Getting Enough Calcium and Vitamin D

Eating a diet that contains adequate amounts of calcium and vitamin D is key to maintaining strong bones. Muscles and nerves need calcium to work; when your diet doesn’t include enough calcium, your body takes the calcium it needs from your bones. Many Americans don’t consume enough dietary calcium or vitamin D, which the body needs to absorb calcium.

Foods such as milk, yogurt, and cheese are good sources of calcium. Low-fat and fat-free milk and yogurt contain the same amount of calcium as full-fat varieties, with fewer calories. Spinach and sweet potatoes also contain calcium, but the body absorbs the calcium in these foods less efficiently than it absorbs the calcium in milk. (You would need to eat 8 cups of cooked spinach to obtain the same amount of calcium found in an 8-ounce glass of milk.) Many products such as breakfast cereal and orange juice are fortified with calcium.

Because the body can absorb only about 500 mg of calcium at a time, it’s best to spread your calcium intake throughout the day. For example, try to eat at least one calcium-rich food at each meal. Adding a few tablespoons of nonfat powdered milk to soups, gravy, puddings, and home-baked bread and cookies is an easy way to add calcium to food (1 tablespoon adds 52 mg of calcium).

If you just can’t eat enough calcium-rich foods to get to 1,000 or 1,200 mg per day, talk to your doctor about taking a calcium supplement. If you decide to take a supplement, be sure to check whether it should be taken with food.

 

The Vitamin D Difference

Your body needs vitamin D to absorb calcium. The skin manufactures vitamin D when exposed to sunlight. Exposing the hands, arms, and face to the sun for 10 to 15 minutes two to three times a week without sunscreen enables the body to make enough vitamin D to meet its needs. Fair-skinned people make more vitamin D than dark-skinned people. Clothing, air pollution, window glass, the use of sunscreen, and the natural process of aging—all reduce the skin’s ability to make vitamin D.

People who spend a lot of time outdoors or who live at southern latitudes can usually make enough vitamin D through the skin to meet the body’s needs. Elderly people as well as people who don’t spend much time outdoors, who always use sunscreen, or who live at northern latitudes may need to take vitamin D supplements. Few foods naturally contain vitamin D, although some foods such as milk and breakfast cereal are fortified with it (see chart).

Recommended Calcium Intake*

Age Amount (mg/day)
Children and adolescents
Birth-6 months 210
6 months-1 year 270
1-3 years 500
4–8 years 800
9–18 1,300
Adults
19-50 1,000
51 and older 1,200
Pregnant or breast-feeding women
14–18 years 1,300
19–50 1,000

*National Academy of Sciences, 1997

Source: National Osteoporosis Foundation Web site. Available at http://www.nof.org/prevention/calcium.htm. Accessed October 3, 2007

 

 

 

Examples of Food Sources of Calcium

Serving Size Calcium (mg) Calories
Milk 8 ounces
Whole 291 150
Skim 302 86
Yogurt 8 ounces
Plain, low-fat 400 130
Flavored, low-fat 300–400* 200–250*
Cheese 1 ounce
Cheddar 204 114
Swiss 272 107
Parmesan 2 tablespoons 138 46
Vegetables ½ cup
Broccoli (chopped) 47 26
Peas (boiled) 20 62
Squash (acorn or butternut, baked) 32 90
Sweet potato (baked) 32 90
Beans ½ cup
Chick peas (canned) 38 142
Kidney beans (canned) 34 103
Hummus 62 210
Fruit and fruit juice
Raspberries (fresh) 1 cup 27 60
Orange 1 medium 52 60
Orange juice 8 ounces 22 112
Orange juice (calcium fortified) 300 112
Fish and shellfish
Rainbow trout 3 ounces 75 135
Sardines (with bones, canned) 4 pieces 242 100
Tuna (light, canned in water) 3 ounces 10 99
Other foods
Blackstrap molasses 1 tablespoon 172 47
Soy milk (calcium fortified) 8 ounces 150–300* 108–130*

*Varies by brand

Source: Calcium Content of Common Foods. Harvard University Web site. Available at: http://www.huhs.harvard.edu/HealthInformation/CalciumContent.htm. Accessed October 3, 2007.

 

Recommended Vitamin D Intake*

Age Amount (IU/day)
Children and adolescents
Birth-18 years 200
Adults (including women who are pregnant or breast-feeding)
19-50 200
51 and older 800-1,000

Source: Dietary Supplement Fact Sheet: Vitamin D. Office of Dietary Supplements, NIH Clinical Center, National Institutes of Health Web site. Available at: http://ods.od.nih.gov/factsheets/vitamind.asp#h3. Accessed October 3, 2007.