Micronutrients (Other than iron) and Helicobacter pylori Infection: A Systematic Review

Background: Many micronutrients depend on a healthy stomach for absorption. Helicobacter pylori chronic gastritis may alter gastric physiology affecting homeostasis of vitamins and minerals. Objectives: Systematic review to assess whether H. pylori infection is associated with reduced micronutrient levels (other than iron) in the plasma or gastric juice and whether low micronutrient levels are modified by eradication treatment. Method: Medline was searched for relevant publications from inception to June 2010. Studies describing micronutrient levels in H. pylori-infected and not-infected adults and/or the effect of eradication treatment on micronutrient levels were included. Findings: Fifty-two publications were selected: 46 investigated the association between H. pylori infection and reduced micronutrient levels and 14 the effect of eradication treatment on micronutrient levels. Sixty-four studies investigated vitamins (23 ascorbic acid, four beta-carotene, 21 cobalamin, 11 folate, and five alpha-tocopherol) and 10 addressed minerals (one calcium, one copper, one magnesium, one phosphorus, three selenium, and three zinc). Pooled standardized mean differences in micronutrient levels showed positive associations with H. pylori infection for ascorbic acid (gastric juice, -1.087) and cobalamin (-0.744), and a positive effect of eradication treatment, which increased ascorbic acid in the gastric juice (-1.408) and serum cobalamin (-1.910). No significant association between infection and low folate levels was observed. Meta-analyses for other micronutrients were not performed owing to insufficient data. Conclusions: Meta-analyses indicate that H. pylori infection is associated with reduced levels of ascorbic acid and cobalamin, supported by the positive effect of eradication treatment. For other micronutrients, further studies are needed.