Calcium and vitamin D intake influence bone mass, but not short-term fracture risk, in Caucasian postmenopausal women from the National Osteoporosis Risk Assessment (NORA) study

Abstract

The impact of calcium and vitamin D intake on bone density and one-year fracture risk was assessed in 76,507 postmenopausal Caucasian women. Adequate calcium with or without vitamin D significantly reduced the odds of osteoporosis but not the risk of fracture in these Caucasian women.

Introduction: Calcium and vitamin D intake may be important for bone health; however, studies have produced mixed results.

Methods: The impact of calcium and vitamin D intake on bone mineral density (BMD) and one-year fracture incidence was assessed in 76,507 postmenopausal Caucasian women who completed a dietary questionnaire that included childhood, adult, and current consumption of dairy products. Current vitamin D intake was calculated from milk, fish, supplements and sunlight exposure. BMD was measured at the forearm, finger or heel. Approximately 3 years later, 36,209 participants returned a questionnaire about new fractures. The impact of calcium and vitamin D on risk of osteoporosis and fracture was evaluated by logistic regression adjusted for multiple covariates.

Results: Higher lifetime calcium intake was associated with reduced odds of osteoporosis (peripheral BMD T-score < or =-2.5; OR = 0.80; 95% CI 0.72, 0.88), as was a higher current calcium (OR = 0.75; (0.68, 0.82)) or vitamin D intake (OR = 0.73; 95% CI 0.0.66, 0.81). Women reported 2,205 new osteoporosis-related fractures. The 3-year risk of any fracture combined or separately was not associated with intake of calcium or vitamin D.

Conclusions: Thus, higher calcium and vitamin D intakes significantly reduced the odds of osteoporosis but not the 3-year risk of fracture in these Caucasian women.