Severe deficiencies of
iron (Fe) and
iodine (I) affect more than one third of the world's population. A
table salt, fortified with I and Fe, would be useful in areas in which
anemia and
goiter coexist. However, interactions between the two minerals have prevented their simultaneous use as fortificants. A method has been developed to coat I with
dextran such that after spraying onto
table salt, Fe and I do not interact. Our objective was to determine the absorption of Fe and the urinary excretion of I from
table salt when provided in meals designed to significantly inhibit or enhance Fe absorption. Subjects (n = 16) ingested Fe-enhancing and Fe-inhibiting meals containing 5 g of
table salt with 0.39 micromol
dextran-coated I as
potassium iodide and 1 mg of Fe (
ferrous fumarate labeled with 59Fe) per gram of
salt. Subjects also received a reference dose of 3 mg of
ferrous fumarate labeled with 59Fe to "correct" for interindividual variation in
iron absorption at a later date. Measured by whole-body counting, Fe-absorption from the Fe-enhancing meal (36.2 +/- 12.0%, corrected; 13.5 +/- 13.8% uncorrected) was significantly higher than that from the Fe-inhibiting meal (7.4 +/- 11.3%, corrected; 4.0 +/- 8.4%, uncorrected) (P < 0.0001). Urinary excretion of
iodine at baseline and postingestion were not significantly different (0.89 +/- 0.5 vs. 1.06 +/- 0.39 micromol/L, P < 0.47) and were within the normal range. We conclude that Fe was well absorbed but influenced by the composition of the meal and that urinary excretion of
iodine was maintained in the normal range with
dextran-coated
iodine.