Effect of infant cereals on zinc and copper absorption during weaning
J. G. Bell, C. L. Keen and B. Lonnerdal
Zinc and copper absorption from five infant cereal products mixed with
water, human milk, or cow's milk was measured using an in vivo absorption
model (rat pup) involving gastric intubation of extrinsically radiolabeled
diets. Whole-body copper 64 uptake, nine hours after intubation, ranged
from 14% to 31% of the dose given for the different cereal combinations.
The resultant bioavailability of copper from human milk-cereal combinations
(23% to 26%) was significantly lower than that from human milk alone (38%).
Whole-body zinc 65 uptake, nine hours after intubation, ranged from 13% to
54% of the dose given for the different cereal combinations. These values
were significantly lower than the whole-body zinc 65 uptake from milk alone
(61%). Zinc availability was lower (13% to 25%) from dry cereal
combinations that contained phytic acid (oatmeal and high-protein
varieties) compared with the ready-to-serve cereal-fruit combinations (24%
to 54%). The highest zinc uptake (37% to 54%) was from rice-fruit
combinations that do not contain phytic acid. We estimated the amounts of
zinc and copper that would be absorbed from these cereal products and
speculated on the potential impact of these foods on the weaning infant's
zinc and copper nutriture. Depending on the feeding practices employed
during the weaning period, it is apparent that infant cereals may
compromise utilization of zinc and copper from milk diets during weaning.
