[Calcium intake and bone density in menopause. Data of a sample of Chilean women followed-up for 5 years with calcium supplementation].

BACKGROUND

A low calcium intake is considered a risk factor for osteoporosis.

AIM

To measure calcium intake and its relationship to bone mineral density in postmenopausal women and to assess the long term changes in bone mineral density after calcium supplementation.

PATIENTS AND METHODS

In 80 postmenopausal women, older than 41 years of age, calcium intake was assessed using dietary inquiries and bone mineral density was measured using a double beam radiological densitometer. Twenty-four randomly selected women received a daily calcium supplementation of 500 mg during five years and their bone mineral density was measured at 1, 3 and 5 years.

RESULTS

Initial calcium intake was 745 +/- 37 mg/day, and it did not change in the five-year follow up. There was no relationship between bone mineral density and calcium intake. In supplemented women, bone density did not change significantly at year one. At year three, a significant reduction was observed in the spine (-4.2%), Wards triangle (-4%) and whole body mineral content (-1.14%). At year five, there was a significant increase in bone density at the spine, femoral neck and Wards triangle as compared with year three, but not with baseline measurements. No significant differences after supplementation were observed between women with initial calcium intake of less than 500 mg/day or over this value.

CONCLUSIONS

Calcium intake in urban Chilean postmenopausal women is below recommendations and stable over time. Calcium intake and bone mineral density after the menopause are not correlated. A 500 mg/day calcium supplementation during five years is associated with a late reversal of the postmenopausal bone-losing trend.