Effect of dietary phytate on bioavailability of iron

Experiments were carried out on iron-chelating capacity of phytic acid in fortified and unfortified diets of whole wheat, white flour and wheat bran using albino rats in a 10-day balance study. The results revealed that gross digestibility was highest in control diet (93.25%), least in the wheat brain diet with added ferrous sulfate (86.70%) and intermediate in other diets. Among the unfortified and fortified diets, the highest amount of phytate was present in the diet having wheat bran (2.69–4.99 mg/g). Phytate concentration of the rat faeces followed the pattern of dietary phytate content of test diets. The data indicated high values for iron (200.00–236.64 mg/g) in fortified diets while in the unfortified diets, the value was the same (16.67 mg/g) except the casein diet, which contained 69.99 mg/g of iron. Iron concentration of the fat faeces ranged 16.25–23.50 mg/g; the higher value being in the excreta of animals given fortified diets. The casein diet had iron 46.75 mg/g. The overall results showed that the phytate absorption was relatively higher in groups fed fortified diets. Iron absorption almost followed the pattern of phytate absorption. Correlation co-efficient analysis showed insignificant relationship between iron and phytate absorption indicating little effect of dietary phytate on the biovailability of iron.