Chow Line: Do what you can to get enough calcium (for 3/8/09)

February 27, 2009

Is there an age-related guideline for calcium intake? As an older man, I want to be sure I'm getting enough.

The recommended intakes for calcium are the same for men and women, but they do change with age. According to the guidelines released in 1997, the adequate intake for ages 9 to 18 is 1,300 milligrams a day. Adults 18 to 50 should get 1,000 milligrams a day, and those 50 and older should get 1,200 milligrams.

Getting enough calcium is important not only to keep bones strong, but there's growing evidence that calcium plays a role in regulating blood pressure and may help prevent some types of cancer. In fact, a study by the National Cancer Institute, published in February 2009 in the Archives of Internal Medicine, indicates that calcium intake of up to 1,300 milligrams a day appears to reduce the risk of cancers of the digestive system, such as colorectal cancer, in both men and women, as well as all types of cancer in women.

Calcium is not easily absorbed by the body, so do what you can to help. First, try to spread calcium consumption over the course of the day, taking no more than 500 milligrams at once. Also, be sure to pair calcium with vitamin D, which helps with absorbability. Most supplements, as well as fortified milk and orange juice, also contain vitamin D, but some products, even some dairy products, don't. Check the label.

On the other hand, many high-fiber foods (particularly those made from wheat bran), and some vegetables, such as spinach, beans and sweet potatoes, contain phytic acid or oxalic acid which inhibit calcium absorption. That's just something to keep in mind -- you don't want to consume all of your calcium every day with a bowl of bran cereal, for example. This is why you might have heard advice to take your calcium supplement separate from meals.

And, be sure you know what you're reading when you examine Nutrition Facts labels for calcium content. Calcium is not listed in milligrams but as a "percent of Daily Value." The reference point for the Daily Value for calcium is just 1,000 milligrams. So, if your goal is to consume 1,200 milligrams of calcium a day, keep track of the percentage listed in the foods you eat and keep going until you hit 120 percent of the Daily Value -- equal to 1,200 milligrams.

Most people don't get enough calcium in their diets, but there is a risk of consuming too much. As long as you keep it under 2,500 milligrams a day, you should be OK, according to the upper limit set as part of the 1997 guidelines.

The National Institutes of Health has detailed information about calcium at http://ods.od.nih.gov/factsheets/calcium.asp.

Chow Line is a service of Ohio State University Extension and the Ohio Agricultural Research and Development Center. Send questions to Chow Line, c/o Martha Filipic, 2021 Coffey Road, Columbus, OH, 43210-1044, or filipic.3@cfaes.osu.edu.

Editor: This column was reviewed by Jackie Buell, director of sports nutrition in the Department of Human Nutrition, College of Education and Human Ecology.

Author(s): 
Martha Filipic
Source(s): 
Jackie Buell