Predictors of cobalamin deficiency in Guatemalan school children: diet, Helicobacter pylori, or bacterial overgrowth?

Abstract

The authors investigated whether low vitamin B12 intake, impaired gastric function, infection, and bacterial overgrowth were risk factors for the high prevalence of cobalamin deficiency observed in Guatemalan children. The plasma cobalamin concentration of 556 school children was measured and classified as low, marginal, or adequate. In 60 children from each of these three groups, concentrations of serum methylmalonic acid (MMA), plasma homocysteine, and plasma holotranscobalamin II were measured, and usual dietary B12 intake was estimated. Serum gastrin and pepsinogen I concentrations were measured, and and bacterial overgrowth were diagnosed using C-urea and C-xylose breath tests, respectively. infection was present in 83% (144 of 174) of children, and bacterial overgrowth was found in 25% (28 of 113). Children with infection had higher serum gastrin and pepsinogen I. There were no significant differences among the plasma cobalamin groups in the prevalence of infection, bacterial overgrowth, serum gastrin, or pepsinogen I concentrations. However, there was a significant positive correlation between serum MMA and gastrin concentrations. The average daily consumption of dietary B12 was 5.5 +/- 5.2 microg/day, but intakes for 23% of children were <1.8 micro g/day. B12 intake from fortified snacks added an additional 0.3 +/- 0.2 microg/day. B12 intake was not significantly different among the plasma cobalamin groups, but it was significantly correlated with plasma cobalamin. The specific cause of cobalamin deficiency in this population remains unclear, but these results suggest that low dietary B12 intake is a risk factor and alterations in gastric secretions may also play a role.