After the age of 50 or so, with each passing year our bones begin to lose substance and become more fragile. The medical term for this is osteoporosis. Osteoporosis is more pronounced in women after menopause, in people who are thin, in those who lead sedentary lives, in patients who take certain drugs, and in patients with certain illnesses. And, of course, osteoporosis is more likely in persons with poor dietary intake of calcium and vitamin D. Backache, falls, and fractures are the commonest complications of osteoporosis in the elderly.

Calcium is the most important mineral constituent of bone. Vitamin D helps in the absorption of calcium and phosphorus, and in the formation and maintenance of skeletal tissue. A study published in the Lancet in August 2007 suggested that persons aged 50 years and older could benefit from the routine use of calcium and vitamin D supplements.

This study meta-analysed data from 29 clinical trials which had assigned a total of 63,897 men and women, aged 50 years and older, to calcium supplementation with or without vitamin D. The analysis showed that calcium supplementation reduced the risk of fracture by 12%, and reduced the rate of bone loss in the hip and spine by 0.5% to 1.2%. Both these findings are of considerable clinical significance.

The benefits were greater when the daily dose of calcium was 1200 mg or more; and when the daily dose of vitamin D was 800 IU or more. The benefits were greater in those who were regular with their medication.
Another study, conducted as part of the Women's Health Initiative clinical trial in the USA, found that supplementation with calcium and vitamin D was associated with less weight gain in postmenopausal women. The benefits were greatest in women whose dietary intake of these was poor. This study was published in the Archives of Internal Medicine in May this year.

Here is a word of warning: supplementation with calcium and vitamin D may increase the risk of kidney stones. The risk-benefit ratio, however, favours the use of the supplements because osteoporosis is a far more common clinical problem than kidney stones.

The author is professor and Head, Department of Psychopharmacology Nimhans, Bangalore and can be contacted at andradec@gmail.com