METHODS AND RESULTS: A systematic review and dose-response meta-analysis of randomized controlled trials (RCTs) was performed employing in Scopus, PubMed/Medline, Web of Science, Embase and Google Scholar, then including relevant articles that addressed the effects of DHEA supplementation on the lipid profile, up to February 2020. Combined findings were generated from 23 eligible articles. Hence, total cholesterol (TC) (weighted mean difference (WMD): -3.5 mg/dl, 95% confidence interval (CI): -8.5 to 1.6)), low-density lipoprotein-cholesterol (LDL-C) (WMD: 0.34 mg/dl, 95% CI: -3 to 3.7) and triglycerides (TG) levels (WMD: -2.85 mg/dl, 95% CI: -9.3 to 3.6) did not alter in DHEA group compared to the control, but HDL-C levels significantly reduced in DHEA group (WMD: -3.1 mg/dl, 95% CI: -4.9 to -1.3). In addition, a significant reduction in HDL-C values was observed in studies comprising women (WMD: -5.1 mg/dl, 95% CI: -7.2 to -3) but not in males (WMD: 0.13 mg/dl, 95% CI: -1.4 to 1.7).
CONCLUSIONS: Overall, supplementation with DHEA did not change circulating values of TC, LDL-C and TG, whereas it may decrease HDL-C levels. Further long-term RCTs are required to investigate the effects of DHEA particularly on major adverse cardiac events.
METHODS: A comprehensive systematic search was performed in Scopus, EMBASE, Web of Science, and PubMed/MEDLINE, by investigators, from database inception until November 2019, without using any restrictions. Weighted mean difference (WMD) with the 95 % CI was used for assessing the effects of maternal vitamin D supplementation on 25(OH) D levels in infants.
RESULTS: Overall results from 14 studies revealed a non-significant effect of maternal vitamin D administration on the level of 25(OH) D in breastfeeding infants (WMD: -0.464 ng/mL, 95 % CI: -6.68 to 5.75, p = 0.884, I2 = 98 %). Subgroup analyses demonstrated that vitamin D supplementation dosage ≥2000 IU/day (WMD: 9 ng/mL, 95 % CI: 8.19, 9.82, I2 = 99 %) and intervention duration ≥20 weeks (WMD: 16.20 ng/mL, 95 % CI: 14.89, 17.50, I2 = 99 %) significantly increased 25(OH) D.
CONCLUSIONS: The main results indicate a non-significant increase in infant vitamin D following maternal vitamin D supplementation. Additionally, vitamin D supplementation dosage ≥2000 IU/day and intervention duration ≥20 weeks significantly increased infant 25(OH) D.
METHODS: The literature search was implemented in four following databases: Web of Science, Scopus, PubMed/Medline, and Google Scholar, thus, determining studies that measured the effects of walnut consumption on adiponectin, leptin, and glycemic biomarkers levels from 2004 up to December 2019.
RESULTS: Fourteen trials were include in the meta-analysis, with an intervention period ranging from 5 weeks to 12 months.Walnut intake increased leptin (weighted mean difference (WMD): 2.502 ng/mL; 95 % CI: 2.147-2.856, p
METHODS: A comprehensive systematic search was carried out in PubMed/MEDLINE, Web of Science, SCOPUS and Embase for RCTs that investigated the impact of vitamin D intake on circulating IGF-1 levels from inception until June 2019. Weighted mean difference (WMD) with the 95 % CI were applied for estimating combined effect size. Subgroup analysis was performed to specify the source of heterogeneity among studies.
RESULTS: Pooled results from eight studies demonstrated an overall non-significant increase in IGF-1 following vitamin D supplementation (WMD: 4 ng/ml, 95 % CI: -4 to 11). However, a significant degree of heterogeneity among studies was observed (I2 = 66 %). The subgroup analyses showed that vitamin D dosage of ≤1000 IU/day (WMD: 10 ng/ml) significantly increased IGF-1 compared to the vitamin D dosage of <1000 IU/day (WMD: -1 ng/ml). Moreover, intervention duration ≤12 weeks (WMD: 11 ng/ml) significantly increased IGF-1 compared to intervention duration <12 weeks (WMD: -3 ng/ml). In the epidemiological cohort study, participants under 60 years of age with a higher dietary vitamin D intake had significantly higher IGF-1 levels when compared to those with lower dietary vitamin D intake in second categories.
CONCLUSION: The main results indicate a non-significant increase in IGF-1 following vitamin D supplementation. Additionally, vitamin D dosages of <1000 IU/day and intervention durations of <12 weeks significantly raised IGF-1 levels.