Cross-sectional and prospective associations between dietary and plasma vitamin C, heel bone ultrasound, and fracture risk in men and women in the European Prospective Investigation into Cancer in Norfolk cohort

卷:102

Finck, Henriette ; Hart, Andrew R. ; Lentjes, Marleen A. H. ; Jennings, Amy ; Luben, Robert N. ; Khaw, Kay-Tee ; Welch, Ailsa A.

关键词: ascorbic acid;    collagen;    fracture risk;    osteoporosis;    vitamin C;   

DOI  :  10.3945/ajcn.115.111971

学科分类：食品科学和技术

【 摘 要 】

Background: Vitamin C sufficiency may help prevent osteoporosis and fractures by mediating osteoclastogenesis, osteoblastogenesis, and bone collagen synthesis. Objective: We determined whether dietary intakes and plasma concentrations of vitamin C were associated with a heel ultrasound and hip and spine fracture risks in older men and women. Design: Participants were recruited from the European Prospective Investigation into Cancer in Norfolk study with 7-d diet diary estimates of vitamin C intake and plasma concentrations. A random subset (4000 of 25,639 subjects) was available for the cross-sectional (ultrasound) study of broadband ultrasound attenuation (BUA) and velocity of sound (VOS), which were determined during the second health examination. The prospective (fracture) study was a case-cohort sample of all participants with a fracture up to March 2009 and the random subset (n = 5319). ANCOVA-determined associations between quintiles of vitamin C intake and plasma status with adjusted BUA and VOS and adjusted Prentice-weighted Cox proportional HRs were calculated for fracture risk. Results: Women were 58% of the population (39-79 y old), and the median follow-up was 12.6 y (range: 0-16 y). Positive associations across all quintiles of vitamin C intake but not plasma status were significant for VOS in men (beta = 2.47 m/s, P = 0.008) and BUA in women (beta = 0.82 dB/MHz, P = 0.004). Vitamin C intake was not associated with fracture risk, but there was an inverse association with plasma concentrations in men, with quintile 4 having significantly lower risks of hip fractures (HR: 0.35; 95% CI: 0.16, 0.80) and spine fractures (HR: 0.26; 95% CI: 0.10, 0.69) than quintile 1. Conclusions: Higher vitamin C intake was significantly associated with higher heel ultrasound measures in men and women, and higher plasma vitamin C concentrations were significantly associated with reduced fracture risk in men only. Our findings that vitamin C intake and status were inconsistently associated with bone health variables suggest that additional research is warranted.