The first of the essential minerals, dietary iron comes in two forms, haem iron and non-haem iron. Haem iron is found in meats and animal products, while non-haem iron is found in legumes, wholegrain cereals and green leefy vegetables.
The human body recognises and absorbs haem iron much better than non-haem iron, absorbing up to 23% haem iron compared with 8% or less for non-haem iron.
Vegetarians can improve the absorbtion of iron from plant foods by eating foods rich in vitamin C at the same time. Adding tomato to a green salad or drinking orange juice with your breakfast cereal, for example.
Some foods inhibit the absorbtion of iron and should be avoided. Unprocessed bran is one such food so don't eat large quantities with wholegrain breakfast cereals. Tannin, found in tea, binds with iron and stops it being absorbed so drinking tea with a meal is not a good idea.
If you have an iron deficiency, confirmed by a blood test, you will probably need to take an iron supplement because it is difficult to boost your iron levels quickly with diet alone. Once your iron levels are satisfactory you should follow an iron-rich diet and not rely on the supplement...
Like iron, zinc from plant foods is not absorbed well by the body. The absorbtion is improved by eating some animal protein with good vegetable sources of zinc. Yogurt with wholemeal cereal or egg on toast for example.
Legumes, seeds, nuts and wholegrain cereals are all good sources of this mineral.
The third essential mineral, calcium is needed to maintain healthy bones and teeth. It is plentiful in dairy products and is easily absorbed. Tofu and fortified soy drinks also provide calcium.
Leafy vegetables also contain calcium, but the body does not absorb the mineral well from these sources.
Calcium supplements should be avoided if at all possible as they interfere with the absorbtion of iron and zinc.