Effect of wheat bran on zinc absorption.

The effect of wheat bran on zinc absorption was studied in normal volunteers using a zinc tolerance test (ZTT) and whole-body monitor to measure the 7-day percentage retention of 65zinc (65Zn). Twenty-three subjects (age 21-26 years) were randomized into three groups. All were given 5 microCi of 65Zn orally in a 10 ml solution of zinc sulphate which contained 15 mg of elemental zinc. In addition, Group A were given 20 g wheat bran, Group B 20 g Rice Krispies (a low-fibre food) and Group C had zinc alone. The differences between the retention of 65Zn in the three groups were all statistically significant (A vs B P less than 0.005; B vs C and A vs C P less than 0.001). Similarly the differences in the areas under the ZTT curves in the three groups were all statistically significant (A vs B P less than 0.005; B vs C and A vs C P less than 0.001). We conclude that wheat bran leads to a significant reduction in zinc absorption which could eventually induce a state of zinc deficiency.