|This is one in a series of fact sheets containing information to help you select
foods that provide adequate daily amounts of vitamins, minerals, and dietary fiber as you follow
the Dietary Guidelines for Americans. |
The Guidelines are -
- Eat a Variety of Foods
- Maintain Desirable Weight
- Avoid Too Much Fat, Saturated Fat, and Cholesterol
- Eat Foods with Adequate Starch and Fiber
- Avoid Too Much Sugar
- Avoid Too Much Sodium
- If You Drink Alcoholic Beverages, Do So in Moderation
WHAT IS MEANT BY A GOOD FOOD SOURCE?
A good food source of iron contains a substantial amount of iron in relation to its calorie
content and contributes at least 10 percent of the U.S. Recommended Dietary Allowance (U.S. RDA)
for iron in a selected serving size. The U.S. RDA for iron is 18 milligrams per day.
(The U.S. RDA given is for adults, except pregnant or lactating women, and children over 4 years of age.)
Pregnant women have many increased nutrient needs. Iron needs, in particular, drastically increase with pregnancy, due to the body’s increased blood volume. You can easily add iron to your diet with a simple iron supplement.
The U.S. RDA for iron is the amount of the mineral used as a standard in nutrition labeling of foods.
This allowance is based on the 1968 Recommended Dietary Allowances (RDA) for 24 sex-age categories set
by the Food and Nutrition Board of the National Academy of Sciences. The 1989 RDA has been set at 15
milligrams per day for women 19 to 50 years of age and 10 milligrams for men 25 to 50 years of age.
In 1985 and 1986, 43 percent of the iron in the diets of women was contributed by
grain products and 26 percent was supplied by meat, poultry, and fish. Foods that contain small
amounts of iron but are not considered good sources can contribute significant amounts of iron to
an individual's diet if these goods are eaten often or in large amounts.
WHY DO WE NEED IRON?
Iron, a mineral, functions primarily as a carrier of oxygen in the body, both as a part of hemoglobin
in the blood and of myoglobin in the muscles.
DO WE GET ENOUGH IRON?
According to recent USDA surveys, over three-fourths of American women 19 to 50 years of age had iron
intakes below 80 percent of their RDA. Average iron intake was 67 percent of the RDA. Men of the same
age met their RDA.
The ability of the body to absorb and utilize iron from different foods varies. The iron in meat,
poultry, and fish is absorbed and utilized more readily than iron in other foods. The presence of
these animal products in a meal increases the availability of iron from other foods. The presence
of vitamin C (ascorbic acid) in a meal also increases iron absorption. The body increases or
decreases iron absorption according to need. The body absorbs iron more efficiently when iron
stores are low and during growth spurts or pregnancy. The most common indication of poor iron
status is iron deficiency anemia, a condition in which the size and number of red blood cells are
reduced. This condition may result from inadequate intake of iron or from blood loss.
HOW CAN WE GET ENOUGH IRON?
Eating a variety of foods that contain iron is the best way to get an adequate amount. Healthy
individuals who eat a balanced diet rarely need supplements. Intakes of iron tend to be low in
relation to recommendations, and there aren't that many foods that are really good sources; thus,
it may take special care to ensure an adequate intake. Many doctors recommend feeding a fortified
milk formula or breakfast cereal or giving an iron supplement to infants and toddlers, because it
is especially difficult to meet their iron needs. Doctors usually prescribe iron supplements for
pregnant or lactating women. The list of foods will help you select those that are good sources
of iron as you follow the Dietary Guidelines. The list of good sources was derived from the same
nutritive value of foods tables used to analyze information for recent food consumption surveys
of the U.S. Department of Agriculture, Human Nutrition Information Service.
CAN YOU HAVE TOO MUCH IRON?
Hemochromatosis (HE-mo-kro-ma-TO-sis) is a disease in which too much iron builds up in your body (iron overload).
Most people who have primary hemochromatosis inherit it from their parents.
HOW TO PREPARE FOODS TO RETAIN IRON
Iron is lost in cooking some foods even under the best conditions. To retain iron:
- Cook foods in a minimal amount of water.
- Cook for the shortest possible time.
WHAT ABOUT ENRICHED OR FORTIFIED FOODS?
Pasta, white rice, and most breads made from refined flours are enriched with iron, because iron
is one of the nutrients lost in processing. Other nutrients added to refined flours and pasta are
thiamin, niacin, and riboflavin. Enriched products or products made from enriched flour are labeled
as such. Minimum and maximum enrichment levels are specified for thiamin, riboflavin, and niacin,
but only a minimum level of iron is required in farina. Thus, iron enrichment levels for farina
vary from brand to brand.
Most ready-to-eat and instant-prepared cereals are fortified with iron. Fortified ready-to-eat
cereals usually contain at least 25 percent of the U.S. RDA for iron. Since cereals vary, check
the label on the package for the percentage of the U.S. RDA for a specific cereal.
WHAT IS A SERVING?
The serving sizes used on the list of good sources are only estimates of the amounts of food you
might eat. The amount of nutrient in a serving depends on the weight of the serving.
For example, 1/2 cup of cooked spinach contains more iron than a 1/2-cup serving of spinach
served raw, because the cooked spinach weighs more. Therefore, the cooked spinach appears on
the list while the raw form does not. Raw spinach provides the nutrient - but just not enough
in a 1/2-cup serving to be considered a good source.
WHAT ARE GOOD SOURCES OF IRON?
FOOD SELECTED PERCENTAGE
SERVING SIZE U.S. RDA (1)
(1) A selected serving size contains -
BREADS, CEREALS, AND OTHER GRAIN PRODUCTS (1)
Bagel, plain, pumpernickel, or
whole-wheat 1 medium +
Farina, regular or quick, cooked 2/3 cup ++
Muffin, bran 1 medium +
Noodles, cooked 1 cup +
Oatmeal, instant, fortified,
prepared 2/3 cup ++
Pita bread, plain or whole-wheat 1 small +
Pretzel, soft 1 +
Ready-to-eat cereals, fortified 1 ounce ++
Rice, white, regular or
converted, cooked 2/3 cup +
Apricots, dried, cooked,
unsweetened 1/2 cup +
Beans, lima, cooked 1/2 cup +
Spinach, cooked 1/2 cup +
MEAT, POULTRY, FISH, AND ALTERNATES
Meat and Poultry
Brisket, braised, lean only 3 ounces +
Ground; extra lean, lean, or
regular; baked or broiled 1 patty +
Pot roast, braised, lean only 3 ounces +
Roast, rib, roasted, lean only 3 ounces +
Shortribs, braised, lean only 3 ounces +
Steak, baked, broiled, or
braised; lean only 3 ounces +
Stew meat, simmered, lean only 3 ounces +
Beef 3 ounces ++
Calf 3 ounces +
Pork 3 ounces +++
Chicken or turkey 1/2 cup diced ++
Liverwurst 1 ounce +
Tongue, braised 3 ounces +
Turkey, dark meat, roasted
without skin 3 ounces +
Fish and Seafood
Clams; steamed, boiled, or
canned; drained 3 ounces +++
Mackerel, canned, drained 3 ounces +
Mussels, steamed, boiled,
or poached 3 ounces +
Baked, broiled, or steamed 3 ounces ++
Canned, undrained 3 ounces ++
Shrimp; broiled, steamed,
boiled, or canned; drained 3 ounces +
Trout, baked or broiled 3 ounces +
Dry Beans, Peas, and Lentils
Beans; black-eyed peas (cowpeas),
chickpeas (garbanzo beans),
red kidney, or white; cooked 1/2 cup +
Lentils, cooked 1/2 cup +
Soybeans, cooked 1/2 cup ++
Nuts and Seeds
Pine nuts (pignolias) 2 tablespoons +
Pumpkin or squash seeds,
hulled, roasted 2 tablespoons +
+ 10-24 percent of the U.S. RDA for adults and children over 4 years of age
++ 25-39 percent of the U.S. RDA for adults and children over 4 years of age
+++ 40 percent or more of the U.S. RDA for adults and children over 4 years of age
(2) Breads, pasta, and cereals listed are enriched unless otherwise noted.
See section on enriched or fortified foods.