A review on iron, zinc and calcium biological significance and factors affecting their absorption and bioavailability

Micronutrients are needed for the human body in very small amounts and have a visible impact on human health. Deficiencies of micronutrients like iron (Fe), zinc (Zn), calcium (Ca) and other minerals can cause life threatening conditions while Fe deficiency and anemia has been the biggest issue. Through the proper selection of food these micronutrients deficiencies can be prevented to a reasonable extent. This review highlights the dietary sources of Fe, Zn and Ca, their biological significance, and effects against various diseases. Also, it focuses on the bioavailability of Fe, Zn, Ca and the factors affecting their bioavailability. The effects of phytate, tannin, oxalate, ascorbic acid, food processing, soaking, germination/sprouting, fermentation, cooking methods and interaction among minerals, which inhibit or enhance minerals bioavailability, have also been reviewed and critically discussed. The food processing techniques which reduce phytate concentration in foods and enhance minerals bioavailability have also been reviewed. •The review shows dietary sources of Fe, Zn & Ca and their biological significance.•The review focuses on Fe, Zn, Ca and the factors affecting their bioavailability.•The factors affecting Fe, Zn & Ca bioavailability have been critically reviewed.•Phytate, tannin & ascorbic acid effects on nutrients bioavailability are reviewed.•The effects of food processing techniques & minerals interaction have been reviewed.