<i>Helicobacter pylori</i> Infection, Vitamin B<sub>12</sub> and Homocysteine

It has been suggested that there is an association between <i>Helicobacter pylori</i> infection, reduced cobalamin absorption and cobalamin status and, consequently, elevated homocysteine levels. This would offer an explanation why <i>H. pylori</i> infection is associated with coronary heart disease. To date, more than 25 studies have been published that either deal with <i>H. pylori</i> infection and homocysteine, <i>H. pylori</i> infection and cobalamin status, or both. The design of these studies differs widely in terms of definition of <i>H. pylori</i> status, measuring cobalamin status, selection of study cohorts and geographical study areas. Therefore, results are fairly inconclusive at present and do not suggest a major role of <i>H. pylori </i>infection in the development of cobalamin deficiency and elevated homocysteine levels.