Food Sources of Calcium that May not Give You What You Want

For a food to be a good source of calcium, the calcium must be in a form that is well absorbed into the body. Some foods commonly recommended as good calcium sources don’t quite make the grade.

For some foods, you need to eat too much of them to absorb much calcium.

Others contain too many calories along with the absorbable calcium to fit into a reasonable diet.

As you look at the numbers below for the amounts of calcium absorbed from each food, remember that a good estimate for the total amount of calcium a person should absorb each day is 300 milligrams (mg).

Ice Cream

The calcium in ice cream is likely absorbed as well as it is from milk. However, ice cream can pack too many calories along with the calcium. Here are the numbers for the amounts of calcium you would absorb and the calories you get from three types of vanilla ice cream. These are examples from the USDA Nutrient Database. What’s on the market could be quite different.

Absorbable Calcium for One-cup Servings:
Light Ice Cream (5% fat) - 78 mg calcium (250 calories) - not bad!
Regular Ice Cream (11% fat) - 60 mg calcium (290 calories) - not so good.
Rich Ice Cream (16 % fat) - 80 mg calcium (530 calories) - not good.

The main reason that the rich ice cream is not a good source of calcium is because it packs too many calories along with the calcium. To absorb your daily 300 mg of calcium, you need about 2000 calories of the ice cream. It might be fun, but you wouldn’t have much room for other foods!

Green Vegetables

Some Green Vegetables can provide a good amount of calcium for the few calories they contain, but many people won’t eat the volume of vegetables that is required. Check out these numbers.

Absorbable Calcium for One-cup Servings:
Broccoli, cooked - 38 mg
Brussel Sprouts, cooked - 36 mg
Green Cabbage, cooked - 30 mg
Kale, cooked - 46 mg
Spinach, cooked - 12 mg
Watercress, fresh - 26 mg

To put these numbers into perspective, remember that you absorb about 100 mg of calcium from one cup of milk or yogurt. To absorb this much calcium from broccoli requires almost 3 cups of it. For spinach, you need over 8 cups to absorb 100 mg of calcium. And that’s only one-third of your daily needs.

Tofu

The calcium in tofu is absorbed well. However, different types and brands can vary greatly in the amount of calcium they contain. Here are some examples from the USDA Nutrient Database.

Absorbable Calcium for Half-cup Servings:
Regular Tofu - 135 mg
Firm Tofu - 78 mg
Soft Tofu - 43 mg
Silken Tofu (soft or firm) - 12 mg

One problem with these tofu numbers is that they are based on values in the United States Department of Agriculture (USDA) Nutrient Database. When I check labels of tofu products in the market, the amounts of calcium are usually lower than USDA’s values. So, if you are eating tofu for the calcium, check the label and hope that you can trust the manufacturer’s numbers.

Cottage Cheese

Cottage cheese is a great source of high quality protein that provides some calcium too. However, it is not as good for calcium as most other milk products.

Absorbable Calcium for Half-cup Servings:
All Types of Cottage Cheese - 22 mg

A cup of lowfat cottage cheese provides less than 50 mg of calcium for about 200 calories.

Beans

The fractional absorption of calcium from beans is only about 22 percent. Beans contribute some calcium to the diet, but not enough to be considered a good source.

Absorbable Calcium for Half-cup Servings (cooked):
Cowpeas - 23 mg
Kidney Beans - 6 mg
Pinto Beans - 11 mg
Soybeans - 21 mg
White Beans - 14 mg

If you work out the amount of calories you need to eat to get enough calcium from beans, you get the picture. To absorb the daily need of 300 mg of calcium would require over 2000 calories of soybeans and over 3000 calories of pinto beans. Cowpeas come out the best, requiring just over 1000 calories worth to meet daily need for absorbable calcium. In comparison, less than 300 calories of skim milk delivers 300 mg of absorbable calcium.