近日，刊登在国际杂志Journal of Clinical Endocrinology & metabolism上的一篇研究论文中，来自伊斯法罕大学的研究人员通过研究表明，维生素D缺失的个体患精神分裂症的风险是正常个体（维生素D水平充足）的两倍。
维生素D可以帮助机体吸收钙质，其同样对于骨骼和肌肉的健康也至关重要，正常情况下皮肤暴露于太阳光后会产生维生素；人们通过食物比如牛奶等获得的维生素量非常少，据估计世界范围内超过10亿人都因晒太阳不够而出现维生素D缺失的情况。精神分裂症是一种精神疾病，其主要表现为妄想和幻觉，该疾病在寒带气候和高纬度地区较为流行，研究人员推测维生素D或许和精神分裂症之间存在千丝万缕的关系。
研究者Ahmad Esmaillzadeh表示，这项研究中我们首次对维生素D和精神分裂症之间的关系进行了一项综合性的分析，我们检测了2804名成年个体参与者的机体维生素D水平和其精神健康状况，文章中我们通过检测参与者的血液来测定其机体维生素D水平。
结果显示，相比对照组个体来讲，精神分裂症个体机体中的维生素D水平明显较低，而且精神分裂症个体和正常个体之间的维生素D水平平均差异为-5.91 ng/ml；而维生素D缺乏个体患精神分裂症的风险是正常个体风险的2.16倍，另外65%的精神分离症患者机体都会出现维生素D缺失的情况。
最后研究人员Esmaillzadeh说道，目前在营养科学领域存在一种日益盛行的趋势，就是维生素D和其它疾病比如'糖尿病'、癌症等疾病之间会存在某种关联，而本文中研究者通过研究发现，维生素D的确可以明显影响个体的心理健康，未来还需要更为深入的研究来确定维生素D的缺失是否还会引发机体的其它健康问题。
原文摘要：
Serum Vitamin D Levels in Relation to Schizophrenia: A Systematic Review and meta-Analysis of Observational Studies
Introduction: Although several observational studies have investigated the association between vitamin D status and schizophrenia, we are aware of no comprehensive meta-analysis in this regard. Objective: We aimed to conduct a systematic review and a meta-analysis of observational studies to summarize the available data on the association between serum vitamin D levels and schizophrenia. Methods: A systematic research on all published articles until October 2013 was conducted in PubMed, ISI (Web of science), SCOPUS, and Google Scholar. All observational studies that had measured serum vitamin D levels in schizophrenic patients were included in the systematic review. After considering exclusion criteria, we had 19 studies for the systematic review that were included in three separate meta-analyses: 1) a meta-analysis on mean levels of 25-hydroxyvitamin D [25(OH)D] (n = 13); 2) a meta-analysis on the prevalence of vitamin D deficiency (n = 8); 3) a meta-analysis on odds ratios (n = 8). Results: Findings from a meta-analysis on means revealed that the overall mean difference in serum 25(OH)D levels between schizophrenic patients and control participants was −5.91 ng/mL [95% confidence interval (CI) −10.68, −1.14]. Subgroup analyses based on study design, the patient's hospitalization status, study quality, and study location did not explain between-study heterogeneity; however, type of biomarker assessed [25-dihydroxyvitamin D3 vs 25OH)D)] could account for some degree of heterogeneity. Results from the meta-analysis on the prevalence of vitamin D deficiency indicated that the overall prevalence of vitamin D deficiency in schizophrenic patients was 65.3% (95% CI 46.4%–84.2%). Findings from the meta-analysis on odds ratios indicated that vitamin D-deficient persons were 2.16 times (95% CI 1.32, 3.56) more likely to have schizophrenia than those with vitamin D sufficiency. No evidence of heterogeneity was detected. Conclusion: We found a strong association between vitamin D deficiency and schizophrenia. However, randomized clinical trials are required to confirm our findings.
