Comparing Vitamin D Level Between Patients with Psoriasis and Healthy Individuals: A Systematic Review and Meta-Analysis.

BACKGROUND: Psoriasis is nowadays regarded as a systemic inflammatory disorder. Among the topicals, vitamin D derivates are often applied on the skin for their anti-inflammatory and immune-modulatory properties. Vitamin D serum levels in psoriasis (PsO) patients are still debated and an eventual depletion may offer the rational to integrate anti-psoriatic therapies with oral vitamin D. Then, we aimed to perform a systematic review and meta-analysis on the current evidence towards serum vitamin D level in PsO. METHODS: We searched in PubMed, Scopus, Web of Sciences, ScienceDirect and Science Information Database (SID) using the terms "Vitamin D" and "Psoriasis" including manuscripts in English, Italian and Persian. Duplications were excluded using EndNote software and records were screened by title, abstract and full-text. Quality assessment of studies was assessed using Newcastle Ottawa Checklist (NOS). Psoriasis odds ratio (OR) and mean serum vitamin D levels were calculated and displayed in Forest-plots. Heterogeneity indexes were evaluated using I2 and Q. Sensitivity analysis and publication biases were also considered. RESULTS: From 3006 records extracted, after removing duplicates and analyzing full texts we finally included 19 manuscripts involving a total of 1387 PsO cases and 6939 controls. PsO patients exhibited a substantial odds ratio (3.07, 95% CI: 1.56-6.04) for lower serum vitamin D levels compared to the control group. Standardized Mean Difference (SMD) of vitamin D in PsO versus controls was -0.92 (-1.33 to -0.51). CONCLUSION: Psoriatic patients displayed higher risk to have a vitamin D deficiency. Interventional studies to verify the preventive value are mandatory.

Vitamin D status and disability among patients with multiple sclerosis: a systematic review and meta-analysis.

Association between the serum vitamin D level and disability of patients with multiple sclerosis (MS) has been investigated during several researches. However, these studies reported different results. The current study aims to estimate the correlation between the concentrations of 25 (OH) vitamin D and the level of disability among MS patients. Using Mesh and non-Mesh terms related to MS, disability level and vitamin D, different data banks were searched. Required information was extracted from the selected eligible primary articles. Stata version 11 software was applied for combining the primary correlation coefficients using random effect model. The effect of MS type and patients' age was assessed using meta-regression models. Sensitivity analysis was performed to investigate the role of each primary study in the pooled estimate. Egger test was applied to find any publication bias. Of 14 eligible studies, the total correlation coefficient (95% confidence interval) between 25 (OH) vitamin D level and disability in both sexes as well as among female was estimated as of -0.29 (-0.40, -0.17) and -0.35 (-0.46, -0.24) respectively. Two articles carried out among male did not report significant results. Our meta-analysis showed a significant negative correlation between 25 (OH) vitamin D level and disability of MS patients so that the disability reduces with increasing the 25 (OH) vitamin D level.