To determine whether serum vitamin B12 levels in non-vitamin B12 deficient healthy adults correlate with serological evidence of H. pylori infection.Background
An association between H. pylori infection and vitamin B12 deficiency has been recently reported.Study
133 adults, presenting to a community based primary care clinic who met the following exclusion criteria; history of H. pylori eradication or antacid use, liver disease, inflammatory bowel disease, previous gastrointestinal surgery, a vegetarian diet or multivitamin supplementation were studied. Blood was drawn for a complete blood count, serum vitamin B12, gastrin, folic acid and H. pylori IgG antibodies. Subjects with vitamin B12 ≤ 145 ng/mL (deficient range) were excluded.Results
Of 133 subjects 96 (72.2%) were seropositive for H. pylori IgG antibodies (HP+). Age of HP(+) subjects did not differ from that of seronegative subjects (HP−); 52.8 ± 1.6 mean ± SE versus 49.2 ± 2.9 (p = NS). Prevalence of HP seropositivity was significantly higher among subjects with borderline (>145–180 pg/mL) or low normal (>180–250 pg/mL) vitamin B12 levels than among those with vitamin B12 >250 pg/mL; among 25 subjects with vitamin B12 >145–180 pg/mL 92% were seropositive and among 47 subjects with vitamin B12 >180–250 pg/mL 89% were seropositive as compared with 31/61 (51%) of subjects with B12 >250 pg/mL, Fisher exact test p < 0.0001. Vitamin B12 levels did not correlate with age (r = −0.07). Gastrin levels (pg/mL) did not differ significantly between groups; 70.2 ± 5.8 in HP(+) versus 56.0 ± 12.4 in HP(−).Conclusions
The higher prevalence of H. pylori infection among subjects with serum vitamin B12 levels that are within the lower end of the normal range suggests a causal relationship between H. pylori infection and vitamin B12 levels in healthy adults.