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.

The effect of cumin supplementation on metabolic profiles in patients with metabolic syndrome: A randomized, triple blind, placebo-controlled clinical trial.

Metabolic syndrome (MetS) is a cluster of interconnected serious disorders, which is a major health problem whose prevalence is increasing. Oxidative stress and inflammation contribute to the disease pathogenesis and its complications. The present study aimed to investigate the effect of Cuminum cyminum L. (which has antioxidant and anti-inflammatory properties) essential oil (CuEO) supplementation on inflammatory and antioxidant status in patients with MetS. In this clinical trial, 56 patients with MetS aged 18-60 years received either 75-mg CuEO or placebo soft gel, thrice daily, for 8 weeks. Data on anthropometric parameters, food consumption, tumor necrosis factor alpha, high-sensitivity C-reactive protein, superoxide dismutase (SOD), glutathione peroxidase, catalase, total antioxidant capacity (TAC), and malondialdehyde (MDA) were assessed at the beginning and at the end of the study. Compared with the placebo group, CuEO increased SOD (149.17; 95% CI, [67.93, 230.42]), TAC (0.24; 95% CI, [0.09, 0.38]) and decreased MDA (-0.36; 95% CI, [-0.66, 0.06]), (p < 0.01). In within-group analysis, CuEO led to 13.3% decrease in MDA and 6.7% increase in TAC levels (p < 0.04). The results indicated that CuEO supplementation can improve some antioxidative indices, as SOD and TAC, while decreasing MDA in patients with MetS.

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.