Department of Biomedical and Nutritional Sciences, Center for Population Health, Zuckerberg College of Health Sciences, University of Massachusetts Lowell, Lowell, MA, USA.
Human Nutrition Research Center on Aging at Tufts University, Boston, MA, USA.
J Nutr. 2021 Dec 3;151(12):3764-3772. doi: 10.1093/jn/nxab291.
Vitamin C may benefit bone as an antioxidant.
This cross-sectional study evaluated associations between dietary, supplemental, and plasma vitamin C with bone mineral density (BMD) among Puerto Rican adults.
Diet was assessed by food-frequency questionnaire (n = 902); plasma vitamin C, measured in fasting blood (n = 809), was categorized as sufficient (≥50 μmol/L), insufficient (20-49 μmol/L), or low (<20 μmol/L). Associations between vitamin C and BMD (measured by DXA) were tested, with false discovery rate correction for multiple comparisons, and interactions by smoking, sex, and estrogen status. Least-squares mean BMDs were compared across tertiles of diet and plasma vitamin C.
Participants' mean age was 59 ± 7 y (range: 46-78 y), 72% were women, mean dietary vitamin C was 95 ± 62 mg/d, and plasma vitamin C ranged from 1.7 to 125 μmol/L. No associations were observed between dietary vitamin C and BMD (P-value range: 0.48-0.96). BMD did not differ by vitamin C supplement use (P-value range: 0.07-0.29). Total femur BMD was higher (P = 0.04) among plasma vitamin C-sufficient participants (mean: 1.06; 95% CI: 1.035, 1.076 g/cm2) compared with low plasma vitamin C participants (1.026; 0.999, 1.052 g/cm2) in adjusted models. Findings at the trochanter were similar (P = 0.04). Postmenopausal women without estrogen therapy, with sufficient plasma vitamin C, showed greater total femur BMD (1.004 ± 0.014 g/cm2) compared to those with low plasma vitamin C (0.955 ± 0.017 g/cm2; P = 0.001). Similar findings were observed at the trochanter (P < 0.001). No significant associations were observed among premenopausal women or those with estrogen therapy or men. Interactions with smoking status were not significant.
Dietary vitamin C was not associated with BMD. Low plasma vitamin C, compared with sufficiency, was associated with lower hip BMD, particularly among postmenopausal women without estrogen therapy. Future research is needed to determine whether vitamin C status is associated with change in BMD or reduction in fracture risk.
维生素 C 作为一种抗氧化剂可能有益于骨骼健康。
本横断面研究评估了波多黎各成年人的饮食、补充和血浆维生素 C 与骨密度 (BMD) 之间的关联。
通过食物频率问卷评估饮食（n=902）；测量空腹血中的血浆维生素 C（n=809），分为充足（≥50 μmol/L）、不足（20-49 μmol/L）和低（<20 μmol/L）。用虚假发现率校正多重比较和吸烟、性别和雌激素状态的交互作用，检验维生素 C 与 BMD（通过 DXA 测量）之间的关系。比较饮食和血浆维生素 C 三分位的最小二乘平均 BMD。
参与者的平均年龄为 59±7 岁（范围：46-78 岁），72%为女性，平均饮食维生素 C 为 95±62mg/d，血浆维生素 C 范围为 1.7-125 μmol/L。饮食维生素 C 与 BMD 之间无关联（P 值范围：0.48-0.96）。维生素 C 补充剂的使用与 BMD 无差异（P 值范围：0.07-0.29）。在调整后的模型中，血浆维生素 C 充足的参与者（1.06；95%CI：1.035，1.076 g/cm2）与血浆维生素 C 低的参与者（1.026；0.999，1.052 g/cm2）相比，全股骨 BMD 更高（P=0.04）。转子间部位的结果相似（P=0.04）。没有雌激素治疗的绝经后妇女，血浆维生素 C 充足，全股骨 BMD 更高（1.004±0.014 g/cm2），而血浆维生素 C 低的妇女（0.955±0.017 g/cm2；P=0.001）。转子间部位也观察到类似的结果（P<0.001）。在绝经前妇女或接受雌激素治疗的妇女或男性中，未观察到显著关联。与吸烟状态的相互作用不显著。
饮食维生素 C 与 BMD 无关。与充足相比，低血浆维生素 C 与髋部 BMD 降低相关，尤其是在没有雌激素治疗的绝经后妇女中。需要进一步研究维生素 C 状态是否与 BMD 变化或骨折风险降低相关。
