Meta-analyses of interventional and observational studies investigating the efficacy and the relationship between vitamin D and depression provided inconsistent results. The current umbrella meta-analysis was conducted to assess the available evidence and provide a conclusive outcome in this regard. The following international databases were systematically searched till March 2022: PubMed, Scopus, Embase, Web of Science, and Google Scholar. Random-effects model was carried out to calculate the pooled point estimates and their respective 95 % confidence intervals (CI). Ten meta-analyses of randomised controlled trials (RCTs) revealed significant reduction in depression symptoms comparing participants on vitmain D supplements to those on placebo (Pooled standardised mean difference: - 0.40; 95 % CI: - 0.60, - 0.21, p < 0.01: I² = 89.1 %, p < 0.01). Four meta-analyses of cohort studies (with one having two subgroups) revealed that participants with lower levels of serum vitamin D were at increased odds of depression than those with higher levels of serum vitamin D (Pooled odds ratio: 1.60; 95 % CI: 1.08, 2.36, p < 0.01; I² = 91.3 %, p < 0.01). The present umbrella meta-analysis confirms the potential benefits of vitamin D supplementation and higher serum vitamin D levels in reducing the development and symptoms of depression.

Degradation of RBM39 by indisulam leads to exceptional response in high-risk neuroblastoma.

Integration of scientific research training into undergraduate medical education: a reminder call

Background: The importance of undergraduate research (UR) to students is well acknowledged in literature; however, little is known about its perceived barriers. The aim of study is to explore the perceived barriers toward participation in UR activities among students at Alfaisal University—College of Medicine, Saudi Arabia. Methods: An online, anonymous, cross-sectional, self-rating survey was administered. A two-tailed Mann–Whitney U-test was used to compare the average five-point Likert scale responses between male and female students. Results: Two-hundred and twenty-one students (n = 221/350) participated in the survey with a 63.1% response rate. The percentage of participation in UR significantly differed by gender (males vs. females: 68.6% vs. 45.4%; p < 0.0005, Chi-square test). The top three barriers toward participation in UR were “lack of time” (77.4%), “lack of formal UR courses in curriculum” (76%) and “lack of UR mentors” (70.1%). Statistically significant differences of means were identified between male and female students regarding the following statements: “lack of supervising research mentors” (p < 0.01), “lack of interest in research” (p < 0.04), “lack of finding same-gender research mentor” (p < 0.00) and “lack of UR opportunities” (p < 0.00). Conclusion: Our results were fairly comparable to the Western studies. Medical educators should carefully look into all UR barriers and consider implementing applicable solutions.