iron [AS. iren; L. ferum]

A metallic element widely distributed in nature.  Compounds (oxides,
hydroxides, salts) exist in two forms: ferrous in which iron has a
valence of 2 [Fe++] and ferric in which it has a valence of 3 [Fe+++].
It is widely used in the treatment of certain forms of anemia.  Iron is
essential for the formation of chlorophyll in plants (although is is
not a constituent of chlorophyll).  It is part of the hemoglobin and
myoglobin molecules.

FUNCTION:  Iron, as part of hemoglobin, is essential for the transport
of oxygen in the blood; it is also part of some of the enzymes needed
for cell respiration.

Men require from 0.1 to 1.0 mg of iron a day.  A woman of menstrual age
requires about twice this amount.  During pregnancy and lactation from
2 to 4 mg of iron per day is required.  Because only a fraction of the
iron present in food is absorbed, it is necessary to provide from 15 to
30 mg of iron in the diet to be certain that 1 to 4 mg will be
absorbed.

There are 2 broad types of dietary iron.  About 90% of iron from food
is in the form of iron salts and is called nonheme iron, which is
poorly absorbed.  The other 10% of dietary iron is in the form of heme
iron, which is derived primarily from the hemoglobin and myoblobin of
meat and is well absorbed.

About 50% of iron from breast milk is absorbed, but only about 10% of
iron in whole cow's milk is absorbed.

Ascorbic acid, meat, fish, and poultry enhance absorption of nonheme
iron.  Bran, oxalates, vegetable fiber, tannins in tea, and phosphates
inhibit absorption of iron.  Orange juice doubles the absorption of
iron from a meal and tea decreases it by 75%

DEFICIENCY SYMPTOMS:  Iron deficiency is characterized by anemia,
lowered vitality, exertional breathlessness, pale complexion,
conjunctival pallor, retarded development, and a decreased amount of
hemoglobin in each red cell.

IRON OVERLOAD:  Organ failure that results from excessive accumulation
of iron in the body, USUALLY as a result of frequent transfusions or
hemochromatosis.