The effect of vitamin D supplementation on clinical symptoms and metabolic profiles in patients with endometriosis.

BACKGROUND: To our knowledge, data on the effects of vitamin D supplementation on clinical symptoms and metabolic profiles in patients with endometriosis are limited. This study was conducted to determine the effects of vitamin D supplementation on clinical symptoms and metabolic profiles in patients with endometriosis. METHODS: The current randomized, double-blind, placebo-controlled trial was conducted among 60 patients (aged 18-40 years old) with endometriosis. Participants were randomly allocated into two groups (30 participants each group) to receive either 50,000 IU vitamin D or placebo each 2 weeks for 12 weeks. RESULTS: Vitamin D supplementation significantly decreased pelvic pain (ß - 1.12; 95% CI, -2.1, -0.09; p=.03) and total-/HDL-cholesterol ratio (ß - 0.29; 95% CI, -0.57, -0.008; p=.04) compared with the placebo. Moreover, vitamin D intake led to a significant reduction in high-sensitivity C-reactive protein (hs-CRP) (ß - 0.64 mg/L; 95% CI, -0.97, -0.30; p<.001) and a significant increase in total antioxidant capacity (TAC) (ß 47.54 mmol/L; 95% CI, 19.98, 75.11; p=.001) compared with the placebo. CONCLUSIONS: Overall, our study demonstrated that vitamin D intake in patients with endometriosis resulted in a significant improvement of pelvic pain, total-/HDL-cholesterol ratio, hs-CRP and TAC levels, but did not affect other clinical symptoms and metabolic profiles.

Effects of Carnitine Administration on Carotid Intima-media Thickness and Inflammatory Factors in Patients with Polycystic Ovary Syndrome: A Randomized, Double-blind, Placebo-controlled Trial.

BACKGROUND: This study was performed to evaluate the effects of carnitine administration on carotid intima-media thickness (CIMT) and inflammatory markers in women with polycystic ovary syndrome (PCOS). METHODS: This randomized, double-blind, placebo-controlled trial was conducted among 60 women diagnosed with PCOS according to the Rotterdam criteria, aged 18-40 years. Participants were randomly allocated into two groups to intake either 250 mg/day carnitine (n = 30) or placebo (n = 30) for 12 weeks. High-resolution carotid ultrasonography was conducted at baseline and after the 12-week intervention. RESULTS: After the 12-week intervention, compared with the placebo, carnitine supplementation resulted in a significant decrease in maximum levels of the left CIMT (-0.01 ± 0.02 vs. +0.002 mm ± 0.006 mm, P = 0.001), mean levels of the left CIMT (-0.01 ± 0.02 vs. +0.001 mm ± 0.01 mm, P = 0.001), maximum levels of the right CIMT (-0.01 ± 0.02 vs. +0.006 mm ± 0.01 mm, P < 0.001), and mean levels of the right CIMT (-0.01 ± 0.02 vs. +0.002 mm ± 0.01 mm, P = 0.001). Change in plasma nitric oxide (NO) (+2.4 ± 3.6 vs. +0.2 ± 2.3 µmol/L, P = 0.007) was significantly different between the supplemented patients and placebo group. We did not see any significant effect in serum high sensitivity C-reactive protein (hs-CRP) following the supplementation of carnitine compared with the placebo. CONCLUSIONS: Overall, carnitine administration for 12 weeks to participants with PCOS had beneficial effects on CIMT and plasma NO, but did not affect serum hs-CRP levels.

The Effects of Synbiotic Supplementation on Metabolic Status in Women With Polycystic Ovary Syndrome: a Randomized Double-Blind Clinical Trial.

Data on the effects of synbiotic supplementation on glycemic control, lipid profiles, and atherogenic index of plasma (AIP) of women with polycystic ovary syndrome (PCOS) are limited. The purpose of this study was to assess the effects of synbiotic supplementation on glycemic control and lipid profiles in women with PCOS. A prospective, randomized, double-blind, placebo-controlled trial was done at the Naghavi Hospital affiliated to Kashan University of Medical Sciences, Kashan, Iran, between April 2017 and June 2017. Sixty women with PCOS were randomized to intake synbiotic capsule containing Lactobacillus acidophilus strain T16 (IBRC-M10785), Lactobacillus casei strain T2 (IBRC-M10783), and Bifidobacterium bifidum strain T1 (IBRC-M10771) (2 × 109 CFU/g each) plus 800 mg inulin (n = 30) or placebo (n = 30) for 12 weeks. Fasting blood samples were taken at baseline and after the 12-week intervention to determine related variables. Compared with the placebo, synbiotic supplementation resulted in a significant reduction in serum insulin concentrations (- 2.8 ± 4.1 vs. + 1.8 ± 6.4 µIU/mL, P = 0.002) and homeostasis model of assessment-insulin resistance (- 0.7 ± 1.0 vs. + 0.4 ± 1.5, P = 0.002), and a significant elevation in the quantitative insulin sensitivity check index (+ 0.01 ± 0.01 vs. - 0.01 ± 0.03, P < 0.001). In addition, significant decreases in serum triglycerides (- 16.2 ± 31.4 vs. + 5.8 ± 23.1 mg/dL, P = 0.003), VLDL-cholesterol concentrations (- 3.3 ± 6.3 vs. + 1.1 ± 4.6 mg/dL, P = 0.003), and AIP (- 0.05 ± 0.08 vs. - 0.003 ± 0.10 mg/dL, P = 0.03) were seen following the supplementation of synbiotic compared with the placebo. Overall, we found that synbiotic supplementation to women with PCOS for 12 weeks had beneficial effects on markers of insulin resistance, triglycerides, VLDL-cholesterol concentrations, and AIP, but did not influence other lipid profiles. Trial registration: www.irct.ir: IRCT201604015623N71.

The effect of zinc and vitamin E cosupplementation on metabolic status and its related gene expression in patients with gestational diabetes.

Objective: The aim of this study was to determine the effects of zinc and vitamin E cosupplementation on metabolic status and gene expression related to insulin and lipid metabolism in women with gestational diabetes mellitus (GDM).Methods: Fifty-four women, in the age range of 18-40 years, diagnosed with GDM were recruited for this randomized, double-blinded, placebo-controlled trial. Subjects were randomly allocated into two intervention groups to either taking 233 mg/day Zinc Gluconate plus 400-IU/day vitamin E supplements or placebo (n = 27 each group) for 6 weeks. Gene expression related to insulin and lipid metabolism was evaluated in peripheral blood mononuclear cells (PBMCs) of women with GDM using RT-PCR method.Results: Participants who received zinc plus vitamin E supplements had significantly lower serum insulin levels (ß = -3.81; 95% CI, -5.90, -1.72; p = .001), homeostasis model of assessment-insulin resistance (ß = -0.96; 95% CI, -1.54, -0.38; p = .002), serum total-cholesterol (ß = -8.56; 95% CI, -16.69, -0.43; p = .03) and low density lipoprotein-cholesterol (LDL)-cholesterol (ß = -8.72; 95% CI, -15.27, -2.16; p = .01), and higher quantitative insulin sensitivity check index (ß = 0.01; 95% CI, 0.005, 0.02; p = .007) compared with the placebo. Moreover, zinc and vitamin E cosupplementation upregulated gene expression of peroxisome proliferator-activated receptor gamma (PPAR-γ; p = .03) and low-density lipoprotein receptor (LDLR; p = .04) compared with the placebo. Though, zinc and vitamin E combination did not affect other metabolic parameters.Conclusions: Overall, zinc and vitamin E cosupplementation for 6 weeks in women with GDM significantly improved insulin metabolism, lipid profile, and the gene expression levels of PPAR-γ and LDLR.

The Effects of Omega-3 and Vitamin E Co-supplementation on Carotid Intima-media Thickness and Inflammatory Factors in Patients with Polycystic Ovary Syndrome.

OBJECTIVES: We sought to evaluate the effects of omega-3 and vitamin E co-supplementation on carotid intima-media thickness (CIMT) and inflammatory factors in patients with polycystic ovary syndrome (PCOS). METHODS: This randomized, double-blind, placebo-controlled trial was done among 60 women with PCOS. Participants were randomly assigned into two groups (n = 30 each group) and assigned to take either 1000 mg omega-3 plus 400 IU vitamin E supplements or a placebo for 12 weeks. RESULTS: Compared with placebo, omega-3 and vitamin E co-supplementation led to significant decreases in maximum levels of left CIMT (-0.006±0.006 vs. +0.002±0.007 mm, p < 0.001), mean levels of left CIMT (-0.005±0.006 vs. +0.002±0.010 mm, p = 0.010), maximum levels of right CIMT (-0.006±0.010 vs. +0.006±0.010 mm, p = 0.010), and mean levels of right CIMT (-0.005±0.005 vs. +0.001±0.010 mm, p = 0.020). Change in high-sensitivity C-reactive protein (hs-CRP) (-390.6±942.9 vs. +237.0±754.3 ng/mL, p = 0.006) was significantly different between the supplemented patients and placebo group. We did not observe any significant effect in plasma nitric oxide (NO) values following supplementation with omega-3 plus vitamin E compared with the placebo. CONCLUSIONS: Co-supplementation with omega-3 and vitamin E for 12 weeks among patients with PCOS had beneficial effects on CIMT and serum hs-CRP values, but unchanged NO values.

The influences of vitamin D and omega-3 co-supplementation on clinical, metabolic and genetic parameters in women with polycystic ovary syndrome.

OBJECTIVE: The aim of this study was to evaluate the effect of the co-administration of vitamin D and omega-3 fatty acid on clinical, metabolic and genetic parameters in women with polycystic ovary syndrome (PCOS). METHODS: This randomized, double-blinded, placebo-controlled clinical trial was conducted on 60 subjects, aged 18-40 years old with PCOS. Subjects were randomly allocated to take either 50,000 IU vitamin D every 2 weeks plus 2000 mg/day omega-3 fatty acid from fish oil (n = 30) or placebo (n = 30) for 12 weeks. Gene expression analysis of inflammatory cytokines was conducted on peripheral blood mononuclear cells (PBMCs) of PCOS women using RT-PCR method. RESULTS: Vitamin D and omega -3 fatty acid co-supplementation significantly decreased serum total testosterone levels (-0.2 ±â€¯0.5 vs. + 0.1 ±â€¯0.4 ng/mL, P = 0.02) compared with the placebo. In addition, vitamin D and omega-3 fatty acid co-supplementation resulted in a significant improvement in beck depression inventory (-1.4 ±â€¯1.6 vs. -0.5 ±â€¯0.6, P = 0.01), general health questionnaire scores (-4.5 ±â€¯4.3 vs. -1.9 ±â€¯2.3, P = 0.005) and depression anxiety and stress scale scores (-5.0 ±â€¯5.1 vs. -2.3 ±â€¯3.5, P = 0.01) compared with the placebo. Additionally, vitamin D and omega-3 fatty acid co-administration significantly decreased serum high-sensitivity C-reactive protein (hs-CRP) (-1.2 ±â€¯1.9 vs. + 0.1 ±â€¯0.7 mg/L, P = 0.001) and malondialdehyde (MDA) levels (-0.4 ±â€¯0.4 vs. + 0.2 ±â€¯0.6 µmol/L, P < 0.001), and significantly increased plasma total antioxidant capacity (TAC) levels (+ 114.6 ±â€¯122.2 vs. -2.4 ±â€¯168.2 mmol/L, P = 0.003) compared with the placebo. Results of RT-PCR demonstrated that vitamin D and omega-3 fatty acid co-supplementation significantly downregulated gene expression of interleukin-1 (IL-1) (P = 0.03), and upregulated vascular endothelial growth factor (VEGF) (P = 0.004) in PBMCs of subjects with PCOS, when compared with placebo. CONCLUSIONS: Overall, the co-administration of vitamin D and omega-3 fatty acid for 12 weeks had beneficial effects on mental health parameters, serum total testosterone, hs-CRP, plasma TAC and MDA levels, and gene expression of IL-1 and VEGF among women with PCOS.

Long-Term Vitamin D Supplementation and the Effects on Recurrence and Metabolic Status of Cervical Intraepithelial Neoplasia Grade 2 or 3: A Randomized, Double-Blind, Placebo-Controlled Trial.

OBJECTIVE: This study was conducted to evaluate the effects of vitamin D supplementation on the recurrence and metabolic status of patients with cervical intraepithelial neoplasia grade 2 or 3 (CIN2/3). METHODS: This randomized, double-blind, placebo-controlled trial was carried out among 58 women diagnosed with CIN2/3. Participants were randomly assigned into 2 groups to receive either 50,000 IU vitamin D3 (n = 29) or placebo (n = 29) every 2 weeks for 6 months. RESULTS: The recurrence rate of CIN1/2/3 was 18.5 and 48.1% in the vitamin D and placebo groups respectively (p = 0.02). When we excluded CIN1, the recurrence rate of CIN2/3 became nonsignificant. Vitamin D supplementation significantly decreased fasting plasma glucose (-7.8 ± 9.2 vs. -1.1 ± 8.6 mg/dL, p = 0.006) and insulin levels (-3.2 ± 4.8 vs. -0.9 ± 3.4 µIU/mL, p = 0.03), and significantly increased quantitative insulin sensitivity check index (0.01 ± 0.02 vs. 0.002 ± 0.01, p = 0.02) compared with the placebo. Additionally, there was a significant decrease in high-sensitivity C-reactive protein (-815.3 ± 1,786.2 vs. 717.5 ± 1,827.3 ng/mL, p = 0.002) and a significant increase in total antioxidant capacity (113.4 ± 137.4 vs. -53.7 ± 186.7 mmol/L, p < 0.001) following the supplementation of vitamin D compared with the placebo. CONCLUSIONS: Vitamin D3 supplementation for 6 months among women with CIN2/3 had beneficial effects on CIN1/2/3 recurrence and metabolic status; however, it did not affect CIN2/3 recurrence.

A Randomized Double-Blinded, Placebo-Controlled Trial Investigating the Effect of Fish Oil Supplementation on Gene Expression Related to Insulin Action, Blood Lipids, and Inflammation in Gestational Diabetes Mellitus-Fish Oil Supplementation and Gestational Diabetes.

Gestational diabetes mellitus (GDM) is a common complication of pregnancy, and it is mostly associated with postpartum diabetes, insulin resistance, and dyslipidemia. Fish oil (omega-3) supplementation has been shown to reduce the risk of different chronic diseases such as cardiovascular disease, type 2 diabetes, and cancers, though the evidence of its impact on gestational diabetes is scarce. Our goal in this study was to determine the effect of fish oil administration on gene expression related to insulin action, blood lipids, and inflammation in women with GDM. Participants with GDM (n = 40), aged 18-40 years, were randomized to take either 1000 mg fish oil capsules, containing 180 mg eicosapentaenoic acid and 120 mg docosahexaenoic acid (n = 20), or placebo (n = 20) twice a day for 6 weeks. Gene expression related to insulin, lipids, and inflammation was quantified in peripheral blood mononuclear cells (PBMCs) of GDM women using Reverse Transcription Polymerase Chain Reaction (RT-PCR) method. Results of RT-PCR indicated that omega-3 supplementation upregulated gene expression of peroxisome proliferator-activated receptor gamma (PPAR-γ) (P = 0.04) in PBMCs of patients with GDM, compared with the placebo. In addition, gene expression of the low-density lipoprotein receptor (LDLR) (P < 0.001), interleukin-1 (IL-1) (P = 0.007), and tumor necrosis factor alpha (TNF-α) (P = 0.01) was downregulated in PBMCs of women with GDM, following omega-3 supplementation. No significant effect of omega-3 supplementation was indicated on gene expression of IL-8 in PBMCs of patients with GDM. Overall, fish oil supplementation for 6 weeks in women with GDM significantly improved gene expression of PPAR-γ, IL-1, and TNF-α, but not gene expression of IL-8.

The effects of omega-3 and vitamin E co-supplementation on parameters of mental health and gene expression related to insulin and inflammation in subjects with polycystic ovary syndrome.

OBJECTIVE: The aim of this study was to evaluate the effects of omega-3 and vitamin E co-supplementation on parameters of mental health and gene expression related to insulin and inflammation in subjects with polycystic ovary syndrome (PCOS). METHODS: Forty PCOS women were allocated into two groups and treated with 1000mg omega-3 fatty acids plus 400 IU vitamin E supplements (n = 20) or placebo (n = 20) per day for 12 weeks. Parameters of mental health were recorded at baseline and after the 12-week intervention. Gene expression related to insulin and inflammation were measured in blood samples of PCOS women. RESULTS: After the 12-week intervention, compared with the placebo, omega-3 and vitamin E co-supplementation led to significant improvements in beck depression inventory total score (- 2.2 ± 2.0 vs. - 0.2 ± 1.3, P = 0.001), general health questionnaire scores (- 5.5 ± 4.6 vs. - 1.0 ± 2.3, P < 0.001) and depression anxiety and stress scale scores (- 7.2 ± 5.2 vs. - 1.3 ± 1.3, P < 0.001). Compared with the placebo, omega-3 and vitamin E co-supplementation could up-regulate peroxisome proliferator-activated receptor gamma (PPAR-γ) expression (P = 0.04) in peripheral blood mononuclear cells (PBMC) of PCOS women. In addition, compared with the placebo, omega-3 and vitamin E co-supplementation down-regulated interleukin-8 (IL-8) (P = 0.003) and tumor necrosis factor alpha (TNF-α) expression (P = 0.001) in PBMC of PCOS women. There were no significant difference between-group changes in glucose transporter 1 (GLUT-1), IL-6 and transforming growth factor beta (TGF-ß) in PBMC of PCOS women. CONCLUSION: Omega-3 and vitamin E co-supplementation was effective in improving parameters of mental health, and gene expression of PPAR-γ, IL-8 and TNF-α of women with PCOS.

Effects of Selenium Supplementation on Gene Expression Levels of Inflammatory Cytokines and Vascular Endothelial Growth Factor in Patients with Gestational Diabetes.

Selenium is known to exert multiple beneficial effects including anti-inflammatory actions. The aim of the study was to evaluate the effects of selenium supplementation on gene expression levels of inflammatory cytokines and vascular endothelial growth factor (VEGF) in women with gestational diabetes (GDM). This randomized double-blind, placebo-controlled trial was carried out among 40 subjects diagnosed with GDM aged 18-40 years old. Subjects were randomly allocated into two groups to receive either 200 µg/day selenium supplements (n = 20) or placebo (n = 20) for 6 weeks. Gene expression of inflammatory cytokines and VEGF were assessed in lymphocytes of GDM women with RT-PCR method. Results of RT-PCR indicated that after the 6-week intervention, compared with the placebo, selenium supplementation downregulated gene expression of tumor necrosis factor alpha (TNF-α) (P = 0.02) and transforming growth factor beta (TGF-ß) (P = 0.01), and upregulated gene expression of VEGF (P = 0.03) in lymphocytes of patients with GDM. There was no statistically significant change following supplementation with selenium on gene expression of interleukin (IL)-1ß and IL-8 in lymphocytes of subjects with GDM. Selenium supplementation for 6 weeks in women with GDM significantly decreased gene expression of TNF-α and TGF-ß, and significantly increased gene expression of VEGF, but did not affect gene expression of IL-1ß and IL-8. Clinical trial registration number http://www.irct.ir : IRCT201612045623N95.

The effects of magnesium supplementation on gene expression related to inflammatory markers, vascular endothelial growth factor, and pregnancy outcomes in patients with gestational diabetes.

Magnesium has been introduced as one of the micronutrients with several metabolic benefits, mainly anti-inflammatory properties. The aim of this study was to evaluate the effects of magnesium supplementation on gene expression of inflammatory markers, vascular endothelial growth factor (VEGF), and pregnancy outcomes in women diagnosed with gestational diabetes mellitus (GDM). This randomized, double-blinded, placebo-controlled trial was conducted among 36 women, aged 18-40 years old, diagnosed with GDM. Study participants were randomly allocated into two groups to receive either 250 mg/day magnesium oxide (n = 18) or placebo (n = 18) for six weeks. Gene expression related to inflammatory markers and VEGF was assessed using peripheral blood mononuclear cells (PBMCs) of women with GDM, via RT-PCR method. Quantitative results of RT-PCR demonstrated that magnesium supplementation downregulated gene expression levels of interleukin-8 (IL-8) (P = 0.03) and tumor necrosis factor-α (TNF-α) (P = 0.006) and upregulated gene expression levels of transforming growth factor beta (TGF-ß) (P = 0.03) in PBMCs of women with GDM, compared with placebo. Magnesium supplementation did not significantly affect gene expression of IL-1 and vascular endothelial growth factor. Additionally, magnesium administration resulted in a lower incidence of newborn hyperbilirubinemia (11.1% versus 44.4%, P = 0.02) and newborn hospitalization (11.1% versus 44.4%, P = 0.02) compared with placebo. Overall, magnesium supplementation for six weeks significantly decreased gene expression levels of IL-8 and TNF-α, and increased TGF-ß in women with GDM. Therefore, magnesium supplementation might be recommended to decrease metabolic complications in women with GDM, due to its beneficial effects on gene expression of inflammatory markers.

The effects of coenzyme Q10 supplementation on gene expression related to insulin, lipid and inflammation in patients with polycystic ovary syndrome.

OBJECTIVE: This research was conducted to assess the effects of coenzyme Q10 (CoQ10) intake on gene expression related to insulin, lipid and inflammation in subjects with polycystic ovary syndrome (PCOS). METHODS: This randomized double-blind, placebo-controlled trial was conducted on 40 subjects diagnosed with PCOS. Subjects were randomly allocated into two groups to intake either 100 mg CoQ10 (n = 20) or placebo (n = 20) per day for 12 weeks. Gene expression related to insulin, lipid and inflammation were quantified in blood samples of PCOS women with RT-PCR method. RESULTS: Results of RT-PCR shown that compared with the placebo, CoQ10 intake downregulated gene expression of oxidized low-density lipoprotein receptor 1 (LDLR) (p < 0.001) and upregulated gene expression of peroxisome proliferator-activated receptor gamma (PPAR-γ) (p = 0.01) in peripheral blood mononuclear cells of subjects with PCOS. In addition, compared to the placebo group, CoQ10 supplementation downregulated gene expression of interleukin-1 (IL-1) (p = 0.03), interleukin-8 (IL-8) (p = 0.001) and tumor necrosis factor alpha (TNF-α) (p < 0.001) in peripheral blood mononuclear cells of subjects with PCOS. CONCLUSIONS: Overall, CoQ10 intake for 12 weeks in PCOS women significantly improved gene expression of LDLR, PPAR-γ, IL-1, IL-8 and TNF-α.

Magnesium supplementation affects gene expression related to insulin and lipid in patients with gestational diabetes.

Magnesium is known to exert several beneficial effects, including antiglycemic and antilipidemic properties. The aim of this study was to evaluate the effects of magnesium supplementation on gene expression related to insulin and lipid metabolism in women with gestational diabetes (GDM) who were not on oral hypoglycemic agents. This randomized double-blind, placebo-controlled trial was conducted among 40 patients diagnosed with GDM, aged 18-40 years. Participants were randomly allocated into two groups to take either 250 mg/day of magnesium supplements in the form of magnesium oxide (n = 20) or placebo (n = 20) for 6 weeks. Gene expression related to insulin and lipid metabolism was assessed in peripheral blood mononuclear cells (PBMCs) of women with GDM using RT-PCR method. Compared with the placebo, magnesium supplementation to women with GDM resulted in a significant decrease in levels of fasting plasma glucose (FPG) (-9.7 ± 5.6 vs. -0.1 ± 8.5 mg/dL, P<0.001). Quantitative results of RT-PCR demonstrated that compared with the placebo, magnesium supplementation upregulated gene expression of peroxisome proliferator-activated receptor gamma (PPAR-γ) (P = 0.003) and glucose transporter 1 (GLUT-1) (P = 0.004) and downregulated gene expression of oxidized low-density lipoprotein receptor (LDLR) (P = 0.001) in PBMCs of women with GDM. In addition, a trend toward a greater decrease in gene expression of lipoprotein (a) [LP(a)] was observed in the patients belonging to magnesium group compared to placebo group (P = 0.08). Overall, magnesium supplementation for 6 weeks in women with GDM significantly improved FPG levels, and gene expression of PPAR-γ, GLUT-1, and LDLR.

The Effects of Vitamin D Supplementation on Glucose Metabolism and Lipid Profiles in Patients with Gestational Diabetes: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

This systematic review and meta-analysis of randomized controlled trials (RCTs) was conducted to summarize the effect of vitamin D supplementation on glucose homeostasis parameters and lipid profiles in gestational diabetes (GDM) patients. We conducted an electronic systematic search of MEDLINE, and 4 other research databases from inception to August 2016, in addition to performing hand searches and consulting with experts in the field. The index of heterogeneity between studies was determined using Cochran (Q) and I-squared tests. Given the existing heterogeneity between studies, a fix or random effect model was performed to estimate the standardized mean difference (SMD) for each variable by using inverse variance method and Cohen statistics. Six randomized clinical trials (187 subjects and 184 controls) were included. The results showed that vitamin D supplementation significantly reduced the homeostasis model assessment of insulin resistance (HOMA-IR) [SMD -0.66; 95% confidence interval (CI), -1.14 to -0.18], homeostatic model assessment-B cell function (HOMA-B) (SMD -0.52; 95% CI, -0.79 to -0.25), LDL-cholesterol levels (SMD -0.33; 95% CI, -0.58 to -0.07), and significantly increased quantitative insulin sensitivity check index (QUICKI) (SMD 0.73; 95% CI, 0.26 to 1.20). We found no beneficial effect of vitamin D supplementation on fasting plasma glucose (FPG), insulin, HbA1c, total-, HDL-cholesterol, and triglycerides concentrations. In conclusion, this meta-analysis demonstrated that vitamin D supplementation may lead to an improvement in HOMA-IR, QUICKI, and LDL-cholesterol levels, but did not affect FPG, insulin, HbA1c, triglycerides, total- and HDL-cholesterol levels; however, vitamin D supplementation increased HOMA-B.

The effects of vitamin D supplementation on metabolic profiles and liver function in patients with non-alcoholic fatty liver disease: A systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: A systematic review and meta-analysis of randomized controlled trials (RCTs) was conducted to summarize the evidence on the effect of vitamin D supplementation on metabolic profiles in patients with non-alcoholic fatty liver disease (NAFLD). METHODS: We systematically searched PubMed, EMBASE and five other databases to identify all RCTs investigating the association between vitamin D and NAFLD up until 5 October 2016. Seven RCTs with 452 participants (227 patients and 225 controls) were included in the meta-analysis. RESULTS: The results showed that vitamin D administration had no beneficial effect on fasting plasma glucose (FPG) (standardized mean difference [SMD]-0.23; 95% confidence interval [CI], -0.88, 0.42), insulin (SMD -1.09; 95% CI, -2.70,0.52) and homeostasis model assessment of insulin resistance (HOMA-IR) (SMD -1.89; 95% CI, -3.88,0.09). Vitamin D supplementation also had no effect on lipid profiles including triglycerides (SMD -0.36; 95% CI, -1.77, 1.04), and total-cholesterol (SMD -0.46; 95% CI: -1.3, 0.39), as well as on aspartate transaminase (AST) (SMD -0.53; 95% CI, -1.11, 0.05), alanine aminotransferase (ALT) (SMD -0.66; 95% CI, -1.43,0.11), and body mass index (BMI) (SMD -0.25; 95% CI, -0.76,0.27). CONCLUSIONS: Vitamin D supplementation had no effect on FPG, insulin, HOMA-IR, triglycerides, total-, LDL-cholesterol, AST, ALT, and BMI.

Effect of Two Different Doses of Vitamin D Supplementation on Metabolic Profiles of Insulin-Resistant Patients with Polycystic Ovary Syndrome: A Randomized, Double-Blind, Placebo-Controlled Trial.

The current study was conducted to evaluate the effects of 2 different doses of vitamin D supplementation on metabolic profiles of insulin-resistant patients with polycystic ovary syndrome (PCOS). This randomized double-blind, placebo-controlled trial was performed on 90 insulin-resistant patients with PCOS according to the Rotterdam criteria aged 18-40 years old. Participants were randomly allocated into 3 groups to receive either 4 000 IU of vitamin D (n=30) or 1 000 IU of vitamin D (n=30) or placebo (n=30) per day for 12 weeks. Vitamin D supplementation (4 000 IU), compared with vitamin D (1 000 IU) and placebo, led to reduced fasting plasma glucose (-4.3±8.6 vs. -4.7±7.1 and +0.1±6.7 mg/dl, respectively, p=0.02), serum insulin concentrations (-2.7±2.7 vs. -1.4±4.2 and -0.1±4.1 µIU/ml, respectively, p=0.02), and HOMA-IR (-0.6±0.6 vs. -0.4±1.0 and -0.1±0.9, respectively, p=0.02). In addition, we found significant decreases in mean change of serum triglycerides (-10.3±7.3 vs. -3.6±14.5 and +6.9±23.8 mg/dl, respectively, p=0.001), VLDL- (-2.0±1.5 vs. -0.7±2.9 and +1.4±4.8 mg/dl, respectively, p=0.001), total- (-14.0±9.5 vs. -6.2±24.0 and +7.1±29.7 mg/dl, respectively, p=0.002), LDL- (-10.8±8.3 vs. -5.7±21.9 and +6.8±28.2 mg/dl, respectively, p=0.005), and total-/HDL-cholesterol ratio (-0.2±0.3 vs. -0.1±0.6 and +0.2±0.7 mg/dl, respectively, p=0.003) in the high-dose vitamin D group compared with low-dose vitamin D and placebo groups. Overall, vitamin D supplementation at a dosage of 4 000 IU/day for 12 weeks in insulin-resistant patients with PCOS had beneficial effects of glucose metabolism and lipid profiles compared with 1 000 IU/day of vitamin D and placebo groups.