VITAMIN-B12 ABSORPTION CAPACITY IN HEALTHY-CHILDREN

  • 1 January 1986
    • journal article
    • research article
    • Vol. 5  (2) , 274-277
Abstract
B12 absorption was investigated in 47 healthy children aged 7 months to 15.8 years (median 4.9 years). The patients had either recovered from giardiasis, the postgastroenteritis syndrome, or had celiac disease in remission (treated with a gluten-free diet). The B12 absorption was measured by a double-isotope technique using 57CoB12 and 51CrCl3, the latter being the inabsorbable marker. The radiation dose was minimal. The results were presented as fractional absorption of B12 (FAB12). Within the different age groups, the absorption test was performed by means of the following oral amounts of B12: 0- < 1 year, 0.5 .mu.g; 1-3 years: 1.7 .mu.g, 4-6 years, 2.5 .mu.g; 7-10 years: 3.3 .mu.g; and 11-15 years, 4.5 .mu.g. When using these oral amounts of B12 the medians (and ranges) of FAB12 were found to be: 1-3 years (n = 18), 37% (16-80%); 4-6 years (n = 10), 27% (19-40%); 7-10 years (n = 9), 32% (21-44%); and 11-15 years (n = 8), 27% (19-59%). The FAB12 in two children aged 7 and 11 months was 31% and 32%, respectively. These results may be interpreted as reference values for B12 absorption in children. Further absorption tests were performed in seven children representing the four age groups from 1 to 15 years. When a high oral amount of B12 was given (i.e., three times the saturation dose), the FAB12 ranged from 0 to 20% (median 9%), whereas a low amount (i.e., one-ninth of the saturation dose) produced fractional absorptions from 65 to 82% (median 74%). These observations provide evidence that the saturation mechanism of B12 absorption in children is, in principle, similar to the one in adults. As the median FAB12 values for the above mentioned reference values for B12 absorption in children averaged about 30%, it may be concluded that the corresponding oral doses of B12 represent saturation amounts. Furthermore, our data show that children''s absorption capacity makes it possible for them to absorb a considerable fraction of the amounts of B12 stated as Recommended Dietary Allowances (RDA) for children in the different age groups. To the best of our knowledge, this study is the first of its kind in children.