Association between Plasma 25-Hydroxyvitamin D,Ancestry and Aggressive Prostate Cancer among African Americans and European Americans in PCaP

Background

African Americans (AAs) have lower circulating 25-hydroxyvitamin D3 [25(OH)D3] concentrations and higher prostate cancer (CaP) aggressiveness than other racial/ethnic groups. The purpose of the current study was to examine the relationship between plasma 25(OH)D3, African ancestry and CaP aggressiveness among AAs and European Americans (EAs).

Methods

Plasma 25(OH)D3 was measured using LC-MS/MS (Liquid Chromatography Tandem Mass Spectrometry) in 537 AA and 663 EA newly-diagnosed CaP patients from the North Carolina-Louisiana Prostate Cancer Project (PCaP) classified as having either ‘high’ or ‘low’ aggressive disease based on clinical stage, Gleason grade and prostate specific antigen at diagnosis. Mean plasma 25(OH)D3 concentrations were compared by proportion of African ancestry. Logistic regression was used to calculate multivariable adjusted odds ratios (OR) and 95% confidence intervals (95%CI) for high aggressive CaP by tertile of plasma 25(OH)D3.

Results

AAs with highest percent African ancestry (>95%) had the lowest mean plasma 25(OH)D3 concentrations. Overall, plasma 25(OH)D3 was associated positively with aggressiveness among AA men, an association that was modified by calcium intake (OR_T3vs.T1: 2.23, 95%CI: 1.26–3.95 among men with low calcium intake, and OR_T3vs.T1: 0.19, 95%CI: 0.05–0.70 among men with high calcium intake). Among EAs, the point estimates of the ORs were <1.0 for the upper tertiles with CIs that included the null.

Conclusions

Among AAs, plasma 25(OH)D3 was associated positively with CaP aggressiveness among men with low calcium intake and inversely among men with high calcium intake. The clinical significance of circulating concentrations of 25(OH)D3 and interactions with calcium intake in the AA population warrants further study.     

Long Term Association between Serum 25-Hydroxyvitamin D and Mortality in a Cohort of 4379 Men

Objective

A number of observational studies have shown an inverse association between circulating 25-hydroxyvitamin D and total mortality, but a reverse J-shaped association has also been reported. In a large nested case-control study, serum-25-hydroxyvitamin D (s-25(OH)D) was positively associated with incident prostate cancer. Based on the same study population, the primary aim of the present study was to investigate the association between s-25(OH)D and total mortality.

Methods

Men participating in population based health screenings during 1981–1991 and enrolled in a nested case-control study were followed throughout 2007 with respect to all-cause and cause-specific mortality. Hazard ratios (HR) with 95% confidence intervals (CI) were calculated using Cox proportional hazards regression.

Results

In men with prostate cancer (n = 2282), there was a significant inverse association between s-25(OH)D and total mortality after controlling for potential confounders (HR = 1.25 (95% CI 1.05–1.50), s-25(OH)D <50 nmol/l versus s-25(OH)D ≥50 nmol/l). The corresponding figure among controls (n = 2147) was HR = 1.15 (95% CI 0.88–1.50) and in the total study population HR = 1.19 (95% CI 1.03–1.38). For cause-specific deaths, we found no significant associations.

Conclusions

In this study population, s-25(OH)D was inversely associated with total mortality during more than two decades of follow-up, despite, as previous reported, high s-25(OH)D was associated with increased risk of prostate cancer.     

Treatment with 50000 IU Vitamin D2 Every Other Week and Effect on Serum 25-Hydroxyvitamin D2, 25-Hydroxyvitamin D3, and Total 25-Hydroxyvitamin D in Aclinical Setting

ObjectiveTo examine the effect of 50 000 IU-vitamin D₂ supplementation in a clinical setting on serum total 25-hydroxyvitamin D (25[OH]D), 25-hydroxyvitamin D₂ (25[OH]D₂), and 25-hydroxyvitamin D₃ (25[OH]D₃).MethodsThis retrospective cohort study was performed in an urban tertiary referral hospital in Boston, Massachusetts. Patients who had been prescribed 50 000 IU vitamin D₂ repletion and maintenance programs were identified through a search of our electronic medical record. Baseline and follow-up total serum 25(OH)D, 25(OH)D₂, and 25(OH)D₃ levels were compared.ResultsWe examined the medical records of 48 patients who had been prescribed 50 000 IU vitamin D₂ in our clinic. Mean ± standard deviation baseline total 25(OH) D was 31.0 ± 10.6 ng/mL and rose to 48.3 ± 13.4 ng/mL after treatment (P <.001). 25(OH)D₂ increased from 4.2 ± 4.3 ng/mL to 34.6 ± 12.3 ng/mL after treatment (P <.001), for an average of 158 days (range, 35-735 days). Serum 25(OH)D3 decreased from 26.8 ± 10.8 ng/mL to 13.7 ± 7.9 ng/mL (P <.001).ConclusionsFifty thousand IU vitamin D₂ repletion and maintenance therapy substantially increases total 25(OH)D and 25(OH)D2 despite a decrease in serum 25(OH)D3. This treatment program is an appropriate and effective strategy to treat and prevent vitamin D deficiency.(Endocr Pract. 2012;18:399-402)     

Serum 25-Hydroxyvitamin D and Insulin Resistance in Apparently Healthy Adolescents

Purpose

Vitamin D deficiency is a common condition that is associated with diabetes and insulin resistance. However, the association between vitamin D and insulin resistance has not been fully studied, especially in the general adolescent population. Therefore, we assessed the association between serum 25-hydroxyvitamin D [25(OH)D] level and insulin resistance among apparently healthy Korean adolescents.

Methods

A total of 260 (135 male and 125 female) adolescents in a rural high school were assessed for serum 25(OH)D, fasting plasma glucose, and insulin. All of the participants were aged 15 to 16 years old, and without known hypertension or diabetes. Serum 25(OH)D was analyzed both as a continuous and categorical variable in association with insulin resistance. Insulin resistance was estimated by homeostasis model assessment (HOMA-IR). Increased insulin resistance was operationally defined as a HOMA-IR value higher than the sex-specific 75th percentile.

Results

In male adolescents, every 10 ng/ml decrease in 25(OH)D level was associated with a 0.25 unit increase in HOMA-IR (p = 0.003) after adjusting for age and BMI. Compared to those in the highest quartile, male adolescents in the lowest 25(OH)D quartile were at significantly higher risk for insulin resistance: unadjusted odds ratio 4.06 (95% CI, 1.26 to 13.07); age and BMI adjusted odds ratio 3.59 (95% CI, 1.03 to 12.57). However, 25(OH)D level, either in continuous or categorical measure, was not significantly associated with insulin resistance among female adolescents.

Conclusions

This study suggests that serum 25(OH)D level may be inversely associated with insulin resistance in healthy male adolescents.     

Association of Serum 25-Hydroxyvitamin D with Symptoms of Depression After 6 Months in Stroke Patients

Our aim was to determine whether there was a relationship between 25-hydroxyvitamin D (25[OH] D) and post-stroke depression (PSD). Two hundred and forty-four ischemic stroke patients admitted to the hospital within the first 24 h after stroke onset were consecutively recruited and followed up for 6 months. Clinical information was collected. Serum 25[OH] D levels were measured at baseline. Based on the symptoms, diagnoses of depression were made in accordance with DSM-IV criteria for depression at 6-month after stroke. At 6-month, 91 patients (37.3 %) showed depression and in 60 patients (24.6 %) this depression was classified as major. There was a significant difference in median serum 25[OH] D levels between PSD patients and no depression cases [8.3 (IQR, 6.8–9.5) vs. 15.6 (IQR, 13.2–20.3) ng/ml, respectively; P < 0.001]. Serum 25[OH] D levels ≤11.2 ng/ml were independently associated with PSD [odds ratio 10.32, 95 % confidence interval 4.97–28.63; P < 0.001], after adjusting for possible confounders. Serum 25[OH] D levels reduced at admission was found to be associated with PSD. Additional research is needed on vitamin D supplementation to improve the outcome of patients with PSD.     

The Association between Plasma 25-Hydroxyvitamin D and Subgroups in Age-Related Macular Degeneration: A Cross-Sectional Study

Objectives

To evaluate potential differences in plasma 25-hydroxyvitamin in subtypes of age-related macular degeneration (AMD), and in patients in Clinical Age-Related Maculopathy Staging (CARMS) group 5 with or without subretinal fibrosis.

Methods

This single-center cross-sectional study included 178 participants during a period of 20 months. Ninety-five patients belonged to CARMS 5; twelve belonged to CARMS 4; twenty-two belonged to CARMS 2 or 3; and 49 individuals did not have AMD (CARMS 1). Following a structured interview, a detailed bilateral retinal examination was performed and participants were allocated to their respective subgroups in accordance with the Clinical Age-Related Maculopathy Staging system. Plasma 25-hydroxyvitamin D2 and D3 were analyzed using liquid chromatography-tandem mass spectrometry. Genomic DNA was extracted from leukocytes and genotyped for single nucleotide polymorphisms (SNPs) in the vitamin D metabolism. Differences in plasma 25-hydroxyvitamin D were determined in the subgroups as well as between patients in CARMS 5 with or without subretinal fibrosis.

Results

Plasma 25-hydroxyvitamin D was comparable in patients across CARMS groups 1 to 5 (p = 0.83). In CARMS 5, the presence of subretinal fibrosis was associated with significantly lower concentrations of 25-hydroxyvitamin D as compared to the absence of subretinal fibrosis (47.2 versus 75.6 nmol/L, p<0.001). Patients in CARMS 5 with subretinal fibrosis were more likely to have insufficient levels of 25-hydroxyvitamin D compared to patients without subretinal fibrosis (p = 0.006). No association was found between the SNPs rs10877012, rs2228570, rs4588, or rs7041 and AMD subgroups or plasma 25-hydroxyvitamin levels.

Conclusions

This study suggests that the presence of subretinal fibrosis in patients belonging to CARMS 5 may be associated with a poor vitamin D status. Our observations warrant further investigation into the role of vitamin D in the development of subretinal fibrosis.     

Association of Low Serum 25-Hydroxyvitamin D Levels in Pregnancy with Glucosehomeostasis and Obstetric And Newborn Outcomes

ObjectiveTo evaluate the association of maternal serum 25-hydroxyvitamin D (25[OH]D) status with glucose homeostasis and obstetric and newborn outcomes in women screened for gestational diabetes mellitus (GDM).MethodsConsecutive women were screened for GDM at 24 to 28 weeks’ gestation during the months of maximal sunlight exposure in Spain (June through September). Serum 25(OH)D levels and parameters of glucose homeostasis were measured. Outcomes of the delivery and newborn were collected.ResultsTwo hundred sixty-six women were screened. Vitamin D deficiency (25[OH]D < 20 ng/mL) was observed in 157 women (59%). We observed an inverse correlation between 25(OH)D levels and hemoglobin A_1c, homeostasis model assessment of insulin resistance, serum insulin, and fasting and 1-hour oral glucose tolerance test glucose levels (P <.001). With a 25(OH)D concentration less than 20 ng/mL, the odds ratios were 3.31 for premature birth (95% confidence interval, 1.52-7.19; P <.002) and 3.93 for cesarean delivery (95% confidence interval, 2.00-7.73; P <.001). A 25(OH)D concentration of 20 ng/mL had 79% sensitivity and 51% specificity for cesarean delivery and 80% sensitivity and 45% specificity for premature birth. The cutoffs with the best combination of sensitivity and specificity were 16 ng/mL for cesarean delivery (62.9% sensitivity and 61.2% specificity) and 14 ng/mL for premature birth (66.7% sensitivity and 71.0% specificity).ConclusionsIn the population we sampled, vitamin D deficiency is very common during pregnancy. Lower 25(OH)D levels are associated with disorders of glucose homeostasis and adverse obstetric and newborn outcomes.(Endocr Pract. 2012;18:676-684)     

Prognostic Value of Serum 25-Hydroxyvitamin D in Patients with Stroke

We aimed to evaluate the association between 25-hydroxyvitamin D [25(OH) D] levels and both clinical severity at admission and outcome at discharge in patients with acute ischemic stroke (AIS). From June 2012 to October 2013, consecutive first-ever AIS patients admitted to the Department of Emergency of The Fourth Affiliated Hospital of Harbin Medical University, China were identified. Clinical information was collected. Serum 25(OH) D levels were measured at baseline. Stroke severity was assessed at admission using the National Institutes of Health Stroke Scale (NIHSS) score. Functional outcome was evaluated at discharge using the modified Rankin scale (m-Rankin). Multivariate analyses were performed using logistic regression models. During the study period, 326 patients were diagnosed as AIS and were included in the analysis. Serum 25(OH) D levels reduced with increasing severity of stroke as defined by the NIHSS score. There was a negative correlation between levels of 25(OH) D and the NIHSS (r = ? 0.389, P = 0.000). In multivariate analyses, serum 25(OH) D level was an independent prognostic marker of discharge favorable functional outcome and survival [odds ratio 3.96 (2.85–7.87) and 3.36 (2.12–7.08), respectively, P = 0.000 for both, adjusted for NHISS, other predictors and vascular risk factors] in patients with AIS. Serum 25(OH) D levels are a predictor of both severity at admission and favorable functional outcome in patients with AIS. Additional research is needed on vitamin D supplementation to improve the outcome of post-stroke patients.     

Serum 25-Hydroxyvitamin D Level and Influenza Vaccine Immunogenicity in Children and Adolescents

Background

Vaccination is an important strategy in the prevention of influenza, but immunologic response to vaccination can vary widely. Recent studies have shown an association between serum 25-hydroxyvitamin D (25[OH]D) levels and immune function. The purpose of this study was to determine if serum 25(OH)D level correlates with influenza vaccine immunogenicity in children and adolescents.

Methods

We conducted a prospective cohort study of children age 3 to 15 years of age vaccinated with trivalent influenza vaccine (A/Brisbane/59/2007[H1N1]-like virus, A/Brisbane/10/2007 [H3N2]-like virus and B/Florida/4/2006-like virus) in Hutterite communities in Alberta, Saskatchewan and Manitoba. Serum 25(OH)D levels were measured at baseline and immunogenicity was assessed using hemagluttination inhibition (HAI) titers done at baseline and 3–5 weeks post vaccination. Logistic regression was used to assess the relationship between serum 25(OH)D level as both a continuous and dichotomous variable and seroprotection, seroconversion, fold increase in geometric mean titer (GMT) and post vaccination titer.

Results

A total of 391 children and adolescents were included in the study and 221 (57% had post-vaccination HAI titers. The median serum 25(OH)D level was 61.0 nmol/L (Interquartile range [IQR] 50.0, 71.0). No relationship was found between serum 25(OH)D level and seroprotection (post-vaccination titer ≥40 and ≥320) or seroconversion (post-vaccination titer ≥40 for participants with pre-vaccine titer <10 or four-fold rise in post-vaccination titer for those with a pre-vaccine titer ≥10).

Conclusion

Serum 25(OH)D level was not associated with influenza vaccine immunogenicity in otherwise healthy children and adolescents. Other strategies to enhance influenza vaccine response should continue to be evaluated in this population.The role of serum 25(OH)D level in vaccine responsiveness in other populations, especially those hyporesponsive to influenza vaccination, requires further study.     

Associations between Vascular Health Indices and Serum Total,Free and Bioavailable 25-Hydroxyvitamin D in Adolescents

Objective

The role of vitamin D in cardiovascular health remains debated as results have been inconsistent. Previous studies have not considered the bioavailability of 25-hydroxy vitamin D [25(OH)D]. Objectives of our study were to investigate the association between serum concentrations of total, free and bioavailable 25(OH)D and independent predictors of cardiovascular risk such as flow mediated dilatation (FMD) and augmentation index (AIx).

Design

This cross-sectional study included 47 post-menarchal, adolescent females [31 African American (AA) and 16 European American (EA)].

Methods

AIx was standardized to a heart rate of 75 beats/min (AIx75). Free and bioavailable 25(OH)D concentrations were calculated from standard formulas.

Results and Conclusions

Mean age of the participants was 15.8±1.4 years and mean body mass index was 23.1±4.0 kg/m². Serum total 25(OH)D was not associated with FMD, but was positively associated with AIx75 in the adjusted model (rho = 0.4, P = 0.03). AIx75 was positively associated with bioavailable 25(OH)D (rho = 0.4, P = 0.004) and free 25(OH)D (rho = 0.4, P = 0.009) and the associations persisted after adjusting for covariates. In race-specific analyses, total, free and bioavailable 25(OH)D were strongly positively associated with AIx75 in AA (rho = 0.5, 0.4, 0.4, respectively), which persisted even after adjusting for covariates. Whereas in EA there was an inverse association between total 25(OH)D and AIx75 in EA (rho = −0.6), which attenuated after adjusting for covariates.

Conclusion

Circulating total, free and bioavailable 25(OH)D were associated with arterial stiffness in adolescent girls, and these associations were race dependent. Notwithstanding, the implications of associations between vascular function indices and 25(OH)D remains unclear.     

Inverse Association between High Blood 25-Hydroxyvitamin D Levels and Diabetic Retinopathy in a Representative Korean Population

Purpose

To investigate the association between 25-hydroxyvitamin D and diabetic retinopathy (DR).

Methods

A population-based cross-sectional study using a nation-wide, systemically stratified, multistage, clustered sampling method included a total of 18,363 subjects aged ≥40 years who participated in the Korean National Health and Nutrition Examination Survey during 2008–2012. All participants participated in standardized interviews, blood 25-hydroxyvitamin D level evaluations, and comprehensive ophthalmic examinations. Seven standard retinal fundus photographs were obtained from both eyes after pupil dilatation. DR was graded according to the modified Airlie House classification system.

Results

The blood 25-hydroxyvitamin D levels were 19.2 ng/mL in men and 17.9 ng/mL in women. After adjusting for potential confounders, including age, sex, diabetes duration, hemoglobin A1c levels, and hypertension, the odds ratios (OR) for any DR and proliferative DR among men decreased significantly in the highest blood 25-hydroxyvitamin D level quintile relative to the lowest quintile (OR, 0.37; 95% confidence interval [CI], 0.18–0.76; P for trend  = 0.004 and OR, 0.15; 95% CI, 0.03–0.83; P for trend  = 0.043).

Conclusions

This study provides the first epidemiologic findings of the inverse relationships of blood 25-hydroxyvitamin D levels with any DR and proliferative DR only in men. Considering anti-angiogenic and anti-fibrotic action of vitamin D, further studies including longitudinal and interventional analysis are warranted.     

Association between 25-Hydroxyvitamin D and Intact Parathyroid Hormone Levels Across Latitude among Adults with African Ancestry

Objective: To compare levels of 25-hydroxyvitamin D (25[OH]D) associated with a plateauing of intact parathyroid (iPTH) across latitudes among adults with African ancestry.Methods: This study included approximately 500 adults of African ancestry ages 25 to 45 years living in 4 sites: Chicago, Illinois (41°N), Jamaica (17°N), Ghana (6°N), and South Africa (34°S). Multivariate linear regression models, a nonlinear logistic growth curve model, and piecewise linear models with a single knot were fitted to estimate the 25[OH]D level associated with a plateauing of iPTH with adjustment for covariates. Goodness of fit was compared using computer intensive permutation tests.Results: Mean age was 34.7 (SD 6.2) years, and 46.5% were male. Within each site, the percentage of participants with an iPTH level ≥65 pg/mL was higher among females versus males and was most frequent among South African females (17.1%) and lowest among Jamaican males (0.6%). Goodness of fit tests supported linear regression as the preferred model for the association between iPTH and 25[OH]D in the 4 sites with no 25[OH]D level associated with iPTH plateauing in any site. The slope of the association between 25[OH]D and iPTH differed by latitude; it was strongest in the U.S. (β = -0.81; 95% confidence interval [CI] = -1.03, -0.59), and weakest in Jamaica (β = -0.45; 95% CI -0.71, -0.18) with covariate adjustment, but differences in slopes were small.Conclusion: The association between 25[OH]D and iPTH appears linear among adults with African ancestry regardless of latitude within a range of 25[OH]D levels between 10 and 60 ng/mL.Abbreviations:BMI = body mass indexCI = confidence intervaleGFR = estimated glomerular filtration rateiPTH = intact parathryoid hormone25[OH]D = 25-hydroxyvitamin D     

Serum 25-Hydroxyvitamin D Deficiency in Chinese Patients with Vitiligo: A Case-Control Study

Background

Low vitamin D levels have been noted in patients with a variety of autoimmune diseases. A recent study showed that low vitamin D levels may be associated with vitiligo.

Objectives

To assess 25-hydroxyvitamin D (25(OH)D) status in Chinese patients with vitiligo in comparison of normal controls and explore possible affecting factors.

Methods

We performed a case-control study including 171 patients, 50 controls in 25(OH)D lowest months and 30 patients, 20 controls in 25(OH)D highest months. Demographic and clinical variables of patients were analyzed to determine the correlation with 25(OH) D levels.

Results

25(OH)D mean value of patients was highest in September and October, lowest in March. None of the patients and normal controls had ‘sufficient’ 25(OH)D (> = 75 nmol/L). No significant difference was found in either 25(OH)D mean values or insufficiency/deficiency ratio between patients and controls in 25(OH)D highest and lowest periods. Female patients were at a higher risk of 25(OH)D deficiency than male patients(P = 0.019). For non-segmental type, patients with 25(OH)D deficiency were more likely to have autoimmune thyroid disease than those with insufficiency (P = 0.016). Sex (P = 0.035), thyroid conditions (p = 0.034), testing month (p = 0.049) were independent factors affecting 25(OH)D level in multivariate analysis.

Conclusion

Chinese population lack 25(OH)D universally. 25(OH)D level shows no correlation with onset of vitiligo in Chinese. However deficient 25(OH)D level may be linked to autoimmune disorders in patients.     

Association of Serum 25-Hydroxyvitamin D with Lifestyle Factors and Metabolic and Cardiovascular Disease Markers: Population-Based Cross-Sectional Study (FIN-D2D)

Objectives

Low serum 25-hydroxyvitamin D (25OHD) level has been associated with an increased risk of several chronic diseases. Our aim was to determine lifestyle and clinical factors that are associated with 25OHD level and to investigate connection of 25OHD level with metabolic and cardiovascular disease markers.

Design

In total, 2868 Finnish men and women aged 45–74 years participated in FIN-D2D population-based health survey in 2007. Participants that had a serum sample available (98.4%; n = 2822) were included in this study. 25OHD was measured with chemiluminescent microparticle immunoassay method.

Results

The mean 25OHD level was 58.2 nmol/l in men (n = 1348) and 57.1 nmol/l in women (n = 1474). Mean 25OHD level was lower in the younger age groups than in the older ones (p<0.0001 both in men and women). This study confirmed that low physical activity (p<0.0001 both in men and women), smoking (p = 0.0002 in men and p = 0.03 in women) and high BMI (p<0.0001 in women) are factors that independently associate with low 25OHD level. Of the metabolic and cardiovascular disease markers high triglyceride concentration (p = 0.02 in men and p = 0.001 in women) and high apolipoprotein B/apolipoprotein A1 ratio (p = 0.04 in men and p = 0.03 in women) were independently associated with low 25OHD level.

Conclusions

Higher age did not predict lower 25OHD level in this study population of aged 45–74 years which may derive from a healthy life-style of “active pensioners”. Low physical activity and smoking came up as independent lifestyle factors associated with low 25OHD level. Defining the molecular mechanisms behind the associations of 25OHD with low physical activity and smoking are important objective in future studies. The association of 25OHD with BMI, high triglyceride concentration and apolipoprotein B/apolipoprotein A1 ratio may be related to the role of vitamin D in inflammation, but more detailed studies are needed.     

The Relationship Between Serum 25-Hydroxyvitamin D and Glucose Homeostasis in Obese Children and Adolescents in Zhejiang,China

Objective: Evidence of the association between vitamin D, insulin resistance, and oral disposition index (oDI) in obese children and adolescents is limited. To fill this research gap, we measured serum 25-hydroxyvitamin D (25&lsqb;OH]D) levels in obese children and analyzed the relationship between serum 25(OH)D levels and glucose homeostasis.Methods: Altogether, 348 obese and 445 nonobese children and adolescents (age, 6 to 16 years) were enrolled in this study. Obese children were divided into 4 subgroups: normal glucose tolerance (NGT), impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and combined IFG and IGT (IFG+IGT) according to oral glucose tolerance test results. We measured serum 25(OH)D levels and calculated the homeostasis model assessment (HOMA) of insulin resistance (IR), the whole-body insulin sensitivity index (WBISI), and the disposition index.Results: The levels of 25(OH)D in the obese group were significantly lower than in the nonobese group; serum 25(OH)D level in the NGT subgroup was higher than those of the other 3 subgroups, and it was significantly inversely correlated with logHOMA-IR (r = -0.090; P = .045) and positively correlated with logWBISI and logHOMA-oDI (r = 0.091, P = .049; and r = 0.108, P = .046, respectively). Obese patients with vitamin D deficiency thus have a significantly higher risk of disturbances in glucose metabolism.Conclusion: 25(OH)D deficiency or insufficiency is quite common in obese children and adolescents in Zhejiang, China. Obese patients with 25(OH)D deficiency (<30 nmol/L) are shown to be at higher risk for abnormal glucose metabolism.Abbreviations: 25(OH)D = 25-hydroxyvitamin D ΔI₃₀/ΔG₃₀ = insulinogenic index BMI = body mass index CI = confidence interval HbA_1c = hemoglobin A_1c HOMA = homeostasis model assessment I_F = fasting insulin IFG = impaired fasting glucose IGT = impaired glucose tolerance IR = insulin resistance NGT = normal glucose tolerance oDI = oral disposition index OGTT = oral glucose tolerance test WBISI = whole-body insulin sensitivity index     

Serum Levels of 25-Hydroxyvitamin D and Functional Outcome among Postmenopausal Women with Hip Fracture

Objective

The main objective of the current study was to assess the distribution and its prognostic value of serum 25-hydroxyvitamin D (25[OH] D) levels assessed at admission in Chinese postmenopausal women with hip fracture.

Methods

From January 1, 2012 to December 31, 2013, all postmenopausal women with first-ever hip fracture were recruited to participate in the study. Serum 25[OH] D levels were measured at admission. The functional evaluation at the time of discharge was performed by the Barthel Index (BI). The prognostic value of 25[OH] D to predict the functional outcome within discharge was analyzed by logistic regression analysis, after adjusting for the possible confounders.

Results

In our study, 261 patients were included and assessed. In the 76 patients with an unfavorable functional outcome, serum 25(OH) D levels were lower compared with those in patients with a favorable outcome [11.8(IQR, 9.9–16.1)ng/ml; 16.8(IQR, 13.6–21.4)ng/ml, respectively; P<0.0001]. In multivariate analysis, there was an increased risk of unfavorable outcome associated with serum 25(OH) D levels ≤ 20ng/ml (OR 5.24, 95%CI: 3.11–8.15; P<0.0001) after adjusting for possible confounders.

Conclusions

Our data support an association between serum 25[OH] D levels and prognosis in Chinese postmenopausal women with hip fracture.     

Serum 25-Hydroxyvitamin D and the Incidence of Acute Viral Respiratory Tract Infections in Healthy Adults

Background

Declining serum concentrations of 25-hydroxyvitamin D seen in the fall and winter as distance increases from the equator may be a factor in the seasonal increased prevalence of influenza and other viral infections. This study was done to determine if serum 25-hydroxyvitamin D concentrations correlated with the incidence of acute viral respiratory tract infections.

Methodology/Findings

In this prospective cohort study serial monthly concentrations of 25-hydroxyvitamin D were measured over the fall and winter 2009–2010 in 198 healthy adults, blinded to the nature of the substance being measured. The participants were evaluated for the development of any acute respiratory tract infections by investigators blinded to the 25-hydroxyvitamin D concentrations. The incidence of infection in participants with different concentrations of vitamin D was determined. One hundred ninety-five (98.5%) of the enrolled participants completed the study. Light skin pigmentation, lean body mass, and supplementation with vitamin D were found to correlate with higher concentrations of 25-hydroxyvitamin D. Concentrations of 38 ng/ml or more were associated with a significant (p<0.0001) two-fold reduction in the risk of developing acute respiratory tract infections and with a marked reduction in the percentages of days ill.

Conclusions/Significance

Maintenance of a 25-hydroxyvitamin D serum concentration of 38 ng/ml or higher should significantly reduce the incidence of acute viral respiratory tract infections and the burden of illness caused thereby, at least during the fall and winter in temperate zones. The findings of the present study provide direction for and call for future interventional studies examining the efficacy of vitamin D supplementation in reducing the incidence and severity of specific viral infections, including influenza, in the general population and in subpopulations with lower 25-hydroxyvitamin D concentrations, such as pregnant women, dark skinned individuals, and the obese.     

Serum 25-Hydroxyvitamin D Levels and Dry Eye Syndrome: Differential Effects of Vitamin D on Ocular Diseases

Purpose

To investigate associations between serum 25-hydroxyvitamin D levels and dry eye syndrome (DES), and to evaluate the differential effect of vitamin D on ocular diseases including age-related macular disease (AMD), diabetic retinopathy (DR), cataract, and DES.

Methods

A total of 16,396 participants aged >19 years were randomly selected from the Korean National Health and Nutrition Examination Survey. All participants participated in standardized interviews, blood 25-hydroxyvitamin D level evaluations, and comprehensive ophthalmic examinations. DES was defined by a history of clinical diagnosis of dry eyes by a physician. The association between vitamin D and DES was compared to the associations between vitamin D and AMD, DR, cataract, and DES from our previous studies.

Results

The odds of DES non-significantly decreased as the quintiles of serum 25-hydroxyvitamin D levels increased (quintile 5 versus 1, OR = 0.85, 95%CI: 0.55–1.30, P for trend = 0.076) after adjusting for potential confounders including age, sex, hypertension, diabetes, smoking status, and sunlight exposure times. The relative odds of DES (OR = 0.70, 95% CI: 0.30–1.64) and cataract (OR = 0.76, 95% CI: 0.59–0.99) were relatively high, while those of DR (OR = 0.37, 95% CI: 0.18–0.76) and late AMD (OR = 0.32, 95% CI: 0.12–0.81) were lower in men.

Conclusions

The present study does not support an association between serum 25-hydroxyvitamin D levels and DES. The preventive effect of serum 25-hydroxyvitamin D may be more effective for DR and late AMD than it is for cataract and DES.     

Low Serum 25-Hydroxyvitamin D Concentrations Are Associated with Increased Risk for Melanoma and Unfavourable Prognosis

Background

Low vitamin D status (serum 25(OH)D concentration) is associated with increased incidence and unfavourable outcome of various types of cancer. However, there are limited data on influence of serum 25(OH)D on risk and prognosis of malignant melanoma.

Methods

Basal serum 25(OH)D concentrations were retrospectively analyzed in a cohort of melanoma patients (n = 324) and healthy controls (n = 141). We tested the hypothesis that serum 25(OH)D concentrations are predictive of melanoma risk, thickness of primary melanomas, and overall survival (OS).

Results

Median serum 25(OH)D concentrations were significantly lower (p = 0.004) in melanoma patients (median = 13.6 ng/ml) as compared to controls (median = 15.6 ng/ml). Primary tumors of patients with low serum 25(OH)D concentrations (<10 ng/ml) had significantly (p = 0.006) greater Breslow thickness (median: 1.9 mm) as compared to patients with higher levels (>20 ng/ml; median: 1.00 mm). Patients with 25(OH)D serum concentrations in the lowest quartile had inferior overall survival (median: 80 months) comparing with the highest quartile (median: 195 months; p = 0.049).

Conclusions

Our data support the concept that serum 25(OH)D concentrations are associated with risk and prognosis of melanoma. Whether normalizing serum 25(OH)D concentrations in these patients improves outcomes will require testing in future clinical trials.