Which Milk Product Is the Best Calcium Source?

Calcium, the most abundant mineral in the body, is a must-have for bone growth. According to the National Institutes of Health (NIH), it "makes up much of the structure of bones and teeth and allows normal bodily movement by keeping tissue rigid."

Calcium helps grow healthy bones early in life and minimize bone loss later in life. The bones provide a reservoir of calcium for the blood. Blood calcium helps the muscles move, the heart beat and nerves communicate.

If you're looking for a dietary calcium source, milk and other dairy products can lead the way. Milk products that are good sources of calcium include milk, yogurt, buttermilk and kefir. But which milk product has the most calcium — and does that mean it's "healthier"? Read on.

The calcium in some other foods just isn't as efficiently absorbed as the calcium in dairy. For example, about 30 percent of the calcium from milk products is absorbed, compared with less than 5 percent of the calcium from spinach, due to the oxalic acid in the greens. You would need to eat 8 cups of spinach to get the same amount of absorbable calcium you'd get from a single cup of milk.

The recommended dietary allowance for calcium is 1,000 to 1,200 milligrams a day for adults, per the NIH. Most people need at least three servings from the dairy group to meet that recommendation. When choosing a dairy-based calcium source, consider your weight and health priorities, and also how well your body digests lactose (milk sugar).

Here, we're talking about the kind of liquid dairy milk that comes in a carton and that you drink in a glass or pour on your cereal. It can be whole, 2 percent, 1 percent or skim, depending on its fat content.

But no matter what its fat (or calorie) content, milk's calcium content remains constant across the board, per the U.S. Department of Agriculture (USDA): about 300 milligrams per cup. (Powdered milk has a similar calcium profile. When you put a 1/3-cup scoop of milk powder into one cup of water, you basically get a normal cup of milk.)

Fat-free yogurt is a widely available and healthy source of calcium. Plus, the live, active cultures in lactose-free yogurt make it a digestible dairy choice for those who are lactose-intolerant.

According to material published by University of California San Francisco Health, nonfat yogurt is the healthy dairy product that contains the most calcium, at 450 milligrams per cup. One 8-ounce serving provides about 45 percent of your daily calcium requirement.

Whole-milk yogurt, however, is a rich source of calcium that comes with a high-fat price: One cup contains almost 8 grams of fat, according to the USDA. So stick with nonfat and low-fat yogurt versions, whether plain or flavored.

Use yogurt as salad dressing or sandwich spread, and in dips, desserts and main dishes. Nonfat yogurt is a tasty, healthy, calcium-rich substitute for high-calorie, high-fat mayonnaise, sour cream and ice cream, too. (A mere 2 tablespoons of sour cream contain 5 grams of fat, notes the USDA.)

As a fermented milk drink, sour-tasting kefir is basically drinkable yogurt. Though it contains more calcium than milk (410 milligrams a cup, per the USDA), it also has a lot more fat than whole-fat milk or whole-milk yogurt: up to 10 grams per cup, depending on the type and brand. Therefore, it may be best to enjoy kefir in small amounts, and not as your day-to-day calcium source.

While not as versatile or palatable as some other milk products (due to both its thick texture and to its sour taste), the fermented milk product known as buttermilk can be used in smoothies and baked goods. Surprisingly, buttermilk isn't as fattening as you may think, given that it has "butter" in its name: According to the USDA, 1 cup of low-fat buttermilk has just 2.62 grams of fat, and 284 milligrams of calcium.

Like yogurt and kefir, buttermilk also contains live, active cultures, meaning that it's easier for the lactose-intolerant to digest. It's also beneficial to the gut biome. "Buttermilk is a good source of probiotics, thanks to the live cultures added to ferment the milk sugars," notes a blog published by Oschner Health. "Cooking with it, however, will destroy the live cultures."

Canned condensed and evaporated milks do contain a lot of calcium, but they are not considered to be healthy dairy sources for daily consumption, thanks to their sugar, fat and calorie content. Most people use these forms of milk, from which much of the water is removed in processing, in cooking or as additions to other beverages, such as coffee, tea and hot chocolate.

"To use evaporated milk as a substitute for fresh milk," says the Food Network, "add one and a half cans of water to each can of evaporated milk." They note that the product can be used straight out of the can as a substitute for cream or half-and-half — other high-fat, high-calorie dairy products that are best consumed sparingly.

The FDA defines evaporated milk as "the liquid food obtained by partial removal of water only from milk," and sweetened condensed milk as "the food obtained by partial removal of water only from a mixture of milk and safe and suitable nutritive carbohydrate sweeteners."

"Sweetened condensed milk is very thick and sweet," notes the National Dairy Council. "In fact, it contains about 45 percent sugar."

Although 1 cup of sweetened condensed milk has 863 milligrams of calcium per the USDA, and a cup of undiluted 2 percent evaporated milk has 673 milligrams of calcium, these products are not usually consumed full strength. Good thing, too: One cup of sweetened condensed milk contains 982 calories, 26 grams of fat and 165 grams of sugar, and a cup of undiluted 2 percent evaporated milk has 270 calories and 5 grams of fat.

Remember: Your body needs calcium to contract muscles, expand and contract blood vessels, secrete hormones and enzymes, transmit nerve impulses and strengthen bones and teeth. Consuming low-fat milk products daily will give your body the calcium it so desperately needs for continued growth and renewal.