Research from JAMA Internal Medicine — Effects of Calcium Supplementation on Clinical Fracture and Bone Structure — Results of a 5-Year, Double-blind, Placebo-Controlled Trial in Elderly Women

The influence of urinary sodium excretion and dietary calcium intake was examined in a 2-y longitudinal study of bone density in 124 women postmenopausal for < 10 y. Analysis of bone density changes showed that urinary sodium excretion was negatively correlated with changes in bone density at the intertrochanteric and total hip sites. Multiple-regression analysis of dietary calcium intake and urine sodium excretion on the change in bone density showed that both dietary calcium and urinary sodium excretion were significant determinants of the change in bone mass over 2 y at the hip and ankle sites. These data suggest that an effect of reducing bone loss equivalent to that achieved by a daily dietary increase of 891 mg (22 mmol) Ca can also be achieved by halving daily sodium excretion. No bone loss occurred at the total hip site at a calcium intake of 1768 mg/d (44 mmol/d) or a urine sodium excretion of 2110 mg/d (92 mmol/d). We report a significant effect of sodium excretion on bone loss in this population.

The increased susceptibility to fall with aging is a major clinical problem, especially in women. Approximately one-third of women older than 65 years fall each year, and 6% sustain a fracture as a result of the fall.¹ In addition, fear of falling is a major problem in older people.²