A. Gleerup et al., IRON-ABSORPTION FROM THE WHOLE DIET - COMPARISON OF THE EFFECT OF 2 DIFFERENT DISTRIBUTIONS OF DAILY CALCIUM INTAKE, The American journal of clinical nutrition, 61(1), 1995, pp. 97-104
The possibility of reducing calcium inhibition of iron absorption by d
ecreasing calcium intake in lunch and dinner meals, which provided the
most dietary iron, was examined in 21 healthy female volunteers. Duri
ng a 10-d period, nonheme iron in all meals was extrinsically labeled
with radioisotopic iron to a uniform specific activity. Iron absorptio
n from two identical 10-d periods was compared when meals were labeled
with two different iron radioisotopes and when the same amount of cal
cium (937 mg) was distributed in two ways, in either mainly breakfast
and late evening meals or more evenly in all meals. About 30-50% more
iron was absorbed when no milk or cheese was served with lunch or dinn
er. The difference was statistically significant. Median iron requirem
ents (1.61 mg/d) calculated from body weight and menstrual iron losses
agreed with the mean value of median iron absorption in the two 10-d
periods (1.54 mg/d), which supports the validity of the present method
. A reasonable separation of calcium and iron intakes would improve ir
on nutrition.