Bone Abstracts

This investigation sought to assess the relationship between vitamin D and calcium intake and estimated bone stiffness as assessed by multisite quantitative ultrasound (mQUS) in a large cohort. A total of 1177 men and 2949 women were assessed with mQUS (Beam-Med Omnisense quantitative ultrasound; Isreal) at the distal radius, tibia, and phalanx sites as part of the Canadian Multicentre Osteoporosis Study (clinical sites included Saskatoon, Calgary, Hamilton, Quebec City, Halifax and St Johns). Estimated stiffness was provided at each site as speed of sound (SOS, in m/s). The average daily amount of vitamin D (IU/d) and calcium (mg/d) ingested from all sources (dietary and supplemental) over the past year were estimated via food frequency questionnaire. Daily vitamin D intake was stratified into lowest (<500 IU/d), low (500 to <1000 IU/d), moderate (1000 to <2000 IU/d), high (2000 to <4000 IU/d) and highest (≥4000 IU/d). Mean daily calcium intake was similarly stratified: lowest (<400 mg/d), low (400 to 800 mg/d), moderate (800 to <1200 mg/d), moderate-high (1200 to <1600 mg/d), high (1600 to <2000 mg/d) and highest (≥2000 mg/d). Analysis of variance and Tukey HSD established whether statistical differences among and between groups existed. While there were no significant differences in SOS among groups for mean daily vitamin D or mean daily calcium intake, there were clear trends.

For mean daily vitamin D intake, there was a trend for SOS to decrease in the highest group. For mean daily calcium intake, there was a trend for increasing calcium ingestion to have a lower SOS at all three sites. The relationship between daily vitamin D and calcium intake with bone is complex and requires further study.