Who Are The High-Risk Groups?
Well as you might expect, for women a key reason is heavy menstruation. Other factors are also at play including a diet poor in iron, poor iron absorption from the gut, bleeding from the gut (which may not be obvious) and multiple blood donations. Other high risk groups are:
 adolescent girls, who need iron as they are growing, who also have to replace iron from menstruation, but like many women do not have adequate iron in their diet;
 women with heavy or prolonged periods
 vegetarians, who do not take haem iron and may also be lacking B vitamins
 highly active men and women need extra iron for energy production in their muscles
 pregnant women need extra iron as the baby grows and also as the blood volume expands