Calcium intake beyond a specified level does not further reduce osteoporosis or fracture risk
WEDNESDAY, May 25 (HealthDay News) -- Increasing calcium intake above a satisfactory level is not associated with a further reduction of osteoporotic fracture rates in women, according to a study published online May 24 in BMJ.
Eva Warensjö, Ph.D., from Uppsala University in Sweden, and colleagues investigated the correlation between the long-term dietary intake of calcium and the risk of osteoporosis and hip and any type fractures in 61,433 women, born between 1914 and 1948, who were participants of the Swedish Mammography Cohort. The women were followed up over 19 years; during this time, repeated food frequency questionnaires were used to assess their diets. A subcohort of 5,022 of these women underwent dual energy X-ray absorptiometry to identify osteoporosis.
The investigators identified 14,738 women (24 percent) with a first fracture of any type, of which 3,871 (6 percent) had a first hip fracture. In the subcohort, 1,012 women developed osteoporosis (odds ratio, 1.47). Dietary calcium risk patterns were nonlinear. The crude rate of a first fracture of any type per 1,000 person-years at risk was 17.2 and 14.0 in the lowest and third quintile of calcium intake, respectively (hazard ratio [HR], 1.18). The HR for a first hip fracture was 1.29, and women in the first quintile of calcium intake had an increased rate of fractures if they had low vitamin D intake. Women in the highest quintile of calcium intake did not have any further reduction in the risk of osteoporosis or fractures of any type, but there was a correlation with an increased rate of hip fractures (HR, 1.19).
"In the prevention of osteoporotic fractures emphasis should be placed on individuals with a low intake of calcium rather than increasing the intake of those already consuming satisfactory amounts," the authors write.