Letters to the Editor

Indian Pediatrics 2002; 39:893-894

Reply

We have developed and tested the use of encapsulated ferrous (Fe2+) fumarate ‘sprinkles’ as one means to improve gastric tolerance to iron(1). The encapsulated ferrous fumarate, in powder form, is added directly by a parent to any complementary food. The form of iron is important, since compliance with ferrous sulfate is universally poor, especially with longer term prophylaxis. Another approach to reduce the side effects associated with iron supplementation has been the development of non-ionic trivalent iron (Fe3+) complexed to polysaccharides which can be formulated into liquid or solid preparations as an alternative to conventional iron salts. In addition to fewer side effects, it has been postulated that iron polysaccharide complexes better approximate the body’s metabolic and physiologic regulatory mechanisms of dietary iron absorption. Although a paucity of data exists on the efficacy and bioavailability of compounds such as the iron polymaltose complex (the most commonly investigated iron polysaccharide complex), in the literature that is available, outcomes are mixed. Clinical trials in human subjects treated for iron deficiency anemia have found pharmacokinetic differences between iron polymaltose complexes and ferrous sulfate, the gold standard. Studies have shown significant differences in relation to hemoglobin response and more frequently repletion of body iron stores as measured by serum ferritin levels, in which iron polymaltose complexes were less efficacious(2)(3)(4). It has been suggested that such differences may in fact be due to the varying regulatory and absorption mechanisms between the two types of compounds over long-term supplementation periods. As such, we believe that the role of iron polymaltose as a hematinic remains unproven and further research into its pharmacokinetic and therapeutic properties needs to be addressed.

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References

1. Zlotkin SH, Arthur P, Antwi KY, Yeung G. Treatment of anemia with microencapsulated ferrous fumarate plus ascorbic acid supplied as ‘sprinkles’ to complementary (weaning) foods. Am J Clin Nutr 2001 74: 6, 791-795.

2. Arvas A, Gur E. Are ferric compounds useful in treatment of iron deficiency anemia? Turk J Pediatr 2000; 424: 352-353.

3. Jacobs P, Fransman D, Coghlan P. Comparative bioavailability of ferric polymaltose and ferrous sulphate in iron-deficient blood donors. J Clin Apheresis 1993; 8: 89-95.

4. Jacobs P, Wood L, Bird AR. Erythrocytes: Better Tolerance of Iron Polymaltose Complex Compared with Ferrous Sulphate in the Treatment of Anemia. Hematol 2000; 5: 77-83.