Department of General Medicine, Flinders Medical Centre, Flinders Drive, South Australia, Australia.
College of Medicine and Public Health, Flinders University, Flinders Drive, South Australia, Australia.
Intern Med J. 2019 Feb;49(2):189-196. doi: 10.1111/imj.14030.
Vitamin C has anti-oxidant properties and acts as a cofactor for several enzymes. Hypovitaminosis C has been associated with bleeding, endothelial dysfunction and death. The prevalence of hypovitaminosis C is unknown in Australian hospitalised patients, and its clinical relevance is uncertain.
To determine the prevalence, characteristics and clinical outcomes of hospitalised patients with hypovitaminosis C.
This observational study included general-medical inpatients in a tertiary-level hospital in Australia. High-performance liquid chromatography (HPLC) was used to determine plasma vitamin C levels. As per Johnston's criteria, vitamin C levels of ≥28 μmol/L were classified as normal and <28 μmol/L as low. Clinical outcomes determined included length of hospital stay (LOS), nosocomial complications, intensive care unit admission and in-hospital mortality.
A total of 200 patients participated in this study, and vitamin C levels were available for 149 patients, of whom 35 (23.5%) had normal vitamin C levels, and 114 (76.5%) had hypovitaminosis C. Patients with hypovitaminosis C were older and had higher C-reactive protein (CRP) levels. Median LOS was 2 days longer in patients with hypovitaminosis C (6 days (interquartile range (IQR) 4, 8) vs 4 days (IQR 3, 6), P = 0.02), and they had fourfold higher odds of staying in hospital for >5 days than those with normal vitamin C levels. Other clinical outcomes were similar between the two groups.
Hypovitaminosis C is common in hospitalised patients and is associated with prolonged LOS. Further research is needed to ascertain the benefits of vitamin C supplementation in vitamin C-depleted patients.
维生素 C 具有抗氧化特性，是几种酶的辅助因子。维生素 C 缺乏与出血、内皮功能障碍和死亡有关。在澳大利亚住院患者中，维生素 C 缺乏的患病率尚不清楚，其临床相关性也不确定。
确定维生素 C 缺乏的住院患者的患病率、特征和临床结局。
本观察性研究纳入了澳大利亚一家三级医院的普通内科住院患者。采用高效液相色谱法（HPLC）测定血浆维生素 C 水平。根据 Johnston 的标准，将维生素 C 水平≥28 μmol/L 归类为正常，<28 μmol/L 归类为低。确定的临床结局包括住院时间（LOS）、院内并发症、入住重症监护病房和院内死亡率。
共有 200 名患者参与了这项研究，其中 149 名患者的维生素 C 水平可用于分析，其中 35 名（23.5%）患者的维生素 C 水平正常，114 名（76.5%）患者的维生素 C 缺乏。维生素 C 缺乏的患者年龄较大，C 反应蛋白（CRP）水平较高。维生素 C 缺乏的患者 LOS 中位数长 2 天（6 天（四分位距（IQR）4，8）vs 4 天（IQR 3，6），P=0.02），与维生素 C 水平正常的患者相比，住院时间超过 5 天的可能性高 4 倍。两组的其他临床结局相似。
维生素 C 缺乏在住院患者中很常见，与 LOS 延长有关。需要进一步研究以确定维生素 C 补充对维生素 C 耗竭患者的益处。
