Infants and young children are particularly vulnerable to iron and zinc deficiency, especially in low-resource settings where they are unreached by fortified products. Targeted use of micronutrient powders (MNP), which contain a variety of nutrients mixed with an inert carrier, is a promising approach to reducing deficiencies in such settings, but the high dose of iron normally found in MNPs raises concerns about increased incidence and intensity of malaria and other infections and prevents their widespread use. One reason that MNPs contain a relatively high amount of iron is that they often are added to cereals that are high in phytic acid that inhibits both iron and zinc absorption.
A study, published in the Journal of Nutrition in February 2011, aimed to test whether a new MNP formulation containing less but more-absorbable iron, more vitamin C (to enhance iron absorption), and a phytase (an enzyme that breaks down phytic acid) would improve iron and zinc status and growth. The formulation substituted highly absorbable “ferric sodium EDTA” for the less-absorbable iron normally used in MNP. While the use of phytase to break down phytic acid in high-phytate foods is not new, its use at the time of consumption was previously untested. In this double-blind controlled trial, 200 South African school children (ages 5–11) with low iron status received a high-phytate maize porridge to which either MNP or the unfortified carrier was added at consumption for 5 days per week for 23 weeks. Despite the low iron and zinc dose (2.5 mg for each), the formulation was efficacious, resulting in iron and zinc deficiency reductions of 31 percent and 12 percent, respectively, reduced serum transferrin receptor concentration (a measure of iron-deficient red blood cell production), increased serum ferritin concentration (a measure of iron stores), and increased weight-for-age Z-score.
The authors contend that improvements in iron status occurred despite the relatively low iron dose because of the more-absorbable ferric sodium EDTA and the absorption-enhancing effects of vitamin C and the phytase. An MNP product containing a lower dose of highly absorbable iron with vitamin C and phytase to aid in absorption may hold promise for safe use in areas where malaria and other infectious diseases are common.
Date: Jul 5, 2011 | Category: Research highlights