Effect of vitamin D on insulin resistance and anthropometric parameters in Type 2 diabetes; a randomized double-blind clinical trial A culturally competent intervention of education and care for black women with type 2 diabetes. Impact of Vitamin E Supplementation on Blood Pressure and Hs-CRP in Type 2 Diabetic Patients | doi: 10.5681/hpp.2012.009. Effects of a 12-week aerobic training on glycemic control in type 2 diabetes mellitus male patients. Metformin Based Dual-Combination Therapies in Drug Naïve Type 2 Diabetic Patients Supplementation of Vitamin C Reduces Blood Glucose and Improves Glycosylated Hemoglobin in Type 2 Diabetes Mellitus: A Randomized, Double-Blind Study Effect of vitamin D supplementation on glycemic control in patients with type 2 diabetes: a systematic review of interventional studies Vitamin D 20,000 IU per Week for Five Years Does Not Prevent Progression From Prediabetes to Diabetes. Study protocol: a randomised placebo-controlled clinical trial to study the effect of vitamin D supplementation on glycaemic control in type 2 Diabetes Mellitus SUNNY trial Nonpharmacological interventions to prevent type 2 diabetes in women diagnosed with gestational diabetes mellitus: a systematic overview Association of vitamin D deficiency with incidence of type 2 diabetes in high-risk Asian subjects. Multivariate Path Analysis of Serum 25-Hydroxyvitamin D Concentration, Inflammation, and Risk of Type 2 Diabetes Mellitus Effect of Vitamin D Supplementation on Glucose Control and Inflammatory Response in Type II Diabetes: A Double Blind, Randomized Clinical Trial Taking a Low Glycemic Index Multi-Nutrient Supplement as Breakfast Improves Glycemic Control in Patients with Type 2 Diabetes Mellitus: A Randomized Controlled Trial The effect of vitamin D supplementation on gestational diabetes in high-risk women: Results from a randomized placebo-controlled trial Lack of effect of subtherapeutic vitamin D treatment on glycemic and lipid parameters in Type 2 diabetes: A pilot prospective randomized trial. The Effect of Vitamin D Supplementation on Adiposity, Blood Glycated Hemoglobin, Serum Leptin and Tumor Necrosis Factor-α in Type 2 Diabetic Patients
Background & the purpose of the study Prevalence of type 2 diabetes mellitus ( T2DM ) is increasing worldwide . To reduce its risk and progression , preventive strategies are needed . Vitamin supplementation such as vitamin D is one of the strategies . This study was design ed to investigate the effect of injection of vitamin D on insulin resistance and anthropometric parameters in T2DM . Methods This r and omized double-blind clinical trial was conducted with 42 diabetic patients in two groups ; intervention group with  single intramuscular injection of 300,000 International Unit ( IU ) of vitamin D3 and the placebo group . After recording demographic and anthropometric factors ( waist circumference , blood pressure and body mass index ) , fasting blood sample s was taken for measurement of blood glucose , 25-hydroxyvitamin D3 ( 25-OHD3 ) , insulin , glycosylated hemoglobin A1c ( HbA1c ) and estimation of Homeostasis Model Assessment Index ( HOMA ) in two times ; before study and after three months . Results Two groups had similar baseline characteristics ( each group = 21 subjects ) . Three months after vitamin D injection , HbA1c , anthropometric factors and HOMA index in intervention group stayed constant , however , serum 25- OHD3 was significantly increased ( p = 0.007 ) . Conclusion The present data is not convincing and further studies with large sample sizes are needed to show the definite effect of injection of vitamin D on control of diabetes and its risk This article reports on the development and pilot feasibility testing of a culturally competent intervention of education and care for black women with type 2 diabetes mellitus ( T2DM ) . Using a one group , pretest posttest quasi-experimental design , the intervention was tested with a convenience sample of 25 community black women with T2DM . The conceptual basis , process , and content of the intervention as well as the feasibility and acceptability of study material s and methods are described . Significant improvements from baseline to 3 months were observed in measures of glycemic control , weight , body mass index , and diabetes-related emotional distress . The findings suggest that a culturally sensitive intervention of nurse practitioner diabetes care and education is beneficial for black women with T2DM , result ing in program attendance , kept appointments , improved glycemic control and weight , and decreased diabetes-related emotional distress BACKGROUND Type 2 diabetes mellitus ( T2DM ) is a major public health problem worldwide . Hypertension and inflammation are well recognized as risk factors for the macrovascular complications of diabetes . The aim of this study was to assess the impact of vitamin E supplementation on blood pressure ( BP ) , serum high-sensitivity C-reactive protein ( hs-CRP ) and fasting blood glucose in patients with T2DM . METHODS In a double blind , r and omized , controlled clinical trial , 83 patients with T2DM were divided r and omly into two groups of vitamin E ( 400 mg/d , n=42 ) and placebo ( n=41 ) . All patients received the pearls for 8 weeks . Baseline and eighth week BP , serum hs-CRP , fasting blood glucose , anthropometric and dietary intake data were obtained from each patient . Data were analyzed using SPSS version 11.5 . RESULTS Vitamin E supplementation significantly increased serum levels of vitamin E  ( P < 0.001 ) and decreased mean arterial pressure and fasting blood glucose ( P = 0.047 , P = 0.028 , respectively ) in vitamin E group as compared with placebo group . A significant decrease in systolic blood pressure and diastolic blood pressure was observed in the vitamin E group comparing with baseline values ( all P < 0.01 ) . There were no significant changes in serum hs-CRP in both of the studied groups . CONCLUSION Vitamin E had beneficial effects on serum vitamin E , BP and blood glucose in patients with T2DM . Improvement in BP and glucose control may contribute to reducing complications of diabetes including cardiovascular risk in these patients T 2 diabetes mellitus ( T2DM ) is a metabolic disease affecting the metabolism of carbohydrates , proteins and lipids due to initial insulin resistance at the cellular levels followed by progressive insulin deficiency . The consequence of that is gradual increment of serum blood glucose , which binds independent of the enzymes to the proteins in the blood , as well as the tissue proteins ; one of these measurable protein is the red blood cells hemoglobin , which enabled the clinician to assess diabetes control by the percentage of glycosylation of this protein every 3 months , which correlates well to the other tissue involvement and the disease control . Diabetes-related complications are related to the micro and macro vascular derangement due to glycosylated protein in these vessels tissues , leading to nephropathy , retinopathy , neuropathy , myocardial infa rct ion , stroke , and death found to be more frequent and seen at earlier age.1 Estimate of global T2DM indicates that diabetes now affects 246 million people worldwide , and is expected to affect approximately 380 million by 2025 , representing 7.1 % of the world adult population .2 The Kingdom of Saudi Arabia ( KSA ) has one of the highest prevalence of T2DM worldwide since the percentage of diabetes mellitus is estimated to be 23.7 % of the overall population .3 Structured exercise interventions have been shown to be at least as efficacious as the pharmaceutical agents for improving glycemic control.4 Most people with T2DM do not do enough physical activity to benefit their health , and in comparison with the general population , people with diabetes experience a higher frequency of relapse to sedentary behavior.5 Our primary objective is to investigate the effects of supervised aerobic exercise on glycemic control , the glycosylated hemoglobin ( HbA1c ) level , as well as the effect on medication doses adjustments , before and after the study in T2DM Saudi male patients . Our secondary objective was to assess its effect on their lipid profile . This study was performed as collaboration between the Department of Physical Education at the King Fahd University of Petroleum and Minerals ( KFUPM ) and King Fahd Hospital of the University ( KFHU ) , University of Dammam from July to October 2012 . Fifty male patients registered in the diabetes clinic records at KFHU , Al-Khobar , KSA were r and omly selected using the stratified r and om sampling and pooled in the study for inclusion and exclusion criteria filtering . Twenty-four patients diagnosed with T2DM , age range of 25 - 55 years ( 43.86±10.3 years ) were selected to be enrolled in the study . Their medication profiles were documented at the beginning and at the end of the program from their medical files . Diet and lifestyle of patients were not controlled by the study . We excluded patients known to have cardiovascular disease , hypertension , retinopathy , neuropathy , bronchial asthma , arthritis , and morbidly obese . We also excluded those who were involved in any physical exercise program or subjects living very far from KFUPM , the site of the physical exercise . After initial screening and baseline assessment s , all 24 subjects were r and omly allocated to 2 different groups namely ; intervention group ( n=12 ) and control group ( n=12 ) . The exercise group subjects signed a written informed consent after being informed regarding all possible risks associated with exercise training programme .  Comprehensive clinical examination , as well as laboratory testing and fitness assessment were performed for each subject before participation in the exercise training programme , as well as at the end of the programme . All subjects went through one week of familiarization before the start of the programme . After a few weeks , 2 subjects withdrew from the intervention group due to personal reasons . Only 10 subjects completed the 12 weeks of the exercise training programme  . The exercise training programme was given at the fitness centre of KFUPM . The entire duration of the 12-week exercise training programme was closely supervised by 2 qualified personnel . Attendance was verified every day through direct observation and documented records . Exercise data were recorded every day on a chart . The exercise session includes running or walking on treadmill , and cycling on bicycle ergometer . We provided 10 minutes of warming up period and 10 minutes of cooling down period in each exercise session . Each participant had to check his blood glucose levels before and after the exercise . Subjects performed exercise 3 times per week on alternate days with no more than a 2-day gap . The training was design ed to provide an alternate day as a replacement for missed training sessions during the week . Subjects started with training intensity of 40 - 50 % of maximum heart rate Brief There is an explosive growth of type 2 diabetes mellitus ( T2DM ) in South Korea . According to Korea National Health and Nutritional Examination Survey performed in 2011 , the prevalence of diabetes among the population of 30 years and old is 12.4 % , and the number of patients with T2DM is expected to reach 6 million by 2050 [ 1 ] . Through studies such as UK Prospect i ve Diabetes Study , it has been well established that aggressive glycemic control in patients with newly diagnosed T2DM reduces microvascular and macrovascular complications of the disease [ 2 ] . Therefore , it is important to diagnose and treat T2DM in early phase . Several institutions have suggested target glycemic goals -for instance , American Diabetes Association ( ADA ) has recommended glycated hemoglobin ( HbA1c ) to be controlled below 7 % and stated that it should be maintained as close to normal level as possible in patients with short duration of T2DM , long life expectancy , and no cardiovascular disease [ 3,4 ] . Korean Diabetes Association ( KDA ) has recommended HbA1c below 6.5 % as target glycemic goal [ 5 ] . In general , a regimen of single oral hypoglycemic agent reduces HbA1c by approximately 1.5 % ; therefore , a combination therapy is recommended as initial management in HbA1c greater than 8 % [ 3 - 7 ] . The benefits of early combination therapy includes reduced glucotoxicity to β-cells through early normalization of blood glucose , reduced exposure time to hyperglycemia , and simultaneous blocking of multiple pathophysiology of T2DM [ 5,6 ] . The treatment guideline provided by ADA and European Association for the Study of Diabetes ( EASD ) , as well as that by KDA , recommends metformin in addition to lifestyle modification in patients with newly diagnosed T2DM as long as there are no contraindications [ 3 - 5 ] . In the past , addition of oral hypoglycemic agents with different mechanism of action or insulin was indicated after failure of metformin monotherapy ; however , since the recent recognition of importance of early aggressive glycemic control , metformin-based combination therapy has been widely employed in patients with HbA1c greater than 7.5 % to 8 % [ 3 - 6 ] . However , if combination of oral agents other than metformin is determined to be more effective based on several studies , an appropriate combination may be tailored to each patient depending not only on the mechanism , efficacy , side effect , and drug-drug interaction of each agent but also on individual lifestyle [ 3,6 ] . The major classes of hypoglycemic agents that may be combined with metformin include sulfonylurea ( SU ) , thiazolidinedion ( TZD ) , dipeptidyl-peptidase-4 inhibitor ( DPP4-i ) , insulin , and glucagon-like peptide-1 ( GLP-1 ) receptor agonist [ 6 ] . There is no clear guideline on the most effective combination regimen available for uncontrolled T2DM , and few studies investigated the effect of metformin-based early combination therapy . SU acts on β-cells of the pancreas as an insulin secretagogue-it is the most commonly used drug in conjunction with metformin [ 5,7 ] . One study evaluated the efficacy and safety of glyburide/metformin combination regimen as initial therapy in drug-naive T2DM patients over 2 years . The mean HbA1c at baseline and at 104 weeks after treatment was 8.4 % and 6.8 % , respectively . Combination with SU result ed in good glycemic control , but a significant increase in body weight and hypoglycemic episodes was noted [ 8 ] . While second generation SU ( e.g. , gliclazide , glimepiride ) report lower incidence of hypoglycemic episodes compared to long acting SU ( glyburide ) , it still needs to be taken into account in elderly patients [ 9 ] . In addition , another problem has been raised by a study entitled " A diabetes outcome progression trial (ADOPT)"-SU , when used as monotherapy agent , shows higher secondary failure rate compared to metformin or TZD [ 10 ] . Nonetheless , whether a similar result is observed when combined with metformin has not been reported as of yet . Pioglitazone , a peroxisomal proliferator-activated receptor γ agonist , reduces insulin resistance in the liver and peripheral tissues , leading to increases in suppression of hepatic glucose production and glucose uptake in peripheral tissues [ 6,7 ] . One cohort follow-up study compared and analyzed the results of initial combination therapy consisting of metformin and pioglitazone and initial sequential monotherapy of metformin and pioglitazone in T2DM patients with HbA1c greater than 7 % . This study found that initial combination therapy of metformin and pioglitazone was more effective than sequential combination therapy of metformin and pioglitazone in reaching and maintaining glycemic control , especially in subjects with HbA1c greater than 9 % [ 11 ] . Although pioglitazone  reduces the risk of death , myocardial infa rct ion , and stroke , there is potential weight gain , and its long-term use is associated with elevated risk of other side effects , such as bone fracture [ 12,13 ] . DPP4 inhibits DPP4 , an enzyme that de grade s incretin hormone GLP-1 , result ing in hypoglycemic effect [ 6,14 ] . Its combination with metformin is the subject of numerous recent studies . Lim et al. [ 15 ] reported a decrease in mean HbA1c of approximately 1.5 % in drug-naive Korean T2DM patients who initially underwent 52 weeks of combination therapy with metformin and stagliptin-this  efficacy was found to be greater in those with higher initial HbA1c after adjusting for BMI , insulin resistance , and other factors . In addition , it has suggested that DPP4-i may offer assistance in subjects with low β-cell function [ 15 ] . A series of recent studies have reported a combination regimen of metformin and DPP4-i to be associated with effective and safe glycemic control with no weight gain and low risk of hypoglycemia [ 16 - 18 ] . Nonetheless , there is a lack of studies on the effects of long-term DPP4-i use on cardiovascular disease , cancer , or the pancreas . The study by Lee et al. [ 19 ] was design ed to evaluate the efficacy of glycemic control in drug-naive or newly detected Korean T2DM patients receiving metformin-based dual combination therapy with SU , pioglitazone , or DPP4-i  , and they found similar hypoglycemic efficacy among SU , pioglitazone , and sitagliptin after 24 weeks of treatment in newly diagnosed T2DM subjects : this efficacy was similar or superior to that reported by other studies that combined SU , TZD , or DPP4-i to metformin [ 8,11,15 - 17 ] . Several studies have investigated which medications are more effective in Korean subjects [ 15,20,21 ] . In a study that reported more frequent  β-cell dysfunction  in Asian population compared to Westerners , combination therapy with SU could be effective in Korean [ 20 ] . DPP4-i was reported to be more effective in Asians than in Western [ 21 ] ; however , in another study that included diabetes in early stages , TZD demonstrated equal hypoglycemic efficacy when compared to SU [ 22 ] . These findings imply that it is difficult to label a specific drug as superior to others . Furthermore , patients with relatively high HbA1c at baseline responded well to combination oral hypoglycemic agent therapy [ 19 ] . Insulin therapy is the recommended treatment of choice in patients with HbA1c greater than 10 % to 11 % or with symptoms of hyperglycemia [ 3 - 6 ] ; however , in this study , dual therapy was initiated in subjects with HbA1c greater than 11 % . These patients showed a mean HbA1c below 6.5 % after 24 weeks of treatment , demonstrating that oral hypoglycemic agents can achieve adequate glycemic control within 24 weeks in early diabetic patients with severe hyperglycemia [ 19 ] . As the authors have stated , this maybe be due to relatively spared pancreatic β-cell function , as well as due to lower insulin resistance compared to study groups of other research es . The 2013 ADA/EASD guideline also recommended that glycemic target and control should be tailored to individuals [ 3 ] . In this study by Lee et al. [ 19 ] , metformin-based dual therapies with SU , TZD , and DPP4-i all showed similar efficacy . This suggests that the choice of oral hypoglycemic agents should be based on side effects , compliance , cost , and other factors rather than relying on a specific class of drug . Nonetheless , the analysis included only 24 weeks of data since the initial diagnosis , requiring further studies that evaluates not only the continued hypoglycemic efficacy of the combination therapy but also its side effects and its preventative effect on complications . A special attention should be paid in the future to the incidence of cardiovascular diseases and hypoglycemia in SU group , fracture and edema in TZD group , and pancreatitis , neoplasm , and cardiovascular disease in DPP4-i group No study has ever examined the effect of vitamin C with metformin on fasting ( FBS ) and postmeal blood glucose ( PMBG ) as well as glycosylated hemoglobin ( HbA1c ) in the treatment of type 2 diabetes mellitus ( DM ) . The goal was to examine the effect of oral vitamin C with metformin on FBS , PMBG , HbA1c , and plasma ascorbic acid level ( PAA ) with type 2 DM . Seventy patients with type 2 DM participated in a prospect i ve , double-blind , placebo-controlled , 12-week study . The patients with type 2 DM were divided r and omly into placebo and vitamin C group of 35 each . Both groups received the treatment for twelve weeks . Decreased PAA levels were found in patients with type 2 diabetes mellitus . This level was reversed significantly after treatment with vitamin C along with metformin compared to placebo with metformin . FBS , PMBG , and HbA1c levels showed significant improvement after 12 weeks of treatment with vitamin C. In conclusion , oral supplementation of vitamin C with metformin  reverses ascorbic acid levels , reduces FBS , PMBG , and improves HbA1c . Hence , both the drugs in combination may be used in the treatment of type 2 DM to maintain good glycemic control Background Diabetes and vitamin D deficiency are global epidemics . Research ers have long been exploring the role of potentially modifiable factors to manage type 2 diabetes . We conducted a systematic review of prospect i ve studies and r and omized controlled trials that involved vitamin D supplementation and specifically intended to study glycemic outcomes related to type 2 diabetes . Methods Two authors independently search ed Medline and PubMed for longitudinal studies that had assessed the effect of vitamin D supplements on glycemic control , insulin resistance and beta-cell dysfunction in patients with diabetes . Results Seventeen r and omized control trials and seven longitudinal studies with a minimum follow-up of one month were included . Results of the various short-term studies ( follow up ≤ 3 months ) suggested that vitamin D supplementation had a positive impact on glycemic control and metabolic parameters such as insulin resistance and beta cell dysfunction . However , the evidence was weak due to the low method ological quality of the studies . There was no significant effect on HbA1c , beta cell function and insulin resistance in the long-term studies ( follow up > 3 months ) . There existed heterogeneity in the methodology of the studies , inclusion criteria , mode of supplementation of vitamin D and the duration of follow up . Conclusions Current evidence based on r and omized controlled trials and longitudinal studies do not support the notion that vitamin D supplementation can improve hyperglycemia , beta cell secretion or insulin sensitivity in patients with type 2 diabetes . Large-scale trials with proper study design , optimal vitamin D supplementation and longer follow up need to be conducted CONTEXT Vitamin D deficiency is associated with insulin resistance and risk of future diabetes . OBJECTIVE The objective of the study was to test whether supplementation with vitamin D to subjects with prediabetes will prevent progression to type 2 diabetes mellitus ( T2DM ) . DESIGN This was a r and omized controlled trial performed in 2008 through 2015 . SETTING The study was conducted at the clinical research unit at a teaching hospital . PATIENTS Five hundred eleven subjects ( mean age 62 y , 314 males ) with prediabetes diagnosed with an oral glucose tolerance test as part of the Tromsø Study 2007–2008 were included . A total of 256 were r and omized to vitamin D and 255 to placebo .  Twenty-nine subjects in the vitamin D and 24 in the placebo group withdrew because of adverse events . INTERVENTIONS Interventions included vitamin D ( cholecalciferol ) 20 000 IU/wk vs placebo for 5 years . Annual oral glucose tolerance tests were performed . MAIN OUTCOME MEASURE Progression to T2DM was the main outcome measure . Secondary outcomes were change in glucose levels , insulin resistance , serum lipids , and blood pressure . RESULTS The mean baseline serum 25-hydroxyvitamin D level was 60 nmol/L ( 24 ng/mL ) . One hundred three in the vitamin D and 112 in the placebo group developed T2DM ( hazard risk 0.90 ; 95 % confidence interval 0.69–1.18 , Cox regression , P = .45 , intention to treat analysis ) . No consistent significant effects on the other outcomes were seen . Subgroup analyses in subjects with low baseline 25-hydroxyvitamin D yielded similar results . No serious side effects related to the intervention were recorded . CONCLUSIONS In subjects without vitamin D deficiency , vitamin D supplementation is unlikely to prevent progression from prediabetes to diabetes . Very large studies with inclusion of vitamin D-deficient subjects will probably be needed to show such a putative effect . This study tested if supplementation with  vitamin D to subjects with prediabetes will prevent progression to type 2 diabetes ( T2DM ) Background Besides the classical role of vitamin D on calcium and bone homeostasis , vitamin D deficiency has recently been identified as a contributing factor in the onset of insulin resistance in type 2 diabetes mellitus . However , it is uncertain whether vitamin D deficiency and poor glycaemic control are causally interrelated or that they constitute two independent features of type 2 diabetes mellitus . There are limited clinical trials carried out which measured the effect of vitamin D supplementation on glycaemic control . The objective of this study is to investigate the effect of vitamin D supplementation on glycaemic control and quality of life in patients with type 2 diabetes mellitus . Methods / design In a r and omised double-blind placebo-controlled trial conducted in five general practice s in the Netherl and s three hundred patients with type 2 diabetes mellitus treated with lifestyle advises or metformin or sulphonylurea-derivatives are r and omised to receive either placebo or 50,000 IU Vitamin D3 at monthly intervals . The primary outcome measure is the change in glycated haemoglobin level between baseline and six months . Secondary outcome measures include blood pressure , anthropometric parameters , lipid profile , insulin resistance , quality of life , advanced glycation end products and safety profiles . Quality of life will be measured by The Short Form ( SF-36 ) Health Survey question naire . Advanced glycation end products are measured by an AGE-reader . Discussion This trial will be the first study exploring the effect of vitamin D supplementation on both glycaemic control and quality of life in patients with type 2 diabetes mellitus . Our findings will contribute to the knowledge of the relationship between vitamin D status and insulin resistance in patients with type 2 diabetes mellitus . Trial registration The Netherl and s trial register : This systematic overview summarizes the relevant evidence from multiple systematic review s of the benefits of nonpharmacological interventions for preventing  type 2 diabetes mellitus ( T2MD ) in women diagnosed with gestational diabetes mellitus ( GDM ) . A comprehensive search using the Cochrane Library , CINAHL , EMBASE and MEDLINE via Ovid SP , and PubMed data bases was completed on 18 November 2015 . Any systematic review s that evaluated r and omized controlled trials ( RCTs ) with defined nonpharmacological interventions for preventing T2DM in women diagnosed with GDM were eligible for inclusion . The authors independently performed critical appraisal s and quality assessment s of the included review s using the AMSTAR tool , and extracted data were converted to coherent values for tabular summarization . Six eligible review s of diet and /or exercise , breastfeeding , and reminder interventions were identified ; however , the method ologies of the review s varied greatly , and the majority of the evidence suggested unclear bias . We found inconsistent reporting on the rates at which diet and exercise interventions reduced the risk of T2DM progression , but these interventions were found to be effective at reducing glycemic load . Combined diet , exercise , and breastfeeding interventions proved to be effective at returning women to their postpartum weight . Neither diet alone nor exercise alone proved to be effective at lowering the risk of T2DM . Overall , there was no robust evidence to support the hypothesis that nonpharmacological interventions are effective at lowering the risk of T2DM in women diagnosed with GDM , and there was no consistent evidence showing that these interventions improved the predictor outcomes of T2DM , such as glycemic load or anthropometric changes BACKGROUND Recent studies suggest an association between 25-hydroxyvitamin D [ 25(OH)D ] and type 2 diabetes ( T2D ) risk . However , prospect i ve studies investigating the relation between vitamin D inadequacy and incidence of T2D incorporating obesity and dynamic measures of insulin resistance ( IR ) and pancreatic β cell function are limited . OBJECTIVE We tested the hypothesis that baseline 25(OH)D is associated with the incidence of T2D in high-risk subjects for up to 5 y of follow-up , independently of obesity , baseline IR , and β cell function . DESIGN We recruited 1080 nondiabetic Korean subjects [ mean ± SD age : 49.5 ± 11.4 y ] based on the presence of one or more risk factors for T2D , including obesity , hypertension , dyslipidemia , and /or family history of T2D . We measured anthropometric and biochemical indicators , HOMA2-IR , and the insulinogenic index ( IGI ; calculated as change in insulin at 30 min/change in glucose at 30 min ) from a 75-g oral-glucose-tolerance test . RESULTS Of the participants , 10.5 % had a serum 25(OH)D deficiency ( < 10 ng/mL ) , 51.6 % had an insufficiency ( 10.0 - 19.9 ng/mL ) , and 38.0 % had a sufficiency ( ≥20 ng/mL ) , and the incidence of T2D at 32.3 ± 15.6 mo ( ±SD ) declined accordingly : 15.9 % , 10.2 % , and 5.4 % , respectively ( P < 0.001 ) . After adjustment for age , sex , blood pressure , lifestyles , family history , season , parathyroid hormone , and high-sensitivity C-reactive protein , the participants with 25(OH)D deficiency had an increased risk of T2D independently of BMI , HOMA2-IR , and IGI ; the HRs were 2.06 ( 95 % CI : 1.22 , 3.49 ) for 25(OH)D 10 - 19.9 ng/mL compared with ≥20 ng/mL and 3.23 ( 95 % CI : 1.66 , 6.30 ) for 25(OH)D < 10 ng/mL compared with ≥20 ng/mL. CONCLUSION The current prospect i ve study suggests that vitamin D metabolism may play a role in T2D pathogenesis independently of known risk factors . This trial was registered at clinical trials.gov as NCT01508481 Background and Aims . Despite growing interest in the protective role that vitamin D may have in health outcomes , little research has examined the mechanisms underlying this role . This study aim ed to test two hypotheses : ( 1 ) serum 25-hydroxyvitamin D [ 25(OH)D ] is inversely associated with type 2 diabetes mellitus ( T2DM ) and elevated hemoglobin A1c ; ( 2 ) these associations are mediated by serum C-reactive protein ( CRP ) . Methods . Participants aged 20 and older in 2001–2006 National Health and Nutrition Examination Surveys ( n = 8,655 ) with measures of serum 25(OH)D , CRP , hemoglobin A1c , and other important covariates were included in the present study . Logistic regression and path analysis methods were applied to test the study hypotheses . Results . Decreased serum 25(OH)D concentration was significantly associated with increased odds of T2DM .  In males , an estimated 14.9 % of the association between 25(OH)D and hemoglobin A1c was mediated by serum CRP . However , this mediation effect was not observed in females . Conclusion . Using a nationally representative sample , the present study extends previous research and provides new evidence that the effect of  decreased serum vitamin D concentration on T2DM may proceed through increased systemic inflammation in males . Longitudinal studies and r and omized control trials are needed to confirm the present findings Background : Diabetes mellitus ( DM ) and vitamin D deficiency are major health concerns around the world . Evidence suggests a possible role of vitamin D in improvement of insulin secretion and sensitivity . Objectives : We assessed whether vitamin D supplementation could be used in vitamin D deficient-type II diabetes to improve glucose metabolism , components of metabolic syndrome ( MetS ) and specific inflammatory biomarkers . Patients and Methods : A double blind , r and omized clinical trial was conducted in King Khalid University Hospital , Saudi Arabia to evaluate the effect of cholecalciferol supplementation on glycemic control , MetS components and specific inflammatory biomarkers including tumor necrosis factor-alpha ( TNF-α ) , Interleukin ( IL-6 ) , leptin , adiponectin and vascular cell adhesion molecule-1 ( VCAM-1 ) . Twenty-two patients with type II diabetes with insulin resistance , glycated hemoglobin ( HbA1c ) ≥ 6 ( 42 mmol/mol ) and serum 25(OH)D < 50 nmol/L were r and omized using a computer program to receive either supplementation with cholecalciferol ( 5000 IU/day ) or placebo for 12 weeks . The primary outcome was change in HbA1c levels from baseline . Results : Median [ IQR ] 25(OH)D levels increased significantly in the vitamin D group as 58.1 [ 48 , 67.3 ] nmol/L ( P = 0.002 ) . There was no significant difference in the change of HbA1c between the groups ( P = 0.5 ) with a decrease of -0.1 % [ -1 , 0.5 ] in the vitamin D group and an increase of 0.15 % [ 0.1 , 0.2 ] in the placebo group . A significant improvement was observed in the homeostasis model of assessment of β-cell activity ( HOMA-%B ) ( P = 0.03 ) with vitamin D supplementation compared to baseline . Conclusions : Vitamin D repletion for 12 weeks increased serum vitamin D concentrations and improved β-cell activity in vitamin D-deficient type II diabetes with no significant changes in HbA1c or insulin sensitivity Dietary therapy is the mainstay of treatment for diabetes . This study examined the effect of a low glycemic index ( GI ) multi-nutrient supplement , consumed in place of breakfast , on glycemic control in patients with type 2 diabetes mellitus ( T2DM ) . A total of 71 participants were r and omized at a 2:1 ratio into either a breakfast replacement group or a normal breakfast group for a 12-week interventional study . The primary outcome measure was change in hemoglobin A1c ( HbA1c ) . Nutrition status and somatometry were studied as secondary outcomes . The breakfast replacement group displayed a −0.2 % absolute reduction in HbA1c ( 95 % CI ( confidence interval ) , −0.38 % to −0.07 % , p = 0.004 ) , while the HbA1c of the control group increased 0.3 % ( 95 % CI , 0.1 % to 0.5 % , p = 0.005 ) . The baseline Mini Nutritional Assessment score for both groups was 26.0 and no significant changes occurred following intervention . However , there was a statistically significant difference in body mass index between the treatment and control groups ( p = 0.032 ) due to the weight gain in the control group ( increased 0.5 kg , 95 % CI was 0.2 to 0.9 , p = 0.007 ) . These data suggest that breakfast replacement with a low GI multi-nutrient supplement can improve glycemic and weight control in T2DM Background : Vitamin D deficiency is common in pregnancy , leading to increase in the frequency of preeclampsia , cesarean delivery , neonatal bacterial vaginosis , and gestational diabetes . The current study was design ed and implemented to investigate the effect of vitamin D during the first and second trimesters of pregnancy in reducing the risk of gestational diabetes mellitus ( GDM )  in women who are at high risk [ history of GDM , birth macrosomia , family history , and high body mass index ( BMI ) ] . Material s and Methods : In a r and omized , double-blind , and placebo-controlled trial , 90 pregnant women who had at least one risk factor for GDM were r and omized into intervention ( 46 participants ) and control ( 44 participants ) groups . Participants in the intervention group took 5000 units of vitamin D daily and the control group took placebo until the 26th week of pregnancy . Then the  glucose challenge test  ( GCT ) and the  glucose tolerance test ( GTT ) were performed to evaluate GDM . Results : Mean ± st and ard deviation ( SD ) age was 31.28 ± 6.38 years and 29 ± 6.24 years for the intervention group and the placebo group , respectively , ( P > 0.05 ) . In addition , there were no significant differences between two groups in terms of vitamin D levels and GCT ( P > 0.05 ) , and the difference was not significant . The incidence of diabetes in the intervention groups was statistically lower than in control group ( 11.4 % vs 34.8 ; P < 0.01 ) . The results showed that abnormal GCT in the placebo group was statistically higher than in intervention group ( 35.9 % vs 10.9 P < 0.005 ) . Conclusion : The results of the current study showed that the prescription of vitamin D supplementation in the first and second trimesters of pregnancy was effective in reducing GDM and controlling GTT and GTC BACKGROUND Epidemiological studies suggest a higher prevalence of metabolic syndrome and its components among individuals with vitamin D deficiency . The aim of the present study was to determine whether vitamin D treatment  improves glucose control and insulin sensitivity in Type 2 diabetes mellitus ( T2DM ) . METHODS Subjects with T2DM and serum 25-hydroxyvitamin D ( 25(OH)D ) concentrations < 25 ng/mL were r and omized to receive 400 IU ( Group 1 ) or 1200 IU ( Group 2 ) cholecalciferol for 4 months . Fasting plasma glucose , glycosylated hemoglobin ( HbA1c ) , Quantitative Insulin Sensitivity Check Index ( QUICKI ) , serum lipid levels and serum adiponectin were measured at baseline and at 4 months . RESULTS Mean 25(OH)D levels increased in both groups ( from 17.6±1.5 to 25.5±1.8 ng/mL in Group 1 and from 15.6±1.4 to 27.4±2.4 ng/mL in Group 2 ; P≤0.001 vs baseline for each group ) . No significant differences were noted in fasting plasma glucose , HbA1c , QUICKI , serum adiponectin , and lipid levels compared with baseline within groups or between the two groups . CONCLUSIONS In the present pilot study , conventional vitamin D treatment at a level improving , but not optimizing , serum 25(OH)D did not improve glycemia , insulin sensitivity , or lipid profile . However , diabetes and lipids were relatively well controlled at baseline . Future studies should be design ed to achieve optimal concentrations of serum 25(OH)D ( at least > 32 ng/mL ) and should include subjects showing more abnormal parameters of glycemia , lipid , and insulin sensitivity at baseline Background : Since tumor necrosis factor-α ( TNF-α ) could be one of the risk factors at the development of diabetes complications ; as well as serum leptin deficiency is related to increased susceptibility to infections in diabetic patients , they are potential indices from the preventive medicine viewpoint . This study was conducted to represent the effect of supplemental vitamin D3 on serum leptin , TNF-α and adiposity in type 2 diabetic patients . Methods : In this r and omized double-blind placebo-controlled trial , study sample was selected through type 2 diabetic patients ( n = 51 ) . A total of 26 patients were orally supplemented by vitamin D3 ( 400 IU/d ) ( vitamin D group ) and 25 patients by placebo ( placebo group ) for 14 weeks . The blood glycated hemoglobin ( HbA1c ) and the serum ionized Ca , leptin , TNF-α , and serum 25-hydroxyvitamin D ( 25[OH ] D ) were measured at the two groups in the baseline and postintervention stages . Results : It was shown that despite of theplacebo group , serum 25(OH ) D and serum leptin was significantly increased ( P = 0.001 and P = 0.002 , respectively ) , while serum TNF-α was decreased significantly ( P = 0.001 ) in vitamin D group . The remaining parameters , including body fat mass and HbA1c had no alterations between baseline and postintervention stages in vitamin D group . Conclusions : This study may advocate vitamin D supplementation among type 2 diabetic patients due to its beneficial effects on prevention of diabetes complications
Sensitivity analysis showed that overall estimates were not affected by elimination of any study .
We did not observe any evidence regarding publication bias .
In conclusion , vitamin K supplementation had no signiﬁcant effect on glycemic control in healthy subjects .
Type 2 diabetes mellitus ( T2DM ) is one of the most important public health issues .
Vitamin K supplementation might have favorable effect on risk factors of T2DM .
The aim of this study was to perform a systematic review and meta- analysis of interventional studies to examine the effect of vitamin K supplementation on glycemic indices .