Calcium is such an essential mineral to the diet that your body begins removing it from the bones when your intake is not sufficient. Still, most Americans still don't get enough calcium, Oregon State University's Linus Pauling Institute reported in 2010. You can get calcium from many sources, particularly dairy products. Some of the best sources include milk, yogurt and cheese. It's also important to eat foods containing certain other vitamins to help your body absorb that calcium. Consult your doctor before beginning any new diet or supplement regimen.
Vitamin D aids the body's absorption of calcium. It is a a fat-soluble vitamin, meaning it is stored in the liver and fatty tissues. Vitamin D is essential for bone strength, hardness and growth, but is found in very few foods. The main source of vitamin D is sunlight, although it is added to some foods. Vitamin D is available in supplement form, but it's usually not necessary. Foods with high vitamin D content include cod liver oil, salmon, mackerel and tuna. Vitamin D is also present in some fortified milk.
Vitamin C is a water-soluble vitamin that also increases the body's absorption of calcium. Water-soluble means that extra amounts of the vitamin are excreted through urine. Since water-soluble vitamins are eliminated from your body more quickly than fat-soluble vitamins, you need a steadier supply of them in your diet. Vitamin C is present in all fruits and vegetables. The top sources of vitamin C are "green peppers, citrus fruits and juices, strawberries, tomatoes, broccoli, turnip greens and other leafy greens, sweet and white potatoes, and cantaloupe," the National Institutes of Health report.
The human body strictly regulates the amount of calcium present in the blood. When blood levels fall below the desired amount, the parathyroid glands signal for the release of parathyroid hormone. This hormone converts vitamin D into calcitriol, its active form, in the kidneys; this process stimulates the bones to release calcium, the Pauling Institute notes. Calcitriol is important for the body's absorption of calcium from the small intestine.
When you consume large amounts of calcium at one time, not all of the calcium can be absorbed. It's more efficient to consume calcium in smaller portions at intervals throughout the day. Don't take more than 500 milligrams of calcium at one time, and wait four to six hours between doses, the University of Arizona Cooperative Extension advises.
Eating right is the best way to get enough calcium in your diet, but some people do choose to consume calcium in supplement form. Some types of supplements, like calcium carbonate, should be taken with a meal. Calcium citrate, meanwhile, may be taken on an empty or full stomach.
Pair broccoli with cheese or fruit with yogurt to consume vitamin C with your calcium. If you take a supplement, try salmon over a leafy green salad to get both vitamins C and D with your calcium. A glass of vitamin D-fortified milk is another great way to get calcium in your diet. Not only does it pair calcium with vitamin D, but the lactase in the milk even helps your body absorb the calcium.