Effect of high-dose vitamin D supplementation in combination with weight loss diet on glucose homeostasis, insulin resistance, and matrix metalloproteinases in obese subjects with vitamin D deficiency: a double-blind, placebo-controlled, randomized clinical trial.

As there is limited and inconsistent evidence in potential role of vitamin D on insulin resistance and matrix metalloproteinases, this study aimed to examine the effect of vitamin D supplementation on glucose homeostasis, insulin resistance, and matrix metalloproteinases in obese subjects with vitamin D deficiency. A total of 44 participants with serum 25-hydroxyvitamin D (25(OH)D) level ≤ 50 nmol/L and body mass index (BMI) 30-40 kg/m2 were randomly allocated into receiving weight reduction diet with either 50 000 IU vitamin D3 pearl (n = 22) or placebo (n = 22) once weekly for 12 weeks. Primary outcomes were changes in fasting serum glucose (FSG), homeostasis model assessment of insulin resistance (HOMA-IR), quantitative insulin sensitivity check index (QUICKI), and matrix metalloproteinases (MMPs). Secondary outcomes were changes in weight, BMI, 25(OH)D, calcium, phosphorous and parathyroid hormone (PTH). Sun exposure and dietary intakes were also assessed. Serum levels of 25(OH)D3 increased significantly with a simultaneous decrease in serum concentration of PTH in the vitamin D group. Weight, BMI, FSG, and MMP-9 decreased significantly in both groups, and there were significant differences in changes in weight, serum 25(OH)D3, PTH, and MMP-9 levels between the groups. Within- and between-groups analysis revealed no significant differences in serum calcium, phosphorous, serum insulin, HOMA-IR, QUICKI, and MMP-2 after intervention. Our results indicated that improvement in vitamin D status resulted in greater reductions in weight and MMP-9 during weight loss. These preliminary results are sufficient to warrant a bigger study group.

Effect of vitamin D supplementation in combination with weight loss diet on lipid profile and sirtuin 1 in obese subjects with vitamin D deficiency: a double blind randomized clinical trial.

Background: Due to inconsistent evidence regarding the potential role of vitamin D on lipid profile and sirtuin 1 (SIRT-1), this study was designed to investigate the effect of vitamin D supplementation in combination with weight loss diet on lipid profile and SIRT-1 in obese subjects with vitamin D deficiency. Methods: Forty-four obese subjects with vitamin D deficiency were randomly assigned in a randomized clinical trial to receive either a weight reduction diet supplemented with 50000IU vitamin D3 pearl (n = 22) or placebo (n = 22) once weekly for 12 weeks. Changes in total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), triglyceride (TG) and low high density lipoprotein cholesterol (HDL-C) and SIRT-1 were the primary outcomes. Secondary outcomes were changes in body mass index (BMI), 25(OH) D and parathyroid hormone (PTH). Physical activity and dietary intakes were also assessed. Results: During the intervention, PTH (mean difference, -33.36; 95% CI: -49.15 to -17.57;P<0.001) and LDL-C (mean difference, -15.91; 95% CI: -21.76 to -10.07; P<0.001) decreased and 25(OH) D (mean difference, 36.44; 95% CI: 29.05 to 43.83; P<0.001) increased significantly in the vitamin D group. BMI (mean differences: -2.40; 95% CI: [-2.92 to-1.88] in vitamin D group and mean differences: -1.90; 95% CI [-6.58 to -3.01] in placebo group, P<0.05 for both groups), TC (mean difference,-21.31; 95% CI: -27.24 to -15.38; P<0.001 in vitamin D group and mean difference, -12.54; 95% CI: -19.02 to -6.06; P<0.001 in placebo group) and TG (mean difference,-21.31; 95% CI: -27.24 to -15.38; P<0.001in vitamin D group and mean difference, -12.54; 95% CI: -19.02 to -6.06; P<0.001 in placebo group) decreased and SIRT-1(mean difference, 3.95; 95% CI: 1.18 to 6.73; P=0.007in vitamin D group and mean difference,1.91; 95% CI: 0.31 to 3.63 in placebo group, P=0.022) increase significantly in both group. At end of the study, 25(OH) D and PTH showed significant differences in between-group analyses(P<0.05). No significant difference was detected for HDL-C in within and between groups. Conclusion: This study gives no support for any beneficial effect of vitamin D supplementation on lipid profile and SIRT-1 in obese subjects with vitamin D deficiency.

Effect of vitamin D supplementation along with weight loss diet on meta-inflammation and fat mass in obese subjects with vitamin D deficiency: A double-blind placebo-controlled randomized clinical trial.

BACKGROUND & AIMS: Low serum 25-hydroxyvitamin D (25OHD) is common in obese people. Obesity is associated with a state of low-grade inflammation (meta-inflammation). There is an increasing evidence indicating that vitamin D has anti-adipogenic activity and immunoregulatory effect. This study aimed to assess the effect of vitamin D supplementation on meta-inflammation and fat mass in obese subjects with vitamin D deficiency. MATERIALS AND METHODS: In this double-blind placebo-controlled randomized clinical trial, 44 obese subjects with vitamin D deficiency (25OHD < 50 nmol/L) were assigned into vitamin D (a weight reduction diet + bolus weekly dose of 50 000 IU vitamin D) or placebo group (weight reduction diet + edible paraffin weekly) for 12 weeks. Weight, fat mass and serum levels of 25OHD, calcium, parathyroid hormone (PTH), monocyte chemoattractant protein-1 (MCP-1), interleukin-1ß (IL-1ß) and Toll-like receptor 4 (TLR4) were assessed before and after the intervention. RESULTS: Vitamin D supplementation resulted in significant increase of serum 25OHD level (P < 0.001), and significant decrease in PTH (P < 0.001), MCP-1 (P < 0.05), IL-1ß (P < 0.05) and TLR-4 (P < 0.05); compared to the baseline values in vitamin D group. Weight, BMI and fat mass decreased in both groups (P < 0.05). Between the groups, there were significant decrease in weight, fat mass, serum MCP-1 and PTH concentrations and significant increase in serum 25OHD concentrations after intervention with vitamin D supplementation compared to placebo (P < 0.05). CONCLUSIONS: Improvement in vitamin D status in obese subjects with vitamin D deficiency in combination with weight loss diet resulted in weight, fat mass and MCP-1 decrease. Weight loss and vitamin D supplementation may act synergistically to reduce levels of meta-inflammation.

Antioxidant response to artichoke leaf extract supplementation in metabolic syndrome: A double-blind placebo-controlled randomized clinical trial.

BACKGROUND: Oxidative stress is associated with most components and complications of Metabolic Syndrome (MetS). Artichoke Leaf Extract (ALE) has demonstrated anti-oxidant properties in both laboratory and animal studies. AIM: This study was designed to examine the effects of ALE on oxidative stress indices in patients with MetS. METHODS: In the current double-blind placebo-controlled randomized clinical trial, 80 patients with MetS were randomly allocated to either "ALE group" (received 1800 mg ALE as four tablets per day) or "Placebo group" (received placebo containing cornstarch, lactose and avicel as four tablets per day) for 12 weeks. Serum levels of malondialdehyde (MDA), total antioxidant capacity (TAC), oxidized-LDL (ox-LDL), red blood cell glutathione peroxidase (GPx) and superoxidase dismutase (SOD), as well as dietary intakes were assessed at baseline and at the end of the study. RESULTS: A total number of 68 patients completed the study (ALE group = 33; placebo group = 35). Dietary intakes of energy, macronutrients, and micronutrients were not significantly different between two groups throughout the trial, with the exception of zinc (p < 0.05). The concentration of ox-LDL decreased significantly in ALE group in comparison to the placebo group (-266.8 ± 615.9 vs -129.5 ± 591.2 ng/L; p < 0.05). However, no significant inter- and intra-group changes in MDA, SOD, GPx, and TAC concentrations were observed. CONCLUSION: ALE decreased serum ox-LDL level in patients with MetS, with no beneficial effects on other antioxidant indices. CLINICAL TRIAL REGISTRATION NUMBER: IRCT201409033320N9.

Glucose homeostasis, insulin resistance and inflammatory biomarkers in patients with non-alcoholic fatty liver disease: Beneficial effects of supplementation with microalgae Chlorella vulgaris: A double-blind placebo-controlled randomized clinical trial.

BACKGROUND: Chlorella vulgaris (C. vulgaris) is reported to improve dyslipidemia and hypertension; however, its effect on inflammatory biomarkers and insulin resistance has not been noticed thus far. Non-alcoholic fatty liver disease (NAFLD) as a hepatic symptom of metabolic syndrome is strongly associated with insulin resistance and inflammation. AIM OF THE STUDY: In the current interventional trial, we aimed to study the effects of C. vulgaris supplementation on glucose homeostasis, insulin resistance and inflammatory biomarkers in patients with NAFLD. METHODS: Seventy NAFLD patients confirmed by ultra-sonographic findings were randomly assigned into intervention group (four 300 mg tablets of C. vulgaris) or placebo group (four 300 mg tablets of placebos) for 8 weeks. Anthropometric measurements, liver enzymes, fasting serum glucose (FSG), insulin, high sensitive C-reactive protein (hs-CRP) and tumor necrosis factor-alpha (TNF-α) were assessed and homeostatic model assessment (HOMA) score for insulin resistance was estimated before and after the intervention. RESULTS: Anthropometric measurements decreased significantly in both group (p < 0.001). However, mean reduction in weight was significantly higher in C. vulgaris - treated group compared to placebo group. Serum concentrations of liver enzymes, FSG and hs-CRP also significantly decreased and serum insulin concentration and HOMA score increased significantly only in C. vulgaris-treated group (P < 0.001, P < 0.006 and P < 0.025, respectively). Mean change in serum glucose and TNF-α levels were significant between the groups even after adjusting for the serum insulin and baseline values of variables (P = 0.014, P = 0.005, P = 0.014, respectively); between-group differences were not significant for the other variables by the end of study. CONCLUSION: To our finding, C. vulgaris supplementation could be considered as an adjunctive therapy to decrease weight and improve glycemic status and reducing hs-CRP as well as improving liver function in patients with NAFLD. IRCT NUMBER: 201202233320N7.

The Effect of Chlorella vulgaris Supplementation on Liver En-zymes, Serum Glucose and Lipid Profile in Patients with Non-Alcoholic Fatty Liver Disease.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is becoming a public health problem worldwide and using microalgae is a new approach on its treatment. The aim of this study was to investigate the effect of Chlorella vulgaris supplementation on liver enzymes, serum glucose and lipid profile in patients with NAFLD. METHODS: This double-blind randomized placebo-controlled clinical trial was conducted on 60 NAFLD patients from specialized clinics of Tabriz University of Medical Sciences from December 2011 to July 2012. The subjects were randomly allocated into 2 groups: 1) "intervention" (n=30) received 400 mg/day vitamin E plus four 300 mg tablets of Chlorella vulgaris and, 2) "placebo" (n=30) received 400 mg/day vitamin E and four placebo tablets per day for 8 weeks. Weight, liver enzymes and metabolic factors were assessed in fasting serum and dietary data was collected at baseline and end of the study. RESULTS: Weight, liver enzymes, fasting blood sugar (FBS) and lipid profile decreased significantly in both groups (P<0.05). The differences in weight, ALP and FBS between the two groups were statistically significant (P=0.01, P=0.04 and P=0.02, respectively). CONCLUSION: C. vulgaris seems to improve FBS and lipid profile and therefore could be considered as an effective complementary treatment in NAFLD.