Vitamin D deficiency in postmenopausal, healthy women predicts increased cardiovascular events: a 16-year follow-up study

From A to E: Uniting vitamins against stroke risk-A systematic review and network meta-analysis

BACKGROUND AND AIM

Stroke represents a significant public health challenge, necessitating the exploration of preventive measures. This network meta-analysis aimed to assess the efficacy of different vitamin treatments compared to a placebo in preventing stroke.

METHODS

A systematic electronic search in databases including PubMed, EmBASE, Web of Science, clinicaltrials.gov, and Google Scholar until 31 May 2023 was conducted, to identify published studies investigating the association between vitamin intake and the risk of stroke. Pooled risk ratio (RR) with 95% confidence intervals (CIs) was calculated using a frequentist network meta-analysis. Furthermore, we ranked vitamins based on p-scores, facilitating a comparative assessment of their effectiveness in preventing stroke.

RESULTS

A total of 56 studies, including 17 randomized controlled trials (RCTs) and 39 cohort studies were analyzed. Direct estimates obtained from network meta-analysis, we found that vitamin A (RR: .81 [.72-.91]), vitamin B-complex (RR: .85 [.74-.97]), vitamin B6 (RR: 79 [.68-.92]), folate (RR: .86 [.75-.97]), vitamin C (RR: .77 [.70-.85]) and vitamin D (RR: .73 [.64-.83]) were significantly associated with a decreased stroke risk. However, no significant association was observed for vitamin B2, vitamin B12, and vitamin E. Subsequent to network meta-analysis, vitamins were ranked in decreasing order of their efficacy in stroke prevention based on p-score, with vitamin D (p-score = .91), vitamin C (p-score = .79), vitamin B6 (p-score = .70), vitamin A (p-score = .65), vitamin B-complex (p-score = .53), folate (p-score = .49), vitamin B2 (p-score = .39), vitamin E (p-score = .28), vitamin B12 (.13) and placebo (.10).

CONCLUSION

Our study has established noteworthy connections between vitamin A, vitamin B-complex, vitamin B6, folate, vitamin C, and vitamin D in the realm of stroke prevention. These findings add substantial weight to the accumulating evidence supporting the potential advantages of vitamin interventions in mitigating the risk of stroke. However, to solidify and validate these observations, additional research is imperative. Well-designed clinical trials or cohort studies are needed to further explore these associations and formulate clear guidelines for incorporating vitamin supplementation into effective stroke prevention strategies.

Associations of the serum vitamin D with mortality in postmenopausal women

PURPOSE

Current evidence on the association of serum vitamin D with mortality in postmenopausal women is limited and inconsistent. Therefore, the purpose of this study was to examine the relationship between serum vitamin D and mortality in postmenopausal women.

METHODS

In this study, we used data from the NHANES (2001-2018) and conducted a multivariate Cox regression model to examine associations between serum vitamin D and all-cause mortality, cardiovascular mortality (CVD), and cancer mortality.

RESULTS

In a median follow-up period of 8.3 years, 1905 deaths of all causes were reported, 601 were due to CVD, and 385 deaths were due to cancer. After multivariable adjustment, higher serum vitamin D levels were significantly associated with a reduced risk of death. Compared to participants with lower vitamin D levels (<25 nmol/L), those with higher vitamin D levels (≥75.0 nmol/L) had a lower risk of all-cause mortality (hazard ratio 0.60, 95 % confidence interval 0.49 to 0.74), a lower risk of cardiovascular mortality (0.51, 0.35 to 0.74), and a lower risk of cancer mortality (0.43, 0.28 to 0.67). Moreover, we observed an L-shaped dose-response relationship of serum vitamin D levels with all-cause mortality, and cancer mortality, with this inflexion point being 55.9 nmol/L, and 51.2 nmol/L, respectively.

CONCLUSIONS

Higher concentrations of serum vitamin D substantially correlated with a reduction in mortality risk from all-cause, CVD, and cancer in postmenopausal women. These results imply that upholding adequate vitamin D levels may help prevent premature death in postmenopausal women.

Vitamin D Supplementation and Cardiovascular Disease Risks in More Than 134000 Individuals in 29 Randomized Clinical Trials and 157000 Individuals in 30 Prospective Cohort Studies: An Updated Systematic Review and Meta-analysis

BACKGROUND

According to the findings from observational studies and clinical trials assessing the effect of vitamin D supplements on cardiovascular diseases (CVDs), there are still contradictory results. This systematic review aimed to assess the effect of vitamin D supplements on CVDs considering cohort studies and clinical trials. Study Design: A systematic review.

METHODS

MEDLINE/PubMed, Science Direct, Embase, and Cochrane Library databases were reviewed by two reviewers independently until 2022. The study effect is risk ratio (RR) and 95% confidence interval (CI) according to Mantel Haenszel's random-effects model. Then, Stata version 14 was used for statistical analysis.

RESULTS

In clinical trial studies, the incidence of CVDs among the vitamin D-consuming group was not significantly different from that in the placebo group (RR: 0.99, 95% CI: 0.95-1.03; P=0.77; I 2=0%). CVD mortality was also not significantly different between the two groups (RR: 0.97, 95% CI: 0.90-1.05; P=0.72; I2=0%). In cohort studies, circulating 25 (OH) D increased the risk of CVD incidence by 31% (RR: 1.31, 95% CI: 1.19-1.45) and CVD mortality by 37% (RR: 1.37, 95% CI: 1.17-1.61).

CONCLUSION

According to current evidence from clinical trials, vitamin D supplementation should not be recommended for CVD prevention. However, there is a direct association between vitamin D deficiency and the incidence of CVDs as well as its mortality. According to the results of clinical trial studies carrying higher levels of scientific evidence, it can be concluded that vitamin D supplementation does not exert a significant effect on the incidence, mortality, and reduction of CVDs.

Vitamin D status in Psoriasis: impact and clinical correlations

Psoriasis is a continuing, periodic, immune‑mediated, fiery skin disease branded by hyper proliferation of epidermal keratinocytes and accompanying with inflammatory cellular infiltrate in both dermis and epidermis. Immunomodulation could be an important effect of vitamin D in Psoriasis. This case-control study was designed to measure serum 25-hydroxy vitamin D levels in patients with psoriasis and healthy controls and to find out clinical correlation, if any. Six hundred two (n = 602) subjects (285 cases and 317 controls) were taken for the study. Cases and controls were frequency matched with respect to age and gender. Various demographic and clinical details were taken using a questionnaire. Chemiluminescence Micro Particle Immunoassay was used to estimate serum 25-hydroxy vitamin D levels. The vitamin D deficiency in psoriasis patients was 60.0% vs. 17.5% in controls (P < 0.001) with mean vitamin D levels of 28.3 ± 13.9 ng/ml in psoriasis patient’s vs. 37.9 ± 9.7 ng/ml in controls. Vitamin D deficiency was found to be associated with psoriasis independently of gender, age, smoking status, family history, hypertension, chronic medication, nail changes, duration of symptoms and severity of disease. Vitamin D levels were seven times lower in patients with Psoriasis as compared to controls. Reduced vitamin D levels are related to duration and clinical severity of the disease. Early detection of vitamin D deficiency and timely intervention could lead to better clinical outcome and improved quality of life in psoriasis patients.

25-hydroxyvitamin D insufficiency and inflammation increase cardiovascular risk in older people

PURPOSE

The objective of this study was to identify an association between serum levels of 25(OH) D, inflammation and cardiovascular disease risk in older adults.

METHODS

This was a cross-sectional study, with older adults of both sexes, investigating variables on lifestyle, anthropometric assessments (weight, height, waist circumference, BMI), and systemic arterial hypertension (systolic blood pressure, SBP, and diastolic blood pressure DBP), serum levels of 25(OH)D, serum high-sensitive C-reactive protein (hs-CRP), serum lipid profile and fasting blood glucose. Cardiovascular disease risk was assessed using the global risk score for cardiovascular events, the Framingham criteria.

RESULTS

The sample consisted of 124 participants, 50.8% of whom were at high risk for cardiovascular events. Older adults with 25(OH)D insufficiency presented higher levels of blood sugar (p < 0.01), LDL-c (p = 0.03) SBP (p < 0.01) and hs-CRP (p < 0 0.01). When grouped by serum concentrations hs-CRP, it was observed that higher hs-CRP levels were associated with higher blood glucose (p = 0.02), SBP (p = 0.04) and lower HDL-c concentrations (p = 0.02). It was also observed that 25(OH)D insufficiency increased the chance of a high risk for cardiovascular events by 2.8 times (OR = 2.80; p = 0.01), which with high hs-CRP concentrations increased to 4.75 times (OR = 4.75; p < 0.01).

CONCLUSION

Low concentrations of 25(OH)D and the presence of inflammation in older adults are associated with a high risk for cardiovascular diseases.

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

AIMS

Circulating 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 SYNTHESIS

A 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).

CONCLUSIONS

The lowest category of circulating 25(OH)D was associated with a higher risk of CVD incidence events and recurrent CVD events.

Smoking behavior and circulating vitamin D levels in adults: A meta-analysis

To determine the effect of smoking on circulating vitamin D in adults, we performed a meta-analysis. Literature before 9 May 2021 was retrieved from electronic literature databases such as EMBASE, PubMed, and Cochrane. The quality of the included studies was assessed by two researchers against the Newcastle-Ottawa scale and JBI Evidence-based Health Care Centre criteria. All eligible studies and statistical analyses were performed using STATA 14. Twenty-four studies with 11,340 participants meeting the criteria were included in the meta-analysis. The results of meta-analysis showed that the level of circulating 25(OH)D in smokers was lower than that in nonsmokers. A subgroup analysis based on vitamin D supplement use showed that both smokers who used vitamin D supplements and smokers who did not use vitamin D supplements had lower blood 25(OH)D levels compared with the control group. In addition, subjects were divided into different subgroups according to age for meta-analysis, and the results showed that the serum 25(OH)D level in each subgroup of smokers was lower than that in the control group. This meta-analysis revealed differences in circulating vitamin D levels between smokers and nonsmokers, with smokers likely to have lower circulating vitamin D levels.

Association between Vitamin D and Risk of Stroke: A PRISMA-Compliant Systematic Review and Meta-Analysis

BACKGROUND

Previous studies have shown inconsistent results for associations between vitamin D and risk of stroke. We gathered the existing published articles and conducted this meta-analysis with the aim to explore the association between vitamin D and risk of stroke.

METHODS

We searched for articles exploring the association between vitamin D and risk of stroke and published before April 2021 in the following databases: PubMed, Web of Science, MEDLINE, EMBASE, and Google Scholar. All statistical analyses were made using STATA 12.0 software. Q test and I2 were applied to examine heterogeneities between studies.

RESULTS

For the association between serum levels of 25(OH) vitamin D and risks of stroke, the present analysis included 20 cohort studies (including 213,276 participants) and a case-control analysis (including 13,642 participants). Additionally, the analysis included 15 studies (including 41,146 participants given vitamin D supplementation and 41,163 participants given placebo) to evaluate the influence of vitamin D supplementation on risk of stroke. Higher circulating levels of 25(OH) vitamin D were associated with a reduced risk of stroke (odds ratio/relative risk = 0.78, 95% confidence interval [CI]: 0.70-0.86, I2 = 41.5%, p = 0.025). However, the present analysis showed that vitamin D supplementation did not influence the risk of stroke (hazard ratio = 1.05, 95% CI: 0.96-1.14, I2 = 2.3%, p = 0.425).

CONCLUSIONS

Our analysis indicated that lower circulating level of vitamin D was associated with an elevated risk of stroke, but extra supplement of vitamin D failed to show benefit in decreasing the risk of stroke. Further research and study are also needed to show the role of vitamin D in relation to stroke.

Enhancing Mood, Cognition, and Quality of Life in Pediatric Multiple Sclerosis

Pediatric-onset multiple sclerosis (POMS), representing approximately 5% of all MS cases, affects the central nervous system during its ongoing development. POMS is most commonly diagnosed during adolescence but can occur in younger children as well. For pediatric patients with MS, it is critical to manage the full impact of the disease and monitor for any effects on school and social functioning. Disease management includes not only disease-modifying therapies but also strategies to optimize wellbeing. We review the interventions with the highest evidence of ability to improve the disease course and quality of life in POMS. High levels of vitamin D and a diet low in saturated fat are associated with lower relapse rates. Exercise ameliorates fatigue and sleep. Behavioral strategies for sleep hygiene and mood regulation can also improve fatigue and perceived health. POMS management should be addressed holistically, including assessing overall symptom burden as well as the psychological and functional impact of the disease.

Signalling mechanisms in the cardiovascular protective effects of estrogen: With a focus on rapid/membrane signalling

In modern society, cardiovascular disease remains the biggest single threat to life, being responsible for approximately one third of worldwide deaths. Male prevalence is significantly higher than that of women until after menopause, when the prevalence of CVD increases in females until it eventually exceeds that of men. Because of the coincidence of CVD prevalence increasing after menopause, the role of estrogen in the cardiovascular system has been intensively researched during the past two decades in vitro, in vivo and in observational studies. Most of these studies suggested that endogenous estrogen confers cardiovascular protective and anti-inflammatory effects. However, clinical studies of the cardioprotective effects of hormone replacement therapies (HRT) not only failed to produce proof of protective effects, but also revealed the potential harm estrogen could cause. The "critical window of hormone therapy" hypothesis affirms that the moment of its administration is essential for positive treatment outcomes, pre-menopause (3-5 years before menopause) and immediately post menopause being thought to be the most appropriate time for intervention. Since many of the cardioprotective effects of estrogen signaling are mediated by effects on the vasculature, this review aims to discuss the effects of estrogen on vascular smooth muscle cells (VSMCs) and endothelial cells (ECs) with a focus on the role of estrogen receptors (ERα, ERβ and GPER) in triggering the more recently discovered rapid, or membrane delimited (non-genomic), signaling cascades that are vital for regulating vascular tone, preventing hypertension and other cardiovascular diseases.

Association of Hypovitaminosis D with Metabolic Syndrome in Postmenopausal Women

The prevalence of vitamin D deficiency and metabolic syndrome is spreading like a pandemic globally; postmenopausal women are particularly vulnerable population. Hypovitaminosis D is reported to predispose to various components of metabolic syndrome like dyslipidemia, hypertension, diabetes and obesity. The purpose of this review is to highlight the recently published evidence, evaluating the association of vitamin D deficiency with metabolic syndrome in postmenopausal women. Besides, it emphasizes the long-term risks involved with low vitamin D levels and importance of vitamin D supplementation. Data were obtained from PubMed, Google Scholar and individual searches.

Cutoff point estimation for serum vitamin D concentrations to predict cardiometabolic risk in Brazilian children

BACKGROUND/OBJECTIVES

To evaluate serum 25(OH)D concentrations and determine a cutoff point for cardiometabolic risk in children.

SUBJECT/METHODS

This is a cross-sectional study with a representative sample of 378 8-9-year-old children from all urban schools in the city of Viçosa, MG, Brazil. Sociodemographic data and information on lifestyle, and food consumption were collected. Biochemical evaluation included glucose, triglycerides, leptin, calcidiol [25(OH)D], and parathormone. Body composition was assessed by dual energy X-ray absorptiometry. Cardiometabolic risk was considered when nontraditional risk markers were detected, including triglyceride × glycemia index (TyG index), hyperleptinemia, and hypertriglyceridemic waist phenotype (HWP). The receiver operating characteristic curve (ROC) was used to define the cutoff point for serum 25(OH)D to predict cardiometabolic risk.

RESULTS

25(OH)D showed better predictive capacity for grouping of cardiometabolic risk markers than for either single or paired markers. The area under the curve for grouping of risk markers was 0.636 (95% CI: 0.585, 0.685, P < 0.001). The cutoff point to predict cardiometabolic risk was defined as 32.0 ng/mL.

CONCLUSION

25(OH)D presented good predictive capacity for cardiometabolic risk and 25(OH)D concentration higher than 32 ng/mL was associated with a 49% reduction of cardiometabolic risk prevalence in prepubertal Brazilian children.

25-Hydroxyvitamin D level, vitamin D intake, and risk of stroke: A dose-response meta-analysis

BACKGROUND & AIMS

A growing number of studies have shown that vitamin D are related to the risk of stroke, however, the dose-response association between vitamin D and the risk of stroke is still unclear. Accordingly, we conducted a dose-response meta-analysis to evaluate the relationships between 25-hydroxyvitamin D [25(OH)D] level, vitamin D intake, and the risk of stroke by summarizing cohort studies.

METHODS

PubMed, Embase, Cochrane and the Web of Science database were searched for related studies. Cohort studies examining the influence of 25(OH)D level and vitamin D intake on stroke risk were summarized. Dose-response relationships were determined using a random-effect model.

RESULTS

Twenty cohort studies involving 217,235 participants were included. The pooled relative risk for the high-versus-low categories was 0.74 (95% CI: 0.66-0.83) for 25(OH)D level, and 0.75 (95% CI: 0.57-0.98) for vitamin D intake. In addition, there were non-linear relationships between 25(OH)D level, vitamin D intake, and stroke risk. The incidence of stroke was reduced to its lowest point, with a reduction of about 20%, when 25(OH)D level was about 50 nmol/L or vitamin D intake was about 12 μg/day.

CONCLUSION

25(OH)D level and vitamin D intake were both inversely related to stroke risk, with a non-linear dose-response relationship.

Vitamin D Status and Mortality: A Systematic Review of Observational Studies

Epidemiological evidence suggests that vitamin D deficiency is associated with increased mortality, but it is unclear whether this is explained by reverse causation, and if there are specific causes of death for which vitamin D might be important. We conducted a systematic review of observational studies investigating associations between circulating 25-hydroxyvitamin D (25(OH)D) concentration and all-cause or cause-specific mortality in generally healthy populations. Relevant studies were identified using PubMed and EMBASE searches. After screening 722 unique records and removing those that were ineligible, 84 articles were included in this review. The vast majority of studies reported inverse associations between 25(OH)D concentration and all-cause mortality. This association appeared to be non-linear, with progressively lower mortality with increasing 25(OH)D up to a point, beyond which there was no further decrease. There is moderate evidence that vitamin D status is inversely associated with cancer mortality and death due to respiratory diseases, while for cardiovascular mortality, there is weak evidence of an association in observational studies, which is not supported by the data from intervention or Mendelian randomization studies. The relationship between vitamin D status and other causes of death remains uncertain due to limited data. Larger long-term studies are required to clarify these associations.

Out of focus: tailoring the cascade of care to the needs of women living with HIV

Around half of the global adult HIV-positive population are women, yet historically women have been under-represented in clinical studies of antiretroviral therapy (ART) and there has been minimal exploration of gender-specific factors related to the response to and appropriateness of treatment choices in women living with HIV (WLWH). There are several key issues pertaining to the cascade of HIV care that make it important to differentiate WLWH from men living with HIV. Factors that are gender specific may impact on the status of WLWH, affecting access to diagnosis and treatment, optimal clinical management, ART outcomes, retention in care, and the overall long-term wellbeing of WLWH. In this review, we discuss the results of recently reported women-only clinical trials and highlight the key unmet needs of WLWH as they pertain to the cascade of HIV care across World Health Organization European Region countries. As significant knowledge gaps remain, the review identifies key areas where further research is required, in order to support improved management of WLWH and guide informed clinical decision-making, including addressing psychosocial factors as part of comprehensive care.

Lower Vitamin D Status Is Associated with an Increased Risk of Ischemic Stroke: A Systematic Review and Meta-Analysis

In recent years, accumulating evidence has supported the hypothesis that lower vitamin D status is associated with several known risk factors of stroke. However, the relationship between vitamin D and stroke is still uncertain. To explore if there was an association between vitamin D status and the risk of stroke, a systematic review and a meta-analysis were conducted by searching three databases: Pubmed, Embase, and the Cochrane Library. Following the application of inclusion and exclusion criteria, the relative risk estimates of all the included studies were pooled together to compare the risk of stroke between the lowest and the highest category of vitamin D. The Newcastle-Ottawa Scale (NOS) and the Cochrane Risk of Bias Tool were used to assess the risk of bias, and the publication bias was detected by using a funnel plot and Egger's test. Nineteen studies were included and the pooled relative risk was 1.62 (95% CI: 1.34-1.96). Further analysis found that vitamin D status was associated with ischemic stroke (relative risk = 2.45, 95% CI: 1.56-3.86), but not with hemorrhagic stroke (relative risk = 2.50, 95% CI: 0.87-7.15). In conclusion, our meta-analysis supported the hypothesis that lower vitamin D status was associated with an increased risk of ischemic stroke. Further studies are required to confirm this association and to explore the association among different subtypes.

Serum 25-hydroxyvitamin D and the risk of cardiovascular disease: dose-response meta-analysis of prospective studies

Background: During the past decade, an increasing number of prospective studies have focused on the association between vitamin D and cardiovascular disease (CVD). However, the evidence on the relation between serum 25-hydroxyvitamin D [25(OH)D] and the risk of overt CVD is inconclusive.Objective: We performed a dose-response meta-analysis to summarize and prospectively quantify the RR of low serum 25(OH)D concentration and total CVD (events and mortality).Design: We identified relevant studies by searching PubMed and EMBASE up to December 2015 and by hand-searching reference lists. Prospective studies based on the general population and reported RRs and 95% CIs were included. A random-effects model was used to calculate the pooled RRs. Nonlinear association was assessed by using restricted cubic spline analyses.Results: A total of 34 publications with 180,667 participants were eligible for the meta-analysis. We included 32 publications (27 independent studies) for total CVD events and 17 publications (17 independent studies) for CVD mortality. We observed an inverse association between serum 25(OH)D and total CVD events and CVD mortality, and the pooled RRs per 10-ng/mL increment were 0.90 (95% CI: 0.86, 0.94) for total CVD events and 0.88 (95% CI: 0.80, 0.96) for CVD mortality. A nonlinear association was detected for total CVD events (P-nonlinear < 0.001) and CVD mortality (P-nonlinear = 0.022).Conclusion: Serum 25(OH)D concentration was inversely associated with total CVD events and CVD mortality from the observed studies.

Determination of 1,25-dihydroxyvitamin D2 and 1,25-dihydroxyvitamin D3 in human serum using liquid chromatography with tandem mass spectrometry

Vitamin D plays important roles in skeletal metabolism and many other diseases, including chronic renal failure, hypoparathyroidism, sarcoidosis and rickets. 1α,25-dihydroxy vitamin D (1α,25(OH)2D), the active form of vitamin D, exhibits an extremely low serum concentration, which makes its quantification very challenging. High performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) is considered to be the "gold standard" for the determination of these chemicals, which are found in low concentrations in the serum, but conventionally, it needs tedious sample pretreatment procedures, such as solid phase extraction and derivatization. Herein, we describe a simple and rapid HPLC-MS/MS method for the simultaneous quantification of 1α,25-dihydroxy vitamin D3 (1α,25(OH)2D3) and 1α,25-dihydroxy vitamin D2 (1α,25(OH)2D2). The analytes were extracted from the matrix by liquid-liquid extraction, centrifuged to dryness and reconstituted with 75% methanol. Lithium acetate was employed to improve the ionization efficiency of 1α,25(OH)2D. The assay was sensitive with a low limit of quantitation of 10.0pg/mL for both 1α,25(OH)2D3 and 1α,25(OH)2D2 using a 0.5mL sample aliquot. Linearity was obtained over the range of 10.0pg/mL to 500pg/mL. Both the inter-assay and intra-assay precisions were <15%, and the analytical recoveries were within 100±5%. The performance evaluation of this assay demonstrated that it was a practical, sensitive and specific method for measuring the serum 1α,25(OH)2D3 and 1α,25(OH)2D2 concentrations.

Vitamin D Status and Cardio-Metabolic Risk in Indian Postmenopausal Women

INTRODUCTION

The prevalence of chronic and non-communicable health disorders like cardiovascular diseases and metabolic syndrome is increasing worldwide including in India. The various risk factors for these health issues need to be addressed. The role of vitamin D deficiency in the causation of all these abnormal health conditions among postmenopausal women is a matter of debate now-a-days.

AIM

To determine the correlation of serum vitamin D levels with various cardio-metabolic risk factors and metabolic syndrome (MetS) in postmenopausal women (PMW).

MATERIALS AND METHODS

Total of 64 PMW were included in this cross-sectional study. Clinical (waist circumference, body mass index, blood pressure) and biochemical (fasting plasma glucose, lipid profile and serum 25-hydroxyl vitamin D levels) parameters were measured. MetS was defined using modified National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP-III) guidelines. Serum 25-hydroxyl vitamin D levels <50 nmol/l, between 52.5-72.5 nmol/l and >75 nmol/l were classified as deficient, insufficient and sufficient, respectively.

RESULTS

MetS was prevalent in 33 (52%) subjects. There were no differences in serum vitamin D levels or proportion of vitamin D deficient individuals in those with and without MetS. 33 women (52%) had vitamin D deficiency. Cardio-metabolic risk profile was similar in both vitamin D deficient and replete women.

CONCLUSION

Despite a high prevalence of vitamin D deficiency and MetS in Indian PMW, serum vitamin D concentrations do not correlate with the cardio-metabolic risk factors or MetS.

Differences in the prevalence of vitamin D deficiency and hip fractures in nursing home residents and independently living elderly

OBJECTIVE

To compare the prevalence of vitamin D deficiency and fracture history in nursing home residents and community-dwelling elderly subjects and to explore the association of vitamin D levels with various characteristics.

MATERIALS AND METHODS

Sixty-six nursing home residents and 139 community-dwelling elderly subjects participated. Marital status, medical history, medication including vitamin D supplements, smoking, past fractures were assessed. Weight and height were measured and body mass index calculated. Serum 25-hydroxyvitamin D (25-OHD), PTH, Ca, phosphate, creatinine and eGFR were determined.

RESULTS

In the nursing home residents 25-OHD was lower (17.8 nmol/l, [9.4-28.6] vs. 36.7 nmol/l, [26.9-50], p < 0.001), PTH was higher (5.6 pmol/l, [3.9-8.9] vs. 4.7 pmol/l [3.6-5.8], P = 0.003) and 25-OHD deficiency was more prevalent (65.2% [53.7-76.7] vs. 22.3% [15.4-29.2], p < 0.001) as was elevated PTH (23% [12.8-33] vs. 5.8% [2-10], p = 0.001). 25-OHD correlated negatively with PTH (institutionalized r = -0.28, p = 0.025 and community-dwelling r = -0.36, p < 0.001). Hip fractures were reported by 8% of the residents and 2% of the independent elderly. The only predictor for hip fracture was elevated PTH (OR = 7.6 (1.5-36.9), p = 0.013).

CONCLUSION

The prevalence of vitamin D deficiency and secondary hyperparathyroidism was high in the institutionalized subjects. Hip fracture risk was associated with elevated PTH and not directly with vitamin D levels or the residency status.

Impact of gender difference on vitamin D status and its relationship with the extent of coronary artery disease

BACKGROUND AND AIM

There has been a surge of interest in the cardiovascular effects of vitamin D (25(OH)D), preventing the processes leading to vascular wall degeneration and coronary artery disease (CAD). Gender differences have been suggested for vitamin D status, with a higher rate of deficiency occurring especially in post-menopausal women, increasing the risk of bone fractures and osteoporosis. However, to date, few studies have evaluated the differences in 25(OH)D levels according to gender and their impact on the extent of CAD, which was therefore the aim of the present study.

METHODS AND RESULTS

In patients undergoing coronary angiography, fasting samples were collected for the assessment of 25(OH)D levels. Significant CAD was defined as at least one vessel stenosis >50%, while severe CAD was defined as left main and/or three-vessel disease. Of the 1811 patients included, 530 (29.3%) were females, who displayed older age (p < 0.001), higher rate of renal failure (p < 0.001), hypertension (p = 0.05), treatment with angiotensin-receptor blockers (p = 0.03) and diuretics (p < 0.001), acute presentation (p < 0.001), higher platelet count (p < 0.001), glycosylated haemoglobin (p = 0.02) and cholesterol (p = 0.001), but an inverse relationship with smoking (p < 0.001), previous cardiovascular events (p < 0.001), treatment with statins and acetylsalicylic acid (ASA) (p < 0.001), body mass index (p = 0.002), haemoglobin (p < 0.001), leucocytes (p = 0.03) and triglycerides (p < 0.001). Female gender was associated with lower vitamin D levels (14.5 ± 10.9 vs. 15.9 ± 9.5, p = 0.007) and independently associated with severe vitamin D deficiency (41.9% vs. 30.4%, p < 0.001; adjusted odds ratio (OR) (95% confidence interval (CI)) = 1.42 (1.08-1.87), p = 0.01). Lower tertiles of vitamin D were associated with an increased prevalence and severity of CAD in females (adjusted OR (95% CI = 1.26 (1.10-1.44), p = 0.001 for CAD; adjusted OR (95% CI) = 1.6 (1.39-1.87), p < 0.001 for severe CAD). In males, vitamin D status was independently related to the prevalence (adjusted OR (95% CI) = 1.28 (1.02-1.61), p = 0.03) of CAD, but not the extent of CAD (adjusted OR (95% CI) = 1.02 (0.86-1.2), p = 0.84).

CONCLUSION

Gender significantly affects vitamin D status. The lower 25(OH)D levels observed in females, as compared to males, play a more relevant role in conditioning the severity of CAD.

Inverse association of serum vitamin D in relation to carotid intima-media thickness in Chinese postmenopausal women

Objective

This study aimed to investigate the relationship between serum vitamin D level and carotid intima-media thickness (C-IMT) in Chinese postmenopausal women.

Methods

Nine hundred and twenty six Chinese postmenopausal women without carotid artery plaque or history of cardiovascular disease were selected for analysis. Measurements of serum 25 hydroxyvitamin D₃ (25(OH)D₃) concentration and C-IMT were made by electrochemiluminescence immunoassay and B-mode ultrasound, respectively. Trend analysis was conducted according to tertiles of C-IMT.

Results

The median serum 25(OH)D₃ level was 11.03 ng/mL, with an interquartile range of 8.22–14.70. A decreasing trend of serum 25(OH)D₃ level was accompanied by increased C-IMT tertiles (P for trend = 0.001). Correlation analysis found an inverse relationship between serum 25(OH)D₃ level and C-IMT (r = –0.113, P = 0.001). After adjustment for confounding factors, multiple regression analysis showed that serum 25(OH)D₃ level independently and negatively associated with C-IMT (Standard β = –0.112, P < 0.001). Moreover, the inverse correlation of serum 25(OH)D₃ with C-IMT was also found in a subgroup of women with normal glucose tolerance, blood pressure and body mass index, and without undergoing lipid-lowering therapy (standard β = –0.140, P = 0.018).

Conclusions

Serum 25(OH)D₃ level was inversely correlated with C-IMT in Chinese postmenopausal women.

Total 25-hydroxyvitamin D concentration as a predictor for all-cause death and cardiovascular event risk among ethnic Chinese adults: a cohort study in a Taiwan community

BACKGROUND

Evidence of an inverse association between serum 25-hydoroxyvitamin D [25(OH)D] and the risk of all-cause death and cardiovascular disease from prospective studies is inconsistent. We tested the relationship between 25(OH)D and the risk among adult ethnic Chinese in Taiwan.

METHODS

We conducted a community-based cohort study of 1816 participants (age 60.2±10.2 yrs, 45.0% women) in the Chin-Shan Community Cardiovascular Cohort Study who were free of cardiovascular diseases at baseline and provided 25(OH)D measurements.

RESULTS

During a median 9.6 (interquartile range, 8.8- 10.5) years' follow-up period, totally 263 cases developed cardiovascular death events and 559 participants were documented to death from any cause. As 25(OH)D concentration increased, the incidence rates of cardiovascular events and all-cause death decreased progressively. 25(OH)D was inversely associated with all-cause death: the adjusted hazard ratio was 0.49 (95% confidence interval [CI], 0.25-0.97) for the third quartile and a significant J-shape relationship was found. The performance measures by integrated discriminative improvement showed significant improvement after adding 25(OH)D information (0.14%, 95% CI, 0.03-0.31, P=0.050, for all-cause death and 0.32%, 95% CI, 0.02-0.62, P=0.018 for cardiovascular events).

CONCLUSION

These findings suggested a modest inverse association between 25(OH)D and the risk of all-cause death among diabetic participants and a good predictive factor in the community. Further studies to investigate the mechanism of vitamin D role on health effect are warranted.

A prospective observational study of all-cause mortality in relation to serum 25-OH vitamin D3 and parathyroid hormone levels in patients with type 2 diabetes

BACKGROUND

Low levels of vitamin D have been related to increased mortality and morbidity in several non-diabetic studies. We aimed to prospectively study relationships between serum 25-OH vitamin D3 (vitamin D) and of serum parathyroid hormone (PTH) to total mortality in type 2 diabetes. We also aimed to compare the levels of these potential risk-factors in patients with and without diabetes.

METHODS

The main study design was prospective and observational. We used baseline data from 472 men and 245 women who participated in the "Cardiovascular Risk factors in Patients with Diabetes-a Prospective study in Primary care" study. Patients were 55-66 years old at recruitment, and an age-matched non-diabetic sample of 129 individuals constituted controls for the baseline data. Carotid-femoral pulse-wave velocity (PWV) was measured with applanation-tonometry and carotid intima-media thickness (IMT) with ultrasound. Patients with diabetes were followed for all-cause mortality using the national Swedish Cause of Death Registry.

RESULTS

Levels of vitamin D were lower in patients with diabetes than in controls, also after correction for age and obesity, while PTH levels did not differ. Nine women and 24 men died during 6 years of median follow up of the final cohort (n = 698). Vitamin D levels were negatively related to all-cause mortality in men independently of age, PTH, HbA1c, waist circumference, 24-h systolic ambulatory-blood pressure (ABP) and serum-apoB (p = 0.049). This finding was also statistically significant when PWV and IMT were added to the analyses (p = 0.028) and was not affected statistically when medications were also included in the regression-analysis (p = 0.01). In the women with type 2 diabetes, levels of PTH were positively related with all-cause mortality in the corresponding calculations (p = 0.016 without PWV and IMT, p = 0.006 with PWV and IMT, p = 0.045 when also adding medications to the analysis), while levels of vitamin D was without statistical significance (p >0.9).

CONCLUSIONS

Serum vitamin D in men and serum PTH in women give prognostic information in terms of total-mortality that are independent of regular risk factors in addition to levels of ABP, IMT and PWV.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01049737.

Carotid intima-media thickness is not associated with vitamin D and PTH levels in patients admitted to an Internal Medicine Department

Vitamin D (25OHD) and/or parathyroid hormone (PTH) levels have been associated with common carotid intima-media thickness (IMT). We investigated such associations in inpatients consecutively admitted to an Internal Medicine Department. In 168 consecutive patients admitted to our department, 25 hydroxyvitamin D (25OHD) was measured by means of RIA and PTH by means of ICMA, whereas IMT by means of ultrasonography. The main cardiovascular risk factors were also explored. In patients with either diabetes, or hypertension, or both, 25OHD values were not significantly lower than in other patients. No difference was found among the IMT values across tertiles of 25OHD level, as like as in the 25OHD, PTH, PTH/25OHD ratio values of patients either grouped by tertiles of IMT, or categorized according to IMT of <0.9, 0.9-1.5, and >1.5 mm. IMT did not significantly associate with 25OHD, PTH, and PTH/25OHD ratio, whereas it positively associated with age (r = 0.281; p < 0.001) and BMI (r = 0.138; p = 0.074), and negatively with eGFR (r = -154; p = 0.046). Multiple regression models showed that IMT was significantly associated to age and BMI, while 25OHD, PTH, or PTH/25OHD ratio did not increase the significance of the models. IMT assessment does not seem to be associated with 25OHD and PTH levels in unselected inpatients.

Could vitamin D supplements be a new therapy for heart failure? Possible pathogenic mechanisms from data of intervention studies

Vitamin D deficiency may play a role in the pathogenesis of chronic heart failure (HF), but whether giving patients supplements to raise vitamin D into the normal range improves their survival is not clear. It has been demonstrated that vitamin D deficiency is common in patients with HF, especially the elderly, in obese and in dark skinned people, and that low vitamin D levels are associated with adverse outcome. The epidemiological data have been confirmed by experimental data, which show that knockout mice for the vitamin D receptor developed myocardial hypertrophy and dysfunction. Data from interventional studies are scarce and discordant, and more research is urgently needed to confirm whether add-on supplementation therapy with vitamin D has a role in the management of patients with chronic HF.

Winter 25-hydroxyvitamin D levels in young urban adults are affected by smoking, body mass index and educational level

BACKGROUND/OBJECTIVES

To study the relationship of winter 25-hydroxycholecalciferol (25-OHD) levels with age, education, place of residency, marital status and body mass index (BMI) as they may affect sun exposure, vitamin D synthesis and metabolism.

SUBJECTS/METHODS

Subjects (1952) answered a structured questionnaire concerning education, marital status and smoking; and body weight/height, and parathyroid hormone and 25-OHD were measured.

RESULTS

25-OHD levels were higher in the males with elementary and secondary education compared with higher education (46.8±18.5 and 43.7±16 vs 39.9±15.3 nmol/l, P<0.01). Vitamin D deficiency was more prevalent (16.7%, (13.1-20.2) vs 10.8%, (8.4-13.2), P=0.08) and sufficiency was less prevalent (24.6% (20-29.2) vs 33.7%, (29.5-37.8), P=0.005) in those with higher than secondary education. No differences were found among the females. Male smokers had lower 25-OHD than nonsmokers (40.2±16.6 vs 43.6±15.7 nmol/l, P=0.004). Deficiency was more prevalent in the male smokers than nonsmokers with secondary and higher education (secondary 16.6%, (10.1-22.4) vs 8.2%, (5.1-11.3), P=0.006; higher 27.4%, (17.7-37.1) vs 13.2%, (9.0-17.5), P=0.003). 25-OHD was lower in the obese than in the normal-weight females (34.6±16.2 vs 38.2±17.8 nmol/l, analysis of variance, P=0.014), but not males. Marital status was not related to 25-OHD. Only in the urban residents, increasing BMI in the young females increased the risk for vitamin D deficiency by 1%, and smoking had an odds ratio of 1.99 (1.05-3.78) in the young and 2.5 (1.07-5.75) in the middle-aged males.

CONCLUSIONS

Smoking and higher education in the males and obesity in the females were factors for vitamin D deficiency among Bulgarian urban population.

Vitamin D and the cardiovascular system: an overview of the recent literature

Since the discovery that the enzyme catalyzing the synthesis of the most active natural vitamin D metabolite(calcitriol) and the vitamin D-specific receptor (VDR)were expressed in a wide range of tissues and organs, not only involved in the mineral metabolism (MM), there has been increasing interest on the putative ‘non classical’ roles of vitamin D metabolites, particularly on their possible effects on the cardiovascular (CV) system. These hypothetical CV effects of vitamin D gained particular interesting the nephrology field, given the high prevalence of CV disease in patients affected by either acute or chronic kidney diseases. However, notwithstanding a huge amount of experimental data suggesting a possible protective role of vitamin D on the CV system, the conclusions of two recent meta-analyses from the Cochrane group and a recent statement from the Institute of Medicine, based on a complete revision of the available data, concluded that there is no clear evidence for a role of vitamin D other than that strictly associated with bone health. However, a continuous and increasing flow of new studies still continues to add information on this topic. In the present review, we have tried to critically address the data added on this topicin the last 2 years, considering separately the experimental,observational, and intervention studies that have appeared in PubMed in the last 2 years, discussing the data providing proof, pro or contra, the involvement of vitamin D in CV disease, both in the absence or presence of kidney function impairment.

Effect of diet on vascular health

Cardiovascular disease (CVD) is a major cause of morbidity and mortality in the Western world in older people. Diet and lifestyle change can reduce CVD risk in older people, and this evidence base is reviewed. For example, diets low in trans fats can reduce CVD risk, while for saturated fats the CVD-lowering effect depends on what is substituted for the saturated fat. Diets rich in fish reduce CVD risk, although n-3 supplements have not been shown to have a consistent effect on CVD end-points. Antioxidant and B-group vitamin supplementation are unlikely to reduce CVD risk, but diets rich in these micronutrients (e.g. rich in fruits and vegetables and the Mediterranean diet) are associated with lower CVD risk, while, for the Mediterranean diet, this has been supported by randomized controlled trials. Maintaining a healthy weight and being physically active reduce CVD risk factors and CVD incidence and mortality.

The role of vitamin D deficiency in cardiovascular disease: where do we stand in 2013?

The high worldwide prevalence of vitamin D deficiency is largely the result of low sunlight exposure with subsequently limited cutaneous vitamin D production. Classic manifestations of vitamin D deficiency are linked to disturbances in bone and mineral metabolism, but the identification of the vitamin D receptor in almost every human cell suggests a broader role of vitamin D for overall and cardiovascular health. The various cardiovascular protective actions of vitamin D such as anti-diabetic and anti-hypertensive effects including renin suppression as well as protection against atherosclerosis and heart diseases are well defined in previous experimental studies. In line with this, large epidemiological studies have highlighted vitamin D deficiency as a marker of cardiovascular risk. However, randomized controlled trials (RCTs) on vitamin D have largely failed to show its beneficial effects on cardiovascular diseases and its conventional risk factors. While most prior vitamin D RCTs were not designed to assess cardiovascular outcomes, some large RCTs have been initiated to evaluate the efficacy of vitamin D supplementation on cardiovascular events in the general population. When considering the history of previous disappointing vitamin RCTs in general populations, more emphasis should be placed on RCTs among severely vitamin D-deficient populations who would most likely benefit from vitamin D treatment. At present, vitamin D deficiency can only be considered a cardiovascular risk marker, as vitamin D supplementation with doses recommended for osteoporosis treatment is neither proven to be beneficial nor harmful in cardiovascular diseases.

Optimal vitamin D status: a critical analysis on the basis of evidence-based medicine

CONTEXT

Public health authorities around the world recommend widely variable supplementation strategies for adults, whereas several professional organizations, including The Endocrine Society, recommend higher supplementation.

METHODS

We analyzed published randomized controlled clinical trials to define the optimal intake or vitamin D status for bone and extraskeletal health.

CONCLUSIONS

The extraskeletal effects of vitamin D are plausible as based on preclinical data and observational studies. However, apart from the beneficial effects of 800 IU/d of vitamin D3 for reduction of falls in the elderly, causality remains yet unproven in randomized controlled trials (RCTs). The greatest risk for cancer, infections, cardiovascular and metabolic diseases is associated with 25-hydroxyvitamin D (25OHD) levels below 20 ng/mL. There is ample evidence from RCTs that calcium and bone homeostasis, estimated from serum 1,25-dihydroxyvitamin D and PTH, calcium absorption, or bone mass, can be normalized by 25OHD levels above 20 ng/mL. Moreover, vitamin D supplementation (800 IU/d) in combination with calcium can reduce fracture incidence by about 20%. Such a dose will bring serum levels of 25OHD above 20 ng/mL in nearly all postmenopausal women. Based on calculations of the metabolic clearance of 25OHD, a daily intake of 500-700 IU of vitamin D3 is sufficient to maintain serum 25OHD levels of 20 ng/mL. Therefore, the recommendations for a daily intake of 1500-2000 IU/d or serum 25OHD levels of 30 ng or higher for all adults or elderly subjects, as suggested by The Endocrine Society Task Force, are premature. Fortunately, ongoing RCTs will help to guide us to solve this important public health question.