Calcium and bone health of women

Abstract

The calcium content of a 2400 kcal Canadian diet patterned after the Nutrition Canada Food Consumption Patterns Report (1977) was found to be 900 mg and the phosphorus content was 1280 mg. Milk and dairy products provided 64% of the calcium and only 33% of the phosphorus. An examination of the calcium intake of females in different age groups revealed that about 25% of those 10 yr and older had less than 60% of the recommended intake. In the U.S. the results of HANES 1 (1971–74) were similar. In HANES 2 (1976–80) also, the average calcium intakes of females over 14 yr were 60 to 70% of the recommended intakes. The median daily calcium intake of 30 to 65 yr old Belgian women was reported to be 540 mg, which was two-thirds of the recommendation. Although the distribution of phosphorus intakes is not known, the average amount in the diets of Canadian females was up to 1.5 times the calcium content. The amount of calcium in the Canadian food supply did not change appreciably from 1970 to 1983. Although an excess of dietary phosphorus in relation to calcium does not adversely affect absorption of calcium, it has been reported that habitual consumption of a diet with a low Ca:P ratio is detrimental to bone density in women, especially when calcium intake is suboptimal. Recent reports indicate that a low calcium intake in suboptimal. Recent reports indicate that a low calcium intake in adolescence and early adulthood does not provide for optimal consolidation of bone and results in a relatively low bone mass in the premenopausal period. This can be an important risk factor in the development of postmenopausal osteoporosis. Vertebral bone density was reported to be higher in 24–5 yr old women who had high calcium intakes (755 mg or more/day) and high physical activity than in those who had lower calcium intakes and were less active. Since the evidence for the efficacy of calcium supplements in the treatment of postmenopausal osteoporosis is not consistent, the best approach appears to be prevention by ensuring optimal calcium and vitamin D nutrition throughout the life span, adequate physical activity; and by avoiding heavy smoking, high consumption of alcohol and caffeine.