Iron

The element iron is essential to human life. As part of hemoglobin, the oxygen-carrying protein found in red blood cells, iron plays an integral role in nourishing every cell in the body with oxygen. It also functions as a part of myoglobin, which helps muscle cells store oxygen. Without iron, your body could not make ATP (adenosine triphosphate, the body's primary energy source), produce DNA, or carry out many other critical processes. Iron deficiency can lead to anemia, learning disabilities, impaired immune function, fatigue, and depression. However, you shouldnt take iron supplements unless lab tests show that you are genuinely deficient.

The official U.S. recommendations for daily intake of iron are as follows:

•  Infants 0–6 months, 0.27 mg
  7–12 months, 11 mg
   
•  Children 1–3 years, 7 mg
  4–8 years, 10 mg
   
•  Males 9–13 years, 8 mg
  14–18 years, 11 mg
  19 years and older, 8 mg
   
•  Females 9–13 years, 8 mg
  14–18 years, 15 mg
  19–50 years, 18 mg
  50 years and older, 8 mg
   
•  Pregnant women, 27 mg
   
•  Nursing women 9 mg, (10 mg if 18 years old or younger)

Iron deficiency is the most common nutrient deficiency in the world; worldwide, at least 700 million individuals have iron-deficiency anemia. While iron deficiency is widespread in the developing world, it is also prevalent in developed countries. Groups at high risk are children, teenage girls, menstruating women, pregnant women, and the elderly.
There are two major forms of iron: heme iron and nonheme iron. Heme iron is bound to the proteins hemoglobin or myoglobin, whereas nonheme iron is an inorganic compound. (In chemistry, organic has a very precise meaning that has nothing to do with farming. An organic compound contains carbon atoms. Thus inorganic iron is an iron compound containing no carbon.) Heme iron, obtained from red meats and fish, is easily absorbed by the body. Nonheme iron, derived from plants, is less easily absorbed.
Rich sources of heme iron include oysters, meat, poultry, and fish.The main sources of nonheme iron are dried fruits, molasses, whole grains, legumes, egg yolks, leafy green vegetables, nuts, seeds, and kelp. Acidic foods, such as fruit preserves and tomatoes, are a good source of iron when theyve been cooked in iron or stainless steel cookware (some of the iron leaches into the food).
Iron absorption may be affected by the following substances: antibiotics in the quinolone (Floxin, Cipro) or tetracycline families, levodopa, methyldopa, carbidopa, penicillamine, thyroid hormone, captopril (and possibly other ACE inhibitors), calcium, soy, zinc, copper, or manganese. Conversely, iron may inhibit their absorption, too.
In addition, drugs in the H2 blocker or proton pump inhibitor families may impair iron absorption.

The typical short-term therapeutic dosage to correct iron deficiency is 100 to 200 mg daily. Once your body's iron stores reach normal levels, however, this dose should be reduced to the lowest level that can maintain iron balance.

The most obvious use of iron supplements is to treat iron deficiency. Severe iron deficiency causes anemia, which in turn causes many symptoms. Iron deficiency too slight to cause anemia appears to impair health as well. A double-blind trial suggests that women with mild iron deficiency might have difficulty increasing their physical fitness. In addition, an observational study suggests that adolescent girls who are marginally iron deficient may experience reduced mental function. However, dont take iron just because you feel tired. Make sure to get tested to see whether you are indeed deficient. With iron, more is definitely not better. Heavy menstruation (menorrhagia) can certainly cause iron loss. Iron has also been tried as a treatment for attention deficit disorder, but there is as yet no real evidence that it works. Preliminary studies have linked low iron levels to restless legs syndrome. However, a small double-blind study found no benefit with iron supplements among individuals who were not iron deficient. A study of 71 HIV-positive children noted a high rate of iron deficiency. One observational study of 296 men with HIV infection linked high intake of iron to a decreased risk of AIDS 6 years later. Individuals taking ACE inhibitors frequently develop a dry cough as a side effect. One study suggests that iron supplementation can alleviate this symptom. (However, iron can interfere with ACE inhibitor absorption, so it should be taken at a different time of day).

Sports Performance A double-blind placebo-controlled trial of 42 non-anemic women with evidence of slightly low iron reserves found that iron supplements significantly increased the benefits gained from exercise. Participants were put on a daily aerobic training program for the latter 4 weeks of this 6-week trial. At the end of the trial, those receiving iron showed significantly greater gains in speed and endurance as compared to those given placebo. In addition, a double-blind placebo-controlled study of 40 non-anemic elite athletes with mildly low iron stores found that 12 weeks of iron supplementation enhanced aerobic performance. Menorrhagia One small double-blind study found good results using iron supplements to treat heavy menstruation. This study, which was performed in 1964, saw an improvement in 75% of the women who took iron (compared to 32.5% of those who took placebo). Women who began with higher iron levels did not respond to treatment. This suggests once more that supplementing with iron is only a good idea if you are deficient in it.

At the recommended dosage, iron is quite safe. Excessive dosages, however, can be toxic—damaging the intestines and liver, and possibly resulting in death. Iron poisoning in children is a surprisingly common problem, so make sure to keep your iron supplements out of their reach. Mildly excessive levels of iron may be unhealthy for another reason: it acts as an oxidant (the opposite of an antioxidant), perhaps increasing the risk of cancer and heart disease, although this is controversial. Elevated levels of iron may also play a role in brain injury caused by stroke. In addition, excess iron appears to increase complications of pregnancy. Simultaneous use of iron and high-dose vitamin C can cause excessive iron absorption.

If you are taking

•  Antibiotics in the tetracycline or quinolone (Floxin, Cipro)families, levodopa, methyldopa, carbidopa, penicillamine, thyroid hormone, calcium , soy, zinc, copper, or manganese:To avoid absorption problems, wait at least 2 hours following your dose of medication or supplement before taking iron.
•  Drugs that reduce stomach acid such as antacids, H2 blockers and proton pump inhibitors: You may need extra iron.
•  High doses of vitamin C: You may absorb too much iron.
•  ACE inhibitors: Iron may reduce coughing side effect; however, to avoid absorption problems, you should wait at least 2 hours following your dose of medication before taking iron.