Medical Department, Geriatric Unit, Azienda ULSS (Unità Locale Socio Sanitaria) 3 "Serenissima", Dolo-Mirano District, Italy.
South London and Maudsley NHS Foundation Trust, Denmark Hill, London SE5 8AZ, United Kingdom; Faculty of Health, Social Care and Education, Anglia Ruskin University, Bishop Hall Lane, Chelmsford CM1 1SQ, United Kingdom; Institute of Psychiatry, Psychology and Neuroscience (IoPPN), King's College London, De Crespigny Park, London SE5 8AF, United Kingdom.
Exp Gerontol. 2018 Jan;101:1-6. doi: 10.1016/j.exger.2017.11.007. Epub 2017 Nov 11.
Hypovitaminosis D is associated with frailty, but if vitamin D supplementation may prevent the onset of frailty is poorly known. Therefore, we aimed to investigate whether vitamin D supplementation is associated with a lower risk of frailty. In this longitudinal study, 4,421 individuals at high risk or having knee osteoarthritis free from frailty at baseline (mean age: 61.3, females=58.0%) were followed for 8 years. Details regarding vitamin D supplementation were captured by asking whether the participant took vitamin D during the previous year, at least once per month. Frailty was defined using the Study of Osteoporotic Fracture (SOF) index as the presence of at least two of the following criteria: (i) weight loss≥5% between baseline and any subsequent follow-up visit; (ii) inability to do five chair stands; (iii) low energy level according to the SOF definition. Multivariable Cox's regression analyses, calculating hazard ratios (HRs) with 95% confidence intervals (CIs), were undertaken. At baseline 69.7% took vitamin D supplements in the previous year, with a mean dose of 384±157 IU per day. During the 8-year follow-up, no difference in the incidence of frailty was evident by vitamin D supplementation status at baseline, even after adjusting for 13 baseline confounders (HR=0.95; 95% CI: 0.72-1.25). Similar results were obtained using the propensity score (HR=0.95; 95% CI: 0.71-1.25) or age- and sex-matched controls (HR=1.00; 95% CI: 0.75-1.33). In conclusion, low-dose vitamin D supplementation was not associated with any decreased risk of frailty during eight years of follow-up in a large cohort of North American people. Future large-scale trials with high doses of oral vitamin D and longer follow-up are needed to confirm/refute our findings.
维生素 D 缺乏与虚弱有关，但维生素 D 补充是否可以预防虚弱的发生尚不清楚。因此，我们旨在研究维生素 D 补充是否与较低的虚弱风险相关。在这项纵向研究中，共有 4421 名高风险或基线时无虚弱的膝骨关节炎患者（平均年龄：61.3 岁，女性=58.0%）接受了 8 年的随访。通过询问参与者在过去一年中是否至少每月服用一次维生素 D 来获取有关维生素 D 补充的详细信息。使用骨质疏松性骨折研究（SOF）指数定义虚弱，存在以下至少两个标准：（i）基线与任何后续随访之间体重减轻≥5%；（ii）无法完成 5 次坐立试验；（iii）根据 SOF 定义能量水平低。进行多变量 Cox 回归分析，计算风险比（HR）及其 95%置信区间（CI）。基线时 69.7%的人在过去一年中服用了维生素 D 补充剂，平均剂量为每天 384±157IU。在 8 年的随访期间，即使在调整了 13 个基线混杂因素后，基线时维生素 D 补充剂的状态与虚弱的发生率之间没有差异（HR=0.95；95%CI：0.72-1.25）。使用倾向评分（HR=0.95；95%CI：0.71-1.25）或年龄和性别匹配的对照组也得到了类似的结果（HR=1.00；95%CI：0.75-1.33）。总之，在一项对北美人群进行的大型队列中，低剂量维生素 D 补充与 8 年随访期间的虚弱风险降低无关。需要进行更大规模的临床试验，使用高剂量口服维生素 D 并进行更长时间的随访，以证实/反驳我们的研究结果。
