Fitness for One and All Home Page

Books and eBooks by the Director

Guest Article
by Keith L. Smith

This fact sheet is one in a series containing information to help you select foods that provide adequate daily amounts of vitamins, minerals, and dietary fiber. Following these guidelines will put your diet in accordance with the Dietary Guidelines for Americans, which are:

• Balance the food you eat with physical activity -- maintain or improve your weight
• Choose a diet with plenty of grain products, vegetables, and fruits
• Choose a diet low in fat, saturated fat, and cholesterol
• Choose a diet moderate in sugars
• Choose a diet moderate in salt and sodium
• If you drink alcoholic beverages, do so in moderation

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.

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.

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.

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.

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.

References:
Federation of American Societies for Experimental Biology, Life Sciences Research Office. Prepared for the Interagency Board for Nutrition Monitoring and Related Research. 1995. Third Report on Nutrition Monitoring in the United States: Volume 1 and 2. U.S. Government Printing Office, Washington D.C.

Subcommittee on the 10th Edition of the RDAs, Food and Nutrition Board, Commission on Life Sciences, National Research Council. 1987. Recommended Dietary Allowances, 10th ed. Academy Press, Washington D.C.

U.S. Department of Agriculture, U.S. Department of Health and Human Services. 1995. Nutrition and Your Health: Dietary Guidelines for Americans, 4th ed. Home and Garden Bulletin No. 232. U.S. Government Printing Office, Washington D.C.

Browne, M.B. 1993. Label Facts for Healthful Eating. Mazer Corporation, Dayton, OH.

Standing Committee on the Scientific Evaluation of Dietary Intakes, Food and Nutrition Board, Institute of medicine. 1997 Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D and Fluoride, National Academy Press, Washington D.C.

Updated and Revised by Sharron Coplin, M.S., R.D., Extension Associate, Food and Nutrition:

Keith L. Smith is the Associate Vice President for Ag. Adm. and Director, Ohio State University Extension.

Calcium. Copyright © 2003 by Fitness Pro Advantage. Used by permission.

I wholeheartedly agree that we should primary look to their diets for their intake of nutrients, including calcium. But the fact remains that many people do not consume sufficient calcium. So supplementation is often beneficial.

It should also be noted that many nutrients besides calcium are involved in bone formation and the other functions that calcium performs in the body. So it is wise to take a wide-spectrum vitamin-mineral supplement. The best such supplement I have found is Jarrow Forumula’s Multi Easy Powder (Gary Zeolla).

The above guest article was posted on this site July 30, 2003.

Guest Articles
Guest Articles: Nutrients

Text Search     Alphabetical List of Pages     Contact Information

Fitness for One and All Home Page

Books and eBooks by the Director