What you need to know about Calcium
What is “a good food source?”
A good food source of calcium contains a substantial amount of calcium in relation to its calorie content and contributes at least 10 percent of the U.S. Recommended Dietary Allowance (U.S. RDA) for calcium in a selected serving size. The U.S. RDA for calcium is 1,000 milligrams per day. The U.S. RDA given is for adults (except pregnant or lactating women) and children over 4 years of age.
The U.S. RDA for calcium 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. Adequate intake (AI) recommendations published in August 1997 were set at 1000 milligrams for men and women aged 19 - 50 and 1200 milligrams for individuals older than age 50.
Where do we get calcium?
In 1990, 3/4 of the calcium in our diet came from dairy products. The other quarter was fairly evenly distributed in all the other foods. Foods that contain small amounts of calcium, but are not considered good sources, can contribute significant amounts of calcium to an individual’s diet if these foods are eaten often or in large amounts.
Why do we need calcium?
Calcium, a mineral, is used for building bones and teeth and in maintaining bone strength. Calcium is also used in muscle contraction, blood clotting, and maintenance of cell membranes.
Do we get enough calcium?
According to recent USDA surveys, average calcium intakes for women and younger men are below their RDA. The average calcium intake by women 20 to 29 years of age was about 778 milligrams per day, and the intake by women 30 to 50 years of age was about 719 milligrams. Average calcium intake by men 20 to 29 years of age was 1075 milligrams.
Calcium absorption is dependent upon the calcium needs of the body, the foods eaten, and the amount of calcium in the foods eaten. Vitamin D, whether from diet or exposure to the ultraviolet light of the sun, increases calcium absorption. Calcium absorption tends to decrease with increased age for both men and women.
How can we get enough calcium?
Eating a variety of foods that contain calcium is the best way to get an adequate amount. Healthy individuals who eat a balanced diet rarely need supplements. The list of foods on pages 3 and 4 of this fact sheet will help you select those that are good sources of calcium 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.
| Average Intake of Calcium in the Typical American Diet |
|---|
 |
| * The “Other foods” category includes eggs (1.7%), fats and oils (0.1%), sugars and sweeteners (0.8%), and miscellaneous foods (2.6%).
Source: Gerrior SA, Zizza C., 1994. Nutrient Content of the U.S. Food Supply, 1909 - 1990. Home Economics Research Report No. 52. U.S. Department of Agriculture, Washington, D.C. |
How to prepare foods to retain calcium
Calcium is lost in cooking some foods even under the best conditions. To retain calcium:
- Cook foods in a minimal amount of water.
- Cook for the shortest possible time.
What about fortified foods?
Some foods, such as orange juice, bread, and ready-to-eat cereals, are not normally good sources of calcium but may have had calcium added. Most instant-prepared cereals are fortified with calcium. Since these products vary in the amount of calcium provided, check the label on the carton or package for the percentage of the U.S. RDA for a specific product.
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, a cup of a cooked vegetable contains more calcium than a cup of the same vegetable served raw, because a serving of the cooked vegetable weighs more. Therefore, the cooked vegetable may appear on the list while the raw form does not. The raw vegetable provides the nutrient — but just not enough in a cup serving to be considered a good source.
Updated and Revised by Sharron Coplin, M.S., R.D., Extension Associate, Food and Nutrition
| Good Sources of Calcium | ||
|---|---|---|
| Food | Selected Serving Size | Percentage of U.S. RDA1 |
| Breads, Cereals, and Other Grain Products | ||
| English Muffin, plain with raisins | 1 | + |
| Muffin, bran | 1 medium | + |
| Oatmeal, instant, fortified, prepared2 2/3 cup + | ||
| Pancakes, plain, fruit, buckwheat, or whole-wheat | 2 4-inch pancakes | + |
| Waffles: | ||
| Bran, cornmeal or fruit | 2 4-inch squares | + |
| Plain | 2 4-inch squares | ++ |
| Vegetables | ||
| Broccoli, cooked | 1/2 cup | + |
| Spinach, cooked | 1/2 cup | + |
| Turnip greens, cooked | 1/2 cup | + |
| Meat, poultry, fish and alternates | ||
| Fish and Seafood | ||
| Mackerel, canned, drained | 3 ounces | + |
| Ocean perch, baked or broiled | 3 ounces | + |
| Salmon, canned, drained | 3 ounces | + |
| Dry Beans, Peas, and Lentils | ||
| Tofu (bean curd)3 | 1/2 cup cubed | ++ |
| Milk, cheese, and yogurt | ||
| Cheese, natural: | ||
| Blue, brick, camembert, feta, gouda, monterey, mozzarella, muenster, provolone, or roquefort | 1 ounce | + |
| Gruyere or swiss | 1 ounce | ++ |
| Parmesan (hard) or romano | 1 ounce | ++ |
| Cheese, process, cheddar or swiss | 3/4 ounce | + |
| Cheese, ricotta | 1/2 cup | ++ |
| Ice cream or ice milk, soft-serve | 1/2 cup | + |
| Milk | ||
| Buttermilk | 1 cup | ++ |
| Chocolate | 1 cup | ++ |
| Dry, nonfat, reconstituted | 1 cup | ++ |
| Evaporated, whole or skim, diluted | 1 cup | ++ |
| Lowfat or skim | 1 cup | ++ |
| Whole | 1 cup | ++ |
| Yogurt | ||
| Flavored or fruit, made with whole or lowfat milk | 8 ounces | ++ |
| Frozen | 8 ounces | ++ |
| Plain | ||
| made with whole milk | 8 ounces | ++ |
| made with lowfat or nonfat milk | 8 ounces | +++ |
| 1 A selected serving size contains + 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 See section on fortified foods. | ||
| 3 If made with calcium sulfate. | ||
Written by Ting Ting on May 29th, 2006 with
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