BIOAVAILABILITY, ABSORPTION MECHANISM, AND TOXICITY OF MICROENCAPSULATED IRON (I) SULFATE

The iron compounds used for food fortification have to meet certain re quisites related to their bioavailability, absorption mechanism, and t oxicity, since they will be consumed by a massive population group. Wi th these purposes, we evaluated a new product used for the iron fortif ication of milk and lacteous derivatives, called SFE-171(TM) which is a ferrous sulfate, microencapsulated with phospholipids. The bioavaila bility studies were carried out using four groups of 30 female mice ea ch. In two groups, we studied the absorption of ferrous ascorbate and ferrous sulfate, both in water as reference standards, which show abso rptions of 13.1 +/- 4.9% and 13.2 +/- 4.3%, respectively. With the thi rd group, we studied the absorption of ferrous sulfate in milk; its va lue, 7.9 +/- 3.2%, is significantly lower than that of the remaining g roups, with a p < 0.01. The studies with SFE-171(TM) in milk,were perf ormed on the fourth group, with a result of 11.6 +/- 4.5%, demonstrati ng that its absorption does not differ significantly from that of the reference standards. The absorption mechanism was determined by means of in vivo self-displacement studies of the ferrous ion and the SFE-17 1(TM), taking ferrous sulfate as the reference compound. For this stud y, 210 female mice were used, and no significant difference between th e absorption mechanism of both products could be observed. Toxicity st udies of the new product with regard to ferrous sulfate were carried o ut with two groups of 70 female mice each and two groups of 70 male mi ce each. The lethal dose 50% LD50 for SFE-171(TM) and for ferrous sulf ate was 1200 and 680 mg/kg for female mice and 1230 and 670 mg/kg for male mice, respectively demonstrating that the toxicity of the first p roduct is substantially lower than that of the reference standard. We conclude that the iron product under study has a high bioavailability, an absorption mechanism equal to that of nonhemic iron, and lower tox icity than ferrous sulfate.