From ancient times, humans have acknowledged the significance of iron in health and several diseases (Beard and Dawson, 1997). Egyptians, Romans, Greeks and Hindus have been using iron for several medicinal uses, for instance, a disease of the 17th century called chlorosis (green disease) caused due to the deficiency of iron, was treating using iron (Guggenheim, 1995). Iron is an important mineral essential to sustain our overall health. It’s a constitutive part of the hemoglobin molecule present in the RBCs. Hemoglobin facilitates oxygen movement from lungs to all of our cells. Iron is also essential for proper immune activity, protein development and cell differentiation (Dallman et al, 1984).
Iron is recycled and thus preserved by the body. Figure 1 shows a representational diagram of iron cycle in the body. Iron is delivered to tissues by spreading transferrin, a transporter that seizes iron moving freely into the plasma mostly from the intestinal enterocytes or reticuloendothelial macrophages. The binding of iron-loaded transferring to the cell surface transferrin receptor (TfR) 1 leads to endocytosis and absorption of the metal cargo. Internalized iron is passed to mitochondria for the purpose of formation of heme or iron-sulfur clumps, which are fundamental parts of certain metalloproteins, and surplus iron is stockpiled and freed of toxic substances in cytosolic ferritin (Abbaspour, 2014).
Page Contents - Quick Links
- Do not consume iron if
- Daily recommended intake of iron
- Signs and symptoms of iron deficiency
- Top health benefits of iron
- Best natural sources of Iron
- Side effects & concerns of iron
- Special Precautions & Warnings:
- Natural ways and ideas to add more iron into your diet
Do not consume iron if
- You are allergic to any component of iron
- You have suffered from iron metabolism problems (e.g., hemosiderosis or hemochromatosis) or you have high amounts of iron in your blood.
Some medical conditions may interact with iron. Tell your doctor if any of the following applies to you:
- In case you are pregnant, or are breastfeeding
- if you are taking any prescribed or non-prescribed medication, any herbal ingredients, or any other dietary supplement
- In case you are allergic to medicines, particular foods, or some other substances
- If you have stomach or bowel issues (e.g., colitis, ulcers, diverticulitis and Crohn disease)
- If you suffer from anemia like hemolytic anemia or pernicious anemia, or you have a condition like sickle cell disease or glucose-6-phosphate dehydrogenase [G6PD] deficiency.
- If you have hemoglobin problems like thalassemia) or you ever had multiple blood transfusions.
- Some medicines have the tendency to interact with iron, especially any of the following: Doxycycline, penicillamine or thyroid hormones (e.g., levothyroxine) because their efficiency and efficacy may get declined by iron.
Always consume iron after discussing with your health care provider.
Daily recommended intake of iron
During early childhood, human milk makes up for the iron requirements of the body. The requirement for iron increases distinctly 4-6 months after birth and add up to about 0.7-0.9 mg/day in the remaining part of the first year. Between 1 and 6 years of age, the requirement of iron content again gets doubled. Iron demand is also very high in adolescents, mainly during the time of growth spurt. Girls usually have their growth spurt before the first occurrence of menstruation, but growth doesn’t end at that time. In boys, the requirement of iron content increases during puberty. In this stage, iron demand increases to a level much above the average iron needs in menstruating women (FAO, 2005).
The Recommended Daily Allowance (RDA) for iron depends on a person’s age and sex as explained below:
- 0-6 months: 0.27 milligrams (sufficient intake, or AI)
- 7-12 months: 11 mg.
- 1-3 years: 7 mg
- 4-8 years: 10 mg.
- 9-13 years: 8 mg
- 14-18 years: 11 mg
- 19 years and older: 8 mg.
- 9-13 years: 8 mg
- 14-18 years: 15 mg
- 19-50 years: 18 mg
- 51 years and older: 8 mg.
- Pregnancy: 27 mg
- Lactation 14-18 years: 10 mg
- Lactation 19 years and older: 9 mg.
Around 8 million women in the US having a childbearing age suffer from severe anemia due to iron deficiency. Iron deficiency at the time of pregnancy may result in preterm delivery. An average adult conserves about 1-3 g of iron the body. A proper balance between dietary intake and loss keeps this balance. Around 1mg of iron is lost every day through tossing out of cells from the skin and mucosal surfaces and the lining of the gastrointestinal tract (Cook, 1986). Menstruation in women elevates the average daily iron loss to about 2 mg per day in premenopausal adult women (Bothwell et al, 1982). The stimulation of body mass during neonatal and childhood growth spurts causes impermanent boosting of iron requirements (Gibson et al, 1988).
Consuming iron rich diet is required to replace iron lost in the urine, the stools as well as through the skin. These basal losses are indicative of roughly 0.9 mg of iron for an adult male and 0.8 mg for an adult female (DeMaeyer et al, 1989). The iron lost in females during menstrual blood needs to be taken into consideration for females of reproductive age.
Signs and symptoms of iron deficiency
Some of the signs and symptoms of iron deficiency include frangible nails, inflammation or soreness of the tongue, fissures in the sides of the mouth, a dilated spleen, and recurrent infections.People who suffer from iron deficiency anemia have an unusual craving for nonfood items, such as starch, mud, ice, paint and dirt. Such a craving is called pica (PI-ka or PE-ka). Some people who have iron-deficiency anemia develop Restless Legs Syndrome which is a neurological disorder that causes a strong desire to move the legs. This urge is accompanied by unpleasant and unusual feelings in the legs. People having RLS cannot sleep properly in the night.
Iron-deficiency anemia often results in increased risk for lead poisoning and frequent infections in children. Some signs and symptoms of iron-deficiency anemia include bleeding in the intestines which cause bright red blood in the stools or black, tarry-looking stools. Heavy bleeding during periods, long periods, or other kinds of vaginal bleeding are indicative of women being at a risk of iron deficiency anemia. The signs and symptoms of iron deficiency anemia are subject to its severity. There are no symptoms and signs at all in the case of mild to moderate iron deficiency anemia.
Signs and Symptoms of Anemia
Anemia causes tiredness or fatigue and it occurs because of insufficient red blood cells in the body which are responsible for carrying oxygen to other body organs. Also, the inadequate red blood cells in the body means less hemoglobin than normal. Hemoglobin is a kind of protein which is rich in iron present in red blood cells. It facilitates transport of oxygen from lungs to other body parts by the red blood cells. Acute anemia also results in breath shortness, giddiness, and headache, freezing hands and feet, pale yellow skin, pain in the chest, exhaustion, and fatigue (tiredness) (Viteri, 974).
Also, less hemoglobin in the body causes arrhythmias (ah-RITH-me-ahs). This is a condition where there is not enough hemoglobin in the red blood cells, which results in more working by heart to move oxygen-rich blood in the body. This further results in irregular heartbeats, an enlarged heart, or even heart failure. In infants and young children, symptoms of anemia include interrupted growth, poor appetite, poor development, and cognitive development problems.
Top health benefits of iron
First and foremost, iron plays a significant role in hemoglobin formation, since it is an important part of the protein molecule and an element which is responsible for giving a dark shade to the blood. Furthermore, iron also has an important role in the oxygen transportation throughout our body. Since the body has the tendency to lose blood through menstruation in women and through injuries, so iron intake is important for maintaining hemoglobin levels inside our body (McDowell, 2003).
Important for muscle health
Iron is required for muscle health as it facilitates muscle toning and strengthening and also is responsible for flexibility in the muscles. In detail, iron contributes to the oxygen transportation for the contraction of muscles. Our body feels terribly week if we suffer from iron deficiency (Beard, 2001).
Iron is essential for building the immune system of the body, which strengthens and safeguards our biological system and promotes the deterrent line to protect our bodies from various ailments and diseases. Furthermore, red blood cells are advantageous for the healing of damaged cells, tissues and organs since they are responsible for transporting oxygen to various parts of the body. Therefore, in order to have a good health and resistance from various diseases, one needs to consume a balanced diet containing proper concentrations of iron.
Another activity and benefit of iron in the body is to stimulate the development of the brain. As it is known that the brain needs approximately 20 % of oxygen in the blood to do its job properly. Meanwhile, iron is necessary for aiding oxygen supply in the blood, which makes it an inexorable component to cognitive function. To consume a healthy amount of iron is to foster blood flow to the brain, promoting cognitive system and averting various diseases such as dementia and Alzheimer’s disease (Youdim, 2000).
Body temperature has a powerful connection with the metabolic activity as well as the functioning of other organ systems. Therefore, to keep the body performing with its best condition, it is essential to modulate the temperature. Iron is essential for this function, in which the potential to regulate the temperature of iron depends on the body magnitude of absorption.
Oxygen is an ineluctable factor to keep each organ within the body to function properly. Meanwhile, iron acts as an oxygen carrier, transporting oxygen throughout the body and from one cell to another cell. Accordingly, regular iron consumption is very important for the proper functioning of the body (Papanikolaou and Pantopoulos, 2005).
Due to the fact that iron is important for the formation of red blood cells, a deficiency of iron can lead to a condition of anemia, which further results in weakness, dizziness, fatigue and pale skin etc. Anemia is a very common disease and millions of people in the world suffer from it especially the women, who lose blood every month due to monthly cycle called menstruation. In this case, new blood cells will be constructed to make up for the lost ones, which certainly need iron for regeneration (Allen, 2006).
Iron is essential to combat chronic fatigue. Deficiency of iron in the body can lead to lethargy and serious fatigue. So it is advisable to eat iron rich food to keep the body healthy and energetic.
Iron is useful for those with serious diseases related to blood, excretory system or brain activity etc. The reason behind this is that iron is responsible not only for the proper blood circulation but also for various other processes within the body. Therefore, it is important that enough iron is consumed to aid in the treatment of chronic diseases.
Restless leg syndrome
Restless legs syndrome (RLS) is a neurological disease which involves trembling, pulling, squirming, or other unpleasing sensations in the legs and an uncontrollable yearning to move them. Symptoms occur mostly during at night when we are relaxing or are at rest and the condition can increase in severity during the night time. The only solution to treat it is taking a rich iron diet. One can also take iron supplements in addition to iron-rich foods like spinach, beetroot, broccoli, pomegranates, bread or cereal, etc. (Sun et al, 1998).
Blood volume and building of red blood cell increase hysterically during pregnancy in order to provide the growing fetus with required oxygen and essential nutrients. As such, there is an increase in the demand for iron. While the body distinctively upregulates absorption of iron during pregnancy, inadequate iron consumption or other factors influencing iron absorption or usage can lead to iron deficiency. Low iron percentage during pregnancy elevates the risk of premature birth and can also result in low birth weight, as well as declined iron stores and impeded cognitive or behavioral augmentation in infants.
Better athletic performance
Athletes show symptoms of iron deficiency, especially young female athletes. In comparison to sedentary individuals, athletes show more iron deficiency. Iron deficiency in athletes results in poor and weak athletic performance and also impaired immunity function. A lack of hemoglobin reduces physical work performance as it lessens the body’s potential to deliver oxygen to the muscles. So athletes should consume more of iron through iron-rich diet.
Best natural sources of Iron
Heme and non-heme are two types of dietary iron. Animal products like seafood have both non-heme and heme iron. Some other foods which have only non-heme iron sources include beans, nuts, vegetables and fortified grains.
Vegetarians need 1.8 times higher iron intake than the meat eaters in order to bring down the absorption level from plant-based foods. Omnivorous diets like meat, seafood and vitamin C have 14-18% iron bioavailability while from a vegetarian diet it is around 5-12% (Erdman et al, 2012).Taking vitamin C rich foods along with non-heme sources of iron can increase iron absorption.
Non-heme iron absorption is inhibited by:
- Proton pump inhibitors (lansoprazole [Prevacid®] and omeprazole [Prilosec®]) responsible to bring down the acidity of stomach contents
- Polyphenols in spinach, cereals and legumes.
- Tannins in tea, coffee, wine and certain berries
- Phosphates in carbonated beverages such as soda
- Phytates in beans and grains.
Some of the best sources of iron include (Mahan et al, 2007)and (NIH, 2006)
- Canned clams, 3 oz: 24 milligrams
- Fortified cereals: 1-22 milligrams
- Canned white beans, 1 cup: 8 milligrams
- Dark chocolate having 45-69% cacao, 3 oz: 7 milligrams
- Cooked oysters, 3 oz: 6 milligrams
- Cooked spinach, 1 cup: 6 milligrams
- Beef liver, 3 oz: 5 milligrams
- Frozen blueberries, ½ cup: 5 milligrams
- Boiled lentils, ½ cup: 3 milligrams
- Tofu, ½ cup: 3 milligrams
- Boiled chickpeas, ½ cup: 2 milligrams
- Canned and stewed tomatoes, ½ cup: 2 milligrams
- Ground beef, 3 oz: 2 milligrams
- Baked potatoes: 2 milligrams
- Roasted cashew nuts, 1 oz: 2 milligrams
- Egg: 1 milligram
Side effects & concerns of iron
Iron is mostly safe if popped into the mouth in safe proportions. Excessive iron may cause diarrhea, nausea, vomiting, constipation, darkened or green stools and pain and discomfort in the stomach.
It can also cause severe allergic reactions (rash; hives; itching; breathing issues; chest tightness; swelling of the tongue, lips, face and the mouth.) (Hallberg et al, 1966).
However, consuming iron supplements with food brings down some of these side effects. Iron is safe to be taken on an empty stomach but it depends on every individual. Some people suffer side effects if they take it on empty stomach and so it’s advisable for them to take it with food. Iron should not be taken with foods containing dairy products, coffee, tea, or cereals as that might result in certain reactions due to the physiological properties of iron.There are many types of iron products like ferrous sulfate, ferrous gluconate, ferrous fumarate, etc. Some products which contain polysaccharide-iron complex (Niferex-150, etc.), are mild and claim to have fewer side effects than the other forms. But there is no evidence to support this claim as such
Iron supplements which come in liquid form cause an effect on teeth as they result in blackening of teeth. High doses of iron may be harmful to children. Iron is the main cause of poisoning deaths in children. Iron poisoning can result in stomach and intestinal distress, liver failure, very low blood pressure, and even death. If you realize that the child has popped more than the recommended amount of iron, immediate consultation with the nearest health care provider should be done. Research has also shown that people with high consumption of iron, especially from red meat, are at more risk of a heart disease (Sempos, et al, 1994)
Special Precautions & Warnings:
- Pregnancy and breastfeeding:
Iron is mostly safe for pregnant and breastfeeding women who have iron doses below the tolerable upper intake level (UL) of 45 mg per day of elemental iron. But beyond this level, it may prove dangerous as it may cause stomach and intestinal side effects such as nausea and vomiting. High levels of hemoglobin in the blood during delivery may result in bad pregnancy outcomes.
Excessive iron in the diet may result in a heart disease especially in women with type 2 diabetes, although there is research still going on this to prove.
- Stomach or intestinal ulcers:
Iron might cause irritation and make these conditions worse. Use iron with care.
- Intestinal inflammation like ulcerative colitis or Crohn’s disease:
Iron has an ability to worsen these conditions. So it’s important to consume iron with care.
- Hemoglobin disorder (thalassemia):
Taking iron might cause iron overload in people with these conditions. If you suffer from any hemoglobin disease, iron is strictly not recommended unless suggested by your health care provider.
- Premature infants:
Premature infants have low Vitamin E levels and giving iron in such cases can cause serious problems. The vitamin E deficiency needs be fixed before giving iron. It’s important to take advice of your health care provider before giving iron to a premature infant.
Natural ways and ideas to add more iron into your diet
Add lentils in your food
Lentils have rich iron content and are the best source of iron in a vegan diet. They contain 8 % of your iron needs in just a ¼ cup serving. Add a little to a salad bowl or cook some with your favorite spices in replacement to a meat loaf. Lentils can also be added in a curry spiced soup.
It is an algae superfood rich in some of the most important nutrients required by the body, iron being one of those. It contains 80% of your daily iron needs and only a teaspoon can make up for that. Spirulina can be easily added to a smoothie. Just ensure not to have this superfood in excess. A little every day is enough to make up for the iron needs. Spirulina contains Vitamin B12, Vitamin B6, iodine, and Vitamin A. All these nutrients are important for maintaining metabolic health, immunity function, brain function and overall health.
Sprinkle seeds to your spread
Sunflower seeds, pumpkin seeds and hemp seeds are rich in iron and proteins. 3 tablespoons of hemp seeds provide 45% of your daily iron needs. Raw pumpkin seeds and sunflower seeds contain 8-10 percent of your daily iron needs in a 1/4 cup, and chia seeds have roughly around the same amount. These can be used in smoothies, sprinkled on a salad or pureed into a spread. Even a natural peanut butter also can be tried.
Eat lot of greens
Greens like spinach, kale and collards have high iron content. The darker the green, the more iron it has. Greens can be added in soups, salads and even cooked. They can even be eaten raw.
Amaranth, quinoa and teff are grain free options that cook up like grains and have rich iron and amino acids (protein) content.These are commonly called pseudo-grains and they promote a healthy body.
Oats are also rich in iron with 8 percent in a 1/2 cup serving. Oats is a recommended food for gluten-free eaters as they can have certified gluten-free oats. Oats can be easily digested and can be cooked up as a savory or sweet. Oats also contain B vitamins and magnesium which are important for health.
Cacao is the healthiest source of iron. Just 2.5 tablespoons raw powder makes up to 8 % of your daily iron needs. Cacao nibs and whole cacao beans are some of the items.
Iron is an essential element for maintaining our overall health. It has an important role to play in brain development, carrying oxygen to different organs, the formation of hemoglobin and in building our immunity. Iron needs continuous attention at individual and public health levels.
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- Abbaspour, N., Hurrell, R., & Kelishadi, R. (2014). Review on iron and its importance for human health. Journal of Research in Medical Sciences, 19(2).
- Allen, L. H. (2006). Guidelines on food fortification with micronutrients. In Guidelines on food fortification with micronutrients. World Health Organization. Dept. of Nutrition for Health and Development.
- Beard, J. L., & Dawson, H. D. (1997). Iron In: Handbook of nutritionally essential mineral elements. By: O’Dell, BL and Sunole, RA Marcel Dekker Ins. USA.
- Beard, J. L. (2001). Iron biology in immune function, muscle metabolism and neuronal functioning. The Journal of nutrition, 131(2), 568S-580S.
- Bothwell, T. H., & Charlton, R. W. (1982, January). A general approach to the problems of iron deficiency and iron overload in the population at large. In Seminars in hematology (Vol. 19, No. 1, pp. 54-67).
- Cook, J. D., Skikne, B. S., Lynch, S. R., & Reusser, M. E. (1986). Estimates of iron sufficiency in the US population. Blood, 68(3), 726-731.
- DeMaeyer EM, Dallman P, Gurney JM, Hallberg L, Sood SK, Srikantia SG, editors. Geneva: World Health Organization; 1989. WHO. Preventing and controlling iron deficiency anaemia through primary health care: A guide for health administrators and programme managers; p. 58.
- Dallman, P. R., Yip, R., & Johnson, C. (1984). Prevalence and causes of anemia in the United States, 1976 to 1980. The American journal of clinical nutrition, 39(3), 437-445.
- Erdman Jr, J. W., MacDonald, I. A., & Zeisel, S. H. (Eds.). (2012). Present knowledge in nutrition. John Wiley & Sons.
- Gibson, R. S., MacDonald, A. C., & Smit-Vanderkooy, P. D. (1988). Serum ferritin and dietary iron parameters in a sample of Canadian preschool children. Journal of the Canadian Dietetic Association.
- Guggenheim, K. Y. (1995). Chlorosis: The rise and disappearance of a nutritional disease. The Journal of Nutrition, 125(7), 1822-5.
- Hallberg, L., Ryttinger, L., & Solvell, L. (1966). Side effects of oral iron therapy, A double‐blind study of different iron compounds in tablet form. Acta Medica Scandinavica, 180(S459), 3-10.
- Joint, F. A. O. (2005). Vitamin and mineral requirements in human nutrition. In Vitamin and mineral requirements in human nutrition. OMS.
- Mahan, L. K., Escott-Stump, S., & Krause, M. V. (2007). Krause’s food & nutrition therapy. Elsevier Saunders.
- McDowell, L. R. (2003). Minerals in animal and human nutrition (No. Ed. 2). Elsevier Science BV.
- National Institute of Health. (2006). Dietary supplement fact sheet: Iron. Retrieved December 26th, 2016.
- Papanikolaou, G., & Pantopoulos, K. (2005). Iron metabolism and toxicity. Toxicology and applied pharmacology, 202(2), 199-211.
- Sempos, C. T., Looker, A. C., Gillum, R. F., & Makuc, D. M. (1994). Body iron stores and the risk of coronary heart disease. New England Journal of Medicine, 330(16), 1119-1124.
- Sun, E. R., Chen, C. A., Ho, G., Earley, C. J., & Allen, R. P. (1998). Iron and the restless legs syndrome. Sleep, 21(4), 371-377.
- Viteri, F. E., & Torun, B. (1974). Anaemia and physical work capacity. Clinics in haematology, 3(3), 609-626.
- Youdim, M. B. (2000). Nutrient deprivation and brain function: iron. Nutrition, 16(7), 504-508.