Effect of vitamin D supplementation on oral glucose tolerance in individuals with low vitamin D status and increased risk for developing type 2 diabetes (EVIDENCE): A double-blind, randomized, placebo-controlled clinical trial

2016 ◽  
Vol 19 (1) ◽  
pp. 133-141 ◽  
Author(s):  
Tracy S. Moreira-Lucas ◽  
Alison M. Duncan ◽  
Rémi Rabasa-Lhoret ◽  
Reinhold Vieth ◽  
Alison L. Gibbs ◽  
...  
Nutrients ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2651 ◽  
Author(s):  
Uwe Gröber ◽  
Michael F. Holick

The results of epidemiological and several interventional studies suggest an association between vitamin D deficiency and an increased risk of developing insulin resistance or type 2 diabetes. Various studies have indicated that a lack of vitamin D must be regarded as a pathogenic factor for type 2 diabetes and the metabolic syndrome, since a vitamin D deficiency (25(OH)D < 20 ng/mL) increases insulin resistance and reduces insulin secretion from beta cells in the pancreas. A recent study by Pittas et al. did not show a clear preventive effect of vitamin D supplementation with respect to the risk of developing type 2 diabetes. In terms of this study, it must be remembered that more than 70% of the participants in both the vitamin D supplement group and the placebo group did not have a vitamin D deficiency. In medical and pharmaceutical practice, more attention should be paid to vitamin D deficiency than has previously been accorded. Vitamin D status can be assessed objectively when necessary by laboratory testing of the serum 25(OH)D levels. Type 2 diabetes patients benefit from improving their vitamin D status with respect to their glucose metabolism and decreased mortality risk. Patients with insulin resistance who are vitamin D deficient should be treated with an appropriate amount of vitamin D to achieve circulating levels of 25(OH)D of 40–60 ng/mL.


2020 ◽  
Author(s):  
Xiaomin Sun ◽  
Sirui Zhou ◽  
Mengyue Dong ◽  
Wenjuan Xiao ◽  
Xin He ◽  
...  

Abstract Aims This study aimed to examine the effect of a 12-week vitamin D supplementation and exercise training alone and in combination on glycemic control and bone health in Chinese type 2 diabetes patients.MethodsSixty-one type 2 diabetes patients (age, 33–65 years; 72.0% men) with non-insulin dependence were randomized into the 12-week vitamin D group (1000 IU/day), exercise group (60%–80% of maximal heart rate, 1 h/time, 2–3 times/week), vitamin D combined with exercise group, and control group. A 75-g oral glucose tolerance test was used to estimate glycemic control. Dual X-ray absorptiometry was used to examine bone health (bone mass content and bone mass density) and body fat percentage (%).Results During the 75-g oral glucose tolerance test, lower glucose and higher insulin levels were found in the vitamin D combined with exercise group, vitamin D group, and exercise group after intervention than before intervention, although the differences were not statistically significant. A significant exercise and vitamin D interaction for the insulinogenic index (P = 0.032) and a borderline interaction for the glucose disposition index (P = 0.051) were observed, while no further independent effect was observed. Compared with non-vitamin D supplementation, vitamin D supplementation significantly alleviated the loss of total bone mass content (95% CI: -29.9–19.4 vs. -74.9–-24.7), trunk bone mass content (95% CI: -24.1–19.5 vs. -56.1–-11.7), and spine bone mass density (95% CI: -0.03–0.03 vs. -0.07–-0.01).ConclusionsThe findings suggest that 12-week combined vitamin D and exercise intervention has a potentially positive effect on glycemic control, and vitamin D supplementation plays an important role in the prevention of bone loss, which was identified in the exercise alone group. Further studies are needed to elucidate the long-term effect of combined vitamin D and exercise intervention in type 2 diabetes patients.The study was registered in the Chinese Clinical Trial System (No. ChiCTR1800015383).


2014 ◽  
Vol 99 (12) ◽  
pp. E2485-E2493 ◽  
Author(s):  
Maryam Tabesh ◽  
Leila Azadbakht ◽  
Elham Faghihimani ◽  
Marjan Tabesh ◽  
Ahmad Esmaillzadeh

Context: To the best of our knowledge, no study has examined the effects of vitamin D-calcium cosupplementation on inflammatory biomarkers and adipocytokines in vitamin D-insufficient type 2 diabetics. Objective: This study was performed to assess the effects of vitamin D and calcium supplementation on inflammatory biomarkers and adipocytokines in vitamin D-insufficient people with type 2 diabetes. Methods: Totally, 118 diabetic patients were enrolled in this randomized, placebo-controlled clinical trial. After matching for age, sex, body mass index, type and dose of hypoglycemic agents, and duration of diabetes, subjects were randomly assigned into 4 groups receiving the following: 1) 50000 IU/wk vitamin D + calcium placebo; 2) 1000 mg/d calcium + vitamin D placebo; 3) 50 000 IU/wk vitamin D + 1000 mg/d calcium; or 4) vitamin D placebo + calcium placebo for 8 weeks. Blood sampling was done for the quantification of inflammatory biomarkers and adipocytokines at the study baseline and after 8 weeks of intervention. Results: Calcium (changes from baseline: −75±19 ng/ml, P = .01) and vitamin D alone (−56 ± 19 ng/mL, P = .01) and joint calcium-vitamin D supplementation (−92 ± 19 ng/mL, P = .01) resulted in a significant reduction in serum leptin levels compared with placebo (−9 ± 18 ng/mL). This was also the case for serum IL-6, such that calcium (−2 ± 1 pg/mL, P &lt; .001) and vitamin D alone (−4 ± 1 pg/mL, P &lt; .001) and their combination (−4 ± 1 pg/mL, P &lt; .001) led to significant reductions compared with placebo (3 ± 1 pg/mL). After adjustment for potential confounders, individuals in the calcium (−3.1 ± 1.3, P &lt; .05), vitamin D (−3.1 ± 1.3, P &lt; .05), and joint calcium-vitamin D groups (−3.4 ± 1.3, P &lt; .05) had greater reductions in serum TNF-α concentrations compared with placebo (0.1 ± 1.2). Individuals who received joint calcium-vitamin D supplements tended to have a decrease in serum high-sensitivity C-reactive protein levels compared with placebo after controlling for baseline levels (−1.14 ± 0.25 vs 0.02 ± 0.24 ng/mL, P = .09). Conclusion: Joint calcium-vitamin D supplementation might improve systemic inflammation through decreasing IL-6 and TNF-α concentrations in vitamin D-insufficient people with type 2 diabetes.


Author(s):  
Salimah Navaz Gangji

The presence of hyperglycemia in individuals with Type 2 Diabetes Mellitus (T2DM) is associated with systemic complications within multiple organ systems. Specifically, patients with T2DM have an increased risk of developing vascular endothelial damage. Interestingly, patients with T2DM are often found to be deficient in vitamin D, a fat-soluble vitamin that not only plays a role in bone growth and gastrointestinal nutrient absorption, but insulin resistance as well. Thus, the purpose of this review is to summarize the literature that associates vitamin D deficiencies with vascular complications in both human and animal models with T2DM. This review will also summarize developments in genetic testing for VDR mutations and their potential role in diabetes progression, as well as the effects of vitamin D supplementation in patients with T2DM. Since T2DM is an increasingly prevalent disease, it is important to continue evaluating current research that investigates not only genetic causal factors for the disease, but also preventative options (such as vitamin D supplementation) that could potentially be used alongside pharmacological treatments.


2018 ◽  
Vol 88 (1-2) ◽  
pp. 73-79 ◽  
Author(s):  
Farzaneh Rezagholizadeh ◽  
Seyed Ali Keshavarz ◽  
Mahmoud Djalali ◽  
Esmaeel Yussefi Rad ◽  
Shahab Alizadeh ◽  
...  

Abstract. Objective: To explore the effect of vitamin D3 on novel serum adipokines, secreted frizzled-related protein 5 (SFRP5) and Wingless-Type MMTV Integration Site Family Member 5a (Wnt5a) levels in Type 2 Diabetes Mellitus (T2DM) patients. Methods: Forty patients (16 women and 24 men) with type 2 diabetes participated in this double-blind, randomized, placebo-controlled clinical trial study. Participants were randomly assigned to receive 4000 IU vitamin D3 (n = 20) or placebo (n = 20) daily for 2 months. Anthropometric indices, fasting blood glucose (FBS), hemoglobin A1c (HbA1c), insulin, serum tumor necrosis factor (TNF)-α, Wnt5a, SFRP5, physical activity, lipid profile, dietary intake, and serum calcidiol were assessed at the baseline and after 8 weeks. Results: In the group receiving Vitamin D, a significant increase in Calicidiol (15.03 ± 10.44 vs. 27.33 ± 11.2 ng/dl; P = < 0.001), SFRP5 (3.6 ± 0.46 vs. 3.98 ± 0.59 ng/ml; P = 0.01), and Wnt5a (0.33 ± 0.129 vs. 0.29 ± 0.047; P = 0.03) was observed. After two months supplementation, there were significant between-group differences in Calicidiol (27.33 ± 11.2 vs. 17.9 ± 12.95 ng/dl; P = 0.01), TNF-α (89.22 ± 34.28 vs. 164.93 ± 120.45 ng/ml; P = 0.006), Wnt5a (0.29 ± 0.047 vs. 0.33 ± 0.09; P = 0.04), and HbA1c (6.6 ± 0.96 % vs. 7.64 ± 1.15 %; p = 0.002). Moreover, the net changes (end – baseline) of Calicidiol (P = < 0.001), SFRP5 (P = 0.04), Wnt5a (P = 0.005), TNF-α (P = 0.01), insulin (P = 0.03), and QUICKI (P = 0.01) was significant between the groups. There were no significant effects on FBS and homeostasis model of assessment-estimated insulin resistance (HOMA-IR). Conclusion: 8 weeks of vitamin D3 supplementation for patients with type 2 diabetes may increase serum anti-inflammatory adipokine SFRP5 but decrease serum pro-inflammatory Wnt5a and TNF-α.


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