How much iron is needed for iron deficiency? Can you get enough iron through diet alone? This article will answer the question by looking at the essentiality of iron and how it is measured, vegetarian and vegan sources of dietary iron, heme and non-heme sources of non-haeme iron, and the recommended daily allowance for men, women, children and infants.
How Much Iron Is Needed For Iron Deficiency
Iron a mineral that’s necessary for life. Iron plays a key role in the making of red blood cells, which carry oxygen. You can get iron from food and from supplements. If you don’t have enough iron, you may develop anemia, a low level of red blood cells. However, most people in the U.S. get their iron from food.
Iron Intakes and Status
People in the United States usually obtain adequate amounts of iron from their diets, but infants, young children, teenaged girls, pregnant women, and premenopausal women are at risk of obtaining insufficient amounts [28,33-35]. The average daily iron intake from foods is 11.5–13.7 mg/day in children aged 2–11 years, 15.1 mg/day in children and teens aged 12–19 years, and 16.3–18.2 mg/day in men and 12.6–13.5 mg/day in women older than 19 . The average daily iron intake from foods and supplements is 13.7–15.1 mg/day in children aged 2–11 years, 16.3 mg/day in children and teens aged 12–19 years, and 19.3–20.5 mg/day in men and 17.0–18.9 mg/day in women older than 19. The median dietary iron intake in pregnant women is 14.7 mg/day .
Rates of iron deficiency vary by race and other sociodemographic factors. Six percent of white and black toddlers aged 1 to 3 years in the United States are iron deficient (defined as at least two abnormal results for the child’s age and gender on transferrin saturation, free erythrocyte protoporphyrin, and/or serum ferritin tests), compared with 12% of Hispanic toddlers . Deficiency (including IDA) is more common among children and adolescents in food-insecure households than in food-secure households [36,37]. Among pregnant women, deficiency based on depleted iron stores is more common in Mexican American (23.6%) and non-Hispanic black women (29.6%) than in non-Hispanic white women (13.9%) .
Some groups are at risk of obtaining excess iron. Individuals with hereditary hemochromatosis, which predisposes them to absorb excessive amounts of dietary iron, have an increased risk of iron overload . One study suggests that elderly people are more likely to have chronic positive iron balance and elevated total body iron than iron deficiency. Among 1,106 elderly white adults aged 67 to 96 years in the Framingham Heart Study, 13% had high iron stores (serum ferritin levels higher than 300 mcg/L in men and 200 mcg/L in women), of which only 1% was due to chronic disease . The authors did not assess genotypes, so they could not determine whether these results were due to hemochromatosis.
Why do people take iron?
Iron supplements are most often used for certain types of anemia. Anemia can cause fatigue and other symptoms. If you have symptoms of anemia, seek care from your health care provider. Don’t try to treat it on your own.
Iron supplements are often prescribed to treat anemia caused by:
- Heavy menstrual periods
- Kidney disease
Those who may be at risk for iron deficiency include preterm infants, young children, teenage girls, and pregnant women, as well as people with certain health conditions including chronic heart failure, Crohn’s disease, celiac disease and ulcerative colitis. Iron supplements are commonly recommended for women who are pregnant or of childbearing age to help prevent anemia. Before taking an iron supplement, ask your health care provider if it is right for you.
In some cases your doctor may recommend intravenous (IV) iron. IV iron may be necessary to treat iron deficiency in patients who do not absorb iron well in the gastrointestinal tract, patients with severe iron deficiency or chronic blood loss, patients who are receiving supplemental erythropoietin, a hormone that stimulates blood production, or patients who cannot tolerate oral iron. If you need IV iron, your doctor may refer you to a hematologist to supervise the iron infusions. IV iron comes in different preparations:
- Iron dextran
- Iron sucrose
- Ferric gluconate
Large doses of iron can be given at one time when using iron dextran. Iron sucrose and ferric gluconate require more frequent doses spread over several weeks. Some patients may have an allergic reaction to IV iron, so a test dose may be administered before the first infusion. Allergic reactions are more common with iron dextran and may necessitate switching to a different preparation. Severe side effects other than allergic reactions are rare and include urticaria (hives), pruritus (itching), and muscle and joint pain.
Adults with normal intestinal function have very little risk of iron overload from dietary sources of iron . However, acute intakes of more than 20 mg/kg iron from supplements or medicines can lead to gastric upset, constipation, nausea, abdominal pain, vomiting, and faintness, especially if food is not taken at the same time [2,5]. Taking supplements containing 25 mg elemental iron or more can also reduce zinc absorption and plasma zinc concentrations [3,87,88]. In severe cases (e.g., one-time ingestions of 60 mg/kg), overdoses of iron can lead to multisystem organ failure, coma, convulsions, and even death [27,89].