Low dietary calcium intake does not modify fracture risk but increases fall frequency: the results of GO Study

Introduction: The aim of the study was to verify the thesis that dietary calcium intake influences the risk of osteoporotic fractures established by online available calculators. Material and methods: The study was performed in 521 postmenopausal women aged over 55 years, recruited in one osteoporotic outpatient clinic. Mean age was 67.7 ± 8.6 years. Fracture risk was established using FRAX (major and hip fractures, 10 years), Garvan calculator (any and hip fractures, 5 and 10 years), and the Polish algorithm available at www.fracture-risk.pl (any fractures, 5 years). Bone densitometry at the femoral neck was performed using a DPX device (Lunar, GE, USA) to calculate fracture risk by each of those calculators. Calcium intake was established based on a dietary questionnaire. Results: Mean values of fracture risk for all three calculators and T-score value for DXA measurement at the femoral neck did not correlate with calcium intake. A tendency to insignificantly lower calcium intake was observed in the subgroup with high hip fracture risk by FRAX (≥ 3%) vs. low hip FRAX (< 3%): 744 ± 328 mg/day vs. 765 ± 299 mg/day. The same analysis for FRAX major fracture risk revealed a similar tendency: 700 ± 299 mg/day and 760 ± 311 mg/day in high (≥ 20%) and low (< 20%) fracture-risk groups, respectively. Calcium intake did not influence the results obtained in the other two calculators at all. Calcium intake did not differ between subjects with prior falls and those without falls. However, if the number of falls was taken into account, the women who reported three and more falls had significantly lower calcium intake (621 ± 275 mg/day) than subjects with no falls (767 ± 304 mg/day; p < 0.05) or those with one fall (766 ± 317 mg/day; p < 0.05). Conclusions: Calcium intake does not correlate with fracture risk established by calculators available on-line, but low calcium intake may increase the risk of falls.