association of aspirin use with vitamin B12 deficiency (results of the BACH study).

We examined the prevalence of vitamin B(12) deficiency and its association with medication use and characteristics, including infection with Helicobacter pylori (H. pylori), in 255 patients hospitalized for cardiovascular disease. In almost half of the study population, vitamin B(12) deficiency was found; patients using acetylsalicylic acid were more frequently vitamin B(12) deficient in comparison to nonusers (p = 0.02). Fifty-one percent of the patients were infected with H. pylori, and fewer infected patients were vitamin B(12) deficient.