Serum 25-hydroxyvitamin D levels and overall mortality. A systematic review and meta-analysis of prospective cohort studies

Vitamin D and Risk of Incident Type 2 Diabetes in Older Adults: An Updated Systematic Review and Meta-Analysis

Vitamin D deficiency is very common worldwide, particularly in old age, when people are at the highest risk of the negative adverse consequences of hypovitaminosis D. Additionally to the recognized functions in the regulation of calcium absorption, bone remodeling, and bone growth, vitamin D plays a key role as a hormone, which is supported by various enzymatic, physiological, metabolic, and pathophysiological processes related to various human organs and systems. Accruing evidence supports that vitamin D plays a key role in pancreatic islet dysfunction and insulin resistance in type 2 diabetes. From an epidemiological viewpoint, numerous studies suggest that the growing incidence of type 2 diabetes in humans may be linked to the global trend of prevalent vitamin D insufficiency. In the past, this association has raised discussions due to the equivocal results, which lately have been more convincing of the true role of vitamin D supplementation in the prevention of incident type 2 diabetes. Most meta-analyses evaluating this role have been conducted in adults or young older persons (50-60 years old), with only one focusing on older populations, even if this is the population at greater risk of both hypovitaminosis D and type 2 diabetes. Therefore, we conducted an update of the previous systematic review and meta-analysis examining whether hypovitaminosis D (low serum 25OHD levels) can predict incident diabetes in prospective longitudinal studies among older adults. We found that low 25OHD was associated with incident diabetes in older adults even after adjusting for several relevant potential confounders, confirming and updating the results of the only previous meta-analysis conducted in 2017.

Evaluation of the deficiency status of 25-hydroxyvitamin D and associated factors in Southwest China: A hospital-based retrospective cross-sectional analysis of a low-latitude, high-altitude, multiracial region

Vitamin D deficiency is widespread in different populations and regions worldwide and has become a global health issue. The vitamin D status of the population in the Yunnan Province of Southwest China has not been evaluated to date. Therefore, in this study, we evaluated the vitamin D status according to the serum concentrations of 25-hydroxyvitamin D (25(OH)D) in individuals of Yunnan Province, a low-latitude, high-altitude and multiracial region in China. The data on 25(OH)D concentrations from October 2012 to December 2017 were retrospectively collected and assessed using the laboratory information system from 52 950 hospital-based participants (age, 1 day-96 years; females, 73.74%). The serum concentration of 25(OH)D was evaluated using a chemiluminescent immunoassay. The analysis was stratified by sex, age, sampling season, testing year, minority, residential district, latitude, altitude and meteorological factors. Vitamin D status was classified as follows: severe deficiency: <10 ng/mL; deficiency: <20 ng/mL; insufficiency: <30 ng/mL; and sufficiency: ≥30 ng/mL. The results showed that vitamin D deficiency is highly prevalent in Yunnan Province in a hospital-based cohort, with a deficiency and severe deficiency rate of 65.1% and a sufficiency rate of 5.30%. Significantly lower vitamin D levels and sufficiency rates were observed in females than in males (20.13 ± 7.22 ng/mL vs. 17.56 ± 6.66 ng/mL and 8.20% vs. 4.20%; p < 0.01, respectively); in spring and winter (16.93 ± 6.24 ng/mL; 2.97% and 16.38 ± 6.43 ng/mL; 3.06%, respectively) than in summer and autumn (20.23 ± 7.14 ng/mL; 8.02% and 19.10 ± 6.97 ng/mL; 6.61% [p < 0.01], respectively); and in older individuals (0-6 years: 28.29 ± 13.13 ng/mL vs. >60 years: 14.88 ± 8.39 ng/mL; p < 0.01). Relatively higher vitamin D levels were observed in individuals of Yi, Zhuang, Hani, Dai, Miao and Lisu minorities and lower levels in individuals of Hui and Zang minorities compared with those of the Han nationality (p < 0.01). The mean sunlight duration, mean air temperature, maximum ultraviolet value and latitude were significantly correlated with vitamin D levels (r = -0.53, 0.60, 0.31, -0.68, respectively; p < 0.05). These results suggest that vitamin D status is influenced by sex, age, minority, latitude and some meteorological factors in areas with high and low altitudes. Hence, new public health policies, such as advice on sunshine exposure, food fortification and nutrition education, as well as the implementation of vitamin D supplementation programmes must be considered to alleviate vitamin D deficiency in Yunnan province, Southwest China.

About the associations of vitamin D deficiency and biomarkers of systemic inflammatory response with all-cause and cause-specific mortality in a general population sample of almost 400,000 UK Biobank participants

It is unknown whether the well-known association between vitamin D deficiency and mortality could be explained by the immune system modulating effects of vitamin D, which may protect from a systemic inflammatory response (SIR) to adverse health conditions. This study aims to investigate the interrelationships of vitamin D deficiency, biomarkers of SIR, and mortality. We used multivariate logistic regression with adjustment for 51 covariates to assess the associations of vitamin D deficiency with disadvantageous levels of nine biomarkers of SIR in the UK Biobank cohort. Furthermore, we tested with Cox regression and mediation analysis whether biomarkers of SIR and vitamin D deficiency were independently associated with mortality. We included 397,737 participants aged 37-73 years. Vitamin D deficiency was associated with disadvantageous levels of all blood cell count-based biomarkers, but not with C-reactive protein (CRP)-based biomarkers after adjustment for body weight. Vitamin D deficiency and all biomarkers of SIR were significantly associated with all-cause mortality and mortality from cancer, cardiovascular and respiratory disease. The strength of these associations was unaltered if vitamin D deficiency and biomarkers of SIR were put in the same model. This finding was further supported by the mediation analyses. This study showed that vitamin D deficiency is associated with disadvantageous levels of blood cell count-based but not CRP-based biomarkers of SIR. Vitamin D deficiency and systemic inflammation were independently and strongly associated with mortality. The potential of clinical interventions against both vitamin D deficiency and underlying causes of systemic inflammation should be explored.

Association of plasma zinc levels with anti-SARS-CoV-2 IgG and IgA seropositivity in the general population: A case-control study

INTRODUCTION

Some micronutrients have key roles in immune defence, including mucosal defence mechanisms and immunoglobulin production. Altered micronutrient status has been linked with COVID-19 infection and disease severity. We assessed the associations of selected circulating micronutrients with anti-SARS-CoV-2 IgG and IgA seropositivity in the Swiss community using early pandemic data.

METHODS

Case-control study comparing the first PCR-confirmed COVID-19 symptomatic cases in the Vaud Canton (May to June 2020, n = 199) and controls (random population sample, n = 447), seronegative for IgG and IgA. The replication analysis included seropositive (n = 134) and seronegative (n = 152) close contacts from confirmed COVID-19 cases. Anti-SARS-CoV-2 IgG and IgA levels against the native trimeric spike protein were measured using the Luminex immunoassay. We measured plasma Zn, Se and Cu concentrations by ICP-MS, and 25-hydroxy-vitamin D₃ (25(OH)D₃) with LC-MS/MS and explored associations using multiple logistic regression.

RESULTS

The 932 participants (54.1% women) were aged 48.6 ± 20.2 years (±SD), BMI 25.0 ± 4.7 kg/m² with median C-Reactive Protein 1 mg/l. In logistic regressions, log₂(Zn) plasma levels were negatively associated with IgG seropositivity (OR [95% CI]: 0.196 [0.0831; 0.465], P < 0.001; replication analyses: 0.294 [0.0893; 0.968], P < 0.05). Results were similar for IgA. We found no association of Cu, Se, and 25(OH)D₃ with anti-SARS-CoV-2 IgG or IgA seropositivity.

CONCLUSION

Low plasma Zn levels were associated with higher anti-SARS-CoV-2 IgG and IgA seropositivity in a Swiss population when the initial viral variant was circulating, and no vaccination available. These results suggest that adequate Zn status may play an important role in protecting the general population against SARS-CoV-2 infection.

REGISTRY

CORONA IMMUNITAS:: ISRCTN18181860.

Real-world evidence for the effectiveness of vitamin D supplementation in reduction of total and cause-specific mortality

BACKGROUND

Meta-analyses of randomized controlled trials (RCTs) have demonstrated the efficacy of vitamin D supplementation for reduced cancer mortality, all-cause mortality, and respiratory tract infections. However, whether and to what extent this translates into effectiveness in real-world practice is unknown.

METHODS

We assessed the association of vitamin D supplement use (as an over-the-counter drug or as part of a multivitamin product), vitamin D deficiency (25-hydroxyvitamin D, 25[OH]D <30 nmol/L), and insufficiency (25[OH]D 30 to <50 nmol/L) with all-cause and cause-specific mortality in 445,601 participants, aged 40-73 years, from the UK Biobank cohort.

RESULTS

A total of 4.3% and a further 20.4% of the study participants reported regularly taking vitamin D or multivitamin supplements, respectively. Still, the majority had either vitamin D deficiency (21.0%) or insufficiency (34.3%). We detected 49 independent determinants of vitamin D deficiency and vitamin D supplement use and used them to adjust Cox regression models for all mortality outcomes. A total of 29,107 (6.5%) participants died during a median follow-up time of 11.8 years. Both vitamin D deficiency and insufficiency were strongly associated with all mortality outcomes. Self-reported vitamin D supplement use (83% over-the-counter/17% prescription drugs) and multivitamin intake were significantly associated with 10% and 5% lower all-cause mortality, respectively. Furthermore, regular vitamin D supplement users had 11%, 11%, and 29% lower cancer, cardiovascular disease, and respiratory disease mortality than nonusers, respectively (not significant for cardiovascular disease mortality).

CONCLUSION

This large study suggests that in the real world, the efficacy of vitamin D supplements in reducing mortality may be at least as good as observed in RCTs.

Vitamin D-Related Risk Factors for Maternal Morbidity during Pregnancy: A Systematic Review

Vitamin D has well-defined classical functions related to metabolism and bone health but also has non-classical effects that may influence pregnancy. Maternal morbidity remains a significant health care concern worldwide, despite efforts to improve maternal health. Nutritional deficiencies of vitamin D during pregnancy are related to adverse pregnancy outcomes, but the evidence base is difficult to navigate. The primary purpose of this review is to map the evidence on the effects of deficiencies of vitamin D on pregnancy outcome and the dosage used in such studies. A systematic search was performed for studies on vitamin D status during pregnancy and maternal outcomes. A total of 50 studies came from PubMed, 15 studies came from Cochrane, and 150 studies came from Embase, for a total of 215 articles. After screening, 34 were identified as candidate studies for inclusion. Finally, 28 articles met the inclusion criteria, which originated from 15 countries. The studies included 14 original research studies and 13 review studies conducted between 2012 and 2021. This review was finally limited to the 14 original studies. This systematic review was conducted according to the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines, and the quality and strength of the evidence was evaluated using the Navigation Guide Systematic Review Methodology (SING). We found evidence that supports the idea that supplementary vitamin D for pregnant women is important for reducing the risk of gestational diabetes, hypertension, preeclampsia, early labor, and other complications. The data retrieved from this review are consistent with the hypothesis that adequate vitamin D levels might contribute to a healthy pregnancy.

Effect of vitamin D supplementation on cardiac-metabolic risk factors in elderly: a systematic review and meta-analysis of clinical trials

BACKGROUND

There has been a longstanding interest in the potential effect of vitamin D in preventing cardiac-metabolic diseases. However, there are divergent results regarding the impact of vitamin D supplementation (VDS) on managing cardiac-metabolic outcomes in the elderly population.

MATERIAL AND METHOD

We systematically searched electronic databases; Web of Science, PubMed, Scopus, EMBASE, Cochrane, and ProQuest. We included all trials that evaluated the effect of VDS on cardiac-metabolic risk factors in the elderly population, which were published until 30 September 2021. The effects of VDS on cardiac-metabolic outcomes were assessed using standardized mean difference (SMD). A random-effect model was used to pool the SMD and 95% confidence interval (CI).

RESULT

The literature search identified 4409 studies, of which 12 trials met inclusion criteria. Results of random effect meta-analysis indicated a significant reduction in total cholesterol (TC) (SMD: - 0.14 mg/dl; 95% CI: - 0.25, - 0.02) and triglyceride (TG) (SMD: - 0.45 mg/dl; 95% CI: - 0.86, - 0.04) with VDS compared to the placebo. The subgroup analyses revealed that the reduction of TG in patients with diabetes and vitamin D deficiency was significant. Furthermore, short-term intervention (≤ 6 months) induced a significantly lower level of TG and insulin in comparison to longer duration (> 6 months).

CONCLUSION

The study suggests that VDS could improve insulin concentration and dyslipidemia in the elderly population. The systematic review was registered in Alborz university of medical sciences with 2060-01-03-1397 number and the Ethics council IR.ABZUMS.REC.1397.207 number.

Effects of Vitamin D Levels on Cardiovascular Diseases: A Systematic Review

Background:

Cardiovascular diseases (CVDs) are a group of pathologies that involve heart and blood vessel disorders and are considered the main cause of death in the world. Epidemiological studies have shown the association between low vitamin D (VD) levels and CVD. This vitamin, in addition to acting on bone metabolism, plays a role in modulating the cardiovascular system.

Objective:

The present study assesses the effects of VD levels on CVD through a systematic literature review.

Method:

For this purpose, the PICO strategy was used to prepare the guiding question, and articles were searched in the PubMed, Scopus, Science Direct, and Web of Science databases by two authors independently. To guarantee the quality of the evidence of the articles included in the review, the Newcastle-Ottawa scale was used. The literature review followed the PRISMA recommendations.

Results:

In this review, 22,757 articles were identified, but only 10 were considered eligible, of which 70% are prospective cohorts and 30% are retrospective cohorts. The study showed that low 25(OH)D levels correlate with an increased risk of cardiovascular events and death from CVD, including in patients who had preexisting CVD. However, one article did not demonstrate this association.

Conclusion:

As a result, VD correlates with cardiovascular events and the risk of death.

Vitamin D Deficiency Is Significantly Associated with Retinopathy in Type 2 Diabetes Mellitus: A Case-Control Study

AIM

Results from meta-analyses point to an association between vitamin D deficiency and the onset of diabetic retinopathy (DR). The objectives of the present study were to evaluate the association of vitamin D for the development of DR and to determine the levels of vitamin D associated with a greater risk of DR.

METHODS

Between November 2013 and February 2015, we performed a case-control study based on a sample of patients with diabetes in Spain. The study population comprised all patients who had at least one evaluable electroretinogram and recorded levels of 25(OH)D. We collected a series of analytical data: 25(OH)D, 1,25(OH)2D, iPTH, calcium, albumin, and HbA1c. Glycemic control was evaluated on the basis of the mean HbA1c values for the period 2009-2014. A logistic regression analysis was performed to identify the variables associated with DR.

RESULTS

The final study sample comprised 385 patients, of which 30 (7.8%) had DR. Significant differences were found between patients with and without DR for age (69.54 vs. 73.43), HbA1c (6.68% vs. 7.29%), years since diagnosis of diabetes (10.9 vs. 14.17), level of 25(OH)D (20.80 vs. 15.50 ng/mL), level of 1,25(OH)2D (35.0 vs. 24.5 pg/mL), treatment with insulin (14.9% vs. 56.7%), hypertension (77.7% vs. 100%), cardiovascular events (33.2% vs. 53.3%), and kidney failure (22.0% vs. 43.3%). In the multivariate analysis, the factors identified as independent risk factors for DR were treatment of diabetes (p = 0.001) and 25(OH)D (p = 0.025). The high risk of DR in patients receiving insulin (OR 17.01) was also noteworthy.

CONCLUSIONS

Levels of 25(OH)D and treatment of diabetes were significantly associated with DR after adjusting for other risk factors. Combined levels of 25(OH)D < 16 ng/mL and levels of 1,25(OH)2D < 29 pg/mL are the variables that best predict the risk of having DR with respect to vitamin D deficiency. The risk factor with the strongest association was the treatment of type 2 diabetes mellitus. This was particularly true for patients receiving insulin, who had a greater risk of DR than those receiving insulin analogues. However, further studies are necessary before a causal relationship can be established.

Vitamin D and Multiple Health Outcomes: An Umbrella Review of Observational Studies, Randomized Controlled Trials, and Mendelian Randomization Studies

Observational studies, randomized controlled trials (RCTs), and Mendelian randomization (MR) studies have yielded inconsistent results on the associations of vitamin D concentrations with multiple health outcomes. In the present umbrella review we aimed to evaluate the effects of low vitamin D concentrations and vitamin D supplementation on multiple health outcomes. We summarized current evidence obtained from meta-analyses of observational studies that examined associations between vitamin D concentrations and multiple health outcomes, meta-analyses of RCTs that investigated the effect of vitamin D supplementation on multiple health outcomes, and MR studies that explored the causal associations of vitamin D concentrations with various diseases (international prospective register of systematic reviews PROSPERO registration number CRD42018091434). A total of 296 meta-analyses of observational studies comprising 111 unique outcomes, 139 meta-analyses of RCTs comprising 46 unique outcomes, and 73 MR studies comprising 43 unique outcomes were included in the present umbrella review. Twenty-eight disease outcomes were identified by both meta-analyses of observational studies and MR studies. Seventeen of these reported disease outcomes had consistent results, demonstrating that lower concentrations of vitamin D were associated with a higher risk for all-cause mortality, Alzheimer's disease, hypertension, schizophrenia, and type 2 diabetes. The combinations of consistent evidence obtained by meta-analyses of observational studies and MR studies together with meta-analyses of RCTs showed that vitamin D supplementation was associated with a decreased risk for all-cause mortality but not associated with the risk for Alzheimer's disease, hypertension, schizophrenia, or type 2 diabetes. The results indicated that vitamin D supplementation is a promising strategy with long-term preventive effects on multiple chronic diseases and thus has the potential to decrease all-cause mortality. However, the current vitamin D supplementation strategy might not be an efficient intervention approach for these diseases, suggesting that new strategies are highly needed to improve the intervention outcomes.

Socioeconomic status and vitamin D deficiency among women of childbearing age: a population-based, case-control study in rural northern China

OBJECTIVE

To explore the association between socioeconomic status (SES) and vitamin D deficiency/insufficiency of women of childbearing age in rural northern China.

DESIGN

A population-based, case-control study was conducted.

SETTING

Four counties of Henan Province, China from 2009 to 2010.

PARTICIPANTS

1151 non-pregnant healthy women between 18 and 40 years old.

PRIMARY AND SECONDARY OUTCOME MEASURES

Serum 25-hydroxyvitamin D (25(OH)D) levels were measured using high-performance liquid chromatography-tandem mass spectrometry. Vitamin D insufficiency was defined as serum 25(OH)D ≥20 ng/mL and <30 ng/mL, deficiency as ≥10 ng/mL and <20 ng/mL, and severe deficiency as <10 ng/mL. SES was measured separately by women's and their husbands' education level and occupation, household income and expenditure, as well as aggregately by SES index constructed with principal component analysis.

RESULTS

The median serum 25(OH)D level was 20.90 (13.60-34.60) ng/mL, and the prevalence of vitamin D insufficiency, deficiency and severe deficiency was 20.16%, 31.80% and 15.99%, respectively. After adjustment, household annual income <¥10 000 was associated with increased risk of vitamin D insufficiency (adjusted OR (aOR): 2.10, 95% CI 1.41 to 3.14), deficiency (aOR: 1.58, 95% CI 1.09 to 2.29) and severe deficiency (aOR: 2.79, 95% CI 1.78 to 4.38); inadequate household income for expenditure was associated with elevated risk of vitamin D insufficiency (aOR: 1.66, 95% CI 1.08 to 2.54) and deficiency (aOR: 1.81, 95% CI 1.26 to 2.62); low SES index was associated with elevated risk of vitamin D insufficiency (aOR: 2.40, 95% CI 1.52 to 3.80) and deficiency (aOR: 1.64, 95% CI 1.08 to 2.50); and both middle and low SES index were associated with increased risk of vitamin D severe deficiency (aOR: 1.70, 95% CI 1.02 to 2.84; aOR: 2.45, 95% CI 1.45 to 4.14).

CONCLUSIONS

Lower SES was associated with higher risk of vitamin D deficiency/insufficiency in women of childbearing age in rural northern China. More should be done to explore potential mechanisms and to narrow down SES inequalities in vitamin D status.

Prostate cancer management: long-term beliefs, epidemic developments in the early twenty-first century and 3PM dimensional solutions

In the early twenty-first century, societies around the world are facing the paradoxal epidemic development of PCa as a non-communicable disease. PCa is the most frequently diagnosed cancer for men in several countries such as the USA. Permanently improving diagnostics and treatments in the PCa management causes an impressive divergence between, on one hand, permanently increasing numbers of diagnosed PCa cases and, on the other hand, stable or even slightly decreasing mortality rates. Still, aspects listed below are waiting for innovate solutions in the context of predictive approaches, targeted prevention and personalisation of medical care (PPPM / 3PM).A.PCa belongs to the cancer types with the highest incidence worldwide. Corresponding economic burden is enormous. Moreover, the costs of treating PCa are currently increasing more quickly than those of any other cancer. Implementing individualised patient profiles and adapted treatment algorithms would make currently too heterogeneous landscape of PCa treatment costs more transparent providing clear "road map" for the cost saving.B.PCa is a systemic multi-factorial disease. Consequently, predictive diagnostics by liquid biopsy analysis is instrumental for the disease prediction, targeted prevention and curative treatments at early stages.C.The incidence of metastasising PCa is rapidly increasing particularly in younger populations. Exemplified by trends observed in the USA, prognosis is that the annual burden will increase by over 40% in 2025. To this end, one of the evident deficits is the reactive character of medical services currently provided to populations. Innovative screening programmes might be useful to identify persons in suboptimal health conditions before the clinical onset of metastasising PCa. Strong predisposition to systemic hypoxic conditions and ischemic lesions (e.g. characteristic for individuals with Flammer syndrome phenotype) and low-grade inflammation might be indicative for specific phenotyping and genotyping in metastasising PCa screening and disease management. Predictive liquid biopsy tests for CTC enumeration and their molecular characterisation are considered to be useful for secondary prevention of metastatic disease in PCa patients.D.Particular rapidly increasing PCa incidence rates are characteristic for adolescents and young adults aged 15-40 years. Patients with early onset prostate cancer pose unique challenges; multi-factorial risks for these trends are proposed. Consequently, multi-level diagnostics including phenotyping and multi-omics are considered to be the most appropriate tool for the risk assessment, prediction and prognosis. Accumulating evidence suggests that early onset prostate cancer is a distinct phenotype from both aetiological and clinical perspectives deserving particular attention from view point of 3P medical approaches.

The association between circulating 25-hydroxyvitamin D and cardiovascular diseases: a meta-analysis of prospective cohort studies

BACKGROUND

There is a controversy about the association between vitamin D and cardiovascular diseases (CVDs). The effect of serum 25-OH-vitD on the risk of CVDs was evaluated.

METHODS

Major electronic databases including Scopus, Science Direct, and PubMed were searched. All prospective cohort studies on the relationship between vitamin D status and CVDs conducted between April 2000 and September 2017 were included, regardless language. The study participants were evaluated regardless of their age, sex, and ethnicity. The Newcastle-Ottawa Scale was used to assess the quality of the studies. Two investigators independently selected the studies and extracted the data. The designated effects were risk ratio (RR) and hazard ratio (HR). The random effects model was used to combine the results.

RESULTS

A meta-analysis of 25 studies with 10,099 cases of CVDs was performed. In general, a decrease in the level of vitamin D was associated with a higher relative risk of CVDs (incidence-mortality combined) (RR = 1.44, 95% CI: 1.24-1.69). This accounts for 54% of CVDs mortality rate (RR = 1.54, 95% CI: 1.29-1.84(. However, no significant relationship was observed between the vitamin D status and incidence of CVDs (RR = 1.18, 95% CI: 1-1.39). In general, low serum vitamin D level increased the risk of CVD by 44% (RR = 1.44, 95% CI: 1.24-1.69). It also increased the risk of CVD mortality (RR = 1.54, 95% CI: 1.29-1.84) and incidence rates (RR = 1.18, 95% CI: 1-1.39).

CONCLUSIONS

The findings showed that vitamin D deficiency increases the CVDs mortality rate. Due to the limited number of studies on patients of the both genders, further research is suggested to separately evaluate the effect of vitamin D status on CVD in men and women.

Vitamin D as a Biomarker of Ill Health among the Over-50s: A Systematic Review of Cohort Studies

Background: The association between circulating levels of vitamin D and the incidence of chronic diseases is known. The identification of vitamin D as a biomarker of physiological/pathological ageing could contribute to expanding current knowledge of its involvement in healthy ageing. Methods: According to PRISMA guidelines, a systematic review was conducted on cohorts studying the role of 25OH-Vitamin D [25(OH)D] and 1,25(OH)₂-Vitamin D [1,25(OH)₂D] concentrations as biomarkers of healthy ageing. We consulted MedLine, Scopus, and Web of Science to search for studies on the association between vitamin D status in populations of originally healthy adults, and outcomes of longevity, illness, and physical and cognitive functionality. The quality of the studies was assessed using the Newcastle Ottawa scale. Results: Twenty cohorts from 24 articles were selected for this review. Inverse associations were found between low 25(OH)D levels and all-cause mortality, respiratory and cardiovascular events, as well as markers relating to hip and non-vertebral fractures. Associations between 1,25(OH)₂D and healthy ageing outcomes gave similar results, although of lower clinical significance. Conclusions: This systematic review pinpoints peculiar aspects of vitamin D as a multidimensional predictor of ill health in the ageing process. Further well-designed controlled trials to investigate whether vitamin D supplement results in superior outcomes are warranted in the future.

Associated vitamin D deficiency is a risk factor for the complication of HCV-related liver cirrhosis including hepatic encephalopathy and spontaneous bacterial peritonitis

The influence of vitamin D, 25-hydroxyvitamin D (25(OH)D), deficiency on hepatitis C virus (HCV)-related cirrhosis had been poorly elucidated especially in patients with hepatic encephalopathy (HE) and spontaneous bacterial peritonitis (SBP). We aimed to investigate the association between vitamin D deficiency and the risk of SBP or HE, including the mortality rate. Serum 25(OH)D levels were prospectively determined in 135 patients. Of them, 45 patients had complications with HE and 45 patients had complications with SBP; 45 cirrhotic patients without complication served as the control group. Vitamin D deficiency was defined as 25(OH)D levels < 20 ng/ml. Receiver operating characteristic (ROC) and Kaplan-Meier method with log-rank test were used in our statistical analysis. Predictors of survival were determined using Cox regression analysis. Serum 25(OH)D levels were significantly (P < 0.05) lower in the HE and SBP groups than in the control group (6.81 ± 2.75, 7.15 ± 2.10, 16.28 ± 6.60, respectively). Moreover, serum 25(OH)D levels were significantly lower in the high HE grade than in the low grade (P < 0.001). Regarding the SBP group, classic SBP was associated with lower 25(OH)D levels compared to other types (P < 0.001). ROC curve revealed that lower 25(OH)D levels less than 7.1 ng/ml and 6.6 ng/ml could predict the mortality in SBP and HE patients, respectively, with high sensitivity and specificity. Serum 25(OH)D levels < 5 ng/ml were associated with significant higher mortality rate (HR = 2.76, P = 0.001). Lower 25(OH)D levels were associated with HE and SBP in cirrhotic patients. In addition, it may be considered a prognostic parameter for the severity of liver cirrhosis.

When and How to Diagnose and Treat Vitamin D Deficiency in Adults: A Practical and Clinical Update

Vitamin D deficiency is considered a major public health concern. Inadequate sun exposure, limited oral intake, and impaired intestinal absorption are common risk factors for vitamin D deficiency. An increasing amount of research is aimed at answering questions regarding the most convenient test that can assess vitamin D status, the indications for screening, and finally the utility of treatments for vitamin D deficiency. Our review outlines practical strategies to diagnose and treat vitamin D deficiency in adults. This study was undertaken in the PubMed and the Google Scholar databases in April 2018 without limitation as to the publication period. Vitamin D status is determined by measuring the 25-hydroxyvitamin D serum concentration. However, this technique has several limitations. Determining the accurate thresholds for vitamin D deficiency is still a matter of debate. Only individuals at risk for vitamin D deficiency should be screened. The symptoms of vitamin D deficiency are unspecific and very common. Therefore, physicians may easily suspect vitamin D deficiency, measure 25-hydroxyvitamin D levels, and sometimes overprescribe supplementation. Hypovitaminosis D could rarely be treated by increasing consumption of foods naturally containing and fortified with vitamin D. Special attention should be given to vitamin D supplementation to prevent adverse effects. No safe and well-defined threshold of ultraviolet exposure allows adequate vitamin D synthesis without increasing the risk of skin cancer. Unanimous and decisive guidelines are urgently needed to improve knowledge and practices related to vitamin D deficiency.

The Effect of Long-Term Cholecalciferol Supplementation on Vascular Calcification in Chronic Kidney Disease Patients With Hypovitaminosis D

OBJECTIVE

The role of vitamin D supplementation on vascular calcification (VC) in patients with chronic kidney disease (CKD) is controversial. The objective of this study was to evaluate the effects of long-term cholecalciferol supplementation on VC in nondialysis patients with CKD stages 3-4 with hypovitaminosis D.

DESIGN AND METHODS

Eighty patients aged 18-85 years with creatinine clearance between 15 and 60 mL/min/1.73 m² and serum 25(OH)D level < 30 ng/mL were enrolled in a 18-month prospective study. Individuals with vitamin D insufficiency (25-hydroxyvitamin D [25(OH)D] level between 16 and 29 ng/mL) were included in a randomized, double-blind, two-arm study to receive cholecalciferol or placebo. Patients with vitamin D deficiency [25(OH)D < 15 ng/mL] were included in an observational study and mandatorily received cholecalciferol. The coronary artery calcium score was obtained by multislice computed tomography at baseline and the 18th month.

RESULTS

During the study, VC did not change in the treated insufficient group (418 [81-611] to 364 [232-817] AU, P = 0.25) but increased in the placebo group (118 [37-421] to 199 [49-490] AU, P = 0.01). The calcium score change was inversely correlated with 25(OH)D change (r = -0.45; P = 0.037) in the treated insufficient group but not in the placebo group. Renal function did not change in the insufficient, treated, and placebo groups. In multivariate analysis, there was no difference in VC progression between the treated and placebo insufficient groups (interaction P = 0.92). In the deficient group, VC progressed (265 [84-733] to 333 [157-745] AU; P = 0.006) and renal function declined (33 [26-43] to 23 [17-49] mL/min/1.73 m²; P = 0.04). The calcium score change was inversely correlated with cholecalciferol cumulative doses (r = -0.41; P = 0.048) and kidney function change (r = -0.43; P = 0.033) but not with 25(OH)D change (r = -0.08; P = 0.69).

CONCLUSION

Vitamin D supplementation did not attenuate VC progression in CKD patients with hypovitaminosis D.

CONCLUSION

Vitamin D supplementation did not attenuate VC progression in CKD patients with hypovitaminosis D.

Vitamin D Is Inversely Related to Obesity: Cross-Sectional Study in a Small Cohort of Serbian Adults

Objective: Vitamin D (vitD) mediates numerous health conditions other than bone health and mineralization. Its role in cardiometabolic condition is still inconclusive. Methods: We conducted a cross-sectional study in 87 apparently healthy Serbian adults. We assessed their dietary intake, anthropometric and biochemical parameters, blood pressure, and vitD status (as serum 25-hydroxyvitamin D, 25(OH)D). Unexpectedly, the status was significantly higher in January than in July. Therefore, we pooled the data from two time points, to enhance the statistical power for carrying out association analyses. We employed linear regression models to evaluate the associations between vitD status and the obesity biomarkers of serum lipids and blood pressure. Results: Mean vitD intake of 3.85 ± 4.71 μg in the cohort was below recommended. Of the subjects in the pooled cohort, 60.58% were vitD deficient (with serum 25(OH)D below 50 nmol/L), with the majority of them being women who were overweight. VitD status tended to be inversely related to percent body fat and waist/height ratio in the crude regression model. After age and gender adjustment, the status was significantly related to waist circumference, waist/height ratio, and waist/hip ratio (β = -0.116, 95% confidence interval [CI]: -0.206, -0.025, β = -0.001, 95% CI: -0.001, 0.000, and β = -0.001, 95% CI: -0.001, 0.000, respectively). These associations remained only within women. Fully adjusted models supported the notion of vitD being independently associated with central adiposity, regardless of age, gender, and total obesity. Conclusions: In apparently healthy adults with low vitD intake, vitD status was inversely associated with obesity parameters, pronouncedly in women. Our data support the need for development and implementation of public health policies on increasing vitD intake also as part of obesity management strategies.

Vitamin D's role in health and disease: How does the present inform our understanding of the past?

While the role of vitamin D in supporting bone homeostasis during growth and maintenance is well substantiated, emerging evidence from ecological and observational studies suggests that a deficiency of vitamin D is associated with some cancers, immune disorders, cardiovascular disease, abnormal glucose metabolism, and neurodegenerative diseases. Biological plausibility for extraskeletal functions originated with the discovery of the vitamin D receptor in many body tissues and knowledge that the conversion of 25-hydroxyvitamin D (25(OH)D) to its active metabolite 1,25(OH)₂D occurs in many cell types in addition to the kidney. The association of vitamin D status in humans as an etiological factor in developmental programming of bone, in some chronic diseases, and in all-cause mortality, in addition to skeletal morbidity, is supported by some but not all observational studies and randomized controlled trials. These clinical observations have implications for paleopathology, both in terms of specific comorbidities and the potential role of vitamin D in individuals who display no evidence for skeletal disease. This paper outlines recent clinical research on vitamin D metabolism and its novel biological roles, and explores the possible relevance to paleopathological research designs, theoretical models, and interpretations of disease experience.

Serum 25-Hydroxyvitamin D Values and Risk of All-Cause and Cause-Specific Mortality: A Population-Based Cohort Study

OBJECTIVE

To determine the relationship between 25-hydroxyvitamin D (25[OH]D) values and all-cause and cause-specific mortality.

PATIENTS AND METHODS

We identified all serum 25(OH)D measurements in adults residing in Olmsted County, Minnesota, between January 1, 2005, and December 31, 2011, through the Rochester Epidemiology Project. All-cause mortality was the primary outcome. Patients were followed up until their last clinical visit as an Olmsted County resident, December 31, 2014, or death. Multivariate analyses were adjusted for age, sex, race/ethnicity, month of measurement, and Charlson comorbidity index score.

RESULTS

A total of 11,022 individuals had a 25(OH)D measurement between January 1, 2005, and December 31, 2011, with a mean ± SD value of 30.0±12.9 ng/mL. Mean age was 54.3±17.2 years, and most were female (77.1%) and white (87.6%). There were 723 deaths after a median follow-up of 4.8 years (interquartile range, 3.4-6.2 years). Unadjusted all-cause mortality hazard ratios (HRs) and 95% CIs for 25(OH)D values of less than 12, 12 to 19, and more than 50 ng/mL were 2.6 (95% CI, 2.0-3.2), 1.3 (95% CI, 1.0-1.6), and 1.0 (95% CI, 0.72-1.5), respectively, compared with the reference value of 20 to 50 ng/mL. In a multivariate model, the interaction between the effect of 25(OH)D and race/ethnicity on mortality was significant (P<.001). In white patients, adjusted HRs for 25(OH)D values of less than 12, 12 to 19, 20 to 50, and greater than 50 ng/mL were 2.5 (95% CI, 2.2-2.9), 1.4 (95% CI, 1.2-1.6), 1.0 (referent), and 1.0 (95% CI, 0.81-1.3), respectively. In patients of other race/ethnicity, adjusted HRs were 1.9 (95% CI, 1.5-2.3), 1.7 (95% CI, 1.1-2.6), 1.5 (95% CI, 1.0-2.0), and 2.1 (95% CI, 0.77-5.5).

CONCLUSION

White patients with 25(OH)D values of less than 20 ng/mL had greater all-cause mortality than those with values of 20 to 50 ng/mL, and white patients had greater mortality associated with low 25(OH)D values than patients of other race/ethnicity. Values of 25(OH)D greater than 50 ng/mL were not associated with all-cause mortality.

Lower vitamin D levels in Saudi pregnant women are associated with higher risk of developing GDM

BACKGROUND

Gestational diabetes mellitus (GDM) has serious consequences such as increased risks of preeclampsia, macrosomia and cesarean delivery. Even though the mechanistic basis of GDM has not been completely understood, several risk factors have been identified and one of these is vitamin D. However, the link between vitamin D deficiency and development of GDM is yet to be proven with certainty.

METHODS

This study aimed to investigate the link between the incidence of GDM and serum vitamin D level in pregnant women of Saudi Arabia. 515 Saudi women (ages 18-46) in their 24-28th week of pregnancy, visiting various hospitals of Riyadh, participated in this study. Serum vitamin D and various biochemical and anthropometric parameters were determined in the first trimester and the recruits were screened for GDM by OGTT according to IADPSG criteria in their 2nd trimester. The association between vitamin D deficiency and development of GDM was calculated based on odds ratio of the incidence of GDM among vitamin D deficient and normal women.

RESULTS

In this study cohort of 515 pregnant women, in the first trimester vitamin D deficiency (< 50 nmol/l) was detected in 425 (82.5%). On their 2nd visit (2nd trimester), 116 (27.7%) were diagnosed with GDM out of 419 with OGTT, according to IADPSG criteria. GDM risk was significantly higher among vitamin D deficient than non-deficient women (Odds Ratio: 2.87; Confidence Interval: 1.32-6.25; P = 0.008) even after adjusting for season, sun exposure and vitamin D intake (OR: 2.9; CI: 1.07-7.89). Of the various anthropometric and biochemical parameters, the GDM women differed significantly from non-GDM women with respect to serum levels of triglycerides (in mmol/l) (1.3 ± 0.6; 1.5 ± 0.6, p = 0.018) and fasting glucose (in mmol/l) [4.7 (4.3-5.2); 5.1 (4.6-5.6), p < 0.01]. Also, fasting glucose level in the 2nd trimester correlated inversely to serum vitamin D level determined during the 1st trimester (r = - 0.121; p = 0.014).

CONCLUSIONS

Results of our study reveal a significantly higher risk of development of GDM among pregnant women having deficient vitamin D status.

Vitamin D and Ageing

One hundred years has passed since the discovery of vitamin D as the active component of cod-liver oil which cured the bone disease rickets. Since then our knowledge of vitamin D has expanded tremendously and has included recognition of the importance of UV radiation as a source of the vitamin as well as the discovery of the vitamin as a nutrient, a pro-hormone and a potent steroid hormone with a major role in calcium and bone metabolism. In the last 25 years or so, the discovery of the vitamin D receptor in over 30 different body tissues together with the existence of the alpha-1-hydroxylase enzyme in these tissues provided evidence of a pleiotropic role of vitamin D outside its classical role in the skeleton. These important discoveries have provided the basis for the increasing interest in vitamin D in the context of nutritional requirements for health including the prevention of chronic diseases of ageing. The recent publication of the Dietary Reference Intake report on vitamin D and calcium by the North American Institute of Medicine (IOM) is the most comprehensive report to date on the basis for setting nutritional requirements for vitamin D. This chapter will summarize the nutritional aspects of vitamin D and discuss the changes in vitamin D metabolism and requirements with ageing. It will summarize key evidence on the relationship between vitamin D status and some of the main ageing related health outcomes including bone, muscle and cognitive health as well as survival focusing on the published literature in very-old adults (those >= 85 years of age).

Vitamin D deficiency accelerates ageing and age-related diseases: a novel hypothesis

Ageing can occur at different rates, but what controls this variable rate is unknown. Here I have developed a hypothesis that vitamin D may act to control the rate of ageing. The basis of this hypothesis emerged from studyng the various cellular processes that control ageing. These processes such as autophagy, mitochondrial dysfunction, inflammation, oxidative stress, epigenetic changes, DNA disorders and alterations in Ca²⁺ and reactive oxygen species (ROS) signalling are all known to be regulated by vitamin D. The activity of these processes will be enhanced in individuals that are deficient in vitamin D. Not only will this increase the rate of ageing, but it will also increase the probability of developing age-related diseases such as Alzheimer's disease, Parkinson's disease, multiple sclerosis and cardiovascular disease. In individual with normal vitamin D levels, these ageing-related processes will occur at lower rates resulting in a reduced rate of ageing and enhanced protection against these age-related diseases.

Serum 25-hydroxyvitamin D level, chronic diseases and all-cause mortality in a population-based prospective cohort: the HUNT Study, Norway

OBJECTIVE

To investigate the association of vitamin D status with all-cause mortality in a Norwegian population and the potential influences of existing chronic diseases on the association.

DESIGN

A population-based prospective cohort study.

SETTING

Nord-Trøndelag County, Norway.

PARTICIPANTS

A random sample (n=6613) of adults aged 20 years or older in a cohort.

METHODS

Serum 25-hydroxyvitamin D (25(OH)D) levels were measured in blood samples collected at baseline (n=6377). Mortality was ascertained from the Norwegian National Registry. Cox regression models were applied to estimate the HRs with 95% CIs for all-cause mortality in association with serum 25(OH)D levels after adjustment for a wide spectrum of confounding factors as well as chronic diseases at baseline.

RESULTS

The median follow-up time was 18.5 years, during which 1539 subjects died. The HRs for all-cause mortality associated with the first quartile level of 25(OH)D (<34.5 nmol/L) as compared with the fourth quartile (≥58.1 nmol/L) before and after adjustment for chronic diseases at baseline were 1.30 (95% CI 1.11 to 1.51) and 1.27 (95% CI 1.09 to 1.48), respectively. In the subjects without chronic diseases at baseline and with further exclusion of the first 3 years of follow-up, the corresponding adjusted HR was 1.34 (95% CI 1.09 to 1.66).

CONCLUSIONS

Low serum 25(OH)D level was associated with increased all-cause mortality in a general Norwegian population. The association was not notably influenced by existing chronic diseases.

Vitamin D status among infants, children, and adolescents in southeastern China

OBJECTIVE

Vitamin D deficiency and insufficiency are global public health problems, which must first be identified before they can be appropriately addressed, and yet information is strikingly lacking in most parts of the Asia and Pacific region. The study aimed to document and account for the actual situation in Wenzhou on the southeastern coast of China.

SUBJECTS AND METHODS

Serum 25-hydroxyvitamin D levels among a total of 5845 infants, preschool children, school children, and adolescents aged 1-18 years were examined between March 2014 and February 2015.

RESULTS

Their mean levels were (110.2±26.8), (77.5±25.7), (55.6±15.4), and (47.2±13.9) nmol/L, respectively. Older age groups were involved in increasing risk of vitamin D deficiency and insufficiency. There were significant seasonal differences in its median level and prevalence of deficiency and insufficiency among school children and adolescents, but there was no significant sex difference in mean level and prevalence in any age group.

CONCLUSIONS

Vitamin D deficiency and insufficiency were prevalent among infants, preschool children, school children, and adolescents in Wenzhou. A vitamin D-rich diet and outdoor activities for 1-2 h per day under the natural conditions favorable to its endogeous synthesis do not suffice. The vitamin D status in Wenzhounese infants excelling over that in the US was the result of its supplementation thanks to the Chinese Medical Association recommendations, which should be consequently extended to more age groups. Life style shaped by socio-economic environments affects vitamin D status. Knowledge on the importance of vitamin D for healthy growth should be popularized.

Influence of NR3C1 and VDR polymorphisms on stable warfarin dose in patients with mechanical cardiac valves

OBJECTIVES

The aim of this study was to evaluate the associations between polymorphisms of VKORC1, CYP2C9, CYP4F2, NR3C1 and VDR genes and stable warfarin doses in Korean patients with mechanical heart valves.

METHODS

Seventeen single-nucleotide polymorphisms (SNPs) in 204 patients with stable warfarin dose were analyzed: VKORC1 (rs9934438), CYP2C9 (rs1057910), CYP4F2 (rs2108622), NR3C1 (rs41423247, rs1800445, rs56149945, rs10052957, rs6198, rs33388, rs6196, and rs244465), and VDR (rs1544410, rs11568820, rs731236, rs757343, rs7975232, and rs2228570). Statistical analyses were conducted to evaluate the associations of gene variations with stable warfarin dose. Number needed to genotype was obtained by calculating the percentage of patients whose predicted dose was at least 20% higher or lower than the actual stable dose.

RESULTS

The combined genotypes of rs7975232 and rs2228570 of the VDR gene revealed a significant association with stable warfarin dose, along with VKORC1, CYP2C9, and CYP4F2 polymorphisms. Patients with the genotype combination GT,TT/CT,CC of VDR rs7975232/rs2228570 required significantly higher stable warfarin dose (5.79±2.02mg) than those with the other genotypic combinations (5.19±1.78mg, p=0.034). Multivariate analysis showed that VDR rs7975232/rs2228570 explained 2.0% of the 47.5% variability in overall warfarin dose. Adding VDR SNP combinations to the base model including non-genetic variables (age, sex, and body weight) and genetic variables (VKORC1 rs9934438, CYP2C9 rs1057910, and CYP4F2 rs2108622) gave a number needed to genotype of 41.

CONCLUSIONS

This study showed that stable warfarin dose is associated with VDR SNPs along with VKORC1, CYP2C9, and CYP4F2 SNPs.

Low vitamin D levels increase the risk of type 2 diabetes in older adults: A systematic review and meta-analysis

Low serum levels of 25 hydroxyvitamin D (25OHD) (hypovitaminosis D) is common in older adults and associated with several negative outcomes. The association between hypovitaminosis D and diabetes in older adults is equivocal, however. We conducted a meta-analysis investigating if hypovitaminosis D is associated with diabetes in prospective studies among older participants. Two investigators systematically searched major electronic databases, from inception until 10/07/2016. The cumulative incidence of diabetes among groups was estimated according to baseline serum 25OHD levels. Random effect models were used to assess the association between hypovitaminosis D and diabetes at follow-up. From 4268 non-duplicate hits, 9 studies were included; these followed 28,258 participants with a mean age of 67.7 years for a median of 7.7 years. Compared with higher levels of 25OHD, lower levels of 25OHD were associated with a higher risk of developing diabetes (6 studies; n=13,563; RR=1.31; 95% CI: 1.11-1.54; I²=37%). The findings remained significant after adjusting for a median of 11 potential confounders in all the studies available (9 studies; n=28,258; RR=1.17; 95% CI: 1.03-1.33; p=0.02; I²=0%). In conclusion, our data suggest that hypovitaminosis D is associated with an elevated risk of future diabetes in older people. Future longitudinal studies are required and should seek to confirm these findings and explore potential pathophysiological underpinnings.

Dysfunctional immunometabolic effects of vitamin D deficiency, increased cardiometabolic risk. Potential epidemiological alert in America?

Vitamin D deficiency is a serious public health problem worldwide that affects not only skeletal health, but also a wide range of acute and chronic diseases. However, there is still skepticism because of the lack of randomized, controlled trials to support association studies on the benefits of vitamin D for non-skeletal health. This review was based on articles published during the 1980-2015 obtained from the Cochrane Central Register of controlled trials, MEDLINE and PubMed, and focuses on recent challenges with regard to the definition of vitamin D deficiency and how to achieve optimal serum 25-hydroxyvitamin D levels from dietary sources, supplements, and sun exposure. The effect of vitamin D on epigenetic fetal programming and regulation of genes that may potentially explain why vitamin D could have such lifelong comprehensive health benefits is reviewed. Optimization of vitamin D levels in children and adults around the world has potential benefits to improve skeletal health and to reduce the risk of chronic diseases, including some types of cancer, autoimmune diseases, infectious diseases, type 2 diabetes mellitus, and severe cardiovascular disorders such as atherothrombosis, neurocognitive disorders, and mortality.

Genetic Variants in the Vitamin D Pathway, 25(OH)D Levels, and Mortality in a Large Population-Based Cohort Study

CONTEXT

Low 25-hydroxyvitamin D [25(OH)D] concentrations have been consistently associated with excess mortality in epidemiological studies, but this association could be due to confounding by health impairments associated with low 25(OH)D levels. An association of vitamin D-related genetic variants with all-cause mortality could strengthen the claims of causality, because this association is assumed to be unaffected by confounding.

OBJECTIVE

To assess the associations of low 25(OH)D with mortality in the presence or absence of genetic variants in the vitamin D pathway.

DESIGN, SETTING, AND PARTICIPANTS

The study consisted of a population-based cohort of 8417 German older adults in whom genetic variants were genotyped.

MAIN OUTCOME MEASURES

The primary outcome measure was all-cause mortality.

RESULTS

Two single nucleotide polymorphisms (SNPs), rs3755967 (GC) and rs11603330 (DHCR7), were associated with higher risk of low vitamin D status [odds ratio (95% confidence interval) per minor allele, 1.27 (1.18 to 1.36) and 1.16 (1.08 to 1.25), respectively]. Low 25(OH)D (less than the season-specific 33rd percentile) was associated with increased mortality. However, none of the SNPs was associated with increased mortality. Furthermore, the increase in mortality for those with low 25(OH)D was generally smaller in the presence of the risk alleles for low 25(OH)D ["genetically low 25(OH)D"] than in the absence of those risk alleles ["otherwise low 25(OH)D"].

CONCLUSIONS

Although we may have been limited by a low statistical power to detect small associations, our study showed that the strong relationship between low 25(OH)D and increased mortality may be at least partly due to other factors related to low 25(OH)D levels.

Vitamin D Dosing Strategies Among Jordanians With Hypovitaminosis D

OBJECTIVE

To compare between weekly and daily cholecalciferol in patients with hypovitaminosis D and to determine the optimal maintenance dose.

METHODS

Seventy-one volunteers with hypovitaminosis D were randomly assigned to 2 dose regimens: cholecalciferol 50 000 IU weekly for 8 weeks, then 50 000 IU monthly for 2 months (group A) and 7000 IU daily for 8 weeks, then 12 500 IU weekly for 2 months (group B). Cholecalciferol was stopped for 2 months and reintroduced as 50 000 IU bimonthly for group A and 50 000 IU monthly for group B.

RESULTS

Two months after therapy, the mean serum 25-hydroxyvitamin D (25(OH)D) level increased from 11.4 to 51.2 ng/mL and from 11.7 to 44.9 ng/mL in groups A and B, respectively ( P = .065). The levels of 25(OH)D declined similarly in both groups during maintenance and after holding therapy. After resuming cholecalciferol, 25(OH)D levels increased to 33.8 and 28.8 ng/mL in groups A and B, respectively ( P = .027). There was a negative correlation between serum 25(OH)D levels and body mass index (BMI; P = .040).

CONCLUSION

Timing and frequency of the dosing (daily vs weekly) have no effect on the rise in serum 25(OH)D levels as long as the accumulative dose of cholecalciferol is similar. Cholecalciferol 50 000 IU bimonthly is required to maintain sufficient 25(OH)D levels.

Interplay of vitamin D and metabolic syndrome: A review

Vitamin D deficiency is a worldwide public health problem. Vitamin D deficiency plays key role in the pathophysiology of risk factors of metabolic syndrome which affect cardiovascular system, increase insulin resistance and obesity, stimulate rennin-angiotensin-aldosterone system that cause hypertension. The discovery of vitamin D receptor expressed ubiquitously in almost all body cells such as immune, vascular and myocardial cells, pancreatic beta cells, neurons and osteoblasts suggests an involvement of vitamin D mediated effects on metabolic syndrome. Moreover vitamin D deficiency as well as cardiovascular diseases and related risk factors frequently co-occur. This underlines the importance of understanding the role of vitamin D in the context of metabolic syndrome. The paper provides an insight into the physiology of vitamin D and relationship of vitamin D deficiency with risk factors of metabolic syndrome through observational and supplementation studies.

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.

Renal disease and accidental falls: a review of published evidence

BACKGROUND

The pathogenesis of falling is complex, and identification of risk factors may be essential for prevention. The relationship between renal disease and falls is unclear, and the goal of this study was to collect the available evidence and investigate the relationship between accidental falls and renal dysfunction.

METHODS

Electronic searches were performed in the MEDLINE, Scopus, Ovid SP and Web of Science databases to identify the appropriate literature. The themes used were: falls (combined in the title/abstract fall or falls or falling or faller* or fallen or slip* or trip* or (MeSH) accidental falls) and renal insufficiency (chronic or renal insufficiency or kidney diseases combined in title/abstract renal disease* or kidney disease* or renal insufficiency or kidney insufficiency or kidney failure or renal failure or MeSH renal insufficiency, chronic or renal insufficiency or kidney diseases). The incidence, risk factors, complications, and characteristics of the falls were analyzed.

RESULTS

Eight prospective cohorts including five cross-sectional studies, and one case-control study were identified. No randomized controlled studies were found. The incidence of falls in chronic kidney disease patients ranged between 1.18 and 1.60 fall/patient year. These were frequent in frail older adults on hemodialysis treatment. Falling relapses in the same group of patients caused serious consequences. Data on pre-end stage renal disease (ESRD) were scarce.

CONCLUSIONS

The risk of falling appears to be common in patients with renal dysfunction especially in older adults undergoing hemodialysis. On the other hand, we could not find any conclusive data on pre-ESRD patients.

Relationship of Serum Vitamin D Concentrations and Allostatic Load as a Measure of Cumulative Biological Risk among the US Population: A Cross-Sectional Study

INTRODUCTION

The allostatic load (AL) index is a multi-systemic measure of physiologic dysregulation known to be associated with chronic exposure to stress and adverse health outcomes. We examined the relationship between AL and serum 25-hydroxyvitamin D (25(OH)D) concentration in non-institutionalized US adults.

METHODS

Data from the Third National Health and Nutrition Examination Survey (NHANES III, 1988-94) were used to calculate two versions of AL including 9 biomarkers and another two with 14 biomarkers (systolic and diastolic blood pressure, pulse rate, serum cholesterol, serum HDL-cholesterol, glycated hemoglobin, sex-specific waist-to-hip ratio, serum albumin, and serum C-reactive protein for AL1, and, additionally body mass index, serum triglyceride, serum creatinine, and serum herpes I & II antibodies for AL2), each set defined by predefined cut-offs or by quartiles. Serum vitamin D concentration was ranked into quartiles. Logistic regression, Poisson regression and linear regression were used to examine the association of serum 25(OH)D concentrations on AL, after adjusting for biological, physiological, socioeconomic, lifestyle, and health variables.

RESULTS

Odds Ratios (OR) for high AL of the lowest 25(OH)D serum quartile were between 1.45 (95% CI: 1.28, 1.67) and 1.79 (95% CI: 1.39, 2.32) for the fully adjusted model, depending on AL version. Inverse relationships between vitamin D serum concentrations were observed for all AL versions and every adjustment. This relationship was consistent after stratification by sex, age or ethnic background. Sensitivity to low 25(OH)D concentrations was highest among the youngest group (20-39 years) with an OR of 2.11 (95% CI: 1.63, 2.73) for the lowest vitamin D quartile Q1.

CONCLUSIONS

Vitamin D had a consistent and statistically significant inverse association with all tested models of high AL, which remained consistent after adjusting for biological, socioeconomic, lifestyle and health variables. Our study adds evidence linking low 25(OH)D concentrations with poorer health, further-reaching than bone health.

Relation of maternal vitamin D status with gestational diabetes mellitus and perinatal outcome

OBJECTIVE

To investigate the relationship between maternal vitamin D status and glucose intolerance, and its impact on pregnant women and their newborns.

METHODS

A cohort of pregnant women were divided into three groups: women with gestational diabetes mellitus, ones with normal results both after the 50 gr and 100 gr OGTT (CG-1) and ones having a positive result after the 50 gr OGTT screening but negative results for gestational diabetes mellitus (GDM) after the 100 gr OGTT (CG-2).

RESULTS

The newborn length in CG-1 was greater than in GDM and CG-2 (p= 0.002 and p= 0.02). Fasting blood glucose and insulin resistance (IR) were negatively correlated with length of the newborns (r=-0.3, p=0.03 and r=-0.3, p=0.01). The newborns of women with GDM had lower APGAR-1 and 5 scores than those of CG-1 and CG-2 (APGAR-1 p= 0.001 and p= 0.004, APGAR-5 p=0.005 and p=0.007, respectively). APGAR scores were correlated negatively with IR (APGAR-1 r=-0.32, p=0.01, APGAR-5 r=-0.3, p=0.03) and positively with 25OHD levels (APGAR-1 r=0.3, p=0.01, APGAR-5 r=0.3, p=0.02).

CONCLUSION

Vitamin D deficiency, gestational diabetes and insulin resistance are interrelated. Severe vitamin D deficiency during pregnancy is associated with poor pregnancy and neonatal outcome.

Ageing with HIV: a multidisciplinary review

INTRODUCTION

After the introduction of highly active antiretroviral treatment, the course of HIV infection turned into a chronic disease and most of HIV-positive patients will soon be over 50 years old.

MATERIAL AND METHODS

This paper reviews the multiple aspects that physicians have to face while taking care of HIV-positive ageing patients including the definitions of frailty and the prevalence and risk factors of concomitant diseases. From a therapeutic point of view pharmacokinetic changes and antiretroviral-specific toxicities associated with ageing are discussed; finally therapeutic approaches to frailty are reviewed both in HIV-positive and negative patients.

CONCLUSION AND DISCUSSION

We conclude by suggesting that the combined use of drugs with the least toxicity potential and the promotion of healthy behaviours (including appropriate nutrition and exercise) might be the best practice for ageing HIV-positive subjects.

Serum 25-hydroxyvitamin D and cognitive decline: a longitudinal study among non-demented older adults

BACKGROUND/AIMS

Very few studies have investigated the longitudinal association between serum levels of 25-hydroxyvitamin D [25(OH)D] and cognitive impairment not due to dementia. This longitudinal study analysed 25(OH)D and the risk of cognitive decline among non-demented older adults.

METHODS

A subsample of the ESTHER cohort study, aged ≥70 years, was assessed with the Cognitive Telephone Screening Instrument (COGTEL) and underwent 25(OH)D measurements standardized with a reference method (n = 1,302). After an average follow-up of 4.6 years, 527 participants had repeated COGTEL testing and were eligible for analysis. Linear regression models were used to assess longitudinal associations between 25(OH)D levels and cognitive function. Possible practice effects of repeated cognitive testing were addressed with the reliable change index.

RESULTS

A trend of a more pronounced cognitive decline with lower vitamin D levels was observed among both women and men, with a statistically significant difference in COGTEL scores in the lowest vitamin D quintile of the total sample.

CONCLUSIONS

This study indicates that low levels of vitamin D might be associated with cognitive decline among non-demented elderly individuals and highlights the need for further large-scale prospective studies to clarify the potential role of vitamin D in cognitive function at an old age.

Vitamin D status predicts 30 day mortality in hospitalised cats

Vitamin D insufficiency, defined as low serum concentrations of the major circulating form of vitamin D, 25 hydroxyvitamin D (25(OH)D), has been associated with the development of numerous infectious, inflammatory, and neoplastic disorders in humans. In addition, vitamin D insufficiency has been found to be predictive of mortality for many disorders. However, interpretation of human studies is difficult since vitamin D status is influenced by many factors, including diet, season, latitude, and exposure to UV radiation. In contrast, domesticated cats do not produce vitamin D cutaneously, and most cats are fed a commercial diet containing a relatively standard amount of vitamin D. Consequently, domesticated cats are an attractive model system in which to examine the relationship between serum 25(OH)D and health outcomes. The hypothesis of this study was that vitamin D status would predict short term, all-cause mortality in domesticated cats. Serum concentrations of 25(OH)D, together with a wide range of other clinical, hematological, and biochemical parameters, were measured in 99 consecutively hospitalised cats. Cats which died within 30 days of initial assessment had significantly lower serum 25(OH)D concentrations than cats which survived. In a linear regression model including 12 clinical variables, serum 25(OH)D concentration in the lower tertile was significantly predictive of mortality. The odds ratio of mortality within 30 days was 8.27 (95% confidence interval 2.54-31.52) for cats with a serum 25(OH)D concentration in the lower tertile. In conclusion, this study demonstrates that low serum 25(OH)D concentration status is an independent predictor of short term mortality in cats.

Vitamin D as a Resilience Factor, Helpful for Survival of Potentially Fatal Conditions: A Hypothesis Emerging from Recent Findings of the ESTHER Cohort Study and the CHANCES Consortium

There is debate on whether vitamin D deficiency is a risk factor for major chronic diseases and premature death or whether observed associations were just confounded by general health status. Here, we review recent results from the Epidemiologische Studie zu Chancen der Verhütung, Früherkennung und optimierten Therapie chronischer Erkrankungen in der älteren Bevölkerung (ESTHER) cohort study and the Consortium on Heatlh and Ageing: Network of Cohorts from Europe and the United States (CHANCES) that suggest that vitamin D deficiency may not be a risk factor for the development of cardiovascular diseases and cancer but may be a risk factor for fatal instances of these diseases. Furthermore, analyses comprehensively adjusted for the health status showed that the association of vitamin D and mortality was very likely not confounded by general health status. These results suggest that vitamin D could be a marker of resilience to fatality of potentially fatal diseases. Sufficient vitamin D serum concentrations may be needed to regulate the response of the immune system when it is challenged by severe diseases to prevent a fatal course of the disease. If this hypothesis can be verified through basic research studies and adequately designed randomized controlled trials, it could have important public health implications because vitamin D deficiency is very common worldwide, and interventions could be implemented easily.

Effects of an Oral Nutritional Supplementation Plus Physical Exercise Intervention on the Physical Function, Nutritional Status, and Quality of Life in Frail Institutionalized Older Adults: The ACTIVNES Study

OBJECTIVES

The objective of this study was to assess the effects of a hyperproteic, hypercaloric oral nutritional supplement with prebiotic fiber, vitamin D, and calcium, plus a standardized physical intervention, in the functional status, strength, nutritional status, and quality of life of frail institutionalized older adults.

DESIGN

Multicentric prospective observational study under usual clinical practice conditions.

SETTING

Four nursing homes from Burgos (2), Albacete, and Madrid, Spain.

PARTICIPANTS

Participants included 91 institutionalized older adults (age ≥70), able to walk 50 m, and meeting at least 3 of the Fried frailty phenotype criteria.

INTERVENTION

Daily intake of two 200-mL bottles of an oral nutritional supplement, each bottle containing 300 kcal, 20 g protein, 3 g fiber, 500 IU vitamin D, and 480 mg calcium, plus a standardized physical exercise training consisting of flexibility, balance, and strengthening exercises for arms and legs, 5 days per week.

MEASUREMENTS

Short Physical Performance Battery (SPPB), Short-Form-Late-Life Function and Disability Instrument (SF-LLFDI) function subscale, handgrip strength, EuroQoL-5 Dimensions visual analogic scale (EQ5DVAS), weight, body mass index (BMI), and Short-Form Mini Nutritional Assessment (MNA-SF) at baseline and 6 and 12 weeks.

RESULTS

Forty-eight participants (52.7%) improved at least 1 point in the SPPB at week 6, and 44 (48.4%) did so at week 12; 39 participants (42.9%) improved at least 2 points in the SF-LLFDI at week 6, and 46 (50.5%) at week 12. Participants improved their quality of life measured with the EQ5DVAS by 6% (95% confidence interval [CI] 3%-10%) at week 6, and by 5% (95% CI 0%-10%) at week 12. They also improved their nutritional status (weight gain, BMI increase, and higher MNA-SF scores at 6- and 12-week follow-up). This improvement was higher in participants with more frailty criteria, lower functional level, lower vitamin D levels, and poorer nutritional status.

CONCLUSION

A 12-week intervention with oral nutritional supplementation plus physical exercise improves function, nutritional status, and quality of life in frail institutionalized older adults.

Prospective association of vitamin D with frailty status and all-cause mortality in older adults: Results from the KORA-Age Study

OBJECTIVE

To assess the prospective association of serum 25-hydroxyvitamin D [25(OH)D] levels with frailty status and all-cause mortality in a cohort of community-dwelling participants of the population-based KORA [Cooperative Health Research in the Region of Augsburg]-Age Study.

METHODS

727 non-frail participants, aged ≥65years, with 25(OH)D measurement at baseline in 2009, were followed for 2.9±0.1years. Participants were classified as pre-frail or frail if they met 1-2 or ≥3, respectively, of the following five criteria: weight loss, exhaustion, physical inactivity, low walking speed, weakness. The association between 25(OH)D and mortality was assessed in 954 participants. Multivariable adjusted logistic regression models were calculated for each outcome.

RESULTS

The incidence of pre-frailty and frailty was 21.2% and 3.9% respectively. After multivariable adjustment, participants with very low 25(OH)D levels (<15ng/ml vs. ≥30ng/ml) had a significantly higher odds for pre-frailty (OR=2.43 [95% CI: 1.17-5.03]) and pre-frailty/frailty combined (OR=2.53 [95% CI: 1.23-5.22]), but not for frailty alone (OR=2.63 [95% CI: 0.39-17.67]). The association between 25(OH)D and mortality (OR=3.39 [95% CI: 1.08-10.65]) was partly mediated by frailty status.

CONCLUSION

Very low 25(OH)D levels were independently associated with incident pre-frailty, pre-frailty/frailty combined and all-cause mortality.

25-hydroxyvitamin D and increased all-cause mortality in very old women: the Newcastle 85+ study

OBJECTIVE

To investigate the associations between low and high concentrations of baseline serum 25-hydroxyvitamin D [25(OH)D] and all-cause mortality in very old (≥85 years) men and women over 6 years.

DESIGN, SETTING AND SUBJECTS

Prospective mortality data from 775 participants in the Newcastle 85+ Study were analysed for survival in relation to 25(OH)D (season-specific quartiles and predefined cut-off values) and sex using Cox proportional hazards models. The models were fitted to the entire and restricted (nonusers of vitamin D-containing supplements and medication) cohorts.

RESULTS

For the entire cohort, mortality was higher in both the lowest and highest 25(OH)D season-specific quartiles [SQ1: hazard ratio (HR) 1.31, 95% confidence interval (CI) 1.01-1.69, P = 0.04; SQ4: HR 1.44, 95% CI 1.12-1.85, P = 0.004] compared with the combined middle quartiles (SQ2 + SQ3), after adjustment for sociodemographic factors. The increased risk for the highest quartile remained significant after further adjustment for lifestyle variables (SQ4: HR 1.37, 95% CI 1.06-1.77, P = 0.02) and was seen only in women in sex-specific analyses. Similarly, in sensitivity analyses with predefined 25(OH)D cut-off values, the highest 25(OH)D concentration (≥75 nmol L(-1) ) was associated with a 2.4-fold increased risk of mortality in women (restricted cohort) after adjusting for all covariates.

CONCLUSION

Low and high season-specific 25(OH)D quartiles were associated with increased risks of mortality over 6 years in the very old; this effect was particularly noticeable in women, including those who reported taking vitamin D-containing supplements/medication.

The inverse association between serum 25-hydroxyvitamin D and mortality may be modified by vitamin A status and use of vitamin A supplements

BACKGROUND

Low serum 25-hydroxyvitamin D [25(OH)D] levels have been associated with higher risk of many diseases that affect mortality, including cardiovascular disease (CVD) and cancer. The inverse association between serum 25(OH)D and mortality may be modified by excess circulating vitamin A, due to interactions of vitamin A at the level of the vitamin D nuclear receptor. In this prospective cohort study, we investigated whether the association of 25(OH)D with all-cause, cancer, and CVD mortality was modified by circulating vitamin A or preformed vitamin A intake from supplements.

METHODS

We analyzed 15,998 adults in the Third National Health and Nutrition Examination Survey (NHANES III), 1988-1994. Mortality data for all-cause (n = 3890), cancer (n = 844), and CVD mortality (n = 1715) were assessed through December 2006. Serum 25(OH)D was measured using a radioimmunoassay kit, vitamin A biomarkers were measured by HPLC, and information on supplement use was obtained by self-report. Multivariable hazard ratios (HRs) and corresponding 95% confidence intervals (CI) were estimated by proportional hazards regression.

RESULTS

Serum 25(OH)D was significantly inversely associated with all-cause mortality (HR 0.93, 95% CI 0.89, 0.97, per 10 ng/mL increase) and also with CVD mortality and mortality due to non-cancer/non-cardiovascular causes, but not with cancer mortality. The observed inverse associations remained statistically significant only among participants with serum retinyl esters <7.0 μg/dL. High intake (>5000 IU/day) of preformed vitamin A from supplements attenuated the inverse association of 25(OH)D with overall mortality. The observed interactions were not statistically significant.

CONCLUSIONS

25(OH)D was inversely associated with overall mortality, CVD mortality, and mortality due to non-cancer/non-CVD causes, but not with cancer mortality. A possible interaction between vitamin A exposure and 25(OH)D concentration appears to be associated with an attenuation of the inverse association between risk of death and quartile of 25(OH)D concentration.

Serum 25-hydroxyvitamin D, mortality, and incident cardiovascular disease, respiratory disease, cancers, and fractures: a 13-y prospective population study

BACKGROUND

Vitamin D is associated with many health conditions, but optimal blood concentrations are still uncertain.

OBJECTIVES

We examined the prospective relation between serum 25-hydroxyvitamin D [25(OH)D] concentrations [which comprised 25(OH)D3 and 25(OH)D2] and subsequent mortality by the cause and incident diseases in a prospective population study.

DESIGN

Serum vitamin D concentrations were measured in 14,641 men and women aged 42-82 y in 1997-2000 who were living in Norfolk, United Kingdom, and were followed up to 2012. Participants were categorized into 5 groups according to baseline serum concentrations of total 25(OH)D <30, 30 to <50, 50 to <70, 70 to <90, and ≥ 90 nmol/L.

RESULTS

The mean serum total 25(OH)D was 56.6 nmol/L, which consisted predominantly of 25(OH)D3 (mean: 56.2 nmol/L; 99% of total). The age-, sex-, and month-adjusted HRs (95% CIs) for all-cause mortality (2776 deaths) for men and women by increasing vitamin D category were 1, 0.84 (0.74, 0.94), 0.72 (0.63, 0.81), 0.71 (0.62, 0.82), and 0.66 (0.55, 0.79) (P-trend < 0.0001). When analyzed as a continuous variable and with additional adjustment for body mass index, smoking, social class, education, physical activity, alcohol intake, plasma vitamin C, history of cardiovascular disease, diabetes, or cancer, HRs for a 20-nmol/L increase in 25(OH)D were 0.92 (0.88, 0.96) (P < 0.001) for total mortality, 0.96 (0.93, 0.99) (P = 0.014) (4469 events) for cardiovascular disease, 0.89 (0.85, 0.93) (P < 0.0001) (2132 events) for respiratory disease, 0.89 (0.81, 0.98) (P = 0.012) (563 events) for fractures, and 1.02 (0.99, 1.06) (P = 0.21) (3121 events) for incident total cancers.

CONCLUSIONS

Plasma 25(OH)D concentrations predict subsequent lower 13-y total mortality and incident cardiovascular disease, respiratory disease, and fractures but not total incident cancers. For mortality, lowest risks were in subjects with concentrations >90 nmol/L, and there was no evidence of increased mortality at high concentrations, suggesting that a moderate increase in population mean concentrations may have potential health benefit, but <1% of the population had concentrations >120 nmol/L.