Iron Deficiency Symptoms is a mineral that is naturally present in many foods, added to some food products, and available as a dietary supplement. Iron is an essential component of hemoglobin, an erythrocyte protein that transfers oxygen from the lungs to the tissues. As a component of myoglobin, a protein that provides oxygen to muscles, iron supports metabolism. Iron is also necessary for growth, development, normal cellular functioning, and synthesis of some hormones and connective tissue.
Types of Iron
There are two types of iron that are prescribed: ferric and ferrous iron. Ferrous iron is better absorbed by the body than ferric iron. For this reason, most iron supplements contain ferrous iron. Three types of ferrous iron are typically prescribed: ferrous sulfate, ferrous fumarate, and ferrous gluconate. These supplements are available in many forms, including tablets, capsules, liquids, drops, and extended-release.
Because ferric iron is not absorbed as well as ferrous iron, it is not prescribed as often. In addition, studies have shown that ferrous iron is tolerated better by patients than ferric iron. Because the gastrointestinal tract has less ability to reduce ferric iron to its ferrous form, there is a reduced chance of iron poisoning with iron citrate, which is the most commonly used form of ferric iron.
Deficiency Symptoms of Iron
Symptoms of iron deficiency are not unique to iron deficiency (i.e. not pathognomonic). Iron is needed for many enzymes to function normally, so a wide range of symptoms may eventually emerge, either as the secondary result of the anemia or as other primary results of iron deficiency. Symptoms of iron deficiency include:
- Feeling tired and weak
- Decreased work and school performance
- Slow cognitive and social development during childhood
- Difficulty in maintaining body temperature
- Decreased immune function, which increases susceptibility to infection
- Glossitis (an inflamed tongue)
- Struggling to concentrate at work or college.
- Memory problems.
- Reduced ability to exercise.
- Hair losing its condition, and possibly hair loss.
- Nails becoming brittle and breaking or splitting easily. They may even change shape, becoming concave or spoon-shaped, or may develop ridges.
- Cuts and grazes taking a long time to heal.
- A sore tongue.
- Sores at the corners of your mouth.
- Restless legs syndrome.
- Infants with iron deficiency may not develop as quickly as normal.
- Pica syndrome: the craving or eating of substances not normally eaten, such as clay, chalk or coal.
- Brittle or grooved nails
- Hair thinning
- Plummer–Vinson syndrome: painful atrophy of the mucous membrane covering the tongue, the pharynx, and the esophagus
- Impaired immune function
Continued iron deficiency may progress to anemia and worsening fatigue. Thrombocytosis, or an elevated platelet count, can also result. A lack of sufficient iron levels in the blood is a reason that some people cannot donate blood.
Recommended Intakes of Iron
Intake recommendations for iron and other nutrients are provided in the Dietary Reference Intakes (DRIs) developed by the Food and Nutrition Board (FNB) at the Institute of Medicine (IOM) of the National Academies (formerly National Academy of Sciences) . DRI is the general term for a set of reference values used for planning and assessing nutrient intakes of healthy people. These values, which vary by age and gender, include:
- Recommended Dietary Allowance (RDA) – Average daily level of intake sufficient to meet the nutrient requirements of nearly all (97%–98%) healthy individuals; often used to plan nutritionally adequate diets for individuals.
- Adequate Intake (AI) – Intake at this level is assumed to ensure nutritional adequacy; established when evidence is insufficient to develop an RDA.
- Estimated Average Requirement (EAR) – Average daily level of intake estimated to meet the requirements of 50% of healthy individuals; usually used to assess the nutrient intakes of groups of people and to plan nutritionally adequate diets for them; can also be used to assess the nutrient intakes of individuals.
- Tolerable Upper Intake Level (UL) – Maximum daily intake unlikely to cause adverse health effects.
Lists the current iron RDAs for nonvegetarians. The RDAs for vegetarians are 1.8 times higher than for people who eat meat. This is because heme iron from meat is more bioavailable than nonheme iron from plant-based foods, and meat, poultry, and seafood increase the absorption of nonheme iron.
For infants from birth to 6 months, the FNB established an AI for iron that is equivalent to the mean intake of iron in healthy, breastfed infants.
|Birth to 6 months||0.27 mg*||0.27 mg*|
|7–12 months||11 mg||11 mg|
|1–3 years||7 mg||7 mg|
|4–8 years||10 mg||10 mg|
|9–13 years||8 mg||8 mg|
|14–18 years||11 mg||15 mg||27 mg||10 mg|
|19–50 years||8 mg||18 mg||27 mg||9 mg|
|51+ years||8 mg||8 mg|
* Adequate Intake (AI)
Food Sources and Iron Deficiency Symptoms
Several food sources of iron are listed in Table 2. Some plant-based foods that are good sources of iron, such as spinach, have low iron bioavailability because they contain iron-absorption inhibitors, such as polyphenols.
|Breakfast cereals, fortified with 100% of the DV for iron, 1 serving||18||100|
|Oysters, eastern, cooked with moist heat, 3 ounces||8||44|
|White beans, canned, 1 cup||8||44|
|Chocolate, dark, 45%–69% cacao solids, 3 ounces||7||39|
|Beef liver, pan fried, 3 ounces||5||28|
|Lentils, boiled and drained, ½ cup||3||17|
|Spinach, boiled and drained, ½ cup||3||17|
|Tofu, firm, ½ cup||3||17|
|Kidney beans, canned, ½ cup||2||11|
|Sardines, Atlantic, canned in oil, drained solids with bone, 3 ounces||2||11|
|Chickpeas, boiled and drained, ½ cup||2||11|
|Tomatoes, canned, stewed, ½ cup||2||11|
|Beef braised bottom round, trimmed to 1/8” fat, 3 ounces||2||11|
|Potato, baked, flesh and skin, 1 medium potato||2||11|
|Cashew nuts, oil roasted, 1 ounce (18 nuts)||2||11|
|Green peas, boiled, ½ cup||1||6|
|Chicken, roasted, meat and skin, 3 ounces||1||6|
|Rice, white, long grain, enriched, parboiled, drained, ½ cup||1||6|
|Bread, whole wheat, 1 slice||1||6|
|Bread, white, 1 slice||1||6|
|Raisins, seedless, ¼ cup||1||6|
|Spaghetti, whole wheat, cooked, 1 cup||1||6|
|Tuna, light, canned in water, 3 ounces||1||6|
|Turkey, roasted, breast meat and skin, 3 ounces||1||6|
|Nuts, pistachio, dry roasted, 1 ounce (49 nuts)||1||6|
|Broccoli, boiled and drained, ½ cup||1||6|
|Egg, hard boiled, 1 large||1||6|
|Rice, brown, long or medium grain, cooked, 1 cup||1||6|
|Cheese, cheddar, 1.5 ounces||0||0|
|Cantaloupe, diced, ½ cup||0||0|
|Mushrooms, white, sliced and stir-fried, ½ cup||0||0|
|Cheese, cottage, 2% milk fat, ½ cup||0||0|
|Milk, 1 cup||0||0|
* DV = Daily Value. DVs were developed by the U.S. Food and Drug Administration (FDA) to help consumers compare the nutrient contents of products within the context of a total diet. The DV for iron is 18 mg for adults and children age 4 and older. Foods providing 20% or more of the DV are considered to be high sources of a nutrient.
The U.S. Department of Agriculture’s (USDA’s) Nutrient Database Web site lists the nutrient content of many foods and provides a comprehensive list of foods containing iron arranged by nutrient content and by food name.
|World’s Healthiest Foods ranked as quality sources of
|Swiss Chard||1 cup||35.0||3.96||22||11.3||excellent|
|Beet Greens||1 cup||38.9||2.74||15||7.0||very good|
|Collard Greens||1 cup||62.7||2.15||12||3.4||very good|
|Bok Choy||1 cup||20.4||1.77||10||8.7||very good|
|Asparagus||1 cup||39.6||1.64||9||4.1||very good|
|Mustard Greens||1 cup||36.4||1.22||7||3.4||very good|
|Turnip Greens||1 cup||28.8||1.15||6||4.0||very good|
|Leeks||1 cup||32.2||1.14||6||3.5||very good|
|Chili Peppers||2 tsp||15.2||0.93||5||6.1||very good|
|Romaine Lettuce||2 cups||16.0||0.91||5||5.7||very good|
|Sesame Seeds||0.25 cup||206.3||5.24||29||2.5||good|
|Garbanzo Beans||1 cup||269.0||4.74||26||1.8||good|
|Lima Beans||1 cup||216.2||4.49||25||2.1||good|
|Navy Beans||1 cup||254.8||4.30||24||1.7||good|
|Kidney Beans||1 cup||224.8||3.93||22||1.7||good|
|Black Beans||1 cup||227.0||3.61||20||1.6||good|
|Pinto Beans||1 cup||244.5||3.57||20||1.5||good|
|Pumpkin Seeds||0.25 cup||180.3||2.84||16||1.6||good|
|Green Peas||1 cup||115.7||2.12||12||1.8||good|
|Brussels Sprouts||1 cup||56.2||1.87||10||3.3||good|
|Green Beans||1 cup||43.8||0.81||5||1.9||good|
|Summer Squash||1 cup||36.0||0.65||4||1.8||good|
|Black Pepper||2 tsp||14.6||0.56||3||3.8||good|
|Sea Vegetables||1 TBS||10.8||0.56||3||5.2||good|
Density>=7.6 AND DRI/DV>=10%
|very good||DRI/DV>=50% OR
Density>=3.4 AND DRI/DV>=5%
Density>=1.5 AND DRI/DV>=2.5%
Health Benefit or Iron Deficiency Symptoms
- Anemia caused by chronic conditions – Many diseases such as cancer, kidney problems, or heart problems can cause anemia. Taking iron along with other medications such as epoetin alfa can help build red blood cells and prevent or treat anemia in people with kidney problems or being treated for cancer with chemotherapy. Receiving iron by injection is more effective than taking iron by mouth.
- Anemia caused by low iron levels – Taking iron by mouth or by injection is effective for treating and preventing anemia caused by too little iron in the body.
- Low iron levels during pregnancy – Taking iron by mouth might reduce the risk of anemia caused by too little iron in the body when taken by women who are pregnant.
Possibly Effective for
- Coughs caused by ACE inhibitors – Medications used for high blood pressure called ACE inhibitors can sometimes cause coughing as a side effect. Some research shows that taking iron by mouth might reduce or prevent this side effect. The ACE inhibitor medications include captopril (Capoten), enalapril (Vasotec), lisinopril (Prinivil, Zestril), and many others.
- Improving thinking – Taking iron by mouth might help improve thinking, learning, and memory in children ages 6-18 years with low levels of iron. An early study suggests that taking iron might improve attention in girls ages 13-18 with unknown iron status.
- Heart failure – Up to 20% of people who have heart failure also have low levels of iron. Some research shows that giving iron by injection can improve symptoms of heart failure such as the ability to exercise and other symptoms.
- Restless legs syndrome (RLS) – Research shows that taking iron by mouth decreases symptoms of RLS such as leg discomfort and sleep problems. In fact, taking the iron to improve symptoms is recommended for people with RLS and low iron levels. Some people with RLS also have improved symptoms after having iron injected into the vein (by IV). But it’s too soon to know if all forms of ironwork when given by IV.
- Preterm labor – Taking iron during pregnancy starting in the second trimester doesn’t seem to increase the duration of pregnancy or increase the weight of the infant at birth.
- ADHD – Developing research shows that taking iron by mouth for 1-3 months improves some symptoms of attention problems in children with a condition called attention deficit-hyperactivity disorder (ADHD) and low iron levels.
- Breath-holding attacks – Early research suggests that taking iron by mouth or through a shot reduces the number of breath-holding attacks in children.
- Child development – Early research shows that iron does not improve thinking or learning in infants and children who do not have anemia. However, there might be an improvement in movement skills. Other early evidence shows that taking iron does not increase growth in children.
- Cancer of the tube that connects the throat and stomach (esophageal cancer) – Early research found that people who take iron supplements are 32% less likely to develop one type of esophageal cancer.
- Fatigue – There is some early evidence that taking iron as ferrous sulfate might improve unexplained fatigue in women.
- Stomach cancer – Early research found that people who take iron supplements are about 1.6 times more likely to develop one type of stomach cancer.
- Anemia in people with HIV – Early research shows that children with HIV and anemia who take iron along with a multivitamin for 3 months have a lower chance of still having anemia 3 months later compared to children who take only a multivitamin.
- Physical performance – Early research shows that taking iron by mouth can improve the ability to exercise in younger women and children.
- Canker sores.
- A digestive tract disease called Crohn’s disease.
- Female infertility.
- Heavy menstrual bleeding.
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