Iron Deficiency and Anemia

Iron deficiency is the most common nutrient deficiency in the world. About 20% of women, 50% of pregnant women, and 3% of men do not have enough iron in their body.

Our bodies need iron because:

  • Iron is a component of hemoglobin, which transports oxygen in the blood
  • Iron is a component of myoglobin, which makes oxygen available for muscle contraction
  • Iron helps the body utilize energy

Iron requirements

Gender

Age Range

Iron Requirement (mg/day)

Males

9−13

8

14−18

11

19−70+

8

Females

9−13

8

14−18

15

19−50

18

>50

8

Pregnancy (all ages)

27

Lactation (≥19 years)

9

mg=milligrams

Factors that influence iron absorption

Heme iron:

Is found only in animal foods—meats, poultry, fish, and shellfish

  • About 15% is absorbed by the body

Nonheme iron:

  • Is found in both plant-derived and animal-derived foods
  • Roughly 3%−8% is absorbed by the body

Factors that enhance nonheme iron absorption:

  • MFP factor, found in meat, fish, and poultry
  • Vitamin C, found in tomatoes, oranges, and other citrus fruits
  • Citric acid and lactic acid from foods
  • Hydrochloric acid in the stomach
  • Sugars, including those in wine

Factors that inhibit iron absorption:

  • Phytates and fibers, found in grains and vegetables
  • Oxalates, found in spinach
  • Calcium and phosphorus, found in milk and dairy productsEthylene diamine tetraacetic acid (EDTA), a food additive
  • Tannic acid and other polyphenols, found in tea and coffee

Iron-rich foods

Include these iron-rich foods in your diet:

Beans and legumes:

  • Kidney
  • Black
  • Soy
  • Pinto  
  • Navy
  • Garbanzo 
  • Lentils

Dried fruits:

  • Raisins
  • Dates
  • Prunes
  • Apricots

Vegetables:

  • Broccoli
  • Asparagus  
  • Parsley
  • Brussels sprouts
  • Potatoes
  • Peas

Greens:

  • Spinach
  • Kale 
  • Mustard, collard and turnip greens

Fish and shellfish:

  • Tuna
  • Salmon 
  • Oysters
  • Clams
  • Shrimp

Poultry:

  • Chicken
  • Turkey

Lean meats:

  • Beef
  • Pork
  • Lamb

Organ meat:

  • Beef liver

Tofu and soy-based meat alternatives:

  • Veggie burgers

Iron-fortified whole grains:

  • Cereals
  • Bread
  • Tortillas
  • Rice
  • Pasta

Black strap molasses
Egg yolk
Nuts

                                                                                       
Putting it all together

Some foods that are high in iron, such as whole grains, contain the less bioavailable, nonheme type of iron. In addition, some of these foods also contain factors that further inhibit the absorption of iron, such as spinach, which is a nonheme iron source that also contains oxalates. Combining these foods with iron-absorption enhancers, such as vitamin C-rich oranges or tomatoes, improves the bioavailability of iron.

 

References and recommended readings

Conrad ME. Iron deficiency anemia. Available at: http://www.emedicine.com/med/topic1188.htm. Accessed January 24, 2011.

Mahan LK, Escott-Stump S. Krause's Food and Nutrition Therapy. 12th ed. St Louis, MO: Saunders/Elsevier; 2008.

MedlinePlus. Iron deficiency anemia. Available at: http://www.nlm.nih.gov/medlineplus/ency/article/000584.htm. Accessed January 24, 2011.

US Dept of Agriculture, National Agricultural Library. DRI report—vitamin A, vitamin K, arsenic, boron, chromium, copper, iodine, iron, manganese, molybdenum, nickel, silicon, vanadium, and zinc. Available at: http://fnic.nal.usda.gov/nal_display/index.php?info_center=4&tax_level=4&tax_subject=256&topic_id=1342&level3_id=5141&level4_id=10590. Accessed January 24, 2011.