[Oral loading test with a preparation which frees iron gradually in the intestine. Behavior of blood iron and transferrin].

Blood iron, total transferrin, iron-bound transferrin and transferrin iron saturation percentage were determined in non-anaemic subjects after oral administration of 1 and 2 tablets of a commercial preparation (Ferro-grad) containing ferrous sulphate and ensuring slower release of iron in the intestine. After 1 tablet, blood iron and transferrin saturation reached their peaks after 4 hr and returned to start levels after 10 hr. Higher increases were achieved, though later, with 2 tablets and the return to start levels presumibly occurred within 14 hr. There was a slight increase in total transferrin 2 hr after 1 tablet and values remained high throughout the experiment. When 2 tablets were given values fluctuated considerably, with minima coinciding with maximum blood iron values.