Vitamins, Minerals and Dietary Supplements
What is iron? Why do we need it?
Iron is an important trace mineral found in every cell of the body, usually
in combination with protein. Depending on the level of iron in the body,
it can act either as an antioxidant, or it can stimulate the formation
of free radicals.
Why do we need it?
Iron is an essential nutrient because it is a vital part of red blood
cells, which carry oxygen to all body cells. Iron is essential to the
formation of hemoglobin and myoglobin, which carries the oxygen in the
blood and muscles. It makes up part of many proteins and enzymes in the
How much iron should I take?
According to the National Academy of Sciences, the recommended daily
allowance (RDA) of iron is as follows:
- Adult men: between 10-12 milligrams/day
- Adult women: 15 milligrams/day
- Children aged 7-10: 10 milligrams/day
- Infants: 10 milligrams/day
- Pregnant/lactating women: 30 milligrams/day
What are some good sources of iron?
Red meat, fish, poultry, eggs, legumes and fortified cereals are all
good sources of iron. Other sources include oysters, dried fruits, molasses,
and dark, leafy green vegetables such as broccoli and spinach.
The best food sources of easily absorbed iron are animal products. Iron
from vegetables, fruits, grains, and supplements is harder for the body
to absorb. Mixing lean meat, fish, or poultry with beans or dark leafy
greens at a meal can improve absorption of vegetable sources of iron up
to three times. Foods rich in vitamin C also increase iron absorption.
What can happen if I don't get enough iron?
Iron deficiency is the most common nutritional deficiency worldwide.
Deficiency occurs in the form of iron deficiency anemia. Iron deficiency
and anemia can occur during periods of rapid growth, during pregnancy,
and among women who are menstruating more than usual. It can be associated
with any type of intestinal loss of blood, frequent donation of blood,
or from the inability to absorb iron efficiently. Initial symptoms of
iron deficiency anemia are fatigue and lack of energy. Dizziness, weight
loss, headaches and lowered immunity can also occur.
What can happen if I take too much?
Iron toxicity rarely develops from an increased intake of dietary iron
alone; however, increased intake of iron supplements may lead to toxicity.
Symptoms include fatigue, anorexia, dizziness, nausea, vomiting, headache,
weight loss, shortness of breath, and possibly a grayish color to the
- Recommended Dietary Allowances, 10th ed. Washington,
D.C.: National Academy Press, 1989.
- Murray M. Encyclopedia of Nutritional Supplements.
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acid on apparent iron absorption by women with low iron stores. Am
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- Semba RD, Muhilal, West KP Jr, et al. Impact of vitamin
A supplementation on hematological indicators of iron metabolism and
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joint inflammation. Ann Rheum Dis 1993;52:67-73.