And while we're at it, why do we absorb iron so well from meat but hardly at all from vegetable sources? One thing vegetarians love to say is that spinach is full of iron so you can just eat spinach to avoid anaemia. Spinach is full of iron. Stacks of the stuff. The only problem is that it's not in a form our bodies can utilise. For some reason they don't like to consider this, though.
Then there's vitamin B12. Utterly critical for our health, but not available from vegetarian sources.
The absorption of iron is influenced by other constituents of a meal. Phytates, oxalates and phosphates present in plant foods can inhibit absorption, as can tannin in tea. Fibre may also inhibit absorption. Vitamin C greatly increases the absorption of non-haem iron. Foods rich in vitamin C include citrus fruits, green peppers, and fresh leafy green vegetables. Citric acid, sugars, amino acids and alcohol can also promote iron absorption. Iron absorption can also be influenced by the amount of iron in the diet. Lowered levels of iron in the diet result in improved absorption.
Good sources of iron for vegetarians include wholegrain cereals and flours, leafy green vegetables, blackstrap molasses, pulses such as lentils and kidney beans, and some dried fruits.
B12 is available from many sources, milk, seaweed, cheese, yeast extracts, soya milks, vegetable and sunflower margarines, and breakfast cereals.
Bacteria present in the large intestine are able to synthesise B12