Iron absorption is increased by the following factor in diet:

In a vegetarian diet, nonheme iron is absorbed very poorly because of the inhibitory action of a variety of dietary components, paicularly phosphates, phytates and high fibre content. Ascorbic acid and meat facilitate the absorption of nonheme iron. Ascorbate forms complexes with and/or reduces ferric to ferrous iron. Meat facilitates the absorption of iron by stimulating production of gastric acid; other effects also may be involved. Either of these substances can increase availability several fold. Ref: Kaushansky K., Kipps T.J. (2011). Chapter 37. Hematopoietic Agents: Growth Factors, Minerals, and Vitamins. In B.C. Knollmann (Ed), Goodman & Gilman's The Pharmacological Basis of Therapeutics, 12e.