How Much Iron Per Day For Pregnancy :The recommended daily allowance (RDA)for iron varies with age. The RDA is based on the assumption that women need less iron as they get older, because they lose iron due to menstruation. Women younger than age 18 need 15 milligrams a day; those 18 or older need 18 mg/day Full answer: According to the National Institutes of Health Office of Dietary Supplements, most women (and men) take in plenty of iron in their regular diets and therefore don’t need an iron supplement, provided they’re healthy and menstruating.
How Much Iron Per Day For Pregnancy
Body Iron Requirement
Total body iron is about 3.5 g in healthy men and 2.5 g in healthy women; the difference between men and women relates to body size, lower androgen levels, and the dearth of stored iron in women due to menses- and pregnancy-associated iron loss. The distribution of body iron in an average man is 2,100 mg in hemoglobin, 200 mg in myoglobin, 150 mg in tissue (heme and nonheme) enzymes, and 3 mg in transport-iron compartment. Iron is stored in cells and plasma as ferritin (700 mg) and hemosiderin (300 mg).4
It is important to maintain equilibrium between iron absorption and iron loss in the body to ensure multiple metabolic processes, such as oxygen transport, DNA synthesis, and electron transport. On a day-to-day basis, the body absorbs more iron than it loses; therefore, loss of body iron is a more passive process than absorption. It is important to remember that consistent errors in maintaining this equilibrium lead to either iron deficiency or iron overload.
The average American diet, which contains 6 mg of elemental iron per kcal of food, is adequate for iron homeostasis. Of about 15 mg per day of dietary iron, adults absorb only 1 mg, which is the approximate amount lost daily by cell destruction. In iron depletion, absorption increases, although the exact signaling mechanism is unknown; however, absorption rarely increases to more than 6 mg per day unless supplemental iron is added. Children have a greater need for iron and appear to absorb more to meet this need.
Iron is absorbed in the proximal small intestine. Iron uptake occurs by three separate pathways: the heme pathway and two separate pathways for ferric and ferrous iron. Ferric iron utilizes a different pathway to enter cells than does ferrous iron. Which pathway transports the most nonheme iron in humans is unknown. Most nonheme dietary iron is ferric iron. Heme and nonheme iron uptake by intestinal absorptive cells is noncompetitive.
Iron from the intestinal mucosal cell is transferred to transferrin, an iron-transport protein synthesized in the liver; transferrin can transport iron from cells (intestinal, macrophages) to specific receptors on erythroblasts, placental cells, and liver cells. For heme synthesis, transferrin transports iron to the erythroblast mitochondria, which insert the iron into protoporphyrin for it to become heme. Transferrin (plasma half-life, eight days) is recycled for reutilization. Synthesis of transferrin increases with iron deficiency but decreases with any type of chronic disease.
Absorption of iron is determined by the type of iron molecule and by other substances that are ingested. Iron absorption is best when food contains heme iron (e.g., meat). Dietary nonheme iron must be reduced to the ferrous state and released from food binders by gastric secretions. Nonheme iron absorption is reduced by other food items (e.g., vegetable fiber phytates and polyphenols; tea tannates, including phosphoproteins; bran) and certain antibiotics (e.g., tetracycline). Table 1 lists common food sources of iron. Ascorbic acid is the only common food element known to increase nonheme iron absorption. Heme and nonheme iron are absorbed into the enterocyte noncompetitively.4,5
Because iron absorption is so limited, the body recycles and conserves iron. Transferrin grasps and recycles available iron from aging red blood cells undergoing phagocytosis by mononuclear phagocytes. This mechanism provides about 97% of the daily iron needed (~25 mg iron). Iron stores tend to increase as age increases, because iron elimination slows down.
Gentle Iron Supplementation
Even with a healthy diet focused on foods with iron, I know from personal experience that it can be challenging to get all of the iron you need, particularly when you’re pregnant. Fortunately, most prenatal multivitamins do include iron. However, your doctor may recommend an additional iron supplement to meet your individual needs.
When searching for an iron supplement, “gentle” is a characteristic at the top of most women’s wishlist. This is because many iron supplements can cause gastrointestinal side effects such as constipation and nausea. MegaFood Blood Builder® is a unique iron supplement made with nourishing, whole foods like beets and organic oranges, plus folic acid and Vitamin B12 for healthy red blood cell production, and vitamin C to support iron absorption.* Blood Builder was shown in a clinical study to deliver a gentle and effective dose of iron without the side effects of nausea and constipation.
As iron needs increase throughout pregnancy, finding a personalized combination of a healthy diet, high-quality supplements, and regular check-ups with your doctor, can be a winning formula for maintaining optimal amounts of this mighty mineral.
Causes of Iron Deficiency
Two thirds of body iron is present in circulating red blood cells as hemoglobin. One gram of hemoglobin contains 3.47 mg of iron; thus, 1 mL of blood lost from the body (hemoglobin, 15 g/dL) results in a loss of 0.5 mg of iron. Bleeding is the most common cause of iron deficiency in the UnitedStates and Europe.6
Iron deficiency caused solely by diet is uncommon in adults in countries where meat is an important part of the diet. Depending upon the criteria used for the diagnosis of iron deficiency, approximately 4% to 8% of premenopausal women are iron deficient. In countries where little meat is consumed, iron deficiency anemia is six to eight times more prevalent than in the UnitedStates and Europe. This occurs despite consumption of a diet that contains an equivalent amount of total dietary iron, because heme iron is absorbed better from the diet than nonheme iron. In certain geographic areas, intestinal parasites, particularly hookworm, worsen iron deficiency due to blood loss in the gastrointestinal tract. Anemia is more profound among children and premenopausal women in these environs.1,6
Because the average woman eats less than the average man does, she must be more than twice as efficient in absorbing dietary iron in order to maintain equilibrium and avoid developing iron deficiency anemia. A woman loses about 500 mg of iron with each pregnancy. Menstrual iron loss is highly variable, ranging from 10 to 250 mL (4-100 mg of iron) per period. Menstrual iron loss doubles the need for women to absorb iron, compared with men.
Healthy men lose body iron in sloughed epithelium, in secretions from the skin and gut lining, and from small, daily loss of blood from the gastrointestinal tract (0.7 mL of blood daily); cumulatively, this amounts to 1 mg of iron. Men with severe siderosis from blood transfusions can lose a maximum of 4 mg daily via these routes without additional blood loss.
Healthy newborn infants have a total body iron level of 250 mg (80 ppm), which is obtained from maternal sources. Infants consuming cow’s milk have a greater incidence of iron deficiency, because bovine milk has a higher concentration of calcium, which competes with iron for absorption. Subsequently, growing children must obtain approximately 0.5 mg more iron than is lost daily in order to maintain a normal body concentration of 60 ppm.
Prolonged achlorhydria may produce iron deficiency because acidic conditions are required to release ferric iron from food. Then, it can be chelated with mucins and other substances (e.g., sugars, amino acids, amides) to keep it soluble and available for absorption in the more alkaline duodenum.