Vitamin D and cardiovascular disease: an appraisal of the evidence

Serum Vitamin D and Vaspin Levels Among Patients with Acute Myocardial Infarction and Their Association with Risk Factors

Purpose

The current study investigated and compared serum levels of vitamin D (VD) and vaspin in AMI patients and healthy subjects and correlated these biomarkers with other biochemical risk factors for AMI.

Patients and Methods

The research was carried out at King Abdulaziz University Hospital (KAUH) in Jeddah. Blood samples and additional information were gathered from 110 admitted AMI patients in the Intensive Coronary Care Unit (ICCU) (ages 40-65 years) and 50 adult, healthy volunteers whose BMI and age were similar to those of the patients.

Results

AMI patients had significantly lower vaspin (p < 0.001) and VD levels (p < 0.001) than the control group. Fasting plasma glucose (FPG), hemoglobin A1C (HbA1c), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) levels were shown to be significantly different between AMI patients and controls. Among the AMI patients, 15 (13.6%) had deficient serum VD levels (≤20 ng/mL), 60 (54.5%) had insufficient levels (>20 - <30 ng/mL), and 35 (31.8%) had sufficient levels (≥30 ng/mL). In healthy subjects, VD levels were deficient in 4(8%), insufficient in 13 (26%), and sufficient in 33 (66%). VD insufficiency was more prevalent in AMI patients compared to the healthy group (54.5% vs 26%; p < 0.001). In AMI patients, serum vaspin was found to be related to age and HbA1c in the control group. VD did not show a significant correlation with any variable in AMI patients and healthy subjects. Serum vaspin (p = 0.89) and VD levels (p = 0.29) did not differ significantly between female and male control groups.

Conclusion

Compared to the healthy group, AMI patients showed significantly lower vaspin and VD levels. Additionally, AMI patients had a higher prevalence of VD deficiency and insufficiency, suggesting its possible role in the occurrence of AMI.

MC-Au/MSS-Z8 porous network assisted advanced electrochemical immunosensing of 25-hydroxyvitamin D3

On-site monitoring of vitamin D levels is subject matter of immediate attention owing to the serious aftermath of its long standing deficiency. Therefore, a novel and efficient voltammetric immunosensing of 25-hydroxyvitamin D₃ (25(OH)VD₃) has been experimented based on an advanced sensing platform composed of meso-microporous silica-zeolitic imidazolate framework-8 (MSS-Z8) with highly enhanced surface area (S_{BET, MSS-Z8} (643.4 m²g^-1) > S_{BET, MSS} (49.95 m²g^-1)), embedded with gold particles (mass loading of 82 μg), particularly of microcubic morphology (MC-Au). Further, the MC-Au/MSS-Z8/FTO platform was fashioned with antibody specific to 25(OH)VD₃ via interaction between Au and abundant -SH groups present on the antibody surface. After optimization of operational parameters, the Ab/MC-Au/MSS-Z8/FTO immunosensor was employed for the determination of 25(OH)VD₃ within 0.01-10⁶ pg mL^-1 concentration range through differential pulse voltammetry technique in [Fe(CN)₆]^3-/4-. Thus, 0.01 pg mL^-1 concentration of 25(OH)VD₃ was the experimental limit of detection of the immunosensor. Further, upon examination of various analytical parameters, it turns out that the immunosensor exhibited low theoretical LOD (0.23 pg mL^-1) and LOQ (0.76 pg mL^-1), wide linear range (0.01-10⁶ pg mL^-1), ultra-sensitivity (143.9 μA [log (pg mL^-1)]^-1 cm^-2), adequate reproducibility (RSD ≤1.23%) and acceptable shelf life. Most importantly, the immunosensor presented proficient performance with spiked human serum samples (Recovery = 97.20-100.7%, RSD value < 5.6%), evincing the adequacy of present biosensing approach.

Uncoupling proteins: are they involved in vitamin D3 protective effect against high-fat diet-induced cardiac apoptosis in rats?

This study aimed to assess the impact of high-fat diet (HFD) and vitamin D3 supplementation on cardiac apoptosis, inflammation, oxidative stress, and cardiac uncoupling proteins (UCPs) 2&3 expression. Forty rats were fed either (45%) or (10%) fat diet with or without vitamin D3 (500 U/kg/day) for 6 months, then cardiac tissue expression of Bax, Bcl2, Fas, Fas-L (markers for apoptotic pathways), TNF-α, MDA7, GPX1 (inflammatory and oxidative markers) and UCP 2&3 were assessed. Results revealed the enhancement of intrinsic and extrinsic cardiomyocyte apoptosis cascades and increased inflammatory and oxidative burdens on the heart in HFD rats. Downregulation of UCP2 and upregulation of UCP3 gene expression at 6 months. After vitamin D3 supplementation with HFD, cardiac apoptotic, inflammatory and oxidative markers were mitigated and expression of UCP3 was downregulated and UCP2 was upregulated. This work highlights the novel cardioprotective effect of vitamin D3 in the experimental model of HFD feeding through the downregulation of UCP3.

Assessment of a Novel Vitamin D3 Formulation with Nanostructured Lipid Carriers for Transdermal Delivery

OBJECTIVE

Develop and assess a transdermal emulsion loaded with nanostructured lipid carriers for vitamin D3 supplementation.

METHODS

Vitamin D3 loaded nanostructured lipid carriers, produced via high shear homogenization and ultrasonication, were assessed for their particle size, distribution, morphology, zeta potential, entrapment efficiency, and cytotoxicity. They were incorporated into a transdermal vehicle, and the stability and ex vivo permeation were evaluated.

RESULTS

Spherical nanoparticles were developed with a particle size of 192.5 nm, a polydispersity index of 0.13, a zeta potential of -29.0 mV, and an entrapment efficiency of 99.75%. They were stable (particle size and distribution) for 15 days when stored in a refrigerator and for 30 days at room temperature and 32 °C. The nanoparticles decreased the drug cytotoxicity against fibroblasts, as shown by IC50 (nanoparticle: 32.48 μg mL-1; vitamin D3: 16.73 μg mL-1). The emulsion loaded with nanoparticles minimized the degradation of vitamin D3 when compared with the nanoparticle dispersion. Additionally, the emulsion provided the skin permeation of vitamin D3 following the recommended daily allowance.

CONCLUSION

To the best of our knowledge, this is the first study to use nanostructured lipid carriers for transdermal delivery of vitamin D. The developed formulation is a promising strategy to overcome the vitamin D3 variable oral bioavailability. It also represents a comfortable route of administrationd. Thus it could be beneficial for patients and clinicians. However, further studies are needed to allow the permeation of larger amounts of vitamin D3, and the combination of these nanoparticles with microneedles would be interesting.

Vitamin D supplements and prevention of cardiovascular disease

PURPOSE OF REVIEW

The role of vitamin D supplementation for prevention of cardiovascular disease (CVD) outcomes has been rigorously studied only recently. This review briefly summarizes results from recent randomized controlled trials in the context of prior laboratory and epidemiologic data.

RECENT FINDINGS

Randomized trials of vitamin D that included CVD outcomes, as well as two recently published large population-based trials that prespecified CVD as a primary endpoint (The Vitamin D Assessmentand The VITamin D and OmegA-3 TriaL), indicate that vitamin D supplementation does not decrease CVD incidence, when compared with placebo.

SUMMARY

Evidence to date suggests that vitamin D supplementation in the general community does not reduce the risk of major cardiovascular events. Other trials are ongoing and future studies will explore additional CVD outcomes such as heart failure and assess high-risk populations such as those with chronic kidney disease.

Vitamin D2 fortification of Calocybe indica mushroom by natural and artificial UVB radiations and their potential effects on nutraceutical properties

Calocybe indica mushroom was exposed under natural and artificial UVB light to enhance vitamin D₂ contents in the fruit bodies. When Kinetic model was designed to examine the rate of conversion of ergosterol into vitamin D₂ at different time intervals (0, 15, 45, 60 and 90 min), it was found that the conversion was linear with time. The maximum content of vitamin D_2, that is 78.33 µg/g in sunlight and 140.58 µg/g in UVB radiated fruit bodies, was recorded in the samples exposed for 60 min. Interestingly, UVB radiations triggered the synthesis of β-glucan from their actual content (22.42-44.36 g/100 g) and improved the contents of phenols (12.46-47.38 mg GAE/g) and flavonoids (0.85-2.15 mg Quercetin/g). The estimated antioxidant activities, viz., free radical DPPH scavenging activity and ferric reducing antioxidant power was also found to significantly (p < 0.05) increase after 60 min of UVB exposure. For DPPH and FRAP, lowest IC₅₀ values obtained was 1.90 and 4.60 respectively, which are suggestive of high antioxidant capacity. Additionally, the paper also describes how UVB rays chemically altered the scores for all seventeen amino acids that were analyzed.

Effect of Monthly High-Dose Vitamin D Supplementation on Cardiovascular Disease in the Vitamin D Assessment Study : A Randomized Clinical Trial

Importance

Cohort studies have reported increased incidence of cardiovascular disease (CVD) among individuals with low vitamin D status. To date, randomized clinical trials of vitamin D supplementation have not found an effect, possibly because of using too low a dose of vitamin D.

Objective

To examine whether monthly high-dose vitamin D supplementation prevents CVD in the general population.

Design, Setting, and Participants

The Vitamin D Assessment Study is a randomized, double-blind, placebo-controlled trial that recruited participants mostly from family practices in Auckland, New Zealand, from April 5, 2011, through November 6, 2012, with follow-up until July 2015. Participants were community-resident adults aged 50 to 84 years. Of 47 905 adults invited from family practices and 163 from community groups, 5110 participants were randomized to receive vitamin D3 (n = 2558) or placebo (n = 2552). Two participants retracted consent, and all others (n = 5108) were included in the primary analysis.

Interventions

Oral vitamin D3 in an initial dose of 200 000 IU, followed a month later by monthly doses of 100 000 IU, or placebo for a median of 3.3 years (range, 2.5-4.2 years).

Main Outcomes and Measures

The primary outcome was the number of participants with incident CVD and death, including a prespecified subgroup analysis in participants with vitamin D deficiency (baseline deseasonalized 25-hydroxyvitamin D [25(OH)D] levels <20 ng/mL). Secondary outcomes were myocardial infarction, angina, heart failure, hypertension, arrhythmias, arteriosclerosis, stroke, and venous thrombosis.

Results

Of the 5108 participants included in the analysis, the mean (SD) age was 65.9 (8.3) years, 2969 (58.1%) were male, and 4253 (83.3%) were of European or other ethnicity, with the remainder being Polynesian or South Asian. Mean (SD) baseline deseasonalized 25(OH)D concentration was 26.5 (9.0) ng/mL, with 1270 participants (24.9%) being vitamin D deficient. In a random sample of 438 participants, the mean follow-up 25(OH)D level was greater than 20 ng/mL higher in the vitamin D group than in the placebo group. The primary outcome of CVD occurred in 303 participants (11.8%) in the vitamin D group and 293 participants (11.5%) in the placebo group, yielding an adjusted hazard ratio of 1.02 (95% CI, 0.87-1.20). Similar results were seen for participants with baseline vitamin D deficiency and for secondary outcomes.

Conclusions and Relevance

Monthly high-dose vitamin D supplementation does not prevent CVD. This result does not support the use of monthly vitamin D supplementation for this purpose. The effects of daily or weekly dosing require further study.

Trial Registration

clinicaltrials.gov Identifier: ACTRN12611000402943.

Could vitamin D deficiency influence left heart ventricular geometry in youngsters with type 1 diabetes mellitus?

BACKGROUND

Experimental and clinical studies have shown the cardio-protective, anti-inflammatory, and anti-atherosclerotic actions of vitamin D.

MATERIAL AND METHODS

We aimed to investigate a possible correlation between vitamin D status and heart geometry using echocardiographic parameters of the left ventricle in youngsters with type 1 diabetes mellitus (T1D). Seventy-eight pediatric patients (aged 13.47 ± 2.86 years) with T1D of more than two years duration and 74 healthy controls (aged 12.04 ± 2.79 years) were enrolled in this case-control study. Anthropometric parameters were recorded, vitamin D and parathormone serum levels were measured, and trans-thoracic echocardiographic study was performed.

RESULTS

Vitamin D deficiency was found in 74 % T1D patients and in 72 % of the controls, while parathormone levels were normal in both groups. T1D patients presented significantly higher values of interventricular septal thickness at diastole (IVSD) compared to controls (0.76 ± 0.16 cm vs 0.71 ± 0.14 cm, p =0.043). All other echocardiographic parameters did not exhibit significant differences between patients and controls. The diastolic function of the left ventricle (LV) was normal in both groups. After sub-grouping, the participants according to the deficiency or not of vitamin D, only patients with T1D and low vitamin D levels had increased values of IVSD compared to controls (0.78 ± 0.17 vs 0.71 ± 0.14, p =0.008). Patients with T1D and normal vitamin D levels presented similar values of IVSD compared to controls (0.71 ± 0.12 vs 0.73 ± 0.15, p =NS).

CONCLUSIONS

Children and adolescents with T1D and normal vitamin D levels do not exhibit changes in LV dimensions or diastolic function, except for increased IVSD, compared to controls. Larger and longitudinal studies are required to confirm and consolidate this finding. HIPPOKRATIA 2019, 23(1): 9-14.

Vitamin D levels in childhood and adolescence and cardiovascular risk factors in a cohort of healthy Australian children

As the prevalence of obesity appears to be increasing in Australia's youth the overall objective of this study was to examine serum 25-hydroxyvitamin D (25OHD) concentrations in a cohort of 8-year-olds (n=249) followed up at age 15 (n=162) and explore associations between 25OHD with cardiovascular disease (CVD) risk factors in these populations. This was done in two stages: the first, two cross-sectional analyses (at ages 8 and 15); and the second, a prospective analysis from age 8 to 15. At both ages data on 25OHD, blood lipids, and anthropometry were measured. Date of blood draw was used as a surrogate of sunlight exposure. Results were then analysed by multivariate linear analyses taking into account interaction and confounding. Mean 25OHD concentrations decreased from 94±25nmol/L to 63±16nmol/L between age 8 and 15 years (p<0.001). On cross-sectional analysis of 8year olds, no CVD risk factor was found to be significantly associated with 25OHD concentrations. On cross-sectional analysis of 15year olds lower 25OHD levels were significantly associated with higher body fat (adjusted β=-0.24, p=0.003). Prospectively, lower 25OHD levels in 8-year-old boys, but not girls, were significantly associated with higher blood total cholesterol (adjusted β=-0.28, p=0.040) and triglyceride levels (adjusted β=-0.33, p=0.030) at age 15. The limitation of these data is the relatively small sample sizes, however these results suggest that low 25OHD in childhood needs to be further investigated in larger cohort studies as there may be later cardiovascular consequences in adolescence.

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.

Independent and Synergistic Associations of Biomarkers of Vitamin D Status With Risk of Coronary Heart Disease

OBJECTIVE

To comprehensively evaluate the independent associations and potential interactions of vitamin D-related biomarkers including total and bioavailable 25-hydroxyvitamin D (25OHD), VDBP (vitamin D binding protein), and parathyroid hormone (PTH) with risk of coronary heart disease (CHD).

APPROACH AND RESULTS

We prospectively identified incident cases of nonfatal myocardial infarction and fatal CHD among women in the Nurses' Health Study during 20 years of follow-up (1990-2010). Using risk-set sampling, 1 to 2 matched controls were selected for each case. The analysis of 25OHD and PTH included 382 cases and 575 controls; the analysis of VDBP included 396 cases and 398 controls. After multivariate adjustment, plasma levels of total 25OHD, bioavailable 25OHD, and PTH were not significantly associated with CHD risk. VDBP was associated with a lower CHD risk with an extreme-quartile odds ratio of 0.60 (95% confidence interval, 0.39-0.92; P trend=0.02). When examining the biomarkers jointly, a significant, inverse association between 25OHD and CHD was observed among participants with higher PTH levels (P for interaction=0.02). The odds ratio (95% confidence interval) comparing the highest quartile of 25OHD to lowest was 0.43 (0.23-0.82; P trend=0.003) when PTH levels were above population median (35.3 pg/mL), whereas among the rest of participants the corresponding odds ratio (95% confidence interval) was 1.28 (0.70-2.36; P trend=0.43).

CONCLUSIONS

Our data suggest that higher 25OHD levels were associated with a lower CHD risk when PTH levels were high, whereas no association was observed for participants with low PTH levels. VDBP but not bioavailable 25OHD was independently associated with lower CHD risk.

Relationship between Bone Health Biomarkers and Cardiovascular Risk in a General Adult Population

Purpose/Introduction: Osteoporosis (OP) and cardiovascular (CV) disease emerge as closely related conditions, showing common risk factors and/or pathophysiological mechanisms. The aim of this study was to evaluate the association between bone health markers (BHM) and individual CV risk factors and overall CV risk (FRAMINGHAM-FRS, and PROCAM scores) in a general adult population.

METHODS

In 103 subjects (21 males; age: 56 ± 12 years), vitamin D (25(OH)D), osteocalcin (OC), bone alkaline phospatase (BALP), procollagen I aminoterminal propeptide (P1NP), CTx-telopeptide, as well clinical history and life style were evaluated.

RESULTS

Aging (p < 0.001) and glycemia (p < 0.05) emerged as independent 25(OH)D predictors. Aging (p < 0.001), male sex (p < 0.05), and obesity (p < 0.05) represented independent OC determinants. Aging (p < 0.05) was the only independent BALP determinant. After multivariate adjustment, low 25(OH)D (<20 ng/mL) (Odds ratio OR (95% confidence intervals CI)) (5 (1.4-18) p < 0.05) and elevated OC (>75th percentile-16.6 ng/mL) (6.7 (1.9-23.8) p < 0.01) were found to be significant FRS predictors, while subjects with elevated OC and/or BALP (>75th percentile-9.8 μg/L) showed a higher CV risk as estimated by PROCAM (3.6 (1.2-10.7) p < 0.05). CTx and P1NP did not significantly correlate with CV risk factors or scores.

CONCLUSION

As we go further into bone and CV physiology, it is evident that a close relationship exists between these diseases. Further studies are needed to investigate mechanisms by which bone turnover markers are related to metabolic risk and could modulate CV risk. This knowledge may help to develop possible multiple-purpose strategies for both CV disease and OP prevention and treatment.

Non-skeletal health effects of vitamin D supplementation: A systematic review on findings from meta-analyses summarizing trial data

BACKGROUND

A large number of observational studies have reported harmful effects of low 25-hydroxyvitamin D (25OHD) levels on non-skeletal outcomes. We performed a systematic quantitative review on characteristics of randomized clinical trials (RCTs) included in meta-analyses (MAs) on non-skeletal effects of vitamin D supplementation.

METHODS AND FINDINGS

We identified systematic reviews (SR) reporting summary data in terms of MAs of RCTs on selected non-skeletal outcomes. For each outcome, we summarized the results from available SRs and scrutinized included RCTs for a number of predefined characteristics. We identified 54 SRs including data from 210 RCTs. Most MAs as well as the individual RCTs reported null-findings on risk of cardiovascular diseases, type 2 diabetes, weight-loss, and malignant diseases. Beneficial effects of vitamin D supplementation was reported in 1 of 4 MAs on depression, 2 of 9 MAs on blood pressure, 3 of 7 MAs on respiratory tract infections, and 8 of 12 MAs on mortality. Most RCTs have primarily been performed to determine skeletal outcomes, whereas non-skeletal effects have been assessed as secondary outcomes. Only one-third of the RCTs had low level of 25OHD as a criterion for inclusion and a mean baseline 25OHD level below 50 nmol/L was only present in less than half of the analyses.

CONCLUSIONS

Published RCTs have mostly been performed in populations without low 25OHD levels. The fact that most MAs on results from RCTs did not show a beneficial effect does not disprove the hypothesis suggested by observational findings on adverse health outcomes of low 25OHD levels.

Effects of Calcium, Vitamin D, and Hormone Therapy on Cardiovascular Disease Risk Factors in the Women's Health Initiative: A Randomized Controlled Trial

OBJECTIVE

To analyze the treatment effect of calcium+vitamin D supplementation, hormone therapy, both, and neither on cardiovascular disease risk factors.

METHODS

We conducted a prospective, randomized, double-blind, placebo-controlled trial among Women's Health Initiative (WHI) participants. The predefined primary outcome was low-density lipoprotein cholesterol (LDL-C).

RESULTS

Between September 1993 and October 1998, a total of 68,132 women aged 50-79 years were recruited and randomized to the WHI-Dietary Modification (n=48,835) and WHI-Hormone Therapy trials (n=27,347). Subsequently, 36,282 women from WHI-Hormone Therapy (16,089) and WHI-Dietary Modification (n=25,210) trials were randomized in the WHI-Calcium+Vitamin D trial to 1,000 mg elemental calcium carbonate plus 400 international units vitamin D3 daily or placebo. Our study group included 1,521 women who participated in both the hormone therapy and calcium+vitamin D trials and were in the 6% subsample of trial participants with blood sample collections at baseline and years 1, 3, and 6. The average treatment effect with 95% confidence interval, for LDL-C, compared with placebo, was -1.6, (95% confidence interval [CI] -5.5 to 2.2) mg/dL for calcium+vitamin D alone, -9.0 (95% CI -13.0 to -5.1) mg/dL for hormone therapy alone, and -13.8 (95% CI -17.8 to -9.8) mg/dL for the combination. There was no evidence of a synergistic effect of calcium+vitamin D+hormone therapy on LDL-C (P value for interaction=.26) except in those with low total intakes of vitamin D, for whom there was a significant synergistic effect on LDL (P value for interaction=.03).

CONCLUSION

Reductions in LDL-C were greater among women randomized to both calcium+vitamin D and hormone therapy than for those randomized to either intervention alone or to placebo. The treatment effect observed in the calcium+vitamin D+hormone therapy combination group may be additive rather than synergistic. For clinicians and patients deciding to begin calcium+vitamin D supplementation, current use of hormone therapy should not influence that decision.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, https://clinicaltrials.gov, NCT00000611.

Associations between Serum 25-hydroxyvitamin D and Lipids, Lipoprotein Cholesterols, and Homocysteine

Background:

Serum 25(OH) vitamin D levels are inversely associated with cardiovascular disease (CVD) mortality, mediated in part by independent positive relationships with high-density lipoprotein cholesterol (HDLC) and inverse relationships with low-density lipoprotein cholesterol (LDLC), triglyceride, and homocysteine.

Aims:

In this study, we assessed relationships between fasting serum vitamin D and lipids, lipoprotein cholesterols, and homocysteine.

Materials and Methods:

We studied 1534 patients sequentially referred to our center from 2007 to 2016. Fasting serum total 25(OH) vitamin D, plasma cholesterol, triglyceride, HDLC, LDLC, and homocysteine were measured. Stepwise regression models were used with total cholesterol, triglyceride, HDLC, LDLC, and homocysteine as dependent variables and explanatory variables age, race, gender, body mass index (BMI), and serum vitamin D levels. Relationships between quintiles of serum vitamin D and triglycerides, HDLC, LDLC, and homocysteine were assessed after covariance adjusting for age, race, gender, and BMI.

Results:

Fasting serum vitamin D was positively correlated with age, HDLC, and White race, and was inversely correlated with BMI, total and LDL cholesterol, triglyceride, and fasting serum homocysteine (P ≤ 0.0001 for all). Serum vitamin D was a significant independent inverse explanatory variable for total cholesterol, triglyceride, and LDL cholesterol, and accounted for the largest amount of variance in serum total cholesterol (partial R² =3.6%), triglyceride (partial R² =3.1%), and LDLC (partial R² =2.9%) (P < 0.0001 for all). Serum vitamin D was a significant positive explanatory variable for HDLC (partial R² = 1.4%, P < 0.0001), and a significant inverse explanatory variable for homocysteine (partial R² = 6.0–12.6%).

Conclusions:

In hyperlipidemic patients, serum vitamin D was a significant independent inverse determinant of total cholesterol, LDLC, triglyceride, and homocysteine, and a significant independent positive determinant of HDLC. Thus, serum vitamin D might be protective against CVD.

Vitamin D and Its Relevance in the Etiopathogenesis of Oral Cavity Diseases

Vitamin D belongs to a group of fat-soluble secosteroids which assume many roles in the human organism. In humans the most important forms are vitamin D3 and vitamin D2. Their primary function is the regulation of the calcium and phosphorus balance, which promote the growth of healthy bony tissue. Studies over the past few years have revealed a much wider role of vitamin D involving the aging processes, carcinogenesis, the carbohydrate balance as well as the effects on the course of various infections. In this paper we discuss the basic functions of vitamin D in the human body and the mechanisms of its activity and we summarize recent reports on the impact of vitamin D on the oral cavity with a special emphasis on autoimmunologic diseases, including: recurrent aphthous stomatitis, Behçet syndrome and Sjögren syndrome.

The Role of Vitamin D in Diabetes and Cardiovascular Disease: An Updated Review of the Literature

The dietary reference values for Vitamin D were set primarily considering its role in bone health, but with the discovery of Vitamin D receptors throughout body tissues, new links with other health conditions are now studied, such as for diabetes and cardiovascular diseases (CVD). This paper shall analyze and examine all new research studies carried out, especially in 2013–2015 regarding diabetes mellitus (DM) and cardiovascular diseases (CVD). Vast research has been carried out to establish strong relationship between Vitamin D serum levels, supplementation, diabetes, and CVD. However, the results from researches identified in this paper are disputable. Benefits of Vitamin D adequate levels were recognized from gestational period until later in disease development such as diabetes and/or CVD, but since not all studies are in agreement further investigation is suggested. Researches conducting large randomized controlled trials, exploring range of supplement doses, with variable baseline serum Vitamin D levels, and inclusion of array of associated parameters, are still required to conduct large-scale analysis and draw conclusion as a risk factor. Until then it is possible to conclude that maintenance of serum Vitamin D levels holds advantageous aspects in diabetic and cardiovascular conditions, and people should strive to attain them.

Association between Vitamin D and Circulating Lipids in Early Childhood

Vitamin D is associated with established cardiovascular risk factors such as low density lipoprotein (LDL) in adults. It is unknown whether these associations are present in early childhood. To determine whether serum 25-hydroxyvitamin D (25(OH)D) is associated with serum non-high density lipoprotein (non-HDL) cholesterol during early childhood we conducted a cross-sectional study of children aged 1 to 5 years. Healthy children were recruited through the TARGet Kids! practice based research network from 2008-2011 (n=1,961). The associations between 25(OH)D and non-fasting non-HDL cholesterol (the primary endpoint), total cholesterol, triglycerides, HDL, and low density lipoprotein (LDL) cholesterol, were evaluated using multiple linear regression adjusted for age, sex, skin pigmentation, milk intake, vitamin D supplementation, season, body mass index, outdoor play, and screen time. Each 10 nmol/L increase in 25(OH)D was associated with a decrease in non-HDL cholesterol concentration of -0.89 mg/dl (95% CI: -1.16,-0.50), total cholesterol of -1.08 mg/dl (95%CI: -1.49,-0.70), and triglycerides of -2.34 mg/dl (95%CI: -3.23,-1.45). The associations between 25(OH)D and LDL and HDL were not statistically significant. 25(OH)D concentrations were inversely associated with circulating lipids in early childhood, suggesting that vitamin D exposure in early life may be an early modifiable risk factor for cardiovascular disease.

25-hydroxyvitamin D levels, vitamin D binding protein gene polymorphisms and incident coronary heart disease among whites and blacks: The ARIC study

BACKGROUND

In observational studies, low 25-hydroxyvitamin D (25(OH)D) has been associated with increased risk of coronary heart disease (CHD), and this association may vary by race. Racial differences in the frequency of vitamin D binding protein (DBP) single nucleotide polymorphisms (SNPs) might account for similar bioavailable vitamin D in blacks despite lower mean 25(OH)D. We hypothesized that the associations of low 25(OH)D with CHD risk would be stronger among whites and among persons with genotypes associated with higher DBP levels.

METHODS

We measured 25(OH)D by mass spectroscopy in 11,945 participants in the ARIC Study (baseline 1990-1992, mean age 57 years, 59% women, 24% black). Two DBP SNPs (rs7041; rs4588) were genotyped. We used adjusted Cox proportional hazards models to examine the association of 25(OH)D with adjudicated CHD events through December 2011.

RESULTS

Over a median of 20 years, there were 1230 incident CHD events. Whites in the lowest quintile of 25(OH)D (<17 ng/ml) compared to the upper 4 quintiles had an increased risk of incident CHD (HR 1.28, 95% CI 1.05-1.56), but blacks did not (1.03, 0.82-1.28), after adjustment for demographics and behavioral/socioeconomic factors (p-interaction with race = 0.22). Results among whites were no longer significant after further adjustment for potential mediators of this association (i.e. diabetes, hypertension). There was no statistically significant interaction of 25(OH)D with the DBP SNPs rs4588 (p = 0.92) or rs7041 (p = 0.87) in relation to CHD risk.

CONCLUSIONS

Low 25(OH)D was associated with incident CHD in whites, but no interactions of 25(OH)D with key DBP genotypes was found.

Vitamin D status and hypertension: a review

Vitamin D is a steroid prohormone synthesized in the skin following ultraviolet exposure and also achieved through supplemental or dietary intake. While there is strong evidence for its role in maintaining bone and muscle health, there has been recent debate regarding the role of vitamin D deficiency in hypertension based on conflicting epidemiological evidence. Thus, we conducted a scoping systematic literature review and meta-analysis of all observational studies published up to early 2014 in order to map trends in the evidence of this association. Mixed-effect meta-analysis was performed to pool risk estimates from ten prospective studies (n=58,262) (pooled risk for incident hypertension, relative risk [RR] =0.76 (0.63–0.90) for top vs bottom category of 25-hydroxyvitamin D [25OHD]) and from 19 cross-sectional studies (n=90,535) (odds ratio [OR] =0.79 (0.73–0.87)). Findings suggest that the better the assessed quality of the respective study design, the stronger the relationship between higher 25OHD levels and hypertension risk (RR =0.67 (0.51–0.88); OR =0.77 (0.72–0.89)). There was significant heterogeneity among the findings for both prospective and cross-sectional studies, but no evidence of publication bias was shown. There was no increased risk of hypertension when the participants were of older age or when they were vitamin D deficient. Younger females showed strong associations between high 25OHD levels and hypertension risk, especially in prospective studies (RR =0.36 (0.18–0.72); OR =0.62 (0.44–0.87)). Despite the accumulating evidence of a consistent link between vitamin D and blood pressure, these data are observational, so questions still remain in relation to the causality of this relationship. Further studies either combining existing raw data from available cohort studies or conducting further Mendelian analyses are needed to determine whether this represents a causal association. Large randomized controlled trials are also needed to determine whether vitamin supplementation may be beneficial in the prevention or the treatment of hypertension.

Quantitation of 25-hydroxyvitamin D2 and D3 in serum and plasma by LCMS/MS

Objective: We developed and validated an analytical method for quantifying 25-hydroxyvitamin D2 (25OHD2) and 25-hydroxyvitamin D3 (25OHD3) in serum and plasma. Methods: Samples, pretreated with zinc sulfate and methanol, were extracted with hexane. Separation was achieved via UHPLC and 25OHD quantification was accomplished by a triple quadrupole mass spectrometer. Results: Imprecision was 3.6–15.1%CV and bias 88.0–126.0%. Extraction efficiency was 76.5–110.5%, whereas the matrix effect ranged from −46.7 to −32.0%. The method was applied to authentic specimens. The results showed no significant difference between serum and plasma; strong correlation with paired values from an external laboratory; and analyte stability for 15 days. Conclusion: This method provides reliable and accurate measurement of 25OHD for use in clinical practice.

Serum lipoprotein composition and vitamin D metabolite levels in clinically isolated syndromes: Results from a multi-center study

CONTEXT

High serum cholesterol is adversely associated with clinical and imaging disease progression outcomes in multiple sclerosis (MS) and in clinically isolated syndrome (CIS), the earliest stage of MS. Low vitamin D levels are associated with an increased risk of disease progression.

OBJECTIVES

To investigate the mechanisms mediating the adverse effects of cholesterol in CIS and to determine the role of the nexus between the vitamin D3 (D3) and cholesterol pathways.

DESIGN

Multi-center, prospective, longitudinal prospective study.

SETTING

University hospital multiple sclerosis centers.

INTERVENTION

Serum samples were obtained prior to any treatment from study subjects.

METHODS

Serum obtained prior to any treatment from 172 CIS patients enrolled in a multi-center, prospective, longitudinal study (119 females: 53 males, age: 28.1 ± SD 8.1 years) were analyzed for high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), apolipoprotein AI (ApoAI), ApoAII, ApoB, ApoE, and lipoprotein-a. Levels of 25-hydroxy vitamin D3 (25(OH)D3), 1,25-dihydroxy D3, and 24,25-dihydroxy D3 were measured using liquid chromatography-mass spectrometry.

RESULTS

Greater levels of HDL-C biomarkers (e.g., HDL-C itself, ApoAI, ApoAII and paroxonase arylesterase activity) and LDL-C biomarkers (e.g., LDL-C itself, Apo B) were associated with greater 25(OH)D3. The effects of HDL-C biomarkers were stronger than those of LDL-C. Free cholesterol and cholesteryl ester levels were positively associated with higher 25(OH)D3 levels. Cholesterol palmitate was particularly potent. The nexus between the D3 and cholesterol pathways was proximal to, or in linkage disequilibrium with, 7-dehydrocholesterol reductase DHCR7 rs1790349, endothelial lipase LIPG rs4939883 and proprotein convertase subtilisin/kexin type 9 PCSK9 rs11206510.

CONCLUSIONS

The associations between cholesterol biomarkers and vitamin D metabolite levels in CIS are consistent with the biochemical inter-dependence between the two pathways. Cholesterol biomarkers should be considered for inclusion as covariates when assessing vitamin D levels in CIS.