ObjectiveTo systematically review the efficacy of vitamin D supplementation on patients with polycystic ovary syndrome (PCOS).MethodsPubMed, EMbase, The Cochrane Library, Web of Science, EBSCO, CBM, WanFang Data, CNKI and VIP databases were electronically searched to collect randomized controlled trials (RCTs) on the efficacy of vitamin D supplementation for PCOS from inception to July 2019. Two reviewers independently screened literature, extracted data and assessed risk of bias of included studies, then, meta-analysis was performed by using RevMan 5.3 software.ResultsA total of 11 RCTs involving 692 patients were included. The results of meta-analysis showed that compared with placebo, vitamin D could reduce the level of hypersensitive C-reactive protein (hs-CRP) (MD=−0.54, 95%CI −1.00 to −0.08, P=0.02) and total testosterone (MD=−0.17, 95%CI −0.29 to −0.05, P=0.004), and increase endometrial thickness (MD=1.78, 95%CI 0.49 to 3.06, P=0.007). However, there were no significant differences between two groups in the incidence of sex hormone binding globulin (SHBG) level and hypertrichosis’s score (mF-G) (P>0.05).ConclusionsCurrent evidence indicates that vitamin D supplementation can significantly reduce the level of total testosterone and hs-CRP, and increase endometrial thickness of PCOS. Due to the limited quality and quantity of the included studies, more high quality studies are required to verify the above conclusions.
ObjectiveTo systematically review the relationship between cadmium (Cd) and childhood autism.MethodsPubMed, EMbase, Web of Science, The Cochrane Library, CNKI, VIP, WanFang Data and CBM were electronically searched to collect case-control studies on the relationship between Cd and childhood autism from inception to July 2019. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies. Then, meta-analysis was performed by using RevMan 5.3 software.ResultsA total of 8 case-control studies were included. The results of meta-analysis showed that whether the specimen was from whole blood, urine or hair, there were no correlations between Cd and childhood autism (MDblood=0.17, 95% CI −0.06 to 0.39, P=0.15; MDurine=−0.43, 95%CI −1.44 to 0.58, P=0.4; MDhair=−0.08, 95%CI −0.52 to 0.36, P=0.72).ConclusionsCurrent evidence shows that Cd concentration is not correlated with autism in children. Due to limited quality and quantity of the included studies, more high quality studies are required to verify above conclusions.