A Dr. Anthony Komaroff, MD, Internal Medicine, answered. The innate immune system is first and best known for a family of white blood cells called phagocytes, which reside very close to the layer of epithelial cells that line much of the body's surface. Dr. Anthony Komaroff, MD, Internal Medicine, answered. The innate immune system is first and best known for a family of white blood cells called phagocytes, which reside very close to the layer of epithelial cells that line much of the body's surface.
The iron content of the body is highly conserved (Bothwell et al 1979). To achieve iron balance, adult men need to absorb about 1 mg/day and adult menstruating women about 1.5 mg/day, although this is highly variable. Towards the end of pregnancy, the absorption of 4-5 mg/day is necessary. Requirements are higher during periods of rapid growth in early childhood and adolescence.
1 The U.S. RDA for iron is 27 mg per day for pregnant women and 9 - 10 mg for breastfeeding women.  Eating at least three servings of iron-rich foods a day will help ensure that you are getting 27 mg of iron in your daily diet.