Risk factors for vitamin D deficiency in HIV-infected patients in the south central United States

We evaluated the prevalence of serum 25-hydroxyvitamin D [25(OH)D] deficiency and the risk factors for vitamin D deficiency in HIV-infected patients in the South-Central United States. The study consisted of a cross-sectional assessment of vitamin D levels in HIV-infected patients receiving routine clinical care from a private practice in Houston, Texas (latitude 29°N). Vitamin D deficiency was defined as 25(OH)D less than 20?ng/ml (<50?nmol/liter). Two-hundred enrolled patients were surveyed with a vitamin D questionnaire to determine daily supplemental vitamin D intake, dietary vitamin D intake, and average sunlight exposure (minutes/day). Multivariate logistic regression analysis was used to determine significant risk factors for vitamin D deficiency. Median 25(OH)D was 15.5?ng/ml (interquartile range 10.9-24.6) for the total population (n=200). Approximately, two-thirds (64%) of patients had vitamin D deficiency and 20.5% had severe vitamin D deficiency [25(OH)D <10?ng/ml or <25?nmol/liter]. In univariate analysis, African-American race, current tobacco use, increased body mass index (BMI), lower serum calcium level, no supplemental vitamin D use, and low daily supplemental and total daily vitamin D intake were significantly associated with vitamin D deficiency. In multivariate analysis, African-American race [adjusted odds ratio (AOR) 3.53 (95% confidence interval (CI) 1.83-6.82)], higher BMI [AOR 1.07 (95% CI 1.002-1.139)], and low daily vitamin D supplemental intake [AOR 0.997 (95% CI 0.996-0.999)] were significantly associated with vitamin D deficiency. No HIV factors including antiretroviral class use were significantly associated with either vitamin D deficiency or severe vitamin D deficiency. Vitamin D deficiency and severe vitamin D deficiency were highly prevalent in this HIV population. In the HIV population, African-Americans or patients with a high BMI may benefit from vitamin D supplementation.     

Vitamin D: epidemiology of cardiovascular risks and events

Vitamin D may influence blood pressure through the renin-angiotensin system, parathyroid hormone levels, myocardial function, inflammation, and vascular calcification. In the past several years, a number of high-quality prospective studies have examined 25(OH)vitamin D (25(OH)D) levels in relation to risk of cardiovascular disease (CVD). Studies consistently show that levels of 25(OH)D below 20-25 ng/mL are associated with an increased risk of CVD incidence or mortality. Risk appears especially elevated at 25(OH)D levels below 10 or 15 ng/mL. It is unclear if levels higher that 25 ng/mL provide further benefits for CVD disease. Currently, results from randomized clinical trials are sparse and do not allow a definitive conclusion. Given other potential benefits of vitamin D, and low potential for toxicity, deficient levels below 25-30 ng/mL should be avoided and treated when identified. Further observational and randomized clinical trial data are important to better characterize the optimal range for 25(OH)D.     

Vitamin d intake and status are associated with lower prevalence of metabolic syndrome in u.s. Adults: national health and nutrition examination surveys 2003-2006

Abstract Background: Previous reports have shown that metabolic syndrome and some metabolic syndrome components are associated with serum 25-hydroxyvitamin D [25(OH)D]. Methods: Using the National Health and Nutrition Examination Surveys (NHANES), 2003-2006, we evaluated the associations of vitamin D intake (n=3543) and vitamin D status [25(OH)D; n=3529], with the prevalence of metabolic syndrome and its components in adults 20 years and older. Exclusion criteria included nonfasted subjects, those pregnant and/or lactating, and, for intake analyses, those with unreliable 24-h recall records. Subjects were separately classified into quartiles of vitamin D intake (both including and excluding supplements) and serum 25(OH)D. Logistic regression was used to determine odds ratios (OR) for metabolic syndrome after adjusting for multiple confounders. Results: Those in the highest quartile of serum 25(OH)D had 60% lower odds for metabolic syndrome as compared to those in the lowest quartile [OR=0.40; 95% confidence interval (CI) 0.27, 0.59]. Elevated waist circumference (OR=0.57; 95% CI 0.39, 0.84), low high-density lipoprotein cholesterol (HDL-C) (OR=0.54; 95% CI 0.39, 0.75), and high homeostasis model assessment of insulin resistance (HOMA-IR) (OR=0.40; 95% CI 0.29, 0.55) were the main components associated with serum 25(OH)D. Compared with the lowest vitamin D intake quartile (excluding supplements), those in the highest intake quartile had 28% lower odds for metabolic syndrome (OR=0.72; 95% CI 0.58, 0.90). No components of metabolic syndrome were significantly associated with dietary intake of vitamin D with supplements included or excluded. Conclusions: We conclude that higher 25(OH)D, and, to a lesser degree, greater dietary vitamin D intake, are associated with reduced prevalence of metabolic syndrome.     

Low vitamin D status is associated with obesity but no other cardiovascular risk factors in Chinese children and adolescents

Background and aimsEvidence on relationship between vitamin D status and cardiovascular health in childhood remains inconsistent. This study aimed to investigate vitamin D status and its relationship with cardiovascular risk factors in Chinese children and adolescents.Methods and resultsCross-sectional data were obtained from 2680 children and adolescents aged 7-18 y in Guangzhou, South China. Anthropometric and socioeconomic characters, concentration of serum 25-hydroxyvitamin D [25(OH)D], fasting blood glucose and lipids, as well as information about diet and physical activity were measured and collected. Logistic regression model was adopted to analyze the associations between 25(OH)D levels and cardiovascular risk factors including obesity, high blood pressure, dyslipidemia, hyperglycemia, and metabolic syndrome. Overall, median level of 25(OH)D was 19.74 ng/mL. The prevalence rates of vitamin D deficiency and inadequacy were 7.5% and 44.4%, both of which were highest among adolescents aged 14-18 y (14.5% and 51.6%, respectively). As vitamin D level increased, an upward trend in fasting glucose concentrations was observed in subjects with normal fasting glucose level, but not in subjects with hyperglycemia. Among the assessed cardiovascular risk factors, vitamin D status was only inversely associated with general obesity, and the adjusted odds ratio was 1.95 (95% CI: 1.08–3.49), comparing the lowest 25(OH)D quartile with the highest one.ConclusionsVitamin D deficiency and inadequacy remain a concern among school-aged children and adolescents in Guangzhou, South China, particularly in adolescents aged 14-18 y. However, low vitamin D status was found only associated with general obesity but no other cardiovascular risk factors.     

Inverse association between circulating vitamin D and mortality – Dependent on sex and cause of death?

Background and aimsIn various populations, vitamin D deficiency is associated with chronic diseases and mortality. We examined the association between concentration of circulating 25-hydroxyvitamin D [25(OH)D], a marker of vitamin D status, and all-cause as well as cause-specific mortality.Methods and ResultsThe study included 3404 participants of the general adult Swiss population, who were recruited between November 1988 and June 1989 and followed-up until the end of 2008. Circulating 25(OH)D was measured by protein-bound assay. Cox proportional hazards regression was used to examine the association between 25(OH)D concentration and all-cause and cause-specific mortality adjusting for sex, age, season, diet, nationality, blood pressure, and smoking status. Per 10 ng/mL increase in 25(OH)D concentration, all-cause mortality decreased by 20% (HR = 0.83; 95% CI 0.74–0.92). 25(OH)D concentration was inversely associated with cardiovascular mortality in women (HR = 0.68, 95% CI 0.46–1.00 per 10 ng/mL increase), but not in men (HR = 0.97; 95% CI 0.77–1.23). In contrast, 25(OH)D concentration was inversely associated with cancer mortality in men (HR = 0.72, 95% CI 0.57–0.91 per 10 ng/mL increase), but not in women (HR = 1.14, 95% CI 0.93–1.39). Multivariate adjustment only slightly modified the 25(OH)D-mortality association.Conclusion25(OH)D was similarly inversely related to all-cause mortality in men and women. However, we observed opposite effects in women and men with respect to cardiovascular and cancer mortality.     

Association of 25-hydroxyvitamin D levels and metabolic syndrome in Thai postmenopausal women

Background and aimsLow serum 25-hydroxyvitamin D [25(OH)D] levels have been reported to be associated with metabolic syndrome (MetS). In this study, we aimed to investigate the association between serum 25(OH)D levels and MetS in Thai postmenopausal women.MethodsA total of 340 postmenopausal women were enrolled in the study. The concentration of 25(OH)D, lipid profiles, fasting blood glucose (FBG) levels, blood pressure, and demographic and anthropometric parameters were measured. Subjects were divided into the hypovitaminosis D and vitamin D sufficiency groups. The association of serum 25(OH)D levels with MetS in postmenopausal women was analyzed using multivariate regression analysis.ResultsWaist circumference, total cholesterol levels, and triglyceride levels were significantly higher in hypovitaminosis D than in vitamin D sufficiency (p < 0.05). The prevalence of MetS, central obesity, and hypertriglyceridemia in hypovitaminosis D was significantly higher than in vitamin D sufficiency (p < 0.05). In the multivariable logistic regression model, hypovitaminosis D was associated with MetS (OR 1.85; 95% CI 1.12–3.04, p = 0.015), central obesity (OR 2.41; 95% CI 1.20–4.85, p = 0.014), and hypertriglyceridemia (OR 1.91; 95% CI 1.12–3.26, p = 0.018) compared with vitamin D sufficiency after adjusting for covariates. Serum vitamin D concentrations were significantly lower in the MetS group than in the non-MetS group (p = 0.016) and decreased with an increasing number of MetS components (p for trend = 0.034).ConclusionsHypovitaminosis D was associated with an increased risk of MetS, central obesity, and hypertriglyceridemia in Thai postmenopausal women.     

No association of vitamin D intake or 25-hydroxyvitamin D levels in childhood with risk of islet autoimmunity and type 1 diabetes: the Diabetes Autoimmunity Study in the Young (DAISY)

Aims/hypothesis

The aim of the study was to investigate the association between vitamin D intake and status and the risk of islet autoimmunity (IA) and subsequent type 1 diabetes in children at increased risk of type 1 diabetes.

Methods

The Diabetes Autoimmunity Study in the Young (DAISY) in Denver, CO, USA, has been following children at increased risk of diabetes since 1993. As of February 2011, 198 children developed IA during follow-up of 2,644 DAISY children. Vitamin D intake and plasma 25-hydroxyvitamin D [25(OH)D] were measured longitudinally. Proportional hazards regression analyses of time to IA, or type 1 diabetes in IA-positive children, were conducted, with vitamin D intake and 25(OH)D as time-varying covariates. HRs were calculated for a standard deviation difference in exposure, with adjustment for confounders.

Results

Intake of vitamin D was not associated with the risk of IA (adjusted HR 1.13; 95% CI 0.95, 1.35; p?=?0.18) nor progression to diabetes in IA-positive children (adjusted HR 1.30; 95% CI 0.91, 1.86; p?=?0.15). Moreover, 25(OH)D level was not associated with the risk of IA (adjusted HR 1.12; 95% CI 0.88, 1.43; p?=?0.36), nor progression to diabetes in IA-positive children (adjusted HR 0.91; 95% CI 0.68, 1.22; p?=?0.54). In the 128 children in whom we measured 25(OH)D at 9?months of age, 25(OH)D was not associated with risk of IA (n?=?30 IA-positive children) (adjusted HR 1.02; 95% CI 0.96, 1.07; p?=?0.58).

Conclusions/interpretation

Neither vitamin D intake nor 25(OH)D levels throughout childhood were associated with the risk of IA or progression to type 1 diabetes in our population.     

Vitamin D Plasma Levels and In-Hospital and 1-Year Outcomes in Acute Coronary Syndromes: A Prospective Study

Deficiency in 25-hydroxyvitamin D (25[OH]D), the main circulating form of vitamin D in blood, could be involved in the pathogenesis of acute coronary syndromes (ACS). To date, however, the possible prognostic relevance of 25 (OH)D deficiency in ACS patients remains poorly defined. The purpose of this prospective study was to assess the association between 25 (OH)D levels, at hospital admission, with in-hospital and 1-year morbidity and mortality in an unselected cohort of ACS patients.We measured 25 (OH)D in 814 ACS patients at hospital presentation. Vitamin D serum levels >30 ng/mL were considered as normal; levels between 29 and 21 ng/mL were classified as insufficiency, and levels < 20 ng/mL as deficiency. In-hospital and 1-year outcomes were evaluated according to 25 (OH)D level quartiles, using the lowest quartile as a reference.Ninety-three (11%) patients had normal 25 (OH)D levels, whereas 155 (19%) and 566 (70%) had vitamin D insufficiency and deficiency, respectively. The median 25 (OH)D level was similar in ST-elevation myocardial infarction (STEMI) and non-ST-elevation myocardial infarction (NSTEMI) patients (14.1 [IQR 9.0–21.9] ng/mL and 14.05 [IQR 9.1–22.05] ng/mL, respectively; P = .88). The lowest quartile of 25 (OH)D was associated with a higher risk for several in-hospital complications, including mortality. At a median follow-up of 366 (IQR 364–379) days, the lowest quartile of 25 (OH)D, after adjustment for the main confounding factors, remained significantly associated to 1-year mortality (P < .01). Similar results were obtained when STEMI and NSTEMI patients were considered separately.In ACS patients, severe vitamin D deficiency is independently associated with poor in-hospital and 1-year outcomes. Whether low vitamin D levels represent a risk marker or a risk factor in ACS remains to be elucidated.     

Correlates and prevalence of insufficient 25-hydroxyvitamin D status in black and white older adults: the health, aging and body composition study

OBJECTIVES: To determine the prevalence and correlates of vitamin D insufficiency in black and white older adults. DESIGN: Cross‐sectional. SETTING: Health, Aging and Body Composition Study. PARTICIPANTS: Nine hundred seventy‐seven black and 1,604 white adults aged 70 to 81. MEASUREMENTS: Logistic regression and classification and regression tree analysis were used to identify correlates of vitamin D insufficiency (25‐hydroxyvitamin D (25(OH)D) <30 ng/mL) separately in blacks and whites. RESULTS: The prevalence of 25(OH)D insufficiency was 84% in blacks and 57% in whites. Seventy‐six percent of blacks and 56% of whites did not take a multivitamin; those who did not take a multivitamin were more likely to be vitamin D insufficient (odds ratio (OR)=5.17 (95% confidence interval (CI)=3.47–7.70) for blacks; OR=2.56, 95% CI=2.05–3.19 for white). Additional risk factors for vitamin D insufficiency were vitamin D–containing supplement use, female sex, and obesity in blacks; and winter season, low dietary vitamin D intake, obesity, type 2 diabetes mellitus, and female sex in whites. CONCLUSION: Vitamin D insufficiency was more prevalent in blacks than whites. Not consuming a multivitamin increased the odds of vitamin D insufficiency in blacks and whites. Knowledge of additional risk factors such as dietary intake and comorbid conditions may help identify older adults who are likely to be vitamin D insufficient.     

Circulating 25-hydroxy-vitamin D and the risk of cardiovascular diseases. Systematic review and meta-analysis of prospective cohort studies

AimsCirculating vitamin D is linked with the risk of cardiovascular disease (CVD). A meta-analysis has yet to explicitly explore correlation between vitamin D and the risk of CVD incidence and recurrent CVD. This meta-analysis examines the association between 25-hydroxy-vitamin D (25(OH)D) and the risk of CVD incidence (fatal, non-fatal, fatal and non-fatal combined events) and the risk of recurrent CVD (fatal, recurrent, and fatal and recurrent combined events). PROSPERO registration-CRD42021251483.Data synthesisA total of 79 studies (46 713 CVD cases in 1 397 831 participants) were included in the meta-analysis, of which 61 studies examined the risk of CVD incidence events, and 18 studies examined risk of recurrent CVD events. The risk of CVD incidence events (RR = 1.34, 95% CI: 1.26–1.43, p < 0.001) and recurrent CVD events (RR = 1.86, 95% CI: 1.46–2.36, p < 0.001) was higher in the lowest than the highest category of circulating 25(OH)D. Dose–response analysis reported a linear association for every 10 ng/ml increment of 25(OH)D and non-fatal CVD incidence events (RR = 0.94; 95% CI = 0.89–0.98, p = 0.005), lower fatal recurrent CVD events (RR = 0.45; 95% CI = 0.32–0.62, p < 0.001) and lower combined recurrent CVD events (RR = 0.80; 95% CI = 0.65–0.97, p = 0.023). A non-linear association was observed between higher 25(OH)D and lower fatal CVD incidence events (P-nonlinear<0.001), lower combined CVD incidence events (P-nonlinear = 0.001), and lower non-fatal recurrent CVD events (P-nonlinear = 0.044).ConclusionsThe lowest category of circulating 25(OH)D was associated with a higher risk of CVD incidence events and recurrent CVD events.     

Prospective Study of Serum 25-Hydroxyvitamin D Level, Cardiovascular Disease Mortality, and All-Cause Mortality in Older U.S. Adults

OBJECTIVES: To evaluate the association between serum 25‐hydroxyvitamin D (25(OH)D) levels and mortality in a representative U.S. sample of older adults. DESIGN: Prospective cohort from the Third National Health and Nutrition Examination Survey (NHANES III) and linked mortality files. SETTING: Noninstitutionalized U.S. civilian population. PARTICIPANTS: Three thousand four hundred eight NHANES III participants aged 65 and older enrolled from 1988 to 1994 and followed for mortality through 2000. MEASUREMENTS: Primary exposure was serum 25(OH)D level at enrollment. Primary and secondary outcomes were all‐cause and cardiovascular disease (CVD) mortality, respectively. RESULTS: During the median 7.3 years of follow‐up, there were 1,493 (44%) deaths, including 767 CVD‐related deaths. Median 25(OH)D level was 66 nmol/L. Adjusting for demographics, season, and cardiovascular risk factors, baseline 25(OH)D levels were inversely associated with all‐cause mortality risk (adjusted hazard ratio (HR)=0.95, 95% confidence interval (CI)=0.92–0.98, per 10 nmol/L 25[OH]D). Compared with subjects with 25(OH)D levels of 100 nmol/L or higher, the adjusted HR for subjects with levels less than 25.0 nmol/L was 1.83 (95% CI=1.14–2.94) and for levels of 25.0 to 49.9 nmol/L was 1.47 (95% CI=1.09–1.97). The association appeared stronger for CVD mortality (adjusted HR=2.36, 95% CI=1.17–4.75, for subjects with 25[OH]D levels<25.0 nmol/L vs those ≥100.0 nmol/L) than for non‐CVD mortality (adjusted HR=1.42, 95% CI=0.73–2.79, for subjects with 25[OH]D levels<25.0 nmol/L vs those ≥100.0 nmol/L). CONCLUSION: In noninstitutionalized older adults, a group at high risk for all‐cause mortality, serum 25(OH)D levels had an independent, inverse association with CVD and all‐cause mortality. Randomized controlled trials of vitamin D supplementation in older adults are warranted to determine whether this association is causal and reversible.     

Vitamin D deficiency in children and adolescents

Objective Vitamin D deficiency is an important health problem in both developed and developing countries. Recent reports on the extraskeletal effects of vitamin D have led to increased interest in prevalence studies on states of deficiency/insufficiency of vitamin D. The aim of this study was to determine the frequency of vitamin D deficiency and insufficiency in children and adolescents residing in Ankara, Turkey and to investigate the factors associated with low vitamin D status. Methods: A total of 440 children and adolescents aged between 0 and 16 years were enrolled in this study. The subjects were divided into three groups according to their vitamin D status (deficiency ≤15 ng/mL; insufficiency: 15-20 ng/mL; sufficiency ≥20 ng/mL) and also according to their age (preschool<5 years; middle childhood: 5-10 years; adolescence: 11-16 years). Results: Overall, 40% of the subjects were found to have 25 hydroxy vitamin D [25(OH)D] levels of less than 20 ng/mL. The levels indicated a deficiency state in 110 subjects (25%) and insufficiency - in 66 (15%). The rate of vitamin D deficiency was higher in girls, regardless of age. 25(OH)D levels correlated negatively with age (r=-0.48, p<0.001), body mass index (BMI) (r=-0.20, p=0.001) and intact parathyroid hormone (iPTH) level (r=-0.31, p=0.001). A positive correlation was observed between 25(OH)D and serum ferritin levels (r=0.15, p=0.004). Conclusions: The high frequency of vitamin D deficiency in childhood (especially among adolescent girls) indicates a need for supplementation and nutritional support. Conflict of interest:None declared.     

Vitamin d, metabolic dyslipidemia, and metabolic syndrome in rheumatoid arthritis

PurposeVitamin D deficiency is a potential risk factor for cardiometabolic disease. We investigated the associations between vitamin D and dyslipidemia and the metabolic syndrome in patients with rheumatoid arthritis, a group at high risk for cardiovascular disease.MethodsSerum 25(OH)vitamin D and lipoprotein levels were measured at baseline in a random sample of 499 participants, ages 18-85 years, enrolled in a randomized trial of golimumab (GOlimumab Before Employing methotrexate as the First-line Option in the treatment of Rheumatoid arthritis of Early onset or GO-BEFORE Trial). Participants had rheumatoid arthritis with active disease, and were naïve to methotrexate and biologic therapies. Multivariable linear regression was performed to assess associations between vitamin D levels and lipoprotein fractions. Multivariable logistic regression was performed to determine the odds of hyperlipidemia and the metabolic syndrome in participants with vitamin D deficiency (<20 ng/mL).ResultsIn multivariable linear regression, vitamin D levels (per 10 ng/mL) were associated inversely with low-density lipoprotein (β: ?0.029 [?0.049, ?0.0091], P = .004) and triglyceride (β: ?0.094 [?0.15, ?0.039] P = .001) levels, adjusted for demographic, cardiovascular, and disease-specific variables. Vitamin D and high-density lipoprotein levels were not associated in univariate or multivariate analyses. Vitamin D deficiency was associated independently with an increased odds of hyperlipidemia (odds ratio 1.72; 95% confidence interval, 1.10-2.45; P = .014) and metabolic syndrome (odds ratio 3.45; 95% confidence interval, 1.75-6.80; P <.001) in adjusted models.ConclusionsIn conclusion, vitamin D deficiency was associated with the metabolic syndrome and dyslipidemia in rheumatoid arthritis, suggesting a potential role in cardiovascular disease risk. Large-scale, prospective studies are needed to determine if vitamin D supplementation improves lipoprotein levels and reduces cardiovascular risk in rheumatoid arthritis.     

Effect of Vitamin D Serum Levels and GC Gene Polymorphisms in Liver Fibrosis Due to Chronic Hepatitis C

Introduction and aimVitamin D has been associated with chronic liver diseases and low vitamin levels may contribute to progression of chronic hepatitis C. The aim of this study was to evaluate the influence of vitamin D serum levels and GC gene polymorphisms in the severity of liver fibrosis in patients with chronic hepatitis C genotype 1.Material and methodsCross-sectional study that enrolled 132 adult patients with chronic hepatitis C genotype 1 attended at the outpatient Clinic of Gastroenterology Division at Hospital de Clínicas de Porto Alegre. At the time of enrollment patients had a blood withdraw for serum 25(OH)D determination and genotypic analysis of rs7041 and rs4588 polymorphisms in GC gene. None/mild fibrosis was considered as METAVIR F0, F1 and F2 and severe fibrosis as METAVIR F3 and F4.ResultsMedian 25(OH)D levels in the sample were 19.9 ng/mL (P25-P75: 14.0-29.4). Fifty percent of patients presented vitamin D deficiency (< 20 ng/mL). In stepwise multiple linear regression the variables associated with 25(OH)D levels were blood withdrawn in Winter/spring season, the haplotypes AT/AT + AG/AT of rs7041 and rs4588 and female sex. For evaluation of severe fibrosis, variables associated in logistic regression were age, vitamin D severe deficiency (< 10 ng/mL), glucose levels, BMI and platelets count.ConclusionsVitamin D levels are associated with severity of liver fibrosis in chronic hepatitis C genotype 1 patients. Although the rs7041 and rs4588 GC polymorphisms are strong predictors of vitamin D levels, they do not play a direct role in liver fibrosis.     

The Risk of All-Cause Mortality Is Inversely Related to Serum 25(OH)D Levels

Context and Objectives: Vitamin D plays a key role in maintaining bone health, but evidence for its nonskeletal effects is inconsistent. This study aims to examine the association between serum 25-hydroxyvitamin D [25(OH)D] levels and all-cause mortality in a large general population cohort. Design, Participants, and Setting: Using the computerized database of the largest health care provider in Israel, we identified a cohort of subjects 20 years old or older with serum 25(OH)D levels measured between January 2008 and December 2009. Vital status was ascertained through August 2011. Results: Median follow-up was 28.5 months (interquartile range 23.8-33.5 months); 7,247 of 182,152 participants (4.0%) died. Subjects who died had significantly lower serum 25(OH)D levels (mean 44.8 ± 24.2 nmol/liter) than those alive at the end of follow-up (51.0 ± 23.2 nmol/liter), P < 0.001. After adjustment for age, gender, ethnicity, and seasonality, the hazard ratio (HR) for all-cause mortality was 2.02 [95% confidence interval (CI) 1.89-2.15] for the lowest serum 25(OH)D quartile (<33.8 nmol/liter) compared with the highest. After further adjustment for comorbidity, use of vitamin D supplements and statins, smoking, socioeconomic status, and body mass index, the HR was 1.81 (95% CI 1.69-1.95). This remained, even after adjustment for serum low-density lipoprotein, high-density lipoprotein, calcium level (corrected for serum albumin levels), and glomerular filtration rate, 1.85 (95% CI 1.70-2.01). The fully adjusted HR associated with being in the second 25(OH)D quartile (33.8-49.4 nmol/liter) was 1.25 (95% CI 1.16-1.34). Conclusions: All-cause mortality is independently and inversely associated with serum 25(OH)D levels at levels less than 50 nmol/liter.     

Plasma Vitamin D Level and Change in Albuminuria and eGFR According to Sodium Intake

Background and objectives

Low circulating 25-hydroxyvitamin D [25(OH)D] and high sodium intake are both associated with progressive albuminuria and renal function loss in CKD. Both vitamin D and sodium intake interact with the renin-angiotensin-aldosterone system. We investigated whether plasma 25(OH)D or 1,25-dihydroxyvitamin D [1,25(OH)₂D] is associated with developing increased albuminuria or reduced renal function and whether these associations depend on sodium intake.

Design, setting, participants, & measurements

Baseline plasma 25(OH)D and 1,25(OH)₂D were measured by liquid chromatography tandem mass spectrometry, and sodium intake was assessed by 24-hour urine collections in the general population–based Prevention of Renal and Vascular End-Stage Disease cohort (n=5051). Two primary outcomes were development of urinary albumin excretion >30 mg/24 h and eGFR (creatinine/cystatin C–based CKD Epidemiology Collaboration) <60 ml/min per 1.73 m². Participants with CKD at baseline were excluded. In Cox regression analyses, we assessed associations of vitamin D with developing increased albuminuria or reduced eGFR and potential interaction with sodium intake.

Results

During a median follow-up of 10.4 (6.2–11.4) years, 641 (13%) participants developed increased albuminuria, and 268 (5%) participants developed reduced eGFR. Plasma 25(OH)D was inversely associated with increased albuminuria (fully adjusted hazard ratio [HR] per SD higher, 0.86; 95% confidence interval [95% CI], 0.78 to 0.95; P=0.003) but not reduced eGFR (HR, 0.99; 95% CI, 0.87 to 1.12; P=0.85). There was interaction between 25(OH)D and sodium intake for risk of developing increased albuminuria (P interaction =0.03). In participants with high sodium intake, risk of developing increased albuminuria was inversely associated with 25(OH)D (lowest versus highest quartile: adjusted HR, 1.81; 95% CI, 1.20 to 2.73, P<0.01), whereas this association was nonsignificant in participants with low sodium intake (HR, 1.29; 95% CI, 0.94 to 1.77; P=0.12). Plasma 1,25(OH)₂D was not significantly associated with increased albuminuria or reduced eGFR.

Conclusions

Low plasma 25(OH)D is associated with higher risk of developing increased albuminuria, particularly in individuals with high sodium intake, but not of developing reduced eGFR. Plasma 1,25(OH)2D is not associated with risk of developing increased albuminuria or reduced eGFR.     

Association of baseline vitamin D level with genetic determinants and virologic response in patients with chronic hepatitis B

Aim

The role of vitamin D in individuals with chronic hepatitis B (CHB) is unclear. We aimed to explore the association of baseline vitamin D level with genetic determinants and week‐104 treatment outcome in CHB patients.

Methods

Baseline serum 25‐hydroxycholecalciferol (25(OH)D) levels and genetic polymorphism within GC, DHCR7, and CYP2R1 were determined in stored serum of 560 patients who were enrolled into a multicenter, randomized, controlled study and completed 104 weeks of telbivudine monotherapy or telbivudine‐based optimized therapy. Virologic response was defined as hepatitis B virus DNA <300 copies/mL (52 IU/mL) at week 104.

Results

The mean 25(OH)D value was 29.64 ng/mL. The percentage of patients with vitamin D insufficiency (<30 ng/mL) and vitamin D deficiency (<20 ng/mL) were 55.0% and 20.9%, respectively. Gender, season, latitude, and GC rs2282679 polymorphism were independent factors of vitamin D status. Patients with sufficient vitamin D (≥30 ng/mL) achieved a higher virologic response rate than those with vitamin D insufficiency (81.7% vs. 67.2%, P < 0.001). The area under the curve of 25(OH)D to predict virologic response was 0.65 (P < 0.001; 95% confidence interval, 0.62–0.67). On multivariate analysis, 25(OH)D level was an independent predictor of virologic response, but not associated with hepatitis B envelope antigen (HBeAg) seroconversion or alanine aminotransferase (ALT) normalization.

Conclusions

Vitamin D insufficiency was highly prevalent in treatment‐naïve CHB patients in mainland China. Latitude and genetic determinants affect vitamin D status. Baseline vitamin D level can predict week‐104 virologic response, but not HBeAg seroconversion or ALT normalization.     

Brief communication: Vitamin D serum levels in American tegumentary leishmaniasis from an endemic area in Northeast Brazil

IntroductionThe pathogenesis of cutaneous and mucosal leishmaniasis is associated with different immune responses. Vitamin D may modulate the immune system. Here we evaluate the association of vitamin D levels with the severity of the clinical forms of cutaneous and mucosal leishmaniasis.MethodsWe conducted an observational study evaluating the association between vitamin D levels, disease severity and therapeutic response in patients with cutaneous and mucosal leishmaniasis. Additionally, we conducted a cross-sectional study to compare vitamin D levels in patients with leishmaniasis and healthy subjects. Hypovitaminosis D was defined as a serum level of 25 (OH) D < 30 ng/mL.ResultsIn patients with leishmaniasis, vitamin D serum levels were 38.5 ± 11.54 ng/mL, and 37.5 ± 10.43 ng/mL in healthy subjects The prevalence of hypovitaminosis D was 23.3% and 20.0%, respectively (p = 0.72). There was no correlation between vitamin D serum levels, disease severity, and healing time in the mucosal leishmaniasis group.ConclusionVitamin D levels are not associated with neither susceptibility nor severity of tegumentary leishmaniasis.     

Association of serum vitamin D levels with inflammatory response following hip fracture: the Baltimore Hip Studies

BACKGROUND: Vitamin D, known for its role in calcium homeostasis, may also regulate immune function. Whether vitamin D deficiency at the time of hip fracture is associated with the inflammatory response postfracture is not known. METHODS: In a cohort from the Baltimore Hip Studies, women aged >or= 65 years were evaluated at baseline and 2, 6, and 12 months after hip fracture repair. Serum at baseline was analyzed for 25-hydroxyvitamin D [25(OH)D], and serum from all time points was analyzed for interleukin-6 (IL-6). Participants were divided into two groups based on their baseline 25(OH)D levels. Vitamin D deficiency was defined as a 25(OH)D level of 相似文献