Vitamin D improves endothelial function in patients with Type 2 diabetes mellitus and low vitamin D levels. Randomized controlled trial of vitamin D supplement on endothelial function in patients with type 2 diabetes. Enhanced Oxidative Stress and Other Potential Biomarkers for Retinopathy in Type 2 Diabetics: Beneficial Effects of the Nutraceutic Supplements A randomised controlled trial evaluating the impact of targeted vitamin D supplementation on endothelial function in type 2 diabetes mellitus: The DIMENSION trial Oral antioxidant therapy improves endothelial function in Type 1 but not Type 2 diabetes mellitus. Antioxidant Vitamins C and E Improve Endothelial Function in Children With Hyperlipidemia: Endothelial Assessment of Risk from Lipids in Youth (EARLY) Trial The effect of vitamin E on endothelial function of micro- and macrocirculation and left ventricular function in type 1 and type 2 diabetic patients. Effects of vitamins C and E on oxidative stress markers and endothelial function in patients with systemic lupus erythematosus: a double blind, placebo controlled pilot study. A 5-Year Follow-Up of Antioxidant Supplementation in Type 2 Diabetic Retinopathy Resveratrol supplementation improves glycemic control in type 2 diabetes mellitus. Oral L-arginine and vitamins E and C improve endothelial function in women with type 2 diabetes Effect of oral vitamin E (alpha-tocopherol) supplementation on vascular endothelial function in Type 2 diabetes mellitus. Endothelial function, insulin action and cardiovascular risk factors in young healthy adult offspring of parents with Type 2 diabetes: effect of vitamin E in a randomized double-blind, controlled clinical trial. Supplementation of Vitamin C Reduces Blood Glucose and Improves Glycosylated Hemoglobin in Type 2 Diabetes Mellitus: A Randomized, Double-Blind Study Impact of Vitamin E Supplementation on Blood Pressure and Hs-CRP in Type 2 Diabetic Patients | doi: 10.5681/hpp.2012.009. Effect of vitamin D supplementation on glycemic control in patients with type 2 diabetes: a systematic review of interventional studies Vitamin E Supplementation Reduces Cardiovascular Events in a Subgroup of Middle-Aged Individuals With Both Type 2 Diabetes Mellitus and the Haptoglobin 2-2 Genotype: A Prospective Double-Blinded Clinical Trial
AIMS To test whether a single large dose of vitamin D2 can improve endothelial function in patients with Type 2 diabetes mellitus and low serum 25-hydroxyvitamin D levels . METHODS Double-blind , parallel group , placebo-controlled r and omized trial . A single dose of 100,000 IU vitamin D2 or placebo was administered to patients with Type 2 diabetes over the winter , when levels of circulating 25-hydroxyvitamin D were likely to be lowest . Patients were enrolled if their baseline 25-hydroxyvitamin D level was < 50 nmol/l .  Endothelial function and blood pressure were measured and fasting blood sample s were taken at baseline and 8 weeks after administration of vitamin D. RESULTS Forty-nine per cent of subjects screened had 25-hydroxyvitamin D levels < 50 nmol/l . Thirty-four subjects completed the study , with a mean age of 64 years and a baseline 25-hydroxyvitamin D level of 38.3 nmol/l .  Vitamin D supplementation  increased 25-hydroxyvitamin D levels by 15.3 nmol/l relative to placebo and significantly improved flow mediated vasodilatation ( FMD ) of the brachial artery by 2.3 % . The improvement in FMD remained significant after adjusting for changes in blood pressure .  Vitamin D supplementation significantly decreased systolic blood pressure by 14 mmHg compared with placebo ; this did not correlate with change in FMD . CONCLUSIONS Vitamin D insufficiency is common in patients with Type 2 diabetes during winter in Scotl and . A single large dose of oral vitamin D2 improves endothelial function in patients with Type 2 diabetes and vitamin D insufficiency BACKGROUND Suboptimal vitamin D status is associated with endothelial dysfunction and an increased risk of cardiovascular diseases but it is unclear whether vitamin D supplementation is beneficial . The aim was to investigate the effect of vitamin D supplementation on endothelial function in patients with type 2 diabetes mellitus ( DM ) . METHODS In a double-blind , placebo-controlled trial , we r and omized 100 type 2 DM patients to vitamin D supplement  ( 5000 IU/day , n = 50 ) or placebo ( controls , n = 50 ) for 12 weeks . Assessment of vascular function with brachial artery flow-mediated dilatation ( FMD ) , circulating levels of endothelial progenitor cells ( EPCs ) and brachial-ankle pulse wave velocity , and metabolic parameter , high-sensitivity C-reactive protein ( hsCRP ) and oxidative stress markers were performed before and after the supplementation . RESULTS After 12 weeks , vitamin D treated patients had significant increases in serum 25-hydroxyvitamin D [ 25(OH)D ] concentration ( treatment effect 34.7 ng/mL , 95 % CI 26.4 - 42.9 , P < 0.001 ) and serum ionized calcium ( treatment effect 0.037 mmol/L , 95 % CI 0.007 - 0.067 , P = 0.018 ) ; decreased serum parathyroid hormone concentration ( treatment effect -0.55 pmol/L , 95 % CI -1.08 to -0.02 , P = 0.042 ) compared to patients who received placebo . Nevertheless , vitamin D supplementation did not improve vascular function as determined by FMD , circulating EPC count or baPWV ( all P > 0.05 ) . Furthermore , hsCRP , oxidative stress markers , low- and high-density lipoprotein and glycated hemoglobin were also similar between two groups ( all P > 0.05 ) . CONCLUSION In patients with type 2 DM , 12 weeks oral supplementation of vitamin D did not significantly affect vascular function or serum biomarkers of inflammation and oxidative stress . CLINICAL TRIAL NUMBER HKCTR-867 , www.hk clinical trials.com We have studied the global risk of retinopathy in a Mediterranean population of type 2 diabetes mellitus ( T2DM ) patients , according to clinical , biochemical , and lifestyle biomarkers . The effects of the oral supplementation containing antioxidants/omega 3 fatty acids ( A/ω3 ) were also evaluated . Suitable participants were distributed into two main groups : ( 1 ) T2DMG ( with retinopathy ( + DR ) or without retinopathy ( −DR ) ) and ( 2 ) controls ( CG ) . Participants were r and omly assigned ( + A/ω3 ) or not ( −A/ω3 ) to the oral supplementation with a daily pill of Nutrof Omega ( R ) for 18 months . Data collected including demographics , anthropometrics , characteristics/lifestyle , ophthalmic examination ( best corrected visual acuity , ocular fundus photographs , and retinal thickness as assessed by optical coherence tomography ) , and blood parameters ( glucose , glycosylated hemoglobin , triglycerides , malondialdehyde , and total antioxidant capacity ) were registered , integrated , and statistically processed by the SPSS 15.0 program . Finally , 208 participants ( 130 diabetics ( 68 + DR/62 −DR ) and 78 controls ) completed the follow-up . Blood analyses confirmed that the T2DMG+DR patients had significantly higher oxidative stress ( p < 0.05 ) , inflammatory ( p < 0.05 ) , and vascular ( p < 0.001 ) risk markers than the T2DMG−DR and the CG . Furthermore , the A/ω3 oral supplementation positively changed the baseline parameters , presumptively by inducing metabolic activation and ameliorating the ocular health after 18 months of supplementation We sought to determine if vitamin D supplementation , to target 25(OH)D concentrations of 30–40 ng/mL , improves endothelial function in Singapore ’s multi-ethnic type 2 diabetes mellitus population . We r and omised 64 type 2 diabetes mellitus patients with hypovitaminosis D to cholecalciferol 4000 International Unit/matching placebo [ baseline 25(OH)D < 20 ng/mL ] or cholecalciferol 2000 International Unit/matching placebo [ baseline 25(OH)D : 20–30 ng/mL ] daily for 16 weeks with a down titration at 8 weeks if 25(OH)D > 30 ng/mL. Endothelial function was assessed by peripheral tonometry ( reactive hyperaemia index – endothelial peripheral arterial tonometry ) and vascular biomarkers : E-selectin , von-Willebr and factor and high-sensitivity C-reactive protein . We compared the change from baseline parameters in the two groups using Student ’s t-test or Kruskal – Wallis test . A log-normal multivariate regression analysis was used to adjust for relevant baseline variables . The median reactive hyperaemia index in the vitamin D group increased from 0.65 ( interquartile range : 0.42 ) to 0.73 ( interquartile range : 0.36 ) , whereas it decreased from 0.73 ( interquartile range : 0.65 ) to 0.65 ( interquartile range : 0.38 ) ( p = 0.02 ) in the placebo group . After adjustment for baseline variables , the change was not statistically significant for reactive hyperaemia index ( p = 0.07 ) and for other vascular biomarkers ( p > 0.05 ) . Targeted vitamin D supplementation for 16 weeks result ed in a small but non-significant improvement in endothelial function in a type 2 diabetes mellitus cohort Oxidative stress decreases the bioavailability of endothelium-derived nitric oxide in diabetic patients . We investigated whether impaired endothelium-dependent vasodilation ( EDV ) in diabetes can be improved by long-term administration of oral antioxidants .  Forty-nine diabetic subjects [ 26 Type 1 ( T1 ) and 23 Type 2 ( T2 ) ] and 45 matched healthy control subjects were r and omized to receive oral vitamin C ( 1,000 mg ) and vitamin E ( 800 IU ) daily or matching placebo for 6 mo . Vascular ultrasonography was used to determine brachial artery EDV and endothelium-independent vasodilation ( EIV ) . EDV was decreased in both T1 ( 4.9 + /- 0.9 % , P = 0.015 ) and T2 ( 4.1 + /- 1.0 % , P < 0.01 ) subjects compared with control subjects ( 7.7 + /- 0.7 % ) . EIV was decreased in T2 ( 15.0 + /- 1.2 % , P < 0.01 ) but not T1 subjects ( 18.5 + /- 2.3 % , P = 0.3 ) compared with controls ( 21.8 + /- 1.8 % ) . Administration of antioxidant vitamins increased EDV in T1 ( by 3.4 + /- 1.4 % , P = 0.023 ) but not T2 subjects ( by 0.5 . + /- 0.4 % , P = 0.3 ) . Antioxidant therapy had no significant affect on EIV .  Oral antioxidant therapy improves EDV in T1 but not T2 diabetes . These results are consistent with the lack of clinical benefit in studies that have included primarily T2 diabetic patients Background —Hyperlipidemia is associated with endothelial dysfunction , an early event in atherosclerosis and predictor of risk for future coronary artery disease . Epidemiological studies suggest that increased dietary intake of antioxidants reduces the risk of coronary artery disease . The purpose of this study was to determine whether antioxidant vitamin therapy improves endothelial function and affects surrogate biomarkers for oxidative stress and inflammation in hyperlipidemic children . Methods and Results —In a r and omized , double-blind , placebo-controlled trial , the effects of antioxidant vitamins C ( 500 mg/d ) and E ( 400 IU/d ) for 6 weeks and the National Cholesterol Education Program Step II ( NCEP-II ) diet for 6 months on endothelium-dependent flow-mediated dilation ( FMD ) of the brachial artery were examined in 15 children with familial hypercholesterolemia ( FH ) or the phenotype of familial combined hyperlipidemia ( FCH ) .  Antioxidant vitamin therapy  improved FMD of the brachial artery compared with baseline ( P < 0.001 ) without an effect on biomarkers for oxidative stress ( autoantibodies to epitopes of oxidized LDL , F2-isoprostanes , 8-hydroxy-2′-deoxyguanosine ) , inflammation ( C-reactive protein ) , or levels of asymmetric dimethylarginine , an endogenous inhibitor of nitric oxide . Conclusions —Antioxidant therapy with vitamins C and E restores endothelial function in hyperlipidemic children . Early detection and treatment of endothelial dysfunction in high-risk children may retard the progression of atherosclerosis We examined the effects of high-dosage vitamin E treatment over a 12-month period on the vascular reactivity of micro- and macrocirculation and left ventricular function in diabetic patients . Subjects ( n = 89 ) were r and omized to vitamin E ( 1,800 IU daily ) or placebo and were followed for 12 months . High-resolution ultrasound images were used to measure the flow-mediated dilation ( FMD ; endothelium dependent ) and nitroglycerin-induced dilation ( NID ; endothelium independent ) of the brachial artery . Laser Doppler perfusion imaging was used to measure vascular reactivity in the forearm skin . Left ventricular function was evaluated using transthoracic echocardiogram . At the end of the 6-month period , a worsening in endothelium-dependent skin vasodilation ( P = 0.02 ) and rise in endothelin levels ( P = 0.01 ) were found in the vitamin E compared with the placebo group . At the end of the 12-month period , a worsening was observed in NID ( P = 0.02 ) and a marginal worsening was seen in systolic blood pressure ( P = 0.04 ) and FMD ( P = 0.04 ) in the vitamin E compared with the placebo group . In addition C-reactive protein levels decreased marginally in the vitamin E compared with the placebo group ( P = 0.05 ) . No changes were observed in left ventricular function . We concluded that long-term treatment with 1,800 IU of vitamin E has no beneficial effects on endothelial or left ventricular function in diabetic patients . Because vitamin E-treated patients had a worsening in some vascular reactivity measurements when compared with control subjects , the use of high dosages of vitamin E can not be recommended OBJECTIVE Patients with systemic lupus erythematosus ( SLE ) experience excess morbidity and mortality due to coronary artery disease ( CAD ) that can not be fully explained by the classical CAD risk factors . Among emerging CAD risk factors , oxidative stress is currently being emphasized . We evaluated the effects of longterm antioxidant vitamins on markers of oxidative stress and antioxidant defense and endothelial function in 39 patients with SLE . METHODS Patients were r and omized to receive either placebo or vitamins ( 500 mg vitamin C and 800 IU vitamin E daily ) for 12 weeks . Markers of oxidative stress included malondialdehyde ( MDA ) and allantoin . Antioxidants measured included erythrocyte superoxide dismutase and glutathione peroxidase , plasma total antioxidant power ( as FRAP value ) , and ascorbic acid and vitamin E concentrations . Endothelial function was assessed by flow-mediated dilatation ( FMD ) of the brachial artery and plasma concentration of von Willebr and factor ( vWF ) and plasminogen activator inhibitor type 1 ( PAI-1 ) . Primary outcome of the study included the change in lipid peroxidation as revealed by MDA levels . Secondary outcomes included changes in allantoin and antioxidant levels and change in endothelial function . RESULTS After treatment , plasma ascorbic acid and alpha-tocopherol concentrations were significantly ( p < 0.05 ) increased only in the vitamin-treated group , associated with a significant decrease ( p < 0.05 ) in plasma MDA . Other oxidative stress markers and antioxidant levels remained unchanged in both groups . FMD and vWF and PAI-1 levels remained unchanged in both groups . CONCLUSION Combined administration of vitamins C and E was associated with decreased lipid peroxidation , but did not affect endothelial function in patients with SLE after 3 months of therapy Purpose This study was design ed to evaluate the effect of antioxidant supplementation on  diabetic retinopathy ( DR )  over a 5-year follow-up period . To our knowledge , this is the first such clinical trial performed . Methods We recruited 105 type 2 diabetic patients with nonproliferative DR . A complete ophthalmic checkup and a plasma determination of oxidative ( malonyldialdehyde [ MDA ] ) and antioxidant parameters ( total antioxidant status [ TAS ] ) were obtained as the baseline . One part of the cohort was r and omly assigned to oral antioxidant supplementation at nutritional doses . The same examinations were performed with 97 diabetic patients who completed the 5-year follow-up period . The best-corrected visual acuity , DR score , MDA , and TAS values were compared at the beginning and the end of the follow-up . Results Best-corrected visual acuity did not change during the follow-up , irrespective of supplementation . However , the retinopathy stage showed a retardation of progression in the subgroup with supplementation , but worsened in the subgroup with no antioxidant supplementation . Furthermore , the antioxidant supplementation group maintained its antioxidant plasma status levels , which was related to decreased oxidative plasma activity . Conclusions Oral antioxidant supplementation could be a useful adjunctive long-term therapy in the treatment of nonproliferative DR Resveratrol is a naturally occurring polyphenolic compound . Numerous animal studies have been reported on its wide-ranging beneficial effects in the biological system including diabetes mellitus ( DM ) . We hypothesized , therefore , that oral supplementation of resveratrol would improve the glycemic control and the associated risk factors in patients with type 2 diabetes mellitus ( T2DM ) . The present clinical study was therefore carried out to test the hypothesis . Sixty-two patients with T2DM were enrolled from Government Headquarters Hospital , Ootacamund , India , in a prospect i ve , open-label , r and omized , controlled trial . Patients were r and omized into control and intervention groups . The control group received only oral hypoglycemic agents , whereas the intervention group received resveratrol ( 250 mg/d ) along with their oral hypoglycemic agents for a period of 3 months . Hemoglobin A(1c ) , lipid profile , urea nitrogen , creatinine , and protein were measured at the baseline and at the end of 3 months . The results reveal that supplementation of resveratrol for 3 months significantly improves the mean hemoglobin A(1c ) ( means ± SD , 9.99 ± 1.50 vs 9.65 ± 1.54 ; P < .05 ) , systolic blood pressure ( mean ± SD , 139.71 ± 16.10 vs 127.92 ± 15.37 ; P < .05 ) , total cholesterol ( mean ± SD , 4.70 ± 0.90 vs 4.33 ± 0.76 ; P < .05 ) , and total protein ( mean ± SD , 75.6 ± 4.6 vs 72.3 ± 6.2 ; P < .05 ) in T2DM . No significant changes in body weight and high-density lipoprotein and low-density lipoprotein cholesterols were observed . Oral supplementation of resveratrol is thus found to be effective in improving glycemic control and may possibly provide a potential adjuvant for the treatment and management of diabetes Endothelial dilator function is impaired in people with type 2 diabetes mellitus ( T2DM ) . Prior research indicates that this can be improved with intravenous administration of ascorbate or L-arginine , but whether these agents have this effect when administered by the clinical ly practical oral route is unknown . To investigate this question , 10 premenopausal women with T2DM and 10 healthy , premenopausal , non-diabetic women received , in r and om sequence , a 1-week administration of oral L-arginine ( 9 g daily ) or vitamins E ( 1800 mg ) and C ( 1000 mg ) with an intervening 1-week washout period . Flow-mediated brachial artery dilation ( FMD ) was measured by ultrasonography and forearm blood flow was measured by plethysmography before and following blood pressure cuff-induced forearm ischemia before and after each week of treatment . At baseline , the women with T2DM had lesser FMD responses ( 0.028 ± 0.006 cm vs 0.056 ± 0.008 cm , p , 0.05 ) . Post-ischemic forearm hyperemia was reduced at baseline in T2DM compared with controls ( 16.4 ± 1.8 vs 26.0 ± 1.4 ml 100 ml- 1 min- 1 , p < 0.05 ) . Administration of L-arginine caused a 50 ± 12 % increase in FMD in T2DM ( p < 0.05 ) and raised post-ischemic forearm blood flow by 29 ± 8 % ( p < 0.05 ) . No significant changes were seen in controls . Administration of vitamins E and C in women with T2DM produced an increase in the brachial artery diameter response of 79 ± 15 % ( p < 0.05 ) , but did not significantly increase the hyperemic blood flow response ( p = NS ) . No significant changes in the responses of controls from pre to post vitamin administration were observed . We concluded that administration of two types of oral agents improved measures of endothelial function in people with T2DM AIMS Vascular endothelial dysfunction , an early marker of atherosclerosis , has been demonstrated in Type 2 diabetes mellitus ( DM ) .  Vitamin E preserves endothelial function in animal models of diabetes and reduces cardiovascular risk . We examined endothelial function and the effect of vitamin E supplements in uncomplicated Type 2 DM . METHODS Forty-eight subjects with Type 2 DM and 21 controls had endothelial function assessed using forearm venous occlusion plethysmography with endothelium-independent ( sodium nitroprusside ) and dependent ( acetylcholine , bradykinin ) vasodilators . Those with diabetes received 1600 i.u . daily oral alpha-tocopherol or placebo , double-blind for 8 weeks , and had endothelial function reassessed . RESULTS The diabetic group had higher HbA1c ( 6.9+/-1.4 vs 4.8+/-0.6 % ; P<0.01 ) and systolic ( 145+/-15 vs. 130+/-16 mm Hg ; P<0.01 ) but not diastolic blood pressure ( 79+/-8 vs. 76+/-9 mm Hg ; P = 0.15 ) . There was blunted vasodilation to acetylcholine ( 15 microg/min ; P<0.01 ) in subjects with diabetes . Vasodilation to sodium nitroprusside and bradykinin was similar ( all P>0.1 ) . Alpha-tocopherol did not affect vasodilation to nitroprusside ( P>0.1 ) , acetylcholine ( P>0.1 ) or bradykinin ( P>0.1 ) . CONCLUSIONS There may be receptor-specific endothelial dysfunction in subjects with uncomplicated Type 2 DM . This is not improved by treatment with alpha-tocopherol BACKGROUND AND AIMS Endothelial dysfunction , insulin resistance and oxidative stress are believed to be central and associated mechanisms in atherogenesis . We aim ed to determine the effect of the antioxidant vitamin E on endothelial function , insulin action and cardiovascular risk markers in young healthy adult offspring of parents with Type 2 diabetes . METHODS Healthy , glucose-tolerant adults ( 18 - 38 years ) , 14 ( 12 male/2 female ) with at least one parent with Type 2 diabetes , and 14 ( 12 male/2 female ) subjects with no family history of diabetes ( controls ) were studied . Insulin action was assessed by euglycaemic hyperinsulinaemic clamp ( 1 mU/kg/min ) . Endothelial function was assessed by forearm blood flow ( FBF ) responses to intra-brachial artery infusions of acetylcholine ( ACh ) ( endothelium-dependent vasodilation ) , sodium nitroprusside ( SNP ) ( endothelium-independent vasodilation ) and N(G)-monomethyl L-arginine ( LNMMA ) ( nitric oxide synthase inhibition ) . Thirteen offspring ( 18 - 38 years , 11 male/2 female , BMI < 30 kg/m2 ) completed a r and omized , double-blind , crossover trial ( 12 weeks vitamin E 800 IU/day or placebo , 6-week washout ) . RESULTS Exogenous glucose infusion rates to maintain euglycaemia were positively associated with response to acetylcholine in offspring ( r = 0.61 , P < 0.05 ) , and were linked with triglycerides .  Vitamin E had no effect on endothelial function , insulin action or cardiovascular risk markers in healthy adult offspring of parents with Type 2 diabetes . CONCLUSIONS Our results support a positive association between insulin action and endothelial-dependent vasodilation in young healthy adult offspring of parents with Type 2 diabetes , but indicate no effect of vitamin E on these parameters 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 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 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 Objective — Clinical trials of vitamin E have failed to demonstrate a decrease in cardiovascular events . However , these studies did not address possible benefit to subgroups with increased oxidative stress . Haptoglobin ( Hp ) , a major antioxidant protein , is a determinant of cardiovascular events in patients with Type 2 diabetes mellitus ( DM ) . The Hp gene is polymorphic with 2 common alleles , 1 and 2 . The Hp 2 allelic protein product provides inferior antioxidant protection compared with the Hp 1 allelic product . We sought to test the hypothesis that vitamin E could reduce cardiovascular events in DM individuals with the Hp 2 - 2 genotype , a subgroup that comprises 2 % to 3 % of the general population . Methods and Results —1434 DM individuals ≥55 years of age with the Hp 2 - 2 genotype were r and omized to vitamin E ( 400 U/d ) or placebo . The primary composite outcome was myocardial infa rct ion , stroke , and cardiovascular death . At the first evaluation of events , 18 months after initiating the study , the primary outcome was significantly reduced in individuals receiving vitamin E ( 2.2 % ) compared with placebo ( 4.7 % ; P=0.01 ) and led to early termination of the study . Conclusions —Vitamin E supplementation appears to reduce cardiovascular events in individuals with DM and the Hp 2 - 2 genotype ( Clinical Trials.gov NCT00220831 )
Prolonged antioxidant vitamin E and /or C supplementation could be effective to improve endothelial function in non-obese T2DM subjects
Controversy exists among trials assessing whether prolonged antioxidant vitamin supplementation improves endothelial function in type 2 diabetes mellitus ( T2DM ) subjects .
The aim of this study was to systematic ally review and quantify the effect of antioxidant vitamin supplementation on endothelial function in T2DM subjects .