A cross-sectional study.
PARTICIPANTS: Fifty-two healthy subjects, aged 26 to 87 years, apparently free from conditions known to influence the
cobalamin status. Middle-aged subjects were defined as those younger than 65 years of age (median age 57 years) and older subjects as those 65 years and older (median age 75 years).
MEASUREMENTS: RESULTS: The median urinary excretion of egg yolk 57 Co-
cobalamin in middle-aged subjects was 12.3% (25th and 75th percentiles 10.5%-14.5%) compared with 11.7% (25th and 75th percentiles 9.8%-13.6%) in older subjects (P = .283). The median urinary excretion after administration of free 57 Co-
cobalamin in middle-aged subjects was 25.7% (25th and 75th percentiles 20.6%-30.7%) compared with 27.9% (25th and 75th percentiles 21.4%-34.5%) in older subjects (P = .694). Neither egg yolk nor free 57 Co-
cobalamin excretion correlated with age. A ratio of
pepsinogen A to
pepsinogen C less than 1.6, indicating
atrophic gastritis, was found in 13 subjects. Within the
atrophic gastritis group, 11 subjects had a
pepsinogen A concentration greater than or equal to 17 micrograms/L, indicating mild to moderate
atrophic gastritis, and two subjects had a
pepsinogen A concentration less than 17 micrograms/L, indicating severe
atrophic gastritis or gastric
atrophy. All subjects had normal fasting plasma
gastrin concentrations. Free and egg yolk 57 Co-
cobalamin excretions were not reduced in the
atrophic gastritis group when compared with the non-
atrophic gastritis group. Median plasma
cobalamin concentration was not significantly lower in older subjects (P = .205). Nonetheless, plasma
cobalamin concentration correlated negatively with age (r = -.36; P = .008).
CONCLUSIONS: We demonstrated no significant difference in either free or
protein-bound
cobalamin absorption between healthy middle-aged and older adults. In addition, no alteration in
cobalamin absorption was found in subjects identified as having mild to moderate
atrophic gastritis. Therefore, based on our results, the high prevalence of low
cobalamin levels in older people cannot be explained by either the aging process or mild to moderate
atrophic gastritis.