Relation of vitamin D deficiency to cardiovascular risk factors, disease status, and incident events in a general healthcare population. Effect of moderate-dose vitamin D supplementation on insulin sensitivity in vitamin D-deficient non-Western immigrants in the Netherlands: a randomized placebo-controlled trial. Association of vitamin D deficiency with incidence of type 2 diabetes in high-risk Asian subjects. The Effect of Vitamin A Supplementation on Thyroid Function in Premenopausal Women Vitamin D supplementation in obese type 2 diabetes subjects in Ajman, UAE: a randomized controlled double-blinded clinical trial Correcting vitamin D insufficiency improves insulin sensitivity in obese adolescents: a randomized controlled trial. Vitamin D Deficiency and Its Determinants in Adults: A Sample from Community-Based Settings in the United Arab Emirates Response to Vitamin D3 Supplementation in Obese and Non-Obese Caucasian Adolescents Prevalence of cardiovascular risk factors and the serum levels of 25-hydroxyvitamin D in the United States: data from the Third National Health and Nutrition Examination Survey. Effect of Vitamin D Supplementation on Glucose Control and Inflammatory Response in Type II Diabetes: A Double Blind, Randomized Clinical Trial The effects of calcitriol on albuminuria in patients with type-2 diabetes mellitus. Influence of Calcium and Vitamin D Supplementation on Weight and Fat Loss in Obese Women Vitamin D vs broad spectrum phototherapy in the treatment of seasonal affective disorder. Vitamin D: do we get enough? Supplementation with cholecalciferol does not improve glycaemic control in diabetic subjects with normal serum 25-hydroxyvitamin D levels Association between serum level of vitamin D and lipid profiles in type 2 diabetic patients in Iran Cholecalciferol supplementation does not influence β-cell function and insulin action in obese adolescents: a prospective double-blind randomized trial. Vitamin D and health in pregnancy, infants, children and adolescents in Australia and New Zealand: a position statement. Vitamin D status in relation to obesity, bone mineral density, bone turnover markers and vitamin D receptor genotypes in healthy Saudi pre- and postmenopausal women Association of low plasma concentrations of antioxidant vitamins, magnesium and zinc with high body fat per cent measured by bioelectrical impedance analysis in Indian men. A randomized, placebo-controlled trial of vitamin D supplementation to improve glycaemia in overweight and obese African Americans. Vitamin D supplementation and endothelial function in vitamin D deficient HIV-infected patients: a randomized placebo-controlled trial. The Effect of Vitamin D Supplementation on Adiposity, Blood Glycated Hemoglobin, Serum Leptin and Tumor Necrosis Factor-α in Type 2 Diabetic Patients
Vitamin D recently has been proposed to play an important role in a broad range of organ functions , including cardiovascular ( CV ) health ; however , the CV evidence -base is limited . We prospect ively analyzed a large electronic medical records data base to determine the prevalence of vitamin D deficiency and the relation of vitamin D levels to prevalent and incident CV risk factors and diseases , including mortality . The data base contained 41,504 patient records with at least one measured vitamin D level . The prevalence of vitamin D deficiency ( ≤30 ng/ml ) was 63.6 % , with only minor differences by gender or age . Vitamin D deficiency was associated with highly significant ( p < 0.0001 ) increases in the prevalence of diabetes , hypertension , hyperlipidemia , and peripheral vascular disease . Also , those without risk factors but with severe deficiency had an increased likelihood of developing diabetes , hypertension , and hyperlipidemia . The vitamin D levels were also highly associated with coronary artery disease , myocardial infa rct ion , heart failure , and stroke ( all p < 0.0001 ) , as well as with incident death , heart failure , coronary artery disease/myocardial infa rct ion ( all p < 0.0001 ) , stroke ( p = 0.003 ) , and their composite ( p < 0.0001 ) . In conclusion , we have confirmed a high prevalence of  vitamin D deficiency in the general healthcare population and an association between vitamin D levels and prevalent and incident CV risk factors and outcomes . These observations lend strong support to the hypothesis that vitamin D might play a primary role in CV risk factors and disease . Given the ease of vitamin D measurement and replacement , prospect i ve studies of vitamin D supplementation to prevent and treat CV disease are urgently needed BACKGROUND Low serum 25-hydroxyvitamin D [ 25(OH)D ] concentrations have been associated with insulin resistance , the metabolic syndrome , and type 2 diabetes . Because many non-Western immigrants in the Netherl and s are vitamin D deficient , obese , and at high risk of diabetes , vitamin D supplementation may contribute to prevent diabetes and insulin resistance . OBJECTIVE We examined the effect of vitamin D supplementation on insulin sensitivity and β cell function in overweight , vitamin D-deficient , non-Western immigrants at high risk of diabetes . DESIGN The study was a 16-wk , r and omized , placebo-controlled trial . A total of 130 non-Western immigrants with prediabetes ( fasting glucose concentration > 5.5 mmol/L or r and om glucose concentration from 7.8 to 11.1 mmol/L ) and vitamin D deficiency ( serum 25[OH]D concentration < 50 nmol/L ) were r and omly assigned after stratification by sex to receive either cholecalciferol ( 1200 IU/d ) or a placebo for 16 wk . All participants received 500 mg Ca/d as calcium carbonate . The primary outcome was the difference in the area under the curve of insulin and glucose after a 75-g oral-glucose-tolerance test after 4 mo of treatment . Secondary outcomes were insulin-sensitivity variables , β cell-function variables , and metabolic syndrome . RESULTS Mean serum 25(OH)D concentrations increased significantly in the vitamin D compared with placebo groups . After 4 mo of therapy , the mean between-group difference was 38 nmol/L ( 95 % CI : 32.1 , 43.9 nmol/L ; P < 0.001 ) . There was no significant effect on insulin sensitivity and β cell function . In a post hoc analysis , when patients with diabetes at baseline were excluded , a significant increase in the insulinogenic index was observed in participants who obtained a 25(OH)D concentration ≥60 nmol/L ( P = 0.040 ) . CONCLUSIONS Vitamin D supplementation in non-Western vitamin D-deficient immigrants with prediabetes did not improve insulin sensitivity or β cell function or change the incidence of metabolic syndrome . However , after the exclusion of diabetic subjects , an improvement in the insulinogenic index was observed in participants who obtained a 25(OH)D concentration ≥60 nmol/L. This trial was registered at trialregister.nl as NTR1827 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 Objective : Vitamin A and its retinoid derivates play an important role in regulation of normal growth and development . Vitamin A has been shown to regulate thyroid hormone metabolism and inhibit thyroid-stimulating hormone ( TSH ) secretion via down regulation of TSH-β gene expression ; however , the effect of vitamin A on thyroid function in obese individuals who are at higher risk of sub clinical hypothyroidism is still unclear . In the present study we investigate the impact of vitamin A supplementation on thyroid function in obese women . Method : A 4-month r and omized , double blind controlled trial was conducted among 84 healthy women aged 17–50 years old : 56 were obese ( body mass index [ BMI ] 30–35 kg/m2 ) and 28 were nonobese ( BMI 18.5–24.9 kg/m2 ) . Obese women were r and omly allocated to receive either vitamin A ( 25,000 IU/d retinyl palmitate ) or placebo .  Nonobese women  received vitamin A. At baseline and 4 months after intervention , serum concentrations of TSH , total thyroxine ( T4 ) , total triiodothyronine ( T3 ) , retinol-binding protein ( RBP ) , and transthyretin ( TTR ) were measured . Results : Baseline concentrations of thyroid hormones , RBP and TTR were not significantly different between groups . Vitamin A caused a significant reduction in serum TSH concentrations in obese ( p = 0.004 ) and nonobese ( p = 0.001 ) groups . Serum T3 concentrations also increased in both obese and nonobese vitamin A – treated groups ( p < 0.001 ) . Serum T4 decreased in all 3 groups after treatment . The results showed a significant reduction in serum RBP in the obese group after vitamin A supplementation ( p = 0.007 ) , but no significant change was seen in serum TTR . Conclusions : Serum TSH concentrations in vitamin A – treated subjects were significantly reduced ; therefore , vitamin A supplementation might reduce the risk of sub clinical hypothyroidism in premenopausal women Objectives : To study the effect of Vitamin D3 supplementation on metabolic control in an obese type 2 diabetes Emirati population . Methods : This r and omized double-blind clinical trial was conducted with 87 vitamin D-deficient obese , type 2 diabetic participants . The vitamin D-group ( n=45 ) and the placebo group ( n=42 ) were matched for gender , age , HbA1c and 25-hydroxy vitamin D ( 25(OH ) D ) at the baseline . The study was divided into two phases of 3 months each ; in phase 1 , the vitamin D-group received 6000 IU vitamin D3/day followed by 3000 IU vitamin D3/day in phase 2 , whereas the placebo group ( n=42 ) received matching placebo . Results : After supplementation , serum 25(OH ) D peaked in the vitamin D-group in phase 1 ( 77.2±30.1 nmol/l , P=0.003 ) followed by a decrease in the phase 2 ( 61.4±18.8 nmol/l , P=0.006 ) , although this was higher compared with baseline . In the placebo group , no difference was observed in the serum 25(OH ) D levels throughout the intervention . Relative to baseline serum , parathyroid hormone decreased 24 % ( P=0.003 ) in the vitamin D-group in phase 2 , but remained unchanged in the placebo group . No significant changes were observed in blood pressure , fasting blood glucose , HbA1c , C-peptide , creatinine , phosphorous , alkaline phosphatase , lipids , C-reactive protein or thyroid stimulating hormone concentrations compared with baseline in either group . Conclusions : Six months of vitamin D3 supplementation to vitamin D-deficient obese type 2 diabetes patients in the UAE normalized the vitamin D status and reduced the incidence of eucalcemic parathyroid hormone elevation but showed no effect on the metabolic control BACKGROUND Obese adolescents are at a greater risk of vitamin D deficiency because vitamin D is thought to be sequestered by excess adipose tissue . Poor vitamin D status has been associated with a higher prevalence of the metabolic syndrome , type 2 diabetes , or both in adults and adolescents . OBJECTIVE The objective was to determine in obese adolescents the efficacy and safety of 4000 IU vitamin D3/d and whether subsequent increased circulating concentrations of 25-hydroxyvitamin D [ 25(OH)D ] are associated with improved markers of insulin sensitivity and resistance and reduced inflammation . DESIGN Obese adolescent patients [ n = 35 ; mean ± SD age : 14.1 ± 2.8 y ; BMI ( in kg/m(2 ) ) : 39.8 ± 6.1 ; 25(OH)D : 19.6 ± 7.1 ng/mL ] were recruited from the University of Missouri Adolescent Diabetes and Obesity Clinic and were r and omly assigned to receive either vitamin D3 ( 4000 IU/d ) or placebo as part of their st and ard care . Anthropometric measurements , inflammatory markers ( IL-6 , TNF-α , C-reactive protein ) , adipokines ( leptin , adiponectin ) , fasting glucose , fasting insulin , and HOMA-IR values were measured at baseline and at 2 follow-up visits ( 3 and 6 mo ) . RESULTS After 6 mo , there were no significant differences in BMI , serum inflammatory markers , or plasma glucose concentrations between groups . Participants supplemented with vitamin D3 had increases in serum 25(OH)D concentrations ( 19.5 compared with 2.8 ng/mL for placebo ; P < 0.001 ) , fasting insulin ( -6.5 compared with + 1.2 μU/mL for placebo ; P = 0.026 ) , HOMA-IR ( -1.363 compared with + 0.27 for placebo ; P = 0.033 ) , and leptin-to-adiponectin ratio ( -1.41 compared with + 0.10 for placebo ; P = 0.045 ) . Inflammatory markers remained unchanged . CONCLUSION The correction of poor vitamin D status through dietary supplementation may be an effective addition to the st and ard treatment of obesity and its associated insulin resistance . This trial was registered at clinical trials.gov as NCT00994396 Background . Vitamin D deficiency ( VDD ) is a public health concern in adults worldwide . This study aims to explore the extent of VDD and its associated factors among adults in the United Arab Emirates ( UAE ) . Subjects and Methods . Quantitative , cross-sectional research was used to assess VDD and its associated factors in 216 adults recruited from r and omly selected community-based healthcare setting s over a six-month period . Recent values of vitamin D and glycated hemoglobin ( HbA1c ) were abstract ed from medical records , followed by interviews with participants to obtain information on factors related to VDD and other covariates and to measure their heights and weights . Results . A total of 74 % of participants demonstrated VDD ( vitamin D serum level ≤ 30 nmol/L ) . Emirati participants had higher odds of having VDD compared to non-Emiratis ( OR : 2.95 ; 95 % CI : 1.58–5.52 ) , with also significantly increased odds of the condition appearing in older , less educated , and employed adults . Diabetes type 2 ( HbA1c ≥ 6.5 % ) , depression , and obesity were significantly associated with an increased likelihood of VDD  after accounting for other covariates . Conclusion . VDD is a significant problem for UAE adults and requires attention by public health policy makers . Diabetes , obesity , and depression need to be considered when screening for vitamin Background / Aims : Vitamin D deficiency is highly prevalent in obese children , and obese children tend to respond poorly to vitamin D supplementation . The objective of the study was to compare the response to vitamin D3 supplementation ( 2,000 IU once daily for 12 weeks ) between obese and non-obese Caucasian adolescents . Methods : The study design was open label non-r and omized . It was carried out at a single center . Eighteen obese adolescents ( aged 12–18 years ) and the same number of age- , gender- and season-matched non-obese adolescents received vitamin D3 ( 2,000 IU/day ) orally for 12 weeks . Total serum 25-hydroxyvitamin D [ 25(OH)D ] , parathyroid hormone , calcium and phosphorus were measured at baseline and at the end of the 12-week period . Results : The mean baseline 25(OH)D level was higher in the non-obese compared to the obese subjects ( mean 28.9 vs. 25.2 ng/ml ; p = 0.029 ) . The increment in 25(OH)D levels following  vitamin D supplementation was significantly lower in the obese adolescents ( mean change 5.8 vs. 9.8 ng/ml ; p = 0.019 ) . Conclusions : Higher doses of vitamin D are required to treat vitamin D deficiency in obese adolescents compared to their non-obese peers BACKGROUND Results of several epidemiologic and clinical studies have suggested that there is an excess risk of hypertension and diabetes mellitus in persons with suboptimal intake of vitamin D.  METHODS We examined the association between serum levels of  25-hydroxyvitamin D ( 25[OH]D )  and select cardiovascular disease risk factors in US adults . A secondary analysis was performed with data from the Third National Health and Nutrition Examination Survey , a national probability survey conducted by the National Center for Health Statistics between January 1 , 1988 , and December 31 , 1994 , with oversampling of persons 60 years and older , non-Hispanic black individuals , and Mexican American individuals . RESULTS There were 7186 male and 7902 female adults 20 years and older with available data in the Third National Health and Nutrition Examination Survey . The mean 25(OH)D level in the overall sample was 30 ng/mL ( 75 nmol/L ) . The 25(OH)D levels were lower in women , elderly persons ( > or=60 years ) , racial/ethnic minorities , and participants with obesity , hypertension , and diabetes mellitus . The adjusted prevalence of hypertension ( odds ratio [ OR ] , 1.30 ) , diabetes mellitus ( OR , 1.98 ) , obesity ( OR , 2.29 ) , and high serum triglyceride levels ( OR , 1.47 ) was significantly higher in the first than in the fourth quartile of serum 25(OH)D levels ( P<.001 for all ) . CONCLUSIONS Serum 25(OH)D levels are associated with important cardiovascular disease risk factors in US adults . Prospect i ve studies to assess a direct benefit of cholecalciferol ( vitamin D ) supplementation on cardiovascular disease risk factors are warranted 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 The renin-angiotensin system has a major role in the development of diabetic nephropathy ( DN ) . It is reported that vitamin D analogues are able to suppress renin excretion . Thus , this study was conducted to determine whether there is any correlation between albuminuria as a marker of DN with vitamin D levels in diabetic patients . Also , an assessment was made on the effects of vitamin D therapy on albuminuria in this group of patients . We conducted this cross-sectional study on 119 out patients with type-2 diabetes . The serum levels of 25-hydroxy vitamin D [ 25 ( OH ) D ] and the albumin to creatinine ratio were assessed in all the study patients . Patients with vitamin D deficiency/insufficiency received calcitriol therapy for eight weeks , following which the laboratory tests were repeated . The mean age of the study patients was 55.3 ± 11.2 years , 43 ( 36.13 % ) had vitamin D insufficiency [ 25 ( OH ) D < 25 ng/mL ] and 31 ( 26.1 % ) had vitamin D deficiency [ 25 ( OH ) D < 15 ng/mL ] . We found a significant correlation between 25 ( OH ) D levels and presence of microalbuminuria ( P = 0.04 ) in patients with vitamin D deficiency . Therapy with calcitriol had a beneficial effect on the albumin excretion rate , although this change was not significant ( P = 0.22 ) . However , the effects of calcitriol on reduction of diastolic blood pressure ( P = 0.004 ) , glycosylated hemoglobin ( P = 0.014 ) and levels of total cholesterol ( P = 0.019 ) , low-density lipoprotein ( 0.04 ) and high-density lipoprotein ( P = 0.001 ) was significant . Our study suggests that vitamin D deficiency has a negative effect on albuminuria in diabetic patients , and its replacement may be associated with a beneficial effect on the risk factors of DN , such as hyperlipidemia and hypertension Background : Dairy products not only reduce the risk of hypertension and cardiovascular diseases but may play a role in the treatment of obesity . As there is some evidence that calcium ( Ca ) and vitamin D may play a role in effective weight management , we decided to evaluate the influence of Ca and vitamin D supplementation on weight and fat loss  in obese women . Material and Methods : Forty obese women were enrolled in this study . Subjects were divided into 2 groups comparable with body mass index ( BMI ) and age . Group 1 was provided with calcium carbonate and 1-(OH)-vitamin D supplementation . Group 2 was provided with only a diet . Subjects participated in a 3-month weight reduction therapy ( balanced diet , modification of life style , and regular physical exercise ) . Blood sample s ( serum concentration of Ca , phosphorus ( P ) , parathormone ( PTH ) , 25-(OH)-D3 ) and clinical characteristics ( weight , height , BMI , body composition ) were taken at baseline and after the 3-month program . Results : No significant differences of body weight , body fat content , serum parathormone , 25-(OH)-D3 concentration , and plasma total Ca and P concentration were observed between analyzed groups both before and after the treatment . Additionally , we did not observe any significant influence of Ca and vitamin D supplementation on weight and fat loss . Conclusion : Ca plus vitamin D supplementation during a 3-month low caloric diet has no additional effect on weight and fat loss in obese women Seasonal Affective Disorder ( SAD ) is prevalent when vitamin D stores are typically low . Broad-spectrum light therapy includes wavelengths between 280 - 320 nm which allow the skin to produce vitamin D. This study was design ed to test the hypothesis that vitamin D deficiency might play a role in SAD . A prospect i ve , r and omized controlled trial was conducted in a group of 15 subjects with SAD . Eight subjects received 100,000 I.U. of vitamin D and seven subjects received phototherapy . At the onset of treatment and after 1 month of therapy subjects were administered the Hamilton Depression scale , the SIGH-SAD , and the SAD-8 depression scale . All subjects also had serum levels of 25-hydroxyvitamin D ( 25-OH D ) measured before and 1 week after intervention therapy . All subjects receiving vitamin D improved in all outcome measures . The phototherapy group showed no significant change in depression scale measures . Vitamin D status improved in both groups ( 74 % vitamin D group , p < 0.005 and 36 % phototherapy group , p < 0.01 ) . Improvement in 25-OH D was significantly associated with improvement in depression scale scores ( r2=0.26 ; p=0.05 ) . Vitamin D may be an important treatment for SAD . Further studies will be necessary to confirm these findings Summary On September 29 , 2011 , acknowledged experts in the field of vitamin D , mainly European , were brought together in order to discuss the recent scientific advances in relation to vitamin D : the current requirements and associations with various health outcomes . In this article , the discussion s result ing from the meeting are summarized . Introduction Several groups at risk for developing vitamin D insufficiency have been identified . Accordingly , review s indicate that a significant percentage of the population worldwide have serum 25-hydroxyvitamin D levels below 50 nmol/l . In addition to the role of vitamin D in bone health , recent studies suggest that it may play a pivotal role in other systems , e.g. , the cardiovascular system , pancreas , muscle , immune system and brain . Most evidence , however , is obtained from observational studies and yet inconclusive . Methods To exchange and broaden knowledge on the requirements for vitamin D and its effect on various health outcomes , a workshop entitled “ Vitamin D Expert Meeting : Do we get enough ? ” , was organized . Results Despite low vitamin D levels worldwide , consensus on the definition of deficiency is not yet reached . In order to define cut-off points for vitamin D whilst taking into account extraskeletal health effects , r and omized controlled trials in these fields are warranted . The experts do emphasize that there is evidence to suggest an important role for vitamin D in the maintenance of optimal bone health at all ages and that vitamin D supplementation , in most studies co-administered with calcium , reduces fracture risk in the senior population . Conclusion To reach a serum 25-hydroxyvitamin D level of 50 nmol/l older adults aged ≥65 years are therefore recommended to meet a mean daily vitamin D intake of 20 μg ( 800 IU ) , which is best achieved with a supplement Background Studies have suggested that vitamin D may be important for both insulin sensitivity and insulin secretion , and that supplementation with vitamin D may subsequently prevent development of type 2 diabetes . Aim of the study The objective of the current study was to test the hypothesis that supplementation with vitamin D would improve glycaemic control in subjects with type 2 diabetes . Methods Thirty-six subjects with type 2 diabetes , treated with metformin and bed-time insulin  , were r and omised to supplementation with cholecalciferol ( 40,000 IU per week ) versus placebo for 6 months . Thirty-two subjects participated throughout the entirety of the study . Fasting blood sample s were drawn before and at the end of the 6 month study without the previous bed-time insulin injection . The insulin and metformin doses were not changed throughout the study . Results After 6 months , the fasting glucose , insulin , C-peptide , fructosamine , and HbA1c levels were not significantly different from baseline values . In addition , changes in these parameters ( values at 6 months minus values at baseline ) did not differ between the vitamin D and the placebo group . Conclusions We were not able to demonstrate that vitamin D supplementation had a significant effect on glucose metabolism in subjects with type 2 diabetes but without vitamin D deficiency . Further studies are needed in larger groups of subjects with type 2 diabetes or impaired glucose tolerance , who also exhibit low serum 25-hydroxyvitamin D levels Background It is suggested that vitamin D deficiency is associated with cardiovascular disease ( CVD ) via its effect on lipid profiles . The objective of this study was to determine the association between fasting serum levels of  25(OH ) D and lipid profiles in patients with type 2 diabetes . Methods This cross-sectional study was conducted on 108 type 2 diabetics . Patients were selected r and omly among members of the Iranian Diabetes Association according to study criteria .  Fasting concentration of 25(OH ) D , calcium , phosphorus , parathyroid hormone ( PTH ) and lipid profiles ( including triglyceride ( TG ) , high-density lipoprotein ( HDL ) , low-density lipoprotein ( LDL ) , and total cholesterol ) were measured . Results The mean serum levels of 25-hydroxyvitamin D ( 25(OH ) D ) and PTH were 53.41 ± 33.25 nmol/l and 40.24 ± 18.24 pmol/l , respectively , in type 2 diabetic patients . Prevalence of vitamin D deficiency was 58.34 % and vitamin D sufficiency and insufficiency combined was 41.66 % . Although in diabetic patients with vitamin D deficiency , serum levels of total cholesterol , TG , and LDL were higher and HDL was lower compared to patients with vitamin D sufficiency , this association was statistically significant only for serum level of TG ( 145.91 ± 79.00 vs. 122.95 ± 55.82 mg/dl ) . Conclusions The results of present study show that serum concentrations of 25(OH ) D were inversely associated with TG . More interventional studies are needed to confirm the relationship between serum concentration of vitamin D  and lipid profile in patients with type 2 diabetes BACKGROUND There is increasing interest in the extraskeletal effects of vitamin D , particularly in the obese state with regard to the development of insulin resistance and diabetes . OBJECTIVE The objective of the study was to determine the effect of 2 doses of cholecalciferol ( vitamin D3 ) supplementation on insulin action ( Si ) and pancreatic β-cell function in obese adolescents . METHODS We performed a 12-wk double-blind , r and omized comparison of the effect of vitamin D3 supplementation on Si and β-cell function in obese Caucasian adolescents ( body mass index > 95(th ) percentile ) . The subjects were r and omly assigned to receive either 400 IU/d ( n = 25 ) or 2000 IU/d ( n = 26 ) of vitamin D3 . Each subject underwent a 7- sample 75 g oral glucose tolerance test , with glucose , insulin , and C-peptide measurements , to calculate Si and β-cell function as assessed by the disposition index ( DI ) , with use of the oral minimal model before and after supplementation . A total of 51 subjects aged 15.0 ± 1.9 y were enrolled . Included for analysis at follow-up were a total of 46 subjects ( 20 male and 26 female adolescents ) , 23 in each group .  RESULTS Initial serum 25-hydroxyvitamin D [ 25(OH)D ] was 24.0 ± 8.1 μg/L. There was no correlation between 25(OH)D concentrations and Si or DI . There was a modest but significant increase in 25(OH)D concentration in the 2000 IU/d group ( 3.1 ± 6.5 μg/L , P = 0.04 ) but not in the 400 IU/d group ( P = 0.39 ) . There was no change in Si or DI  following vitamin D3 supplementation in either of the treatment groups ( all P > 0.10 ) . CONCLUSIONS The current study shows no effect from vitamin D3 supplementation , irrespective of its dose , on β-cell function or insulin action in obese nondiabetic adolescents with relatively good vitamin D status . Whether obese adolescents with vitamin D deficiency and impaired glucose metabolism would respond differently to vitamin D3 supplementation remains unclear and warrants further studies . This trial was registered at clinical trials.gov as NCT00858247 • The recommended level for serum 25-hydroxyvitamin D ( 25(OH)D ) in infants , children , adolescents and during pregnancy and lactation is ≥ 50 nmol/L. This level may need to be 10 - 20 nmol/L higher at the end of summer to maintain levels ≥ 50 nmol/L over winter and spring . • Sunlight is the most important source of vitamin D. The US recommended dietary allowance for vitamin D is 600 IU daily in children aged over 12 months and during pregnancy and lactation , assuming minimal sun exposure . • Risk factors for low vitamin D are : lack of skin exposure to sunlight , dark skin , southerly latitude , conditions affecting vitamin D metabolism and storage ( including obesity ) and , for infants , being born to a mother with low vitamin D and exclusive breastfeeding combined with at least one other risk factor . • Targeted measurement of 25(OH)D levels is recommended for infants , children and adolescents with at least one risk factor for low vitamin D and for pregnant women with at least one risk factor for low vitamin D at the first antenatal visit . • Vitamin D deficiency can be treated with daily low-dose vitamin D supplements , although barriers to adherence have been identified . High-dose intermittent vitamin D can be used in children and adolescents . Treatment should be paired with health education and advice about sensible sun exposure . Infants at risk of low vitamin D should be supplemented with 400 IU vitamin D₃ daily for at least the first year of life . • There is increasing evidence of an association between low vitamin D and a range of non-bone health outcomes , however there is a lack of data from robust r and omised controlled trials of vitamin D supplementation Summary The various factors that may contribute to vitamin D deficiency or insufficiency were examined among healthy Saudi pre- and postmenopausal women .  Vitamin D deficiency was highly prevalent among studied Saudi women with obesity , poor sunlight exposure , poor dietary vitamin D supplementation and age as the main risk factors . Introduction The various factors that may contribute to vitamin D deficiency or insufficiency in relation to bone health among Saudi women are not known . The main objectives of the present study were to determine the factors influencing  vitamin D status in relation to serum 25-hydroxyvitamin D ( 25(OH)D ) , intact parathyroid hormone ( PTH ) , bone turnover markers ( BTMs ) , bone mineral density ( BMD ) , and vitamin D receptor genotype ( VDR ) in healthy Saudi pre- and postmenopausal women . Methods A total number of 1,172 healthy Saudi women living in the Jeddah area were r and omly selected and studied .  Anthropometric parameters , socioeconomic status , sun exposure index together with serum levels of 25(OH)D , calcitriol , intact PTH , Ca , PO4 , Mg , creatinine , albumin , and biochemical BTMs were measured . BMD was measured by a dual energy X-ray absorptiometry and VDR genotypes were also determined . Results About 80.0 % of Saudi women studied exhibited vitamin D deficiency ( serum 25(OH)D < 50.0 nmol/L ) with only 11.8 % of all women were considered with adequate vitamin D status ( serum 25(OH)D > 75 nmol/L ) . Secondary hyperparathyroidism was evident in 18.5 % and 24.6 % in pre- and postmenopausal women with 25(OH)D < 50 nmol/L. Serum 25(OH)D was lower ( P < 0.001 ) and intact PTH higher ( P < 0.001 ) in the upper quintiles of body mass index ( BMI ) and waist-to-hip ratio ( WHR ) . Multiple linear regression analysis showed that BMI , sun exposure index , poor dietary vitamin D supplementation , WHR , and age were independent positive predictors of serum 25(OH)D values . Conclusions Vitamin D deficiency is highly prevalent among healthy Saudi pre- and postmenopausal women and largely attributed to obesity , poor exposure to sunlight , poor dietary vitamin D supplementation , and age This cross-sectional study was conducted to determine the association of high body fat per cent measured by bioelectric impedance analysis with known risk factors of obesity as well as with serum levels of vitamins , trace elements and magnesium and oxidative stress in an urban population in India . There were 850 men aged 25 - 64 years , r and omly selected from the city of Moradabad . Subjects were divided into high body fat per cent ( n = 357 ) , over fat per cent ( n = 230 ) , desirable fat ( n = 200 ) and low fat ( n = 63 ) based on criteria of body fat per cent analysis . The prevalence of central obesity , sedentary lifestyle , family history and higher visible fat intake showed significant association with higher over fat per cent . Postpr and ial plasma insulin and glucose and serum iron and oxidative stress were significantly higher and plasma levels of vitamin C and E and serum zinc/insulin ratio as well as serum magnesium/insulin ratio showed inverse association with high body fat per cent . Multivariate logistic regression analysis after adjustment of age showed a significant positive association of body mass index ( odds ratio 0.97 ) , sedentary lifestyle ( odds ratio 1.12 ) and serum iron ( OR 1.00 ) with higher body fat per cent . Zinc ( OR 1.03 ) , magnesium ( OR 1.02 ) , vitamins C ( OR 1.08 and E ( OR 1.09 ) deficiency were risk factors of higher body per cent and central obesity . It is possible that some Indian men can benefit by increased intake of zinc , magnesium , vitamin C and vitamin E in conjunction with lifestyle changes AIMS Vitamin D deficiency may increase the risk for type 2 diabetes . African Americans tend to have poor vitamin D status and increased risk of diabetes , but effects of vitamin D supplementation on components of diabetes risk have not been tested in this group . This study was conducted to determine whether vitamin D supplementation improves insulin secretion , insulin sensitivity and glycaemia in African Americans with prediabetes or early diabetes . METHODS In this r and omized , placebo-controlled trial , we examined the effect of 4000 IU/day vitamin D(3 , ) on glycaemia and contributing measures including insulin secretion , insulin sensitivity and the disposition index over 12 weeks in 89 overweight or obese African Americans with prediabetes or early diabetes . Outcome measures were derived from oral glucose tolerance testing . RESULTS Mean plasma 25-hydroxyvitamin D was about 40 nmol/l in the placebo and vitamin D groups at baseline and increased to 81 nmol/l with supplementation . Insulin sensitivity decreased by 4 % in the vitamin D group compared with a 12 % increase in the placebo group ( p = 0.034 ) . Insulin secretion increased by 12 % in the vitamin D group compared with a 2 % increase in the placebo group ( p = 0.024 ) , but changes in the disposition index were similar across groups . There was no effect of supplementation on post-load glucose or other measures of glycaemia . CONCLUSIONS Supplementation with 4000 IU/day vitamin D(3 ) successfully corrected vitamin D insufficiency and had divergent effects on insulin secretion and sensitivity with no overall effect on disposition index or glycaemia . In this study , vitamin D supplementation for 3 months did not change the pathophysiology of prediabetes in overweight and obese African Americans BACKGROUND Studies suggest that vitamin D deficiency is a risk factor for cardiovascular disease and diabetes . Vitamin D deficiency is prevalent in HIV patients but the effect of vitamin D supplementation on cardiovascular risk in this population is unknown . METHODS We conducted a r and omized , double-blind , placebo-controlled trial among 45 HIV-infected adults in Clevel and ( OH , USA ) on stable antiretroviral therapy with durable virological suppression and a baseline serum 25-hydroxyvitamin D level of ≤20 ng/ml . Participants were r and omized 2:1 to vitamin D3 4,000 IU daily or placebo  for 12 weeks . The primary outcome was a change in flow-mediated brachial artery dilation ( FMD ) . RESULTS Baseline demographics were similar except for age ( vitamin D versus placebo , mean ±sd 47 ±8 versus 40 ±10 years ; P=0.009 ) . Both groups had reduced FMD at baseline ( median values 2.9 % [ IQR 1.6 - 4.8 ] for vitamin D versus 2.5 % [ IQR 1.7 - 6.4 ] for placebo ; P=0.819 ) . Despite an increase in the concentration of serum 25-hydroxyvitamin D from baseline to 12 weeks ( 5.0 ng/ml [ IQR -0.9 - 7.4 ] versus -1.9 ng/ml [ IQR -4.0 - 0.1 ] for vitamin D versus placebo , respectively ; P=0.003 ) , there was no difference in FMD change ( 0.55 % [ IQR -1.05 - 2.13 ] versus 0.29 % [ IQR -1.61 - 1.77 ] ; P=0.748 ) . Vitamin D supplementation was associated with a decrease in total and non-high-density lipoprotein cholesterol , and an increase in indices of insulin resistance . CONCLUSIONS Among HIV-infected individuals with vitamin D deficiency , supplementation with 4,000 IU vitamin D3 daily for 12 weeks modestly improved vitamin D status and cholesterol but worsened insulin resistance without change in endothelial function . The mechanisms of resistance to st and ard doses of vitamin D and the complex role of vitamin D in glucose metabolism in this population require further investigation 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
In conclusion , the deficiency of vitamin D is associated with an increased level of BMI in the studies of both diabetic and non-diabetic subjects .
The deficiency of vitamin D is prevalent all over the world .
Studies have shown that vitamin D may play an important role in the development of obesity .
The current study was conducted to quantitatively evaluate the association between serum 25-(OH ) vitamin D levels  and the risk of obesity in both diabetic and non-diabetic subjects .