Plasma non-
transferrin-bound
iron (NTBI) is potentially harmful due to the generation of
free radicals that cause tissue damage in vascular and other diseases. Studies in
iron-replete and
iron-deficient subjects, receiving a single oral test dose of Fe(II)SO₄ or NaFe(III)
EDTA with water, revealed that FeSO₄ was well absorbed when compared with
NaFeEDTA, while only the Fe(II) compound showed a remarkable increase of NTBI. As
NaFeEDTA is successfully used for food fortification, a double-blind randomized cross-over trial was conducted in 11 healthy women with uncomplicated
iron deficiency. All subjects received a placebo, 6.5 mg FeSO₄, 65 mg FeSO₄, 6.5 mg
NaFeEDTA, and 65 mg
NaFeEDTA with a traditional Indonesian breakfast in one-week intervals. Blood tests were carried out every 60 min for five hours. NTBI detection was performed using the
fluorescein-labeled
apotransferrin method. Plasma
iron values were highly increased after 65 mg
NaFeEDTA, twice as high as after FeSO₄. A similar pattern was seen for NTBI. After 6.5 mg of
NaFeEDTA and FeSO₄, NTBI was hardly detectable.
NaFeEDTA was highly effective for the treatment of
iron deficiency if given with a meal, inhibiting the formation of nonabsorbable Fe-complexes, while NTBI did not exceed the range of normal values for
iron-replete subjects.