Calcium, Vitamin D & Bone Health

Calcium is a mineral needed by the body to build and maintain one’s bones and teeth.  Vitamin D helps in the absorption of calcium by the body.  To protect against osteoporosis, an individual’s calcium and vitamin D intake must be adequate.  Though older women are at highest risk for osteoporosis, men and even young adults are often deficient in calcium. Also, many of those who suffer fractures (broken bones) are found to be vitamin D deficient.  In addition, a lack of vitamin D can lead to bone weakness, bowed legs, and skeletal deformities called rickets in children and osteomalacia in adults.

The amount of calcium and vitamin D needed varies according to one’s age and sex. Listed below are the minimum requirements for calcium and vitamin D intake per day:


The average adult female in the United States has an intake of calcium of only 500 milligrams (mg) per day and many women take in far less than even this!

Meeting One’s Calcium and Vitamin D Requirements:

Milk is an excellent source of calcium. A single 8 oz. glass of milk contains about 300 mg. Low-fat and non-fat milk have just as much calcium as whole milk, and they are preferred because of the reduced fat and calorie content.  Milk is also fortified with Vitamin D which is needed to promote calcium absorption (Caution: very large amounts of vitamin D can be toxic). Yogurt and cheese are also high in calcium, although many cheeses are high in fat content.

Other foods that are high in calcium are tofu, red salmon, sardines, nuts, kale, broccoli, and many leafy green vegetables. Drinking water may also provide some calcium: 10-30 mg per quart of soft water, and up to 100 mg for hard water.

As for vitamin D, fishes such as cod, swordfish and salmon can be excellent sources. Vitamin D can also be found in fortified foods such as milk, yogurt and some breakfast cereals.

Calcium & Vitamin D Supplements:

If you are unable to tolerate a diet that is adequate in calcium and vitamin D then taking supplements is an acceptable way to meet your needs. Although there are many calcium containing compounds available, we generally recommend calcium carbonate which has a high calcium content and low cost. Each 500 mg of calcium carbonate contains 200 mg of calcium itself. Bone meal and dolomite are also high in calcium, but these may be contaminated with toxic metals and are not recommended.

Examples of calcium carbonate products and their calcium content are shown:

OsCal          250 or 500 mg

Bronson’s    275 or 375 mg

Titralac                  190 mg

Tums           200 mg

It is best to take calcium supplements by spreading the capsules or tablets out over the day rather than taking them all at the same time. Many calcium supplements also contain small amounts of vitamin D. High doses of Vitamin D should not be consumed without medical supervision.

Can too much calcium intake be harmful?

Consumption of amounts of calcium in excess of 2000 mg per day may increase the risk of kidney stone formation; amounts less than this are generally safe. However, if you have a personal or family history of kidney stones, then you should consult your physician before taking any calcium supplement.