Iron information, FAQ and product listing page. This page contains everything you need to know about iron.
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Iron is one of the oldest and most well-known micronutrients. Iron is the key element in the metabolism of almost every living organism on the planet. In the human body, iron is a key ingredient of hundreds of proteins and important enzymes. It has many vital functions in the body, including oxygen transport and storage, electron transport, energy metabolism, acting as an anti-oxidant, as well as DNA synthesis. (1)
Oxygen transport and storage
The iron-containing compound heme is found in a number of important molecules. A couple of these are the proteins hemoglobin and myoglobin, which are involved in the transport and storage of oxygen. Hemoglobin is the protein that is primarily found in red blood cells and represents approximately two thirds of your body’s iron contents. Myoglobin helps your muscle cells match the supply of oxygen required by muscles that are working and under stress. (2)
Electron transport and energy metabolism
Heme can also be found in cytochromes, compounds necessary for cellular energy production through their role in mitochondrial electron transport. Cytochromes act as electron carriers during the synthesis of ATP, the primary energy-storage compound found in cells. The family of enzymes Cytocrhome P450 functions in the metabolism of a variety of important biological molecules, in addition to the detoxification and metabolism of pollutants and drugs. Other enzymes containing iron, like NADH dehydrogenas and succinate dehydrogenase, are also very crucial to the process of energy metabolism in our bodies.
The heme-containg catalase and peroxidases enzymes protect cells from the accumulation of hydrogen peroxide, a damaging ROS or reactive oxygen species. It does this by catalyzing a reaction that converts hydrogen peroxide to water and oxygen.
Ribonucleotide reductase is an enzyme that is dependent on iron. It is required for the process of DNA synthesis and thus, makes iron responsible for a wide array of vital functions such as growth, reproduction, healing, and immune functions.
Heme iron is derived mainly from the hemoglobin and myoglobin found in meat, poultry, and fish. While heme iron attributes to only about 10-15% of the iron found in your diet, it may provide up to one third of the total absorbed iron in your body. Nonheme iron can be found in plants, dairy products, meat, as well as iron salts added to foods and supplements. (3)
|Beef||3 ounces, cooked||2.31|
|Chicken, dark meat||3 ounces, cooked||1.13|
|Shrimp||8 large, cooked||1.36|
|Tuna, light||3 ounces, canned||1.30|
|Black-strap molasses||1 tablespoon||3.50|
|Raisin bran cereal||1 cup, dry||5.00|
|Raisins, seedless||1 small box (1.5 ounces)||0.89|
|Prune juice||6 fluid ounces||2.27|
|Prunes, dried||~ 5 prunes (1.5 ounces)||1.06|
|Potato, with skin||1 medium potato, baked||2.75|
|Kidney beans||1/2 cup, cooked||2.60|
|Lentils||1/2 cup, cooked||3.30|
|Tofu, firm||1/4 block (~1/2 cup)||6.22|
|Cashew nuts||1 ounce||1.70|
In the United States, the RDA or recommended daily allowance for Iron can be seen in the chart below. These figures are based on the prevention of iron deficiencies.
|Recommended Dietary Allowance (RDA) for Iron|
|Life Stage||Age||Males: mg/day||Females: mg/day|
|Adults||19 years +||8||18|
|Pregnancy||18 years -||-||8|
|Pregnancy||19 years +||-||27|
|Breast-feeding||18 years -||-||10|
|Breast-feeding||19 years +||-||9|
Iron deficiency is one of the most common nutrient deficiencies in the United States and throughout the world. There are three levels of iron deficiency: storage iron depletion, early functional iron deficiency, and iron deficiency anemia.
Symptoms of iron deficiency are the result of associated anemia and can include fatigue, rapid heart rate, rapid breathing, and palpitations. Iron deficiency impairs your performance both physically and athletically numerous ways. In anemia, your diminished hemoglobin content in red blood cells results in a decreased oxygen delivery to your active issues. The decreased myoglobin levels in your muscle cells limit the amount of oxygen your body can deliver to your body’s mitochondria for oxidative metabolism. (2)
Everybody can benefit from iron -- it helps both prevent diseases, as well as treat them. Health problems and diseases that can help be prevented by iron intake include the impaired intellectual development in children, lead toxicity, pregnancy complications, and impaired immune function.
In disease treatment, primarily restless leg syndrome can be treated. Restless leg syndrome, or RLS, occurs in some people that have a deficiency of iron.
Specific benefits to bodybuilders:
- Boost body’s energy level
- Improves physical performance
- Improves the bodies immunity and encourages rest
If taking the RDA, the side effects of iron are rare. Taking excess iron supplements may cause gastrointestinal irritation, vomiting, diarrhea, constipation, or nausea. Stools can also appear darker than usual. (4)
If you’re unsure whether or not you’re susceptible to the side effects of iron, it would be best to consult a physician before taking it.
Sources Used:1. Fairbanks VF. Iron in Medicine and Nutrition. In: Shils M, Olson JA, Shike M, Ross AC, eds. Modern Nutrition in Health and Disease. 9th ed. Baltimore: Williams & Wilkins; 1999:223-239.2. Yip R, Dallman PR. Iron. In: Ziegler EE, Filer LJ, eds. Present Knowledge in Nutrition. 7th ed. Washington D.C.: ILSI Press; 1996:277-292.3. Lynch SR. Interaction of iron with other nutrients. Nutr Rev. 1997;55(4):102-110.4. Minerals. Drug Facts and Comparisons. St. Louis: Facts and Comparisons; 2000:27-51.