A predominantly vegetarian diet reduces bio-availability of essential minerals. Credit: S. Priyadarshini

The widespread prevalence of iron (Fe) and zinc (Zn) deficiency among Indians is not due to the poor mineral content in their diets. It is the poor "bio-availability" of these minerals that makes the largely vegetarian population deficient in these nutrients, scientists at ICAR-Indian Institute of Horticultural Research in Bengaluru report1.

Urging that India's research efforts should therefore be diverted towards "bio-availability" rather than "bio-fortification", the scientists say the intake of Fe and Zn through food sources is quite adequate but they are not available to the body since the phytic acid in vegetarian food binds with these minerals in the digestive tract, making their absorption difficult.

The researchers computed national iron and zinc balance using theoretical mean daily per capita dietary requirement and composition of these minerals in food sources from agriculture, horticulture, animal husbandry and fisheries. Surprisingly, they found that the horticulture sector contributed a small portion (9.1% Zn and 12.9% Fe) and the fisheries sector contributed the least.

The researchers say the phytic acid content among the predominantly vegetarian Indian population is relatively high. Methods for improving the bio-availability of minerals by reducing the phytic acid content of Indian foods should find prime place in nutritional programmes and extension activities, they note.

Iron deficient anaemia is a major cause of maternal mortality and low birth weight in India, and 26% of Indians (312 million) are at a risk for zinc deficiency.