Biostatistics and Computational Biology Unit, University of Otago, Christchurch 8140, New Zealand.
Department of Pathology, University of Otago, Christchurch 8140, New Zealand.
Nutrients. 2017 Aug 3;9(8):831. doi: 10.3390/nu9080831.
A cohort of 50-year-olds from Canterbury, New Zealand ( = 404), representative of midlife adults, undertook comprehensive health and dietary assessments. Fasting plasma vitamin C concentrations ( = 369) and dietary vitamin C intake ( = 250) were determined. The mean plasma vitamin C concentration was 44.2 µmol/L (95% CI 42.4, 46.0); 62% of the cohort had inadequate plasma vitamin C concentrations (i.e., <50 µmol/L), 13% of the cohort had hypovitaminosis C (i.e., <23 µmol/L), and 2.4% had plasma vitamin C concentrations indicating deficiency (i.e., <11 µmol/L). Men had a lower mean plasma vitamin C concentration than women, and a higher percentage of vitamin C inadequacy and deficiency. A higher prevalence of hypovitaminosis C and deficiency was observed in those of lower socio-economic status and in current smokers. Adults with higher vitamin C levels exhibited lower weight, BMI and waist circumference, and better measures of metabolic health, including HbA1c, insulin and triglycerides, all risk factors for type 2 diabetes. Lower levels of mild cognitive impairment were observed in those with the highest plasma vitamin C concentrations. Plasma vitamin C showed a stronger correlation with markers of metabolic health and cognitive impairment than dietary vitamin C.
来自新西兰坎特伯雷的一个 50 岁队列（=404），代表中年成年人，进行了全面的健康和饮食评估。测定了空腹血浆维生素 C 浓度（=369）和饮食中维生素 C 摄入量（=250）。平均血浆维生素 C 浓度为 44.2µmol/L（95%CI 42.4, 46.0）；62%的队列血浆维生素 C 浓度不足（即 <50µmol/L），13%的队列存在维生素 C 缺乏症（即 <23µmol/L），2.4%的队列血浆维生素 C 浓度表明存在缺乏症（即 <11µmol/L）。男性的平均血浆维生素 C 浓度低于女性，维生素 C 不足和缺乏的比例更高。社会经济地位较低和当前吸烟者中观察到更高的维生素 C 缺乏症和缺乏症患病率。维生素 C 水平较高的成年人体重、BMI 和腰围较低，代谢健康指标更好，包括 HbA1c、胰岛素和甘油三酯，所有这些都是 2 型糖尿病的风险因素。在血浆维生素 C 浓度最高的人群中，轻度认知障碍的发生率较低。与饮食中维生素 C 相比，血浆维生素 C 与代谢健康和认知障碍标志物的相关性更强。
