25-hydroxyvitamin-d-2 and Diabetes-Mellitus--Type-2

The Institute of Medicine (IOM) report on dietary reference intakes (DRI) for vitamin D is reviewed, along with its implications.. Evidence-based reviews were completed; the IOM committee conducted its own literature search, an open public workshop, and two open sessions, and maintained a public web site for stakeholder input. The consensus report of the 14 scientists on the committee was reviewed by a panel of experts.. Only bone health could be used as an indicator for DRI development. Evidence for extraskeletal outcomes was inadequate, inconsistent, or insufficient to develop DRI. The recommended dietary allowance was found to be 600 IU/d for ages 1-70 yr, corresponding on average to a serum 25-hydroxyvitamin D (25OHD) level of at least 50 nmol/liter (20 ng/ml), and 800 IU/d for those older than 70 yr. Comparison with current levels of 25OHD in the National Health and Nutrition Examination Survey population survey revealed that the vitamin D intake in the United States and Canada is adequate. An upper limit was set at 4000 IU/d for adults, corresponding to an average serum 25OHD level of 125 nmol/liter (50 ng/ml).. Previous reports of an epidemic of vitamin D deficiency in North America were based on an overestimation of adequacy. Population screening with serum 25OHD is therefore not warranted. Current laboratory reference ranges for serum 25OHD are overestimated and should be revised. Practice guidelines to treat disease should not be applied to the healthy American population where use of the DRI is appropriate.

Topics: 25-Hydroxyvitamin D 2; Accidental Falls; Aged; Bone and Bones; Calcium, Dietary; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Diet; Diet Surveys; Dietary Supplements; Health Status; Humans; Metabolic Syndrome; Neoplasms; North America; Nutrition Policy; Public Health; Reference Values; Sunlight; United States; Vitamin D; Vitamin D Deficiency

Although both vitamin D deficiency and obesity are highly prevalent in the UAE, the role of vitamin D metabolites in mediating obesity-related adverse health effects is not clear. We aimed to assess the role of vitamin D metabolites as potential mediators in the association between obesity, inflammation and metabolic risk factors.. 277 participants who were part of a randomized controlled trial had their assessment that included clinical, anthropometric and physical activity data at baseline and at 6 months. Blood and urine samples were taken for measurements of serum 25(OH)D, 25(OH)D metabolites including 25(OH)D3), 25(OH)D2), 1,25(OH)2D3, 3-Epi-D3), metabolic and inflammatory markers and related biochemical variables. Multiple regression analysis used to assess the role of 25(OH)D metabolites in mediating the effect of increasing body mass index (BMI) on inflammation and metabolic risk factors.. Overall, 277 participants with complete 6 months follow up with a mean (±SD) age of 41 ± 12 and 204 (74%) female were included in the study. Blood pressure, inflammatory, metabolic and lipid profile markers significantly increased in overweight and obese subjects compared to subjects with normal BMI both at baseline and at 6 months (p < 0.05). 25(OH)D revealed significant association with age, gender, HbA1c and type 2 diabetes (p < 0.05). No statistically significant changes in any of 25(OH)D metabolites assessed. Multivariate analysis revealed significant and independent associations between BMI and important inflammatory and metabolic risk factors (p < 0.05). No similar association observed with 25(OH)D metabolites.. Although we found significant association between 25(OH)D and prevalence of type 2 diabetes, we found no evidence however to support a role of 25(OH)D metabolites in mediating the effect of BMI on inflammatory or metabolic risk factors.

Topics: 25-Hydroxyvitamin D 2; Adult; Body Mass Index; Calcifediol; Calcitriol; Diabetes Mellitus, Type 2; Female; Glycated Hemoglobin; Humans; Male; Middle Aged; Multivariate Analysis; Obesity; Risk Factors; Vitamin D; Vitamin D Deficiency

We investigated the effect of daily intake of yogurt drink fortified with either vitamin D alone or with added calcium on resting metabolic rate (RMR), thyroid hormones and homeostatic model assessment for insulin resistance in subjects with type 2 diabetes (T2D). A total of 75 adult subjects with T2D were randomly assigned to 1 of the 3 groups to receive either D-fortified yogurt drink (DY; 1000 IU vitamin D/day), Ca-D-fortified yogurt drink (CDY; 1000 IU vitamin D plus 500 mg calcium), or plain yogurt drink for 12 weeks. All assessments were done at the baseline and after the intervention. The concentrations of anti-thyroid peroxidase antibody (anti-TPO-Ab), intact parathyroid hormone (iPTH) and thyroid stimulating hormone (TSH) had declined significantly compared with baseline values only in the CDY group. The mean RMR increased in both DY and CDY groups (

Topics: 25-Hydroxyvitamin D 2; Adult; Basal Metabolism; Beverages; Calcium, Dietary; Diabetes Mellitus, Type 2; Double-Blind Method; Energy Metabolism; Female; Food, Fortified; Homeostasis; Humans; Insulin Resistance; Male; Middle Aged; Thyroid Hormones; Vitamin D; Yogurt; Young Adult

To study the effects of metformin, as compared to placebo, on serum levels of vitamin D (25-hydroxyvitamin D [25(OH)D]) in patients with advanced type 2 diabetes.. In the HOME trial, a randomized placebo-controlled trial, 390 insulin-treated patients with type 2 diabetes were treated with 850 mg metformin or placebo thrice daily for 52 months. In a post-hoc analysis, we examined changes in the combined levels of 25(OH)D. Mean combined 25(OH)D at baseline was 68.2 nmoL/L (95% confidence interval [CI]: 65.5-71.1). In mixed model analysis, metformin, as compared to placebo, had no effect on 25(OH)D levels during 16 months (coefficient: 1.002 per month, multiplicative model; 95% CI: 0.998-1.006, P = .30). Metformin was associated with a small increase of 25(OH)D. Metformin had no effect on serum 25(OH)D during 16 months in the setting of a clinical randomized controlled trial in patients with type 2 diabetes. Our results show that metformin doesn't lead to vitamin D deficiency.

Topics: 25-Hydroxyvitamin D 2; Age Factors; Aged; Body Mass Index; Calcifediol; Diabetes Mellitus, Type 2; Double-Blind Method; Female; Follow-Up Studies; Humans; Hypoglycemic Agents; Male; Metformin; Middle Aged; Netherlands; Nutritional Status; Outpatient Clinics, Hospital; Overweight; Prevalence; Seasons; Sex Factors; Vitamin D Deficiency

To assess the effect of vitamin D supplementation on neuropathy specific quality of life (NeuroQoL) in patients with painful diabetic neuropathy.. This prospective, open label study was conducted between June 2012 and April 2013. Patients with symptomatic diabetic neuropathy were given a single dose of 600,000 IU intramuscular vitamin D, and NeuroQol was assessed at baseline and at five follow-up visits every 4 weeks.. Of 143 participants, 41.3% were vitamin D deficient (vitamin D < 20 ng/ml). Treatment with vitamin D resulted in a significant increase in 25(OH)D (. Vitamin D is effective in improving quality of life in patients with painful diabetic neuropathy.

Topics: 25-Hydroxyvitamin D 2; Adult; Asymptomatic Diseases; Cost of Illness; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Diabetic Foot; Diabetic Neuropathies; Female; Follow-Up Studies; Humans; Injections, Intramuscular; Male; Middle Aged; Pain; Pakistan; Peripheral Nervous System Diseases; Psychiatric Status Rating Scales; Quality of Life; Severity of Illness Index; Stress, Psychological; Vitamin D; Vitamin D Deficiency

To investigate the effect of short-term vitamin D supplementation on cardiometabolic outcomes among individuals with an elevated risk of diabetes.. In a double-blind placebo-controlled randomized trial, 340 adults who had an elevated risk of type 2 diabetes (non-diabetic hyperglycaemia or positive diabetes risk score) were randomized to either placebo, 100,000 IU vitamin D2 (ergocalciferol) or 100,000 IU vitamin D3 (cholecalciferol), orally administered monthly for 4 months. The primary outcome was change in glycated haemoglobin (HbA1c) between baseline and 4 months, adjusted for baseline. Secondary outcomes included: blood pressure; lipid levels; apolipoprotein levels; C-reactive protein levels; pulse wave velocity (PWV); anthropometric measures; and safety of the supplementation.. The mean [standard deviation (s.d.)] 25-hydroxyvitamin D [25(OH)D]2 concentration increased from 5.2 (4.1) to 53.9 (18.5) nmol/l in the D2 group, and the mean (s.d.) 25(OH)D3 concentration increased from 45.8 (22.6) to 83.8 (22.7) nmol/l in the D3 group. There was no effect of vitamin D supplementation on HbA1c: D2 versus placebo: -0.05% [95% confidence interval (CI) -0.11, 0.02] or -0.51 mmol/mol (95% CI -1.16, 0.14; p = 0.13); D3 versus placebo: 0.02% (95% CI -0.04, 0.08) or 0.19 mmol/mol (95% CI -0.46, 0.83; p = 0.57). There were no clinically meaningful effects on secondary outcomes, except PWV [D2 versus placebo: -0.68 m/s (95% CI -1.31, -0.05); D3 versus placebo -0.73 m/s (95% CI -1.42, -0.03)]. No important safety issues were identified.. Short-term supplementation with vitamin D2 or D3 had no effect on HbA1c. The modest reduction in PWV with both D2 and D3 relative to placebo suggests that vitamin D supplementation has a beneficial effect on arterial stiffness.

Topics: 25-Hydroxyvitamin D 2; Adult; Aged; Calcifediol; Cardiovascular Diseases; Cholecalciferol; Cohort Studies; Diabetes Mellitus, Type 2; Dietary Supplements; Double-Blind Method; England; Ergocalciferols; Feasibility Studies; Female; Follow-Up Studies; Glycated Hemoglobin; Humans; Male; Middle Aged; Pulse Wave Analysis; Risk; Vascular Stiffness

Epidemiologic data suggest that low serum 25-hydroxyvitamin D [25(OH)D] increases insulin resistance and the risk of type 2 diabetes. Few interventional trials have assessed the effect of vitamin D on insulin metabolism, and published results are discordant.. The goal of this study was to perform a detailed assessment of the effect of ergocalciferol administration on glucose and insulin metabolism in healthy people with low total 25(OH)D(total).. This was a 12-wk, double-blinded, randomized controlled trial. We enrolled 90 healthy volunteers aged 18-45 y with serum 25(OH)D ≤20 ng/mL (by immunoassay) and administered 50,000 IU ergocalciferol/wk or placebo for 12 wk. Primary endpoints were change in first-phase insulin response and insulin sensitivity as measured by intravenous glucose tolerance test. Secondary endpoints included change in homeostasis model assessment of insulin resistance; fasting glucose, insulin, and lipids; body mass index (BMI); and blood pressure.. On-study 25(OH)D(total) was assessed by liquid chromatography-tandem mass spectrometry. In the treated group, 25(OH)D(total) rose from 18 ± 7 to 43 ± 12 ng/mL (P < 0.001) with no change in the placebo group. Despite this increase, at 12 wk, there were no between-group differences in either insulin response or insulin sensitivity; nor were there differences in any measured secondary endpoints. There was no evidence of effect modification by sex, race, glucose tolerance status, baseline 25(OH)D(total), or BMI.. In healthy persons with low 25(OH)D(total), ergocalciferol administration for 12 wk normalizes 25(OH)D(total) but does not improve insulin secretion, insulin sensitivity, or other markers of metabolic health.

Topics: 25-Hydroxyvitamin D 2; Adult; Biomarkers; Boston; Calcifediol; Cohort Studies; Diabetes Mellitus, Type 2; Dietary Supplements; Double-Blind Method; Ergocalciferols; Female; Humans; Insulin; Insulin Resistance; Insulin Secretion; Longitudinal Studies; Male; Risk; Severity of Illness Index; Vitamin D Deficiency; Young Adult

In observational studies, low serum 25-hydroxyvitamin D [25(OH)D] concentrations have been associated with insulin resistance and other risk factors for cardiovascular disease.. We present 1-year data from an ongoing 5-year trial in 511 individuals with impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT) randomly assigned to 20,000 IU/week vitamin D3 or placebo. An oral glucose tolerance test was performed at baseline and after 1 year.. Mean baseline serum 25(OH)D was 59.9 nmol/L and 61.1 nmol/L in the vitamin D and placebo groups, respectively, and increased by 45.8 nmol/L and 3.4 nmol/L, respectively. With adjustment for baseline concentrations, no differences in measures of glucose metabolism, insulin secretion or sensitivity, blood pressure, or hs-CRP were found after 1 year. There was a slight, but significant decrease in total and LDL cholesterol in the vitamin D group compared with the placebo group, but as there was also a decrease in HDL cholesterol, the change in the total/HDL cholesterol ratio did not differ significantly. Only analyzing subjects with 25(OH)D <50 nmol/L did not change the results.. This study shows that vitamin D supplementation does not improve glycemic indices, blood pressure, or lipid status in subjects with IFG and/or IGT.

Topics: 25-Hydroxyvitamin D 2; Adult; Aged; Aged, 80 and over; Blood Pressure; Calcifediol; Cholecalciferol; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Dietary Supplements; Double-Blind Method; Female; Glucose Intolerance; Glucose Tolerance Test; Humans; Insulin; Insulin Resistance; Lipids; Male; Middle Aged; Prediabetic State; Risk Factors; Vitamin D; Vitamin D Deficiency; Vitamins; Young Adult

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.. Double-blind, parallel group, placebo-controlled randomized 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 samples were taken at baseline and 8 weeks after administration of vitamin D.. 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.. Vitamin D insufficiency is common in patients with Type 2 diabetes during winter in Scotland. A single large dose of oral vitamin D2 improves endothelial function in patients with Type 2 diabetes and vitamin D insufficiency.

Topics: 25-Hydroxyvitamin D 2; Aged; Blood Pressure; Diabetes Mellitus, Type 2; Dietary Supplements; Endothelium; Female; Humans; Male; Middle Aged; Statistics as Topic; Vitamin D; Vitamin D Deficiency

Previous observational studies have suggested that low vitamin D status is associated with high circulating C-reactive protein levels, as well as other plasma inflammatory cytokines. However, there is no study to explore the relationship between vitamin D status and Lp-PLA2, a new biomarker of vascular-specific inflammation. The aim of this study was to examine the association between vitamin D status and circulating Lp-PLA2 levels in subjects with type 2 diabetes mellitus.. This descriptive cross-sectional study enrolled diabetic subjects who underwent physical examination at Taizhou People's Hospital between August 2016 and January 2017. Blood pressure, anthropometry, metabolic profiles, serum 25(OH)D levels and Lp-PLA2 mass levels were measured in all participants.. A total of 196 participants were recruited into this study. The vitamin D insufficiency group had higher serum LP-PLA2 levels than the vitamin D sufficiency group (t=-2.765, p=.005). A significant negative correlation was noted between Lp-PLA2 and 25(OH)D in the vitamin D insufficiency group (r=-0.364, p=0.009). However, no significant relationship between serum Lp-PLA2 concentration and 25(OH)D levels was observed in subjects with vitamin D sufficiency.. From this cohort of patients with type 2 diabetes, regardless of traditional cardiovascular risk factors, we observed a statistically significant inverse relation between Lp-PLA2 and 25(OH)D at levels <30ng/mL.

Topics: 1-Alkyl-2-acetylglycerophosphocholine Esterase; 25-Hydroxyvitamin D 2; Adult; Aged; Aged, 80 and over; Apolipoprotein A-I; Apolipoproteins B; Biomarkers; Blood Glucose; Body Mass Index; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Fasting; Female; Humans; Male; Middle Aged; Regression Analysis; Risk Factors; Vitamin D; Vitamin D Deficiency; Young Adult

Current studies support the implication of metabolic changes associated with type 2 diabetes in altering bone metabolism, structure and resistance.. We conducted a cross-sectional study on postmenopausal women aimed to analyze the differences in metabolic and bone profile in patients with and without type 2 diabetes Methods. We analyzed the metabolic and bone profile in postmenopausal women with and without type 2 diabetes (T2DM). Clinical, metabolic, hormonal parameters, along with lumbar, hip and femoral bone mineral density (BMD) and trabecular bone score (TBS) were evaluated.. 56 women with T2DM(63.57±8.97 years) and 83 non-T2DM (60.21±8.77 years) were included. T2DM patients presented a higher value of body mass index (BMI) and BMD vs. control group (p = 0.001; p = 0.03-lumbar level, p = 0.07-femoral neck and p = 0.001-total hip). Also, BMI correlated positively with lumbar-BMD and glycated hemoglobin (HbA1c) (r = 0.348, p = 0.01; r = 0.269, p = 0.04), correlation maintained even after age and estimated glomerular filtration rate (eGFR) adjustment (r = 0.383, p = 0.005; r = 0.237, p = 0.08). Diabetic patients recorded lower levels of 25(OH)D(p = 0.05), bone markers (p ≤ 0.05) and TBS(p = 0.07). For the entire patient group we found a negative correlation between HbA1c level and bone markers: r = -0.358, p = 0.0005-osteocalcin, r = -0.40, p = 0.0005-P1NP, r = -0.258, p = 0.005-crosslaps.. Our results indicate the presence of altered bone microarchitecture in T2DZ patients according to the TBS score, combined with lower levels of bone markers, with a statistically significant negative correlation between HbA1c level and bone markers.

Topics: 25-Hydroxyvitamin D 2; Aged; Biomarkers; Body Mass Index; Bone and Bones; Bone Density; Bone Resorption; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Female; Glycated Hemoglobin; Humans; Middle Aged; Obesity; Osteocalcin; Peptide Fragments; Postmenopause; Procollagen

Vitamin D acts through the binding to the vitamin D receptor (VDR). Several polymorphisms in VDR gene have been studied. Among these, the rs2228570 C>T (FokI) variant has been demonstrated to be functional, leading to a protein with a different size and activity. So far, genetic studies on the association between VDR gene rs2228570 single nucleotide polymorphism (SNP) and type 2 diabetes mellitus (T2DM) showed contradictory results. Thus, we performed an association study in a large cohort of adult Italian subjects with T2DM and in nondiabetic controls.. For this study, 1713 subjects, 883 T2DM patients and 830 controls, were genotyped for the polymorphism. All participants without a diagnosis of diabetes underwent oral glucose tolerance test (OGTT), with measurement of glucose and insulin levels. Indices of insulin resistance (Homeostatic model assessment of insulin resistance, insulin sensitivity index), secretion (homeostatic model assessment for beta-cell, corrected insulin response at 30 minutes) and disposition index were calculated.. Genotype distributions and allele frequencies did not show difference between T2DM subjects and controls. We did not find significant differences among the three genotypes regarding gender, age, BMI, waist, hip, waist-to-hip ratio, and blood pressure. There were also no significant differences in lipid parameters, aspartate aminotransferase, and alanine aminotransferase levels. We tested for association with OGTT-derived data and surrogate indices of insulin resistance and secretion. We did not find significant differences among the genotypes in any of above-mentioned parameters. Furthermore, vitamin D levels were measured in a subgroup of subjects. We did not find significant differences among the genotypes.. Our study does not provide evidence for the association of the rs2228570 polymorphism with T2DM in a Caucasian population.

Topics: 25-Hydroxyvitamin D 2; Adult; Calcifediol; Diabetes Mellitus, Type 2; Female; Genetic Association Studies; Humans; Italy; Male; Polymorphism, Single Nucleotide; Receptors, Calcitriol; Reproducibility of Results

To assess the prevalence of vitamin D insufficiency and deficiency and its association with cardiometabolic risk factors, controlled by adiposity, in a representative sample of prepubescent children.. Cross-sectional population-based study. Body composition was evaluated by dual-energy X-ray absorptiometry. Anthropometric measures and blood pressure were performed. Laboratory analyses were performed to determine the levels of vitamin D (25-hydroxyitamin D; 25(OH)D), glucose, insulin, serum lipids and intact parathyroid hormone. Dietary intake was assessed by three 24 h recalls.. Viçosa, Minas Gerais, Brazil, 2015.. Representative sample of 378 children aged 8 and 9 years from urban schools.. Inadequate serum concentrations of 25(OH)D were diagnosed in more than half of the children and none of them met the recommended vitamin D intake. After adjusting for confounding factors in the multiple regression analysis, lower prevalence of insulin resistance and hypertriacylglycerolaemia was found in children with serum 25(OH)D levels ≥75 nmol/l (prevalence ratio=0·25; 95 % CI 0·08, 0·85) and ≥50 nmol/l (prevalence ratio=0·61; 95 % CI 0·37, 0·99), respectively. However, after adjusting for different indicators of adiposity, insulin resistance remained independently associated and the association with hypertriacylglycerolaemia was lost after adjusting for central adiposity. The prevalence of vitamin D insufficiency/deficiency was associated with the number of cardiometabolic alterations in children.. The study results showed that prevalence of vitamin D insufficiency/deficiency was high among the children and insulin resistance was the main cardiometabolic alteration associated with this condition, even in a tropical climate country such as Brazil.

Topics: 25-Hydroxyvitamin D 2; Adiposity; Biomarkers; Brazil; Calcifediol; Cardiovascular Diseases; Child; Child Nutritional Physiological Phenomena; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Female; Humans; Insulin Resistance; Male; Nutritional Status; Poisson Distribution; Prevalence; Risk Factors; Severity of Illness Index; Urban Health; Vitamin D Deficiency

To investigate the possible association between vitamin D deficiency and cardiovascular autonomic neuropathy in people with diabetes.. A total of 113 people with Type 1 or Type 2 diabetes [mean (interquartile range) diabetes duration 22.0 (12-31) years, mean (sd) age 56.2 (13.0) years, 58% men] underwent vitamin D (D2 and D3) assessment, and were screened for cardiovascular autonomic neuropathy using three cardiovascular reflex tests [heart rate response to deep breathing (E/I ratio), to standing (30/15 ratio) and to the Valsalva manoeuvre] and assessment of 5-min resting heart rate and heart rate variability indices.. We found an inverse U-shaped association between serum vitamin D level and E/I ratio, 30/15 ratio and three heart rate variability indices (P < 0.05). Vitamin D level was non-linearly associated with cardiovascular autonomic neuropathy diagnosis (P < 0.05 adjusted for age and sex). Linear regression models showed that an increase in vitamin D level from 25 to 50 nmol/l was associated with an increase of 3.9% (95% CI 0.1;7.9) in E/I ratio and 4.8% (95% CI 4.7;9.3) in 30/15 ratio. Conversely, an increase from 125 to 150 nmol/l in vitamin D level was associated with a decrease of 2.6% (95% CI -5.8;0.1) and 4.1% (95% CI -5.8;-0.5) in the respective outcome measures.. High and low vitamin D levels were associated with cardiovascular autonomic neuropathy in people with diabetes. Future studies should explore this association and the efficacy of treating dysvitaminosis D to prevent cardiovascular autonomic neuropathy.

Topics: 25-Hydroxyvitamin D 2; Aged; Autonomic Nervous System Diseases; Biomarkers; Calcifediol; Cardiovascular Diseases; Cohort Studies; Denmark; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Diabetic Cardiomyopathies; Diabetic Neuropathies; Dietary Supplements; Female; Humans; Male; Middle Aged; Prevalence; Severity of Illness Index; Vitamin D; Vitamin D Deficiency

We aimed to investigate the association between serum 25-hydroxyvitamin D (25[OH]D) and microvascular complications in type 2 diabetes mellitus (T2DM) patients. It was hypothesized that lower 25(OH)D would be associated with increased microvascular complications in T2DM. A total of 257 T2DM patients (111 men, 146 women) who underwent diabetic microvascular complication (peripheral neuropathy, nephropathy, retinopathy) studies were recruited. Patients were categorized into 3 groups according to vitamin D status: vitamin D sufficient (n = 41, 25[OH]D ≥ 20 ng/mL), vitamin D insufficient (n = 132, 10 ≤ 25[OH]D < 20 ng/mL), and vitamin D deficient (n = 84, 25[OH]D < 10 ng/mL). In men, the prevalence of diabetic peripheral neuropathy (DPN) was significantly higher in patients with vitamin D deficiency than in those with insufficiency or sufficiency (38%, 11.7%, and 10%, respectively; P = .005). In addition, the prevalence of diabetic nephropathy (DN) was significantly higher in women with vitamin D deficiency than in the other 2 groups (40%, 20.6%, and 0%; P = .007). Compared with men in the vitamin D-sufficient group (reference), men in the vitamin D-deficient group had an increased risk of DPN after adjusting for confounding factors (odds ratio, 7.79; 95% confidence interval, 1.52-40.05). For women, when the vitamin D-sufficient group was used as a reference, those in the vitamin D-deficient group had an increased risk of DN after adjusting for confounding factors (odds ratio, 4.27; 95% confidence interval, 1.58-11.56). This present study found that a serum 25(OH)D level less than 10 ng/mL is independently associated with increased DPN in male patients and increased DN in female patients with T2DM.

Topics: 25-Hydroxyvitamin D 2; Aged; Calcifediol; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Diabetic Nephropathies; Diabetic Retinopathy; Female; Hospitals, University; Humans; Incidence; Male; Middle Aged; Nutritional Status; Outpatient Clinics, Hospital; Prevalence; Republic of Korea; Risk Factors; Severity of Illness Index; Sex Factors; Vitamin D Deficiency

Topics: 25-Hydroxyvitamin D 2; Diabetes Mellitus, Type 2; Female; Humans; Insulin Resistance; Male; Prediabetic State; Vitamin D

Topics: 25-Hydroxyvitamin D 2; Diabetes Mellitus, Type 2; Female; Humans; Insulin Resistance; Male; Prediabetic State; Vitamin D

Topics: 25-Hydroxyvitamin D 2; Diabetes Mellitus, Type 2; Female; Humans; Insulin Resistance; Male; Prediabetic State; Vitamin D

Topics: 25-Hydroxyvitamin D 2; Diabetes Mellitus, Type 2; Female; Humans; Insulin Resistance; Male; Prediabetic State; Vitamin D

To examine the nature of the association between 25-hydroxyvitamin D [25(OH)D] and newly diagnosed type 2 diabetes.. Serum 25(OH)D concentrations were measured for 761 participants (aged 20-83 years) in the Tehran Lipid and Glucose Study, selected for a 1-to-3 nested case-control study. Cases were 191 cases of Type 2 diabetes diagnosed during a median follow-up of 3.6 years. A total of 570 participants were matched with these cases with regard to age, sex, BMI, and month of entering the study. Diabetes was defined according to the American Diabetes Association criteria, 2003. Serum 25(OH)D was measured using the enzyme immunoassay method. Odds ratios for Type 2 diabetes were obtained from conditional logistic regression models for tertiles of serum 25(OH)D concentrations [tertile-1: 2.82-11.02 (reference), tertile-2: 11.03-21.80, and tertile-3: ≥ 21.82 ng/ml]. The multivariate model was adjusted for age, sex, family history of diabetes, systolic blood pressure, triglyceride-to- HDL cholesterol ratio, waist-to-height ratio, lifestyle modification intervention, leisure time physical activity, and fasting plasma glucose at baseline. Non-linearity in the associations between baseline 25(OH)D and Type 2 diabetes, was examined by using restricted cubic splines.. Unadjusted odds ratios (95% confidence intervals) of diabetes were 0.73 (0.74-1.13), 0.54 (0.34-0.85) for the second and third tertiles, respectively. Multivariate adjusted odds ratios were 0.47 (0.25-0.90) and 0.43 (0.23-0.82), respectively. Below the cutoff of ~ 10 ng/ml the risk of newly diagnosed Type 2 diabetes increased dramatically.. It was found that 25(OH)D concentrations contributed to the Type 2 diabetes incidence rate in a non-linear fashion, with the risk beginning to increase sharply for values < 10 ng/ml.

Topics: 25-Hydroxyvitamin D 2; Adult; Aged; Aged, 80 and over; Calcifediol; Case-Control Studies; Diabetes Mellitus, Type 2; Female; Follow-Up Studies; Humans; Immunoenzyme Techniques; Incidence; Iran; Logistic Models; Male; Middle Aged; Prospective Studies; Vitamin D Deficiency; Young Adult

Topics: 25-Hydroxyvitamin D 2; Diabetes Mellitus, Type 2; Female; Humans; Insulin Resistance; Male; Prediabetic State; Vitamin D

Patients with diabetes and vitamin-D insufficiency have increased insulin resistance. Similar observations among individuals with prediabetes are not well documented. The aim of this study was to find the occurrence of vitamin-D insufficiency/deficiency among individuals with prediabetes and to evaluate the relationship between vitamin-D status and insulin resistance.. One hundred fifty seven individuals with prediabetes who fulfilled all the inclusion and exclusion criteria underwent clinical examination, anthropometric measurements (waist circumference, waist-hip ratio, waist-height ratio) and blood sampling after overnight fast for estimation of fasting blood glucose, fasting insulin, 25(OH)vitamin-D, intact parathyroid hormone (iPTH) and lipid profile. One hour post 75 g glucose (1hPG) blood glucose during oral glucose tolerance test was measured.. Vitamin-D deficiency/insufficiency was found in 115 (73.25%) individuals with prediabetes. Severe vitamin-D deficiency (<10 ng/ml) was seen in 14.65 per cent individuals. Individuals with the lowest vitamin-D levels (<10 ng/ml) had the highest insulin resistance (HOMA2-IR: 2.04 ± 0.67). Serum 25(OH)D had a statistically significant inverse correlation with insulin resistance (HOMA2-IR; r=-0.33; P=0.008), and positive correlation with insulin sensitivity (QUICKI; r=0.39; P=0.002), after adjusting for BMI and HbA1c. There was no correlation between vitamin-D status and estimated beta cell mass (HOMA-β). The mean waist-height ratio among individuals with prediabetes was 0.57 (normal<0.5) indicating a high risk of cardiovascular morbidity. Individuals with elevated 1hPG>155 mg/dl had significantly higher BMI and worse insulin resistance, and 1hPG correlated well with 2 hour post glucose blood glucose (r=0.57; P<0.001). INTERPRETATIONS & CONCLUSIONS: Vitamin-D deficiency/insufficiency may have some role in the development/worsening of insulin resistance in individuals with prediabetes in our country who have a high cardiovascular risk. Prospective studies on a large group of individuals need to be done to confirm the findings.

Topics: 25-Hydroxyvitamin D 2; Adult; Blood Glucose; Diabetes Mellitus, Type 2; Female; Humans; Insulin; Insulin Resistance; Lipids; Male; Middle Aged; Parathyroid Hormone; Prediabetic State; Risk Factors; Vitamin D; Vitamin D Deficiency

Vitamin D is an important regulator of bone health. Previous studies examining the association between vitamin D deficiency and osteoporotic fractures have reported conflicting results. The relationship between vitamin D status and risk of vertebral fractures in diabetic patients is unknown. The objective of this study was to examine whether low serum 25-hydroxyvitamin D [25(OH)D] levels were associated with vertebral fractures in patients with type 2 diabetes. This cross-sectional study was conducted among 161 postmenopausal women and 180 men with type 2 diabetes. Serum concentrations of 25(OH)D were measured and the presence of vertebral fracture was assessed using lateral plain radiographs of the thoracolumbar spine. Women had lower 25(OH)D levels than men (31.3 ± 17.7 vs. 41.3 ± 26.5 ng/mL, p<0.001). Vertebral fractures were found in 16% of patients. Men with a serum 25(OH)D concentration greater than 30 ng/mL showed a lower prevalence of vertebral fractures compared to those with 20-29.9 ng/mL or those with less than 20 ng/mL (9.4% vs. 17.9% vs. 21.7%, p for trend=0.036). However, there was no significant association between vitamin D status and the prevalence of vertebral fractures in women (14.4% vs. 19.2% vs. 26.6%, p for trend=0.111). After adjusting for multiple confounding factors, men with a serum 25(OH)D concentration of less than 20 ng/mL were associated with an increased risk of vertebral fractures (OR 7.87; 95% CI 1.69-36.71), but not women. In conclusion, serum 25(OH)D levels below 20 ng/mL were associated with an increased vertebral fracture risk in men with type 2 diabetes.

Topics: 25-Hydroxyvitamin D 2; Aged; Aged, 80 and over; Calcifediol; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Female; Humans; Male; Middle Aged; Nutritional Status; Osteoporotic Fractures; Prevalence; Radiography; Recurrence; Republic of Korea; Risk Factors; Severity of Illness Index; Sex Factors; Spinal Fractures; Vitamin D Deficiency

Hypovitaminosis D is an international problem; however, there is little information about its prevalence in apparently healthy Indian children living at high altitudes.. To determine (i) the prevalence of hypovitaminosis D and (ii) the association of serum vitamin D with the risk factors for diabetes among Indian Koya children.. A cross-sectional study of 290 (129 males) school children aged 10.7 ± 2.9 yr was performed. Anthropometric measures, blood pressure (BP), Tanner stages and serum levels of glucose, lipids, and insulin were measured. 25-hydroxyvitamin D [25(OH)D] was measured by radioimmunoassay (Dia Sorin).. The prevalence of obesity was 3.4% (10), overweight 3.4% (10), normal weight 79.0% (229), and underweight 14.1 % (41) per CDC reference standards. Concentrations of [25(OH)D] were median 10 (range 8-13 ng/mL); 10 (3.4%) had insufficient vitamin D levels (20 to <30 ng/mL), 136 (46.9%) had deficient levels (10 to <20 ng/mL), 144 (49.7%) had severe deficiency (<10 ng/mL) and none had optimal levels (≥30 ng/mL). There was an inverse significant correlation between [25(OH)D] and age (r = 0.14), body mass index (BMI) (r = 0.16), waist circumference (r = 0.15), systolic BP (r = 0.19), hemoglobin (r = 0.19), glucose (r = 0.22), insulin (r = 0.13), and homeostasis model of assessment-insulin resistance (r = 0.16). Multiple linear regression analysis showed that 25(OH)D concentrations were significantly and inversely associated with glucose concentrations (β = -0.28; p = 0.02) adjusted for age, BMI, systolic BP, hemoglobin, and insulin.. This study demonstrated a high prevalence of both 25(OH)D deficiency and insufficiency and an inverse association between 25(OH)D and glucose concentration in apparently healthy Koya Indian children. Further research is needed to confirm these findings.

Topics: 25-Hydroxyvitamin D 2; Adolescent; Adult; Age Factors; Altitude; Argentina; Calcifediol; Child; Child, Preschool; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Female; Humans; Indians, South American; Insulin Resistance; Male; Prevalence; Risk Factors; Severity of Illness Index; Vitamin D; Vitamin D Deficiency; Young Adult

Obstructive sleep apnea (OSA) and 25-hydroxyvitamin-D₃ (25-OH-D) deficiency are two separate disorders associating with obesity, inflammation, and impaired glucose metabolism. We aimed to investigate the vitamin D status of OSA patients regarding to potential links between lower vitamin D levels and abnormal glucose metabolism, which is one of the main adverse outcomes of OSA. Study group is composed of 190 non-diabetic subjects who were suspected of having OSA. Subjects undergone polysomnography and were grouped due to apnea-hypopnea indices (AHI) as controls (AHI < 5, n = 47), mild OSA (5 ≤ AHI < 15, n = 46), moderate OSA (15 ≤ AHI < 30, n = 47), and severe OSA (AHI ≥ 30, n = 50). Serum 25-OH-D, HbA₁c, insulin levels were measured and 75-g oral glucose tolerance test was performed. Serum 25-OH-D level (ng/ml) of OSA patients were lower than control subjects (17.4 ± 6.9 vs. 19.9 ± 7.8), and decrement was parallel to severity of OSA; as 18.2 ± 6.4 (5 ≤ AHI < 15), 17.5 ± 7.4 (15 ≤ AHI < 30), and 16.3 ± 6.9 (AHI > 30), respectively (P = 0.097, r = -0.13). However, severe female OSA patients had significantly lower 25-OH-D levels (11.55 ng/ml), while control males had the highest mean value (21.7 ng/ml) (P < 0.001). Frequency of insulin resistance (IR) was 48%, prediabetes 41%, diabetes 16% in OSA patients. Mean 25-OH-D level of insulin resistant subjects (HOMA-IR ≥ 2.7, n = 77, AHI = 35.5) was lower than non-insulin resistant subjects (HOMA-IR < 2.7, n = 113, AHI = 19.8) as 16.18 ± 7.81 versus 19.2 ± 6.6, respectively (P = 0.004). 25-OH-D level of 91 non-diabetic subjects (n = 91, AHI = 19.7) was 19.5 ± 7.4, prediabetics (n = 75, AHI = 28.7) was 17.45 ± 6.9, and diabetics (n = 24, AHI = 46.3) was 13.8 ± 5.3 (P = 0.02). We showed that subjects with more severe OSA indices (AHI ≥ 15) tended to present lower vitamin D levels correlated to increased prevalence of IR, prediabetes, and diabetes. Vitamin D deficiency may play a role and/or worsen OSA's adverse outcomes on glucose metabolism. OSA patients may be considered for supplementation treatment which was shown to ameliorate abnormal glucose metabolism and inflammation.

Topics: 25-Hydroxyvitamin D 2; Adult; Calcifediol; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Female; Glucose Metabolism Disorders; Glycated Hemoglobin; Humans; Insulin; Insulin Resistance; Male; Middle Aged; Prediabetic State; Prevalence; Severity of Illness Index; Sex Characteristics; Sleep Apnea, Obstructive; Turkey; Vitamin D Deficiency

We present data from the Korean National Health and Nutritional Examination Survey (KNHANES) 2008-2009 on the association between 25-hydroxyvitamin D[25(OH)D] status and type 2 diabetes in a representative sample of the adult Korean population.. This study was based on data obtained from the KNHANES 2008-2009, which was conducted for 3 years (2007-2009) using a rolling sampling design that involved a complex, stratified, multistage, probability-cluster survey of a representative sample of the noninstitutionalized civilian population of South Korea.. We showed that serum 25(OH)D concentration is inversely associated with type 2 diabetes in the Korean general population. In particular, low serum 25(OH)D concentration was associated with an increased prevalence of type 2 diabetes in young women and old men. The present study showed that 25(OH)D has a significant negative association with fasting insulin and insulin resistance.. The age- and gender-specific association between low 25(OH)D level and type 2 diabetes may be related to interactions between vitamin D, sex hormone concentrations, and type 2 diabetes. In conclusion, we showed that low 25(OH)D concentration is associated with type 2 diabetes in the Korean general population in an age- and gender-specific pattern.

Topics: 25-Hydroxyvitamin D 2; Adult; Aged; Aged, 80 and over; Aging; Calcifediol; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Female; Health Surveys; Humans; Insulin; Insulin Resistance; Male; Middle Aged; Prevalence; Republic of Korea; Sex Factors; Vitamin D Deficiency; Young Adult

To examine the prospective associations of baseline vitamin D [25-hydroxyvitamin D; 25(OH)D] with insulin resistance (IR), β-cell function, and glucose homeostasis in subjects at risk for type 2 diabetes.. We followed 489 subjects, aged 50 ± 10 years, for 3 years. At baseline and follow-up, 75-g oral glucose tolerance tests (OGTTs) were administered. IR was measured using the Matsuda index (IS(OGTT)) and the homeostasis model assessment of IR (HOMA-IR), β-cell function was determined using both the insulinogenic index divided by HOMA-IR (IGI/IR) and the insulin secretion sensitivity index-2 (ISSI-2), and glycemia was assessed using the area under the glucose curve (AUC(glucose)). Regression models were adjusted for age, sex, ethnicity, season, and baseline value of the outcome variable, as well as baseline and change in physical activity, vitamin D supplement use, and BMI.. Multivariate linear regression analyses indicated no significant association of baseline 25(OH)D with follow-up IS(OGTT) or HOMA-IR. There were, however, significant positive associations of baseline 25(OH)D with follow-up IGI/IR (β = 0.005, P = 0.015) and ISSI-2 (β = 0.002, P = 0.023) and a significant inverse association of baseline 25(OH)D with follow-up AUC(glucose) (β = -0.001, P = 0.007). Progression to dysglycemia (impaired fasting glucose, impaired glucose tolerance, or type 2 diabetes) occurred in 116 subjects. Logistic regression analyses indicated a significant reduced risk of progression with higher baseline 25(OH)D (adjusted odds ratio 0.69 [95% CI 0.53-0.89]), but this association was not significant after additional adjustment for baseline and change in BMI (0.78 [0.59-1.02]).. Higher baseline 25(OH)D independently predicted better β-cell function and lower AUC(glucose) at follow-up, supporting a potential role for vitamin D in type 2 diabetes etiology.

Topics: 25-Hydroxyvitamin D 2; Adult; Algorithms; Body Mass Index; Calcifediol; Cohort Studies; Diabetes Mellitus, Type 2; Disease Progression; Female; Follow-Up Studies; Glucose Tolerance Test; Humans; Hyperglycemia; Insulin; Insulin Resistance; Insulin Secretion; Insulin-Secreting Cells; Male; Middle Aged; Ontario; Prospective Studies; Risk Factors; Vitamin D Deficiency

The prevalence of vitamin D insufficiency and secondary hyperparathyroidism is high among morbidly obese subjects. Further, low serum levels of 25-hydroxyvitamin D (25 [OH]D) and magnesium have been associated with increased risk of the metabolic syndrome (MS), and recently, a possible link between PTH and MS has been reported. Although it is well known that the synthesis and secretion of PTH is regulated by serum levels of calcium, phosphate, magnesium and 25(OH)D, less is known about the possible clustered affiliation of these parameters with MS. We aimed to explore whether MS is associated with abnormal serum levels of PTH, 25(OH)D and magnesium in a population of morbidly obese patients.. Fasting serum levels of 25(OH)D, PTH and magnesium were assessed in a cross-sectional cohort study of 1,017 consecutive morbidly obese patients (68% women). Multiple logistic regression analyses were used to assess the independent effect of PTH, 25(OH)D and magnesium on the odds for MS (National Cholesterol Education Program [NCEP]) after adjustment for confounding factors.. Sixty-eight percent of the patients had MS. Patients with MS had lower mean serum magnesium (P < 0.001) and higher mean PTH (P = 0.067) than patients without MS, whereas mean 25(OH)D did not differ significantly. Patients with PTH levels in the second to fourth quartiles had higher odds of prevalent MS (odds ratio 1.47 [95% CI 0.92-2.35], 2.33 [95% CI 1.40-3.87] and 2.09 [95% CI 1.23-3.56], respectively), after adjustment for 25(OH)D, magnesium, calcium, phosphate, creatinine, age, gender, season of serum sampling, BMI, current smoking, albuminuria, CRP, insulin resistance and type 2 diabetes. Further, PTH was significantly correlated with systolic and diastolic pressure (both P < 0.001), but not with the other components of MS. The levels of 25(OH)D and magnesium were not associated with MS in the multivariate model.. The PTH level, but not the vitamin D level, is an independent predictor of MS in treatment seeking morbidly obese Caucasian women and men. Randomized controlled clinical trials, including different therapeutic strategies to lower PTH, e.g. calcium/vitamin D supplementation and weight reduction, are necessary to explore any cause-and-effect relationship.

Topics: 25-Hydroxyvitamin D 2; Adult; Anthropometry; Calcifediol; Calcium; Comorbidity; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Female; Humans; Hyperparathyroidism, Secondary; Magnesium; Magnesium Deficiency; Male; Metabolic Syndrome; Middle Aged; Obesity, Morbid; Parathyroid Hormone; Phosphates; Vitamin D Deficiency; White People

Women with polycystic ovary syndrome (PCOS) frequently suffer from metabolic disturbances, in particular from insulin resistance. Accumulating evidence suggests that vitamin D deficiency may contribute to the development of the metabolic syndrome (MS). Hence, the aim of our study was to investigate the association of 25(OH)D levels and the components of the MS in PCOS women.. 25(OH)D levels were measured by means of ELISA in 206 women affected by PCOS. Metabolic, endocrine, and anthropometric measurements and oral glucose tolerance tests were performed.. The prevalence of insufficient 25(OH)D levels (<30 ng/ml) was 72.8% in women with PCOS. PCOS women with the MS had lower 25(OH)D levels than PCOS women without these features (17.3 vs 25.8 ng/ml respectively; P<0.05). In multivariate regression analysis including 25(OH)D, season, body mass index (BMI), and age, 25(OH)D and BMI were independent predictors of homeostatic model assessment-insulin resistance (HOMA-IR) and quantitative insulin sensitivity check index (QUICKI; P<0.05 for all). In binary logistic regression analyses, 25(OH)D (OR 0.86, P=0.019) and BMI (OR 1.28, P<0.001) were independent predictors of the MS in PCOS women. We found significantly negative correlations of 25(OH)D levels with BMI, waist circumference, waist-to-hip ratio, systolic and diastolic blood pressure, fasting and stimulated glucose, area under the glucose response curve, fasting insulin, HOMA-IR, HOMA-beta, triglycerides, and quotient total cholesterol/high-density lipoprotein (HDL) and positive correlations of 25(OH)D levels with QUICKI and HDL (P<0.05 for all).. We demonstrate that low 25(OH)D levels are associated with features of the MS in PCOS women. Large intervention trials are warranted to evaluate the effect of vitamin D supplementation on metabolic disturbances in PCOS women.

Topics: 25-Hydroxyvitamin D 2; Adolescent; Adult; Anthropometry; Blood Glucose; Body Mass Index; Cohort Studies; Diabetes Mellitus, Type 2; Female; Glucose Intolerance; Hemodynamics; Hormones; Humans; Insulin; Lipids; Metabolic Syndrome; Polycystic Ovary Syndrome; Vitamin D; Vitamin D Deficiency; Young Adult