Added Calcium and Vitamin D Aid Bone Health

Source: Tufts University
October 2, 2000 (Reviewed: January 15, 2003)

Say "strong bones," and many people will think "calcium." Maybe they will even think "vitamin D." Yet, fewer than one in ten older Americans consume the recommended amount of these two nutrients, which are critical to bone health. Dietary supplements can help people bridge the nutrition gap between how much they consume and how much they need, but the benefit lasts only as long as they continue to take them. A study published in the September issue of the American Journal of Clinical Nutrition provides evidence that the bone-building benefits gained from calcium and vitamin D supplements begin to erode when the supplements are discontinued.

Almost 300 elderly men and women participated in a Tufts University study designed to assess the effect of calcium and vitamin D supplements on bone mineral density. Half of the group took 500 mg. calcium and 17.5 micrograms vitamin D, while the other half took inactive placebo pills. Bone mineral density of spine and hip bones was measured several times over a three-year period using an x-ray scanner. At the end of three-years of study, the people who took the calcium and D supplements had significantly higher bone mineral density when compared with those who took the inactive pills.

The researchers then wanted to find out what kind of "staying power" the supplements provided to those people who took them regularly. To answer that question, they continued to monitor some of the study participants after they had discontinued the supplements. Within two years the participants were basically back "at ground zero." Most of the increases in bone mineral density gained during the initial part of the study had been lost during the follow-up period..

Bones need both calcium and vitamin D to stay strong--vitamin D aids in calcium absorption and helps maintain normal bone mineralization. It can be difficult for some people to get enough of these nutrients as they get older. Their ability to absorb nutrients decreases, and the synthesis of D in the skin--the body's primary source of this vitamin--becomes less efficient.

Interestingly, the participants in this study were allowed to take calcium and vitamin D supplements during the second phase of the study if they chose to do so. Only about 60% of the women and fewer than half of the men did, however, and many who did continue consumed too little to be of much use. As this study illustrates, calcium and vitamin D supplements can help maintain bone mineral density, but only if taken regularly and at the correct dose. Older men and women should check with their healthcare providers to see if they should add supplemental calcium and vitamin D to their daily health routine. Intake recommendations for vitamin D vary by country. Current US guidelines recommend 10 micrograms for adults ages 51 to 70, and 15 micrograms for those over age 70. [Note: vitamin D is toxic at high levels. Always follow the recommendations of a healthcare

Source

• Effect of withdrawal of calcium and vitamin D supplements on bone mass in elderly men and women. B. Dawson-Hughes,  et al., American Journal of Clinical Nutrition., 2000, vol. 72, pp. 745--750

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