Does it matter how you get your calcium?

Philip J. Goscienski, M.D.

December 2007

Osteoporosis and the fear of it are so common that you can find scores of different brands and formulations of calcium wherever vitamins are sold. With many kinds of calcium (tablets, chewables, fortified drinks and foods etc.) out there, how do you pick the one that's best for you?

There's no question that calcium is extremely important for strong bones but without other nutrients, as well as moderately intense physical activity, taking lots of calcium will not help you to avoid osteoporosis. When researchers added calcium to the diets of children and adults without changing anything else, the bone mass of those that took extra calcium was no greater than that of those who ate their regular diet.

Protein, omega-3 fats (from fish and green, leafy vegetables) and vitamin K are all necessary ingredients for strong bones. Vitamin D helps us to absorb calcium from food but about one-half of adults and teenagers in the United States, especially in northern parts of the country, are vitamin D-deficient.

Calcium deficiency is extremely common at every age level. Among teenage girls and young women, in whom the need is most critical because that's the time when they are building most of their eventual bone mass, barely 20 percent get enough calcium.

Whole milk and cheese are rich in calcium but they have lots of calories and they contribute to the current obesity epidemic. Low-fat versions don't appeal to everyone. Most persons of African and Asian descent are lactose intolerant. That is, they cannot properly digest lactose, or milk sugar. In some individuals even small amounts can trigger abdominal cramps, diarrhea and excess gas although the symptoms are usually mild in most persons.

In spite of some advertising claims, how fast calcium gets absorbed doesn't matter. It is continually being released from, and incorporated into, the skeleton, which comprises about 99 percent of the body's content of this mineral. Blood levels of calcium are adjusted moment by moment through a remarkably complex system of hormones and other chemicals. How fast a given tablet's worth arrives in this pool just doesn't make any difference.

Calcium carbonate is the cheapest form of supplemental calcium and it comes mainly from oyster shells. Whether it comes in the form of carbonate, citrate, malate, lactate, etc., a quality calcium supplement should contain vitamin D. Some products include magnesium, which may aid in absorption. That is a somewhat controversial matter but many Americans have inadequate magnesium intakes anyway and the amount in a calcium supplement will be helpful, not harmful.

Coral calcium has no advantage over other forms in spite of exaggerated claims and its excessive cost. You will find an unbiased evaluation of this and other forms of calcium at, which does not display advertisements but does charge an annual subscription fee.

Most adults need about 1,000 milligrams of calcium a day. Persons over the age of 50 require 1200, postmenopausal women about 1500 milligrams. There is no need to be obsessed with precise amounts; variations in body weight, other dietary components and serving sizes make such precision a waste of time. Amounts greater than about 2500 milligrams just pass all the way through the intestinal tract.

Philip J. Goscienski, M.D. is the author of Health Secrets of the Stone Age, Better Life Publishers 2005. Contact him at