Department of Epidemiology and Biostatistics, School of Public Health, Tianjin Medical University, Tianjin, China.
Tianjin Key Laboratory of Environment, Nutrition and Public Health, Center for International Collaborative Research on environment, Nutrition and Public Health, Tianjin, China.
J Alzheimers Dis. 2020;78(4):1509-1518. doi: 10.3233/JAD-200926.
Cognitive decline in older adults is a serious public health problem today. Association between vitamin D supplementation and cognition remains controversial.
To determine whether a 12-month vitamin D supplementation improves cognitive function in elderly subjects with mild cognitive impairment (MCI), and whether it is mediated through the mechanism in which telomere length (TL) regulate oxidative stress.
This was a double-blind, randomized, placebo-controlled trial in Tianjin, China. Participants were all native Chinese speakers aged 65 years and older with MCI. 183 subjects were randomized to an intervention group (vitamin D 800 IU/day, n = 93) or a placebo group (the matching starch granules, n = 90), and followed up for 12 months. Tests of cognitive function and mechanism-related biomarkers were evaluated at baseline, 6 months, and 12 months.
Repeated-measures ANOVA showed substantial improvements in the full scale intelligence quotient (FSIQ), information, digit span, vocabulary, block design, and picture arrangement scores in the vitamin D group over the placebo group (p < 0.001). Leukocyte TL was significantly higher, while serum 8-OXO-dG, OGG1mRNA, and P16INK4amRNA revealed greater decreases in the vitamin D group over the placebo group (p < 0.001). According to mixed-model repeated-measures ANOVA analysis, vitamin D group showed a significant enhancement in the FSIQ score for 12 months compared with the control (estimate value = 5.132, p < 0.001).
Vitamin D supplementation for 12 months appears to improve cognitive function through reducing oxidative stress regulated by increased TL in order adults with MCI. Vitamin D may be a promising public health strategy to prevent cognitive decline.
老年人认知能力下降是当今一个严重的公共卫生问题。维生素 D 补充与认知之间的关系仍存在争议。
确定 12 个月的维生素 D 补充是否能改善轻度认知障碍（MCI）老年人的认知功能，以及是否通过端粒长度（TL）调节氧化应激的机制来实现。
这是在中国天津进行的一项双盲、随机、安慰剂对照试验。参与者均为母语为中文、年龄在 65 岁及以上的 MCI 患者。183 名患者被随机分配到干预组（维生素 D 800 IU/天，n=93）或安慰剂组（匹配的淀粉颗粒，n=90），并随访 12 个月。在基线、6 个月和 12 个月时评估认知功能和机制相关生物标志物的测试。
重复测量方差分析显示，维生素 D 组的全量表智商（FSIQ）、信息、数字跨度、词汇、积木和图片排列评分在整个研究过程中均显著高于安慰剂组（p<0.001）。白细胞端粒长度明显升高，而血清 8-氧代脱氧鸟苷（8-OXO-dG）、OGG1mRNA 和 P16INK4amRNA 水平在维生素 D 组中显著低于安慰剂组（p<0.001）。根据混合模型重复测量方差分析，与对照组相比，维生素 D 组在 12 个月时 FSIQ 评分显著提高（估计值=5.132，p<0.001）。
12 个月的维生素 D 补充似乎通过增加 TL 来降低氧化应激，从而改善 MCI 成年人的认知功能。维生素 D 可能是预防认知能力下降的一种有前途的公共卫生策略。
