The effect of vitamin D2 supplementation on vitamin D levels in humans: A time and dose-response meta-analysis of randomized controlled trials.

BACKGROUND: Inconsistencies exist regarding the influence of vitamin D2 (ergocalciferol) supplementation on serum vitamin D levels. These inconsistencies could be attributed to numerous factors, such as dosage, baseline vitamin D levels, and duration of intervention. Hence, this dose-response meta-analysis of randomized controlled trials was conducted to assess the efficacy of vitamin D2 supplementation on vitamin D levels. METHODS: Relevant studies were searched in PubMed/Medline, Web of Science, Embase, and Scopus, from their inception to 3 January 2023. Variable alterations were considered to calculate the pooled weighted mean difference (WMD) with 95% confidence interval (CI) using the random effects model. RESULTS: Pooled results from 33 study arms demonstrated that Vitamin D2 treatment significantly increases total vitamin D concentrations (WMD: 11.47 ng/mL, 95 %CI: 9.29 to 13.64, p < 0.001), 25(OH)D2 concentrations (WMD: 11.40 ng/mL, 95 %CI: 4.72 to 18.09, p = 0.001), and 1,25(OH)D concentrations (WMD: 5.61 ng/mL, 95 %CI: 0.74 to 10.48, p = 0.024), but decreases 25(OH)D3 concentrations (WMD: -4.63 ng/mL, 95 %CI: -6.46 to -2.81, p < 0.001). In subgroup analyses, increase in total vitamin D concentrations was more significant in vitamin D2 doses >2000 IU/day (WMD: 13.82 ng/mL), studies with duration ≤12 weeks (WMD: 12.53 ng/mL), participants aged ≥60 years (WMD: 14.40 ng/mL), and trials with basal 25(OH)D concentrations <20 ng/mL (WMD: 11.47 ng/mL). CONCLUSIONS: This meta-analysis indicates that the supplementation of vitamin D2 significantly increases the serum concentrations of total vitamin D, 25(OH)D2, and 1,25(OH)D, but decreases 25(OH)D3 concentrations. Careful consideration of patient characteristics, dosage, and treatment duration is recommended for vitamin D2 supplementation.

The effect of phytosterol supplementation on lipid profile: A critical umbrella review of interventional meta-analyses.

Despite multiple investigations assessing the impact of phytosterol supplementation on serum lipid levels, there is still a great deal of debate regarding the benefits of this intervention in the management of dyslipidemia. Therefore, we aimed at clarifying this dilemma by conducting the present umbrella review of interventional meta-analyses. Scopus, PubMed, Web of Science, and EMBASE were used to search for pertinent publications on the effect of phytosterol supplementation on the lipid profile in humans up to June 2023. To compute the overall effect size (ES) and confidence intervals (CI), the random-effects model was used. The I2 statistic and Cochrane's Q-test were applied to estimate the heterogeneity among the studies. Seventeen meta-analyses with 23 study arms were included in the umbrella meta-analysis. Data pooled from the 23 eligible arms revealed that phytosterol supplementation reduces low-density lipoprotein cholesterol (LDL-C) (ES = -11.47 mg/dL; 95% CI: -12.76, -10.17, p < 0.001), total cholesterol (TC) (ES = -13.02 mg/dL; 95% CI: -15.68, -10.37, p < 0.001), and triglyceride (TG) (ES = -3.77 mg/dL; 95% CI: -6.04, -1.51, p = 0.001). Subgroup analyses showed that phytosterol administration with dosage ≥2 g/day and duration over 8 weeks and in hypercholesterolemic subjects was more likely to decrease LDL-C, TC, and TG. Phytosterol administration did not significantly modify HDL-C (ES = 0.18 mg/dL; 95% CI: -0.13, -0.51, p = 258) levels when compared to controls. The present umbrella meta-analysis confirms that phytosterol administration significantly reduces LDL-C, TC, and TG, with a greater effect with doses of ≥2 g/day and treatment duration >8 weeks, suggesting its possible application as a complementary therapy for cardiovascular risk reduction. Further studies are needed to determine the efficacy of phytosterols in patients with specific health conditions, as well as to ascertain the adverse effects, the maximum tolerable dose, and the maximum recommended duration of phytosterol administration.

The impact of medroxyprogesterone acetate on lipid profiles in Women: A time and dose-response meta-analysis of randomized controlled trials.

BACKGROUND: The effect of MPA on the lipid profile and CVD risk is still controversial; hence, this comprehensive dose-response meta-analysis of randomized controlled trials was conducted to assess the effect of MPA on lipid profiles in women. METHODS: A comprehensive search was conducted in the following databases: Web of Science, Scopus, PubMed/Medline, and Embase, up to October 20, 2023. A random-effects meta-analysis approach based on the DerSimonian and Laird method was used to compute the combined estimates of the intervention's impact on the lipid profile. RESULTS: 35 eligible studies with 58 arms were included in our meta-analyses analysis. Combined effect sizes suggested a significant effect of MPA on total cholesterol (TC) levels (WMD: -3.43 mg/dL, 95 % CI: -5.38 to -1.48, p < 0.001), HDL-C levels (WMD: -3.34 mg/dL, 95 % CI: -3.77 to -2.91, p < 0.001), and triglyceride (TG) levels (WMD: -9.13 mg/dL, 95 % CI: -10.92 to -7.33, p < 0.001). The subgroup meta-analysis revealed a more substantial reduction in TC in studies with dosages > 2.5 mg/day (WMD: -4.10 mg/dL), mean participant age lower than 60 years (WMD: -3.80 mg/dL), mean BMI lower than 25 kg/m2 (WMD: -5.61 mg/dL), duration of intervention of 12 months or more (WMD: -3.98 mg/dL), and when the baseline TC value was equal to or greater than 200 mg/dL (WMD: -4.13 mg/dL). CONCLUSIONS: The current meta-analysis showed a statistically significant decrease in TC, TG, and HDL-C levels and a non-significant increase in LDL-C levels after MPA administration in women.

The effect of 17beta-estradiol plus norethisterone acetate on anthropometric indices: A systematic review and meta-analysis of randomized controlled trials.

OBJECTIVE: Little evidence exists on the effect of 17beta-estradiol plus norethisterone acetate on all the anthropometric indices. Hence, this systematic review and meta-analysis of Randomized Controlled Trials was conducted to give an evidence-based report on the effect of 17beta-estradiol plus norethisterone acetate on anthropometric indices. METHODS: The literature search was executed in databases including PubMed/Medline, Web of Science, Scopus, Embase, and Google Scholar to recognize clinical trials that examined the influence of 17beta-estradiol plus norethisterone acetate on obesity indices from database inception to Jan 2023. RESULTS: Combined findings were generated from 20 eligible articles. The meta-analysis showed that body weight (Weighted Mean Difference (WMD): -0.47 kg, 95% CI: -1.32, 0.37, p = 0.274), body fat (WMD: 0.16 kg, 95% CI: -1.26, 1.59, p = 0.821), WHR (WMD: 0.001 kg, 95% CI: -0.006, 1.15, p = 0.872), and LBM (WMD: -0.02 kg, 95% CI: -1.19, 1.15, p = 0.970) were not modified in DHEA group compared to the control, but BMI levels were significantly reduced in 17beta-estradiol plus norethisterone acetate group (WMD: -0.15 kg/m2, 95% CI: -0.30, -0.008, p = 0.039). Moreover, based on intervention duration (months), a more significant reduction in BMI was found in trials that were performed on studies with ˃3 months duration (WMD: -0.176 kg/m2) than studies with ≤ 3 months (WMD: 0.05 kg/m2). CONCLUSION: Administration of 17beta-estradiol plus norethisterone acetate for more than 3 months results in a decrease in BMI, which helps to reduce cardiovascular disease risk.