Food sources and facts of Iron


Iron is one of the most recognizable minerals in the body, although an adult may have a little less than a teaspoon’s amount in his or her body. However, quantity should not be associated with importance as the effects of iron deficiency are tragic and severe. Iron is a central component of very essential molecule known as heme which is part of larger protein complexes that rank among the most important in the human body. One aspect that makes animals different from plants is the presence of heme. Plants do not have it.








Iron is essential for human life. It is at the core of hemoglobin, which transports oxygen to the body via red blood cells. Deficiency of iron eventually leads to anemia, which means a low red blood count. Iron deficiency and anemia can lead to fatigue, exercise intolerance, decreased immunity, adverse outcomes during pregnancy, and a whole host of other problems that are still being studied.

In populations with adequate food intake, menstruating, pregnant, and lactating women are at the highest risk for iron deficiency, along with small children. In populations with inadequate access to food, iron deficiency is common.

On the other hand, excessive amounts of iron are stored in body organs where the iron can cause damage. An example of this is a hereditary disease called hemochromatosis, in which iron is deposited in the liver, the heart, and other organs. Treatment of this disease includes phlebotomy, or removal of blood, to decrease the excess iron. Older people may also accumulate excess iron from the diet and/or supplements, which may increase their risk of certain chronic illnesses.

While there is a control system in the body regulating iron absorption that can delay or mask some of the problems with iron deficiency or excess, a deficiency of iron will eventually produce symptoms, as will a chronic excess.

What Foods Provide Iron?

Food name Weight (g) Iron (mg) DV%
Spirulina 112 31 387%
Soybeans 186 29 362%
Winged beans 182 24 300%
Rice bran 118 21 262%
Mothbeans 196 21 262%
Sesame seeds 144 20 250%
Cowpeas 167 16 200%
Kidney beans 184 16 200%
Black turtle beans 184 16 200%
Molasses 337 15 187%
Mungo beans 207 15 187%
Natto 175 15 187%
Teff 193 14 175%
Amaranth grain 193 14 175%
Yardlong beans 167 14 175%
Lima beans 178 13 162%
Sorghum syrup 330 12 150%
Cocoa powder 86 11 137%
Navy beans 208 11 137%
Hyacinth beans 210 10 125%


What Are the Levels of Recommended Intake for Iron?

The following are the Dietary Reference Intake (DRI) standards for iron. These DRI standards include adequate intake (AI) levels for infants up to six months and Recommended Dietary Allowances for all other categories. Males and females 51 years old and older should take in 8 mg per day. Males between the ages of 19 and 50 years should take in 8 mg per day, while females between the ages of 19 and 50 years should take in 18 mg per day. Males between the ages of 14 and 18 should take in 11 mg per day, while females between the ages of 14 and 18 years should take in 15 mg per day. Males and females between the ages of 9 and 13 years should take in 8 mg per day, while children between the ages of 4 and 8 years should take in 10 mg per day. Children between the ages of 1 and 3 years should take in 7 mg per day, while infants between the ages of 7 and 12 months should take in 11 mg. The AI for infants between birth and six months is .27 mg. Pregnant teens and women should take in 27 mg per day; breastfeeding teens should take in 10 mg per day, and breastfeeding women should take in 9 mg per day. There are also tolerable upper intake levels for iron. Teens 14 years and older and adults should take in no more than 45 mg per day, while children from birth to 13 years should take in no more than 40 mg per day.

Health Benefits of Iron

After knowing much about Iron, let us know its health benefits as well:

  1. Useful for Women with Heavy Menstrual Bleeding

In a study published in 2014 in the journal Acta Obstetricia et Gynecologica Scandinavica, researchers from Finland wanted to learn more about how iron supplementation would impact the quality of life of women with heavy menstrual bleeding. The cohort consisted of 236 women, between the ages of 35 and 49 years, who were referred to hospital-based medical providers because of their heavy menstrual bleeding. At baseline, 63 women were anemic and 140 were severely iron deficient. Only 8 percent of the women had taken iron supplementation. The women were randomly assigned to receive a hysterectomy or a levonorgestrel-releasing intrauterine system (an intrauterine device that prevents pregnancy). Hemoglobin concentrations were measured at baseline, at 12 months, and after 5 years. Ferritin (a blood cell protein that contains iron) concentrations and menstrual blood loss were measured before treatments, and after 6 and 12 months and 5 years. The researchers learned that after one year, hemoglobin was still low among anemic women, and it took five years to correct ferritin levels. As a result of their findings, the researchers recommended the earlier treatment of anemia and iron deficiency with iron supplementation. “Clinicians should actively screen for anemia in women with HMB [heavy menstrual bleeding]and emphasize early iron substitution as an integral part of treatment.”

  1. Improve cognition

In a systematic review and meta-analysis published in 2010 in Nutrition Journal, researchers based in the United Kingdom wanted to learn if iron supplementation would impact the cognitive abilities of older children and adults. The researchers noted that previous observational studies have found that anemia and iron deficiency are associated with cognitive deficits. The cohort consisted of 14 randomized, controlled trials that included children six years and older, adolescents, and younger women. Only one study included women over 35 years old. The researchers were unable to locate randomized, controlled trials containing men, postmenopausal women, or the elderly. The researchers learned that irrespective of baseline iron status, iron supplementation improved attention and concentration. In groups that were anemic, supplementation improved intelligence, but the supplementation failed to improve the intelligence, memory, psychomotor skills, or scholastic achievement of nonanemic people. The researchers underscored the need for more studies on this topic. “Further well powered, blinded and independently funded studies of at least one year’s duration in children, adolescents, adults and older people with varying levels of baseline iron status and using well validated tests of cognition are needed to confirm and extend these results.”

  1. May impact an infant’s birth weight

In a double-blind, randomized, controlled trial published in 2015 in the British Journal of Nutrition, researchers from China and Atlanta, Georgia, wanted to learn more about the association between iron supplementation during pregnancy and the birth weight of newborns. The initial cohort consisted of 18,775 pregnant women from five counties in northern China. During a time period that began before 20 weeks of gestation and continued until delivery, the women took daily supplements that contained folic acid (control) or folic acid and iron, or multiple micronutrients including folic acid, iron, and 13 other vitamins and minerals. Mothers’ hemoglobin levels were tested at enrollment and after birth; baby weights were also noted within the first hour of birth. The final cohort included 17,897 women. The researchers learned that the iron–folic acid combination and  the multiple micronutrient supplements had no effect on the birth weight of the infants of women with normal or high baseline hemoglobin levels. On the other hand, in the women with very high baseline hemoglobin levels, the iron–folic acid combination and the multiple micronutrient supplements increased birth weight by 91.44 g and 107.63 g, respectively. The researchers concluded that “the effects of Fe[iron]-containing supplements on birth weight depended on baseline Hb [hemoglobin]concentrations.”

  1. Useful for postpartum depression

In a randomized, double-blind, placebo-controlled study published in 2017 in the European Journal of Nutrition, researchers from Tehran, Iran, wanted to determine if iron supplementation would be useful for nonanemic mothers with postpartum depression. The cohort consisted of 70 mothers with postpartum depression. One week after the delivery of healthy infants, 35 mothers were assigned to receive a daily iron supplementation and 35 were assigned to take a placebo. After six weeks, the researchers learned that the early iron supplementation appeared to result in significant rates of improvement for postpartum depression. As a result of their findings, the researchers advised that iron evaluations should be conducted on all mothers with postpartum depression. “Daily iron supplementation should be considered for the early improvement in PPD [postpartum depression]and iron stores.”

  1. Formation of hemoglobin

The main function of iron is to form hemoglobin. Besides this, it assists in transporting oxygen to body cells. Additional hemoglobin is essential because human beings lose blood in various ways through both internal and external injuries. Especially women lose extensive amounts of blood every month during menstruation which is the major reason women are prone to anemia than men.

  1. Strengthen immunity

Among all the vitamins and minerals, iron is essential for strengthening immune system. Study shows that adequate amount of iron in blood treats various health problems. It is a crucial nutrient which combats facts contributing various infections and diseases. It promotes growth of red blood cells in blood then repairs damaged tissues or cells by preventing further health problems. Hemoglobin is found in blood for strengthening immune system. These components found in blood are essential for providing oxygen to organs including immune system. Thus, iron loaded diet and make this process run without hindrance.

  1. Cure for fatigue

Fatigue is found in both men and women. It is harmful and troubling if ignored. The experts consider iron deficiency to be the major reason related with chronic fatigue. It could be prevents by consuming diet rich in iron. Additionally, adequate amount of iron and hemoglobin in blood not only prevent fatigue but also provides energy throughout the day.

  1. Insomnia cure

It is irritating when one has spent day working and is tired but still can’t sleep. If this remains continued for weeks, it could be stressful and is harmful for overall wellbeing. Hence, it should be treated on time. Furthermore, study shows that insomniacs have deficiency of iron. Study also suggests that frequent fluctuation of blood pressure keeps awake. Iron helps to rescue this problem, so incorporate foods loaded with iron and enjoy sleep.

  1. Brain activity

Iron is beneficial for increased brain development. Iron aids oxygen supply in blood as brain uses about 20% of blood oxygen as it is associated to brain health with its functions. Proper blood flow in brain stimulates cognitive activity and forms new neural pathways preventing cognitive problems such as Alzheimer’s disease and dementia so intake of iron and successive brain oxygenation is essential.

  1. Restless Leg Syndrome

Scientists show that deficiency of iron leads to restless leg syndrome. It occurs due to drop in iron level in blood resulting muscle spasms. This deficiency could be treated with iron supplements. Yet it would be better to consult physician for using supplements.

What Happens If Too Little Iron Is Consumed?

A poor iron intake over time will result in a reduction of blood hemoglobin levels. Anemia is the medical term used to describe a condition whereby hemoglobin levels fall well below normal levels. Normal hemoglobin levels for men and women are less than 14 and 12 milligrams per 100 milliliters of blood, respectively. In an anemic state (less than 7 to 9 milligrams per 100 milliliters), there is a decrease in the oxygen-carrying capability of our blood. Low oxygen reaches cells and anemic people will have a complain of lethargy and early fatigue when they exercise. Beyond transporting oxygen in the blood, iron deficiency decreases the ability of cells to make ATP by aerobic means.

Short-term iron deficiency does not cause any obvious medical problems. The body will obtain the iron it requires from iron stored in the muscles, liver, spleen, and bone marrow. When the levels of iron stored in the body are depleted, the body will demonstrate symptoms of iron-deficiency anemia. Red blood cells will decrease in size and contain less hemoglobin. That will cause less oxygen to travel from the lungs to the body. Symptoms of iron deficiency include fatigue, gastrointestinal upset, difficulty with concentration, problems with controlling body temperature, and an inability to fight off germs and infections. Infants and children with iron deficiency are at increased risk for learning difficulties.

Can Too Much Iron Be Consumed?

Recently, a fair amount of attention has been focused on what happens when there is too much iron in the body. For instance, researchers reported that men in Finland who have higher levels of ferritin in their blood were more likely to experience heart attacks in comparison with men with lower levels.

In more extreme examples of having excessive body iron, people in certain sub-Saharan countries noted for drinking beer with a high iron content seem to develop cirrhosis of the liver beyond what could be expected from excessive consumption of alcohol. Further evidence based on genetic disorders in which  absorption of iron is enhanced. This can lead to excessive body iron content in these people. The disorder is referred to as genetic-based hemochromatosis and is apparent in as many as 12 of every 1,000 people of European descent. This disorder is associated with severe liver disease and early death.

The excess intake of iron, especially iron supplementation on an empty stomach, has the potential to cause other problems such as gastrointestinal upset, constipation, nausea, abdominal pain, vomiting, and fainting. High doses of iron may inhibit the absorption of zinc. Extremely high doses of iron have been associated with organ failure, coma, convulsions, and death. In addition, there is an inherited medical problem known as hemochromatosis in which toxic levels of iron build up in the body. Without treatment, this condition may trigger other problems such as liver cirrhosis, liver cancer, and heart disease.

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