Vitamin D status and its association with quality of life, physical activity, and disease activity in rheumatoid arthritis patients

Vitamin D Knowledge and Awareness Is Associated with Physical Activity among Adults: A Cross-Sectional Survey

The relation between knowledge and awareness of vitamin D (VD) and physical activity in adults has not been well studied. The present cross-sectional study aims to demonstrate this relation among adults living in Saudi Arabia. A total of 774 adults participated and were stratified based on self-reports of whether they were physically active (PA group, N = 562) or not (non-PA, N = 212). The prevalence of VD awareness and its health effects were significantly higher in the PA group compared with their counterparts (97 vs. 93.4%; p = 0.02 and 92.3 vs. 81.6%; p < 0.001, respectively). Sunlight was the preferred overall source of VD among the PA group (91.1%) followed by food, supplements, and fortified foods. Sardine, salmon, oily fish (63.7%) and eggs (54.6%) were reported as good dietary sources. Other positive attitudes, represented by taking supplement or multivitamins (51.2%), high sun exposure (33.1%), and daily duration of exposure to sunlight (15−30 min; 53.4%) were higher in the PA than the non-PA group (p values < 0.05). The body parts exposed to the sun among the PA group were arms (67.1%), hands (64.1%), face and hands (62.5%), legs (58.5%), and face (53.2%), while sunscreen cream (47.2%) was their preferred sun-protection method. High levels of knowledge and positive attitudes were reported by the PA group compared with the non-PA group in regard to walking outdoors for sun exposure (80.6 vs. 62.7%; p < 0.001). Information about good dietary sources, the role of VD in human health, associated diseases, positive attitudes to sun exposure, and the use of supplements or multivitamins were among the determinants of VD knowledge and awareness. In conclusion, VD knowledge and awareness are positively associated with self-reported physical activity in adults. Further objective classifications of PA may strengthen the results of the present investigation.

Role of Intestinal Microbiota on Gut Homeostasis and Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory disease that is immune mediated. Patients typically present with synovial inflammation, which gradually deteriorates to investigate severe cartilage and bone damage, affecting an individual's ability to perform basic tasks and impairing the quality of life. When evaluated against healthy controls, patients with RA have notable variations within the constituents of the gut microbiota. The human gastrointestinal tract mucosa is colonized by trillions of commensal microbacteria, which are key actors in the initiation, upkeep, and operation of the host immune system. Gut microbiota dysbiosis can adversely influence the immune system both locally and throughout the host, thus predisposing the host to a number of pathologies, including RA. Proximal intestinal immunomodulatory cells, situated in specific locales within the intestine, are a promising intermediary through which the gastrointestinal microbiota can influence the pathogenesis and progression of RA. In the early stages of the disease, the microbiota appear to differ from those present in healthy controls. This difference may reflect potential autoimmune mechanisms. Research studies evaluating intestinal microbiota have demonstrated that RA is associated with a bacterial population growth or with a decline when judged against control groups. The aim of this review is to examine the studies that connect intestinal dysbiosis with the autoimmune pathways implicated in the pathogenesis of RA.

Vitamin D and VDR Gene Polymorphisms' Association with Rheumatoid Arthritis in Lithuanian Population

Background and Objectives: Rheumatoid arthritis (RA) is a chronic, inflammatory, autoimmune, multi-factorial disease, in which environmental and genetic factors play a major role. RA is possibly linked to vitamin D deficiency and vitamin D receptor (VDR) gene polymorphisms, and research demonstrates that FokI variant susceptibility is associated with increased disease risk among Caucasians. The aim of this study was to evaluate vitamin D deficiency prevalence and its correlation to RA clinical parameters, and to determine the possible association of VDR gene polymorphisms and RA susceptibility in the Lithuanian population. Materials and Methods: Overall, 206 RA patients and 180 age- and sex-matched healthy controls were enrolled at Vilnius University Hospital Santaros Klinikos after informed consent was obtained. The disease activity score 28 C-reactive protein (DAS28 CRP), rheumatoid arthritis impact of disease (RAID) score, and health assessment questionnaire (HAQ) were recorded in RA patients, and 25(OH)D serum levels were evaluated by chemiluminescent microparticle immunoassay for all subjects. Four VDR gene polymorphisms, BsmI, FokI, ApaI, and TaqI, were assessed using real-time PCR instruments and genotyping assays in both groups. Results: The study registered a high prevalence of 25(OH)D deficiency (<50 nmol/L) in RA patients (61.55% (n = 127)). The mean serum concentration in RA patients (44.96 ± 21.92 (nmol/L)) was significantly lower than in the healthy controls (54.90 ± 22.82 (nmol/L)), p < 0.0001. A significant inverse correlation between vitamin D level, DAS28 CRP, and HAQ scores was confirmed in RA patients, with p < 0.05. Still, there was no significant association between the overall risk of RA disease for any allele or genotype of the four VDR loci tested. Conclusions: The study confirmed that vitamin D deficiency is prevalent among RA patients and the 25(OH)D level is significantly lower compared with healthy controls. Lower vitamin D concentration was related with increased disease activity and disability scores. However, genetic analysis of four VDR polymorphisms did not confer the susceptibility to RA in Lithuanian population.

A Systems Biology Approach for miRNA-mRNA Expression Patterns Analysis in Rheumatoid Arthritis

Objective:

Considering the molecular complexity and heterogeneity of rheumatoid arthritis (RA), the identification of novel molecular contributors involved in RA initiation and progression using systems biology approaches will open up potential therapeutic strategies. The bioinformatics method allows the detection of associated miRNA-mRNA as both therapeutic and prognostic targets for RA.

Methods:

This research used a system biology approach based on a systematic re-analysis of the RA-related microarray datasets in the NCBI Gene Expression Omnibus (GEO) database to find out deregulated miRNAs. We then studied the deregulated miRNA-mRNA using Enrichr and Molecular Signatures Database (MSigDB) to identify novel RA-related markers followed by an overview of miRNA-mRNA interaction networks and RA-related pathways.

Results:

This research mainly focused on mRNA and miRNA interactions in all tissues and blood/serum associated with RA to obtain a comprehensive knowledge of RA. Recent systems biology approach analyzed seven independent studies and presented important RA-related deregulated miRNAs (miR-145-5p, miR-146a-5p, miR-155-5p, miR-15a-5p, miR-29c-3p, miR- 103a-3p, miR-125a-5p, miR-125b-5p, miR-218); upregulation of miR-125b is shown in the study (GSE71600). While the findings of the Enrichr showed cytokine and vitamin D receptor pathways and inflammatory pathways. Further analysis revealed a negative correlation between the vitamin D receptor (VDR) and miR-125b in RA-associated gene expression.

Conclusion:

Since vitamin D is capable of regulating the immune homeostasis and decreasing the autoimmune process through its receptor (VDR), it is regarded as a potential target for RA. According to the results obtained, a comparative correlation between negative expression of the vitamin D receptor (VDR) and miR-125b was suggested in RA. The increasing miR-125b expression would reduce the VitD uptake through its receptor.

The Role of Nutritional Factors and Intestinal Microbiota in Rheumatoid Arthritis Development

Evidence about the role of nutritional factors and microbiota in autoimmune diseases, and in rheumatoid arthritis (RA) in particular, has grown in recent years, however many controversies remain. The aim of this review is to summarize the role of nutrition and of the intestinal microbiota in the development of RA. We will focus on selected dietary patterns, individual foods and beverages that have been most consistently associated with RA or with the occurrence of systemic autoimmunity associated with RA. We will also review the evidence for a role of the intestinal microbiota in RA development. We propose that diet and digestive microbiota should be considered together in research, as they interact and may both be the target for future preventive interventions in RA.

Serum vitamin D level correlates with disease activity and health-related quality of life in antineutrophil cytoplasmic antibody-associated vasculitis

BACKGROUND AND OBJECTIVE

The association between vitamin D levels and disease activity has been established in patients with several autoimmune rheumatic diseases. We aimed to examine the association between vitamin D and disease activity of antineutrophil cytoplasmic antibody-associated vasculitis (AAV).

METHODS

Fifty-four AAV patients and 50 age- and sex-matched healthy controls without vitamin D supplements were included. Clinical and laboratory data were evaluated during the assessment of vitamin D levels. Two different forms of vitamin D in the sera-25(OH)D, which is the sum of 25(OH)D2 and 25(OH)D3, and 25(OH)D3, which only includes 25(OH)D in its D3 form-were measured, and the relationship between vitamin D and the obtained data was assessed. Variations in vitamin D levels relative to the season were also evaluated.

RESULTS

Patients with AAV demonstrated considerably lower 25(OH)D serum levels than healthy controls (16.0 vs. 20.4 ng/mL, p = 0.016), and the proportion of individuals with vitamin D deficiency was higher in patients with AAV than in healthy controls (68.5% vs. 48.0%, p = 0.035). Both serum 25(OH)D and 25(OH)D3 were positively associated with the 36-item Short-form Health Survey (SF-36) physical component summary and SF-36 mental component summary (MCS) scores. A negative correlation was observed between 25(OH)D and 25(OH)D3 serum levels and Birmingham vasculitis activity score (BVAS), C‑reactive protein (CRP), and white blood cell count. Linear regression analysis indicated haemoglobin and 25(OH)D levels to be independently associated with BVAS and CRP and 25(OH)D levels with SF-36 MCS score. No seasonal variations were observed in vitamin D levels.

CONCLUSION

The results from this study suggest that vitamin D levels could provide clinically useful information in AAV.

Immunological analysis of vitamin D receptor gene expression in Egyptian patients with rheumatoid arthritis: relation to disease activity and functional disability

Background

Vitamin D (vit D) deficiency has recently been associated with risk of development of rheumatoid arthritis (RA). The aim of this research was to assess vitamin D receptor (VDR) gene expression in Egyptian patients with RA and its relation with the inflammatory state, disease activity, and functional disability.

Results

RA patients had significantly lower vit D level and VDR gene expression compared to controls (mean ± 17.0 ± 6.65, 20.73 ± 8.42 ng/ml, p < 0.05 and 3.29 ± 5.47, 14.22 ± 12.60, p < 0.001 respectively). Receiver operating characteristic (ROC) curve analysis for VDR gene expression in RA patients revealed (area under the curve 0.826, cutoff value for low VDR expression 1.05 ng/ml). Patients with low VDR expression had significantly higher ESR, CRP, double positive RF+ anti-CCP+, DAS28, and MHAQ (p < 0.001, p = 0.001, p < 0.05, p < 0.001, p < 0.001) respectively.

Conclusion

Vitamin D and VDR expression are significantly lower in RA patients than controls. Patients with low VDR gene expression had significantly higher disease activity and disability. This may suggest that apart from low vit D levels, low VDR expression is associated with inflammatory process and it has a potential role in RA pathogenesis and prognosis. Further multicenter studies are needed to confirm these findings.

Vitamin D Deficiency and Rheumatoid Arthritis: Epidemiological, Immunological, Clinical and Therapeutic Aspects

Background/Aim:

Vitamin D displays an immunologic effect which can modulate function of Th17-related cytokines and thereby prevent perpetuation of inflammation in chronic disorders like rheumatoid arthritis (RA). This review aims to conduct a literature review to provide a summary of recent studies addressing the relationship between vitamin D deficiency and RA based on epidemiological, immunological and therapeutic aspects.

Methods:

PubMed, Scopus and Google scholar were searched for relevant papers published between 2000–2018.

Results:

Low intake of vitamin D increases the risk of incident RA, and vitamin D deficiency has been shown to be inversely associated with RA activity in most of these studies. However, characteristics of RA and serum vitamin D status differ across the studies. The results of studies on the effect of supplemental vitamin D in RA vary, from no efficacy to significant improvement in disease activity, as well as quality of life. This should be attributed to variations in dosage of vitamin D, duration of treatment, baseline serum vitamin D in RA patients and characteristics of RA across diverse studies.

Conclusion:

Current data indicate a therapeutic potential for vitamin D in RA. However, further studies are needed to identify an optimal and effective dosage, duration of treatment and patients who will get the best benefit from the treatment.

Lower Levels of Vitamin D Associated with Disease Activity in Colombian Patients with Systemic Lupus Erythematosus

BACKGROUND

Systemic Lupus Erythematosus (SLE) involves genetic, environmental, and hormonal alterations, including Vitamin D deficiency.

OBJECTIVE

To evaluate the association between vitamin D levels with anti-dsDNA, complement proteins, immunoglobulins levels and disease activity scores.

METHODS

A cross-sectional study was performed. The levels of 25-OH vitamin D were measured in patients older than 18 years with SLE according to ACR/97 [American College of Rheumatology 1997] from 2013 to 2015. The association was assessed by Mann-Whitney U and Kruskal Wallis tests for continuous variables, and by the Chi or Fisher exact test for the nominal variables.

RESULTS

Sixty-nine patients were included; 82% were women; the mean age was 38.5 years; 36.2% had low levels of vitamin D with higher consumption [p=0.006] of C4 and C3 complement proteins, plus higher levels of anti-dsDNA. Lower values of vitamin D were observed in patients with moderate to severe activity [p=0.0001] by SLEDAI [Systemic Lupus Erythematosus Activity Index] and general domain [p=0.039] and renal domain [p=0.009] by BILAG [British Isles Lupus Assessment Group] 2004. The mean vitamin D levels were higher in the group not receiving steroids when compared to those groups with dosages of 0.5-1mg/kg/d [p=0.048].

CONCLUSION

Lower levels of vitamin D are associated with greater complement protein consumption and higher disease activity rates. Therefore, it is important to evaluate vitamin D supplementation in patients with SLE as part of the treatment, especially when it includes the use of steroids.

Emerging role of vitamin D in autoimmune diseases: An update on evidence and therapeutic implications

Vitamin D plays a key role in in calcium homeostasis and, thus, provides an important support in bone growth by aiding in the mineralization of the collagen matrix. However, vitamin D performs various immunomodulatory, anti-inflammatory, antioxidant and anti-fibrotic actions. Autoimmune diseases result from an aberrant activation of the immune system, whereby the immune response is directed against harmless self-antigens. Does vitamin D play a role in the pathophysiology of autoimmune diseases? And, if so, what is its role? In the last decade, researchers' interest in vitamin D and its correlations with autoimmune diseases has considerably increased. We conducted a literature review, covering the period January 1, 2009 through March 30, 2019, in PubMed. We analyzed more than 130 studies in order to find a correlation between vitamin D levels and its effect upon several autoimmune diseases. The analysis demonstrated an inverse association between vitamin D and the development of several autoimmune diseases, such as SLE, thyrotoxicosis, type 1 DM, MS, iridocyclitis, Crohn's disease, ulcerative colitis, psoriasis vulgaris, seropositive RA, polymyalgia rheumatica. International multicenter study could allow us to confirm the data already present in the literature in the single clinical studies and to evaluate when to effectively supplement vitamin D in patients who do not take corticosteroids.

Vitamin D as a Principal Factor in Mediating Rheumatoid Arthritis-Derived Immune Response

Rheumatoid arthritis (RA) is a systemic multifactorial autoimmune disorder. The interactions between diverse environmental and genetic factors lead to the onset of this complex autoimmune disorder. Serum levels of vitamin D (VD) are involved in the regulation of various immune responses. Vitamin D is a key signaling molecule in the human body that maintains calcium as well as phosphate homeostasis. It also regulates the functions of the immune system and, thus, can play a substantial role in the etiology of various autoimmune disorders, including RA. Low serum VD levels have been found to be associated with a higher risk of RA, although this finding has not been replicated consistently. The molecular mechanisms by which VD influences autoimmunity need to be further explored to understand how variation in plasma VD levels could affect the pathogenesis of RA. This mini-review focuses on the influence of VD and its serum levels on RA susceptibility, RA-associated complexities, treatment, and transcriptome products of key proinflammatory cytokines, along with other cytokines that are key regulators of inflammation in rheumatoid joints.

Relationship between vitamin D level and Bechcet's disease activity: A systematic review and meta-analysis

Aim: In the present study, the evidence about the association between vitamin D deficiency and Behcet's disease activity was systematically reviewed and meta-analyzed. Method: We searched the English and Persian databases of Medline (Ovid), CINHAL, Scopus, Proquest, the Cochrane library and SID, IranDoc, Magiran, Iran Medex for articles published up until May 2018 with the keywords were related to serum vitamin D and active and inactive Behcet's disease in adults. Meta-analysis was done using the CMA software. Results: A total of 138 titles were retrieved and reduced to 80 titles after deletion of duplicates and finally after close assessing of titles and abstracts eight eligible studies including a total of 939 participants were identified for systematic review and meta-analysis. According to the results of the meta-analysis, the pooled effect size of the differences in the serum level of vitamin D in patients with inactive Behçet's Disease and healthy controls was [OR:-0.05; 95% CI:-2.05, 1.94; p = 0.95]. The serum vitamin D level was significantly lower in active patients compared with healthy controls [OR:1.21; 95%CI: -0.12, 2.31; p = 0.03]. The pooled effect size of the differences in the serum level of vitamin D in active and inactive Behçet's Disease was [OR:-0.71; 95%CI: -1.41, -0.007; p = 0.04] Conclusion: There is an association between vitamin D deficiency and active Behçet's Disease. Future studies investigating the association of vitamin D deficiency and Behçet's Disease needs to involve following information: dietary intake of calcium and vitamin D, measuring of sun exposure, report of drug consumption and physical activity level.

Vitamin D and rheumatoid arthritis: an ongoing mystery

PURPOSE OF REVIEW

In recent years, there has been a growing interest in the value of vitamin D and its effects on autoimmunity. The aim of this review is to summarize the current knowledge on the association between vitamin D and rheumatoid arthritis (RA) in terms of prevalence, disease activity, clinical expression, serology and gene polymorphisms of vitamin D receptors.

RECENT FINDINGS

Studies have shown contrasting findings concerning the association between vitamin D levels and RA. Vitamin D seems to have immunomodulatory properties. Therefore, low vitamin D levels could contribute to increased immune activation. However, the potential role of vitamin D supplementation in preventing RA manifestation and its beneficial role as a component of RA treatment remain controversial. The relationship between RA susceptibility and vitamin D polymorphisms is also unclear.

SUMMARY

Despite advancements synthesized by some recent meta-analyses, the relationship between vitamin D and RA requires further evaluation. Further research is needed to confirm the relationship between RA susceptibility and vitamin D polymorphisms and to determine whether vitamin D plays a role in preventing the manifestation of RA. Finally, additional studies are required to determine the impact and optimal amount of vitamin D supplementation in the treatment of RA patients.

Serum 25-hydroxyvitamin D levels in patients with Granulomatosis with Polyangiitis: association with respiratory infection

OBJECTIVES

To determine the possible association of serum 25-hydroxyvitamin D (25OHD) levels with disease activity and respiratory infection in granulomatosis with polyangiitis patients during two different periods: winter/spring and summer/autumn.

METHODS

Thirty-two granulomatosis with polyangiitis patients were evaluated in the winter/spring, and the same patients (except 5) were evaluated in summer/autumn (n=27). The 25OHD levels were measured by radioimmunoassay. Disease activity was assessed by the Birmingham Vasculitis Activity Score Modified for Wegener's Granulomatosis (BVAS/WG) and antineutrophil cytoplasmic antibody (ANCA) positivity. Respiratory infection was defined according the Centers for Disease Control and Prevention criteria.

RESULTS

25OHD levels were lower among patients in winter/spring than in summer/autumn (32.31±13.10 vs. 38.98±10.97 ng/mL, p=0.04). Seven patients met the criteria for respiratory infection: 5 in winter/spring and 2 in summer/autumn. Patients with respiratory infection presented lower 25OHD levels than those without infection (25.15±11.70 vs. 36.73±12.08 ng/mL, p=0.02). A higher frequency of low vitamin D levels (25OHD<20 ng/mL) was observed in patients with respiratory infection (37.5% vs. 7.8, p=0.04). Serum 25OHD levels were comparable between patients with (BVAS/WG≥1 plus positive ANCA) and without disease activity (BVAS/WG=0 plus negative ANCA) (35.40±11.48 vs. 35.34±13.13 ng/mL, p=0.98).

CONCLUSIONS

Lower 25OHD levels were associated with respiratory infection but not disease activity in granulomatosis with polyangiitis patients. Our data suggest that hypovitaminosis D could be an important risk factor for respiratory infection in granulomatosis with polyangiitis patients.

Skeletal complications of rheumatoid arthritis

Rheumatoid arthritis (RA) is associated with local and systemic inflammation that induces many changes in the skeletal health. Locally, periarticular bone loss and juxta-articular bone erosions may occur while joint ankylosis, generalized bone loss, osteoporosis, and fractures may develop secondary to inflammation. The aim of this narrative review is to summarize the clinical evidence for abnormal skeletal health in RA, the effects of disease modifying anti-rheumatic drugs (DMARDS) on bone health, and the effects of drugs for the prevention or treatment of osteoporosis in the RA population.

Dietary and Supplemental Vitamin C and D on Symptom Severity and Physical Function in Knee Osteoarthritis

Vitamins C and D have been associated with decreasing pain and increasing function but these associations are not definitive. This cross-sectional study explores what relationships supplemental and dietary intake of vitamins C and D have on pain severity and physical function in patients with knee osteoarthritis. Using data from the Osteoarthritis Initiative, we performed regression analyses to examine relationships between vitamins C and D, pain, and function. Dietary vitamin D and dietary vitamin C were divided into >90th, 50th-90th, and <50th percentile. The high percentile group for supplemental vitamin D was divided into >85th percentile, whereas the high percentile group for supplemental vitamin C was divided into >90th percentile. We found the 90th/85th percentile levels of dietary and supplemental vitamin D to be positively associated with pain (β = 0.180; p = 0.028) and inversely related to physical function (β = -0.150, p = 0.028), respectively. Daily intake of vitamin C showed no statistical significance. We found that supplementary vitamin D was strongly associated with lessened disability for knee OA patients. The unexpected finding that associated dietary vitamin D with greater knee pain merits further study.

European multicentre pilot survey to assess vitamin D status in rheumatoid arthritis patients and early development of a new Patient Reported Outcome questionnaire (D-PRO)

OBJECTIVE

To collect data on vitamin D (25(OH)D) serum levels in a large number of rheumatoid arthritis (RA) patients from different European countries, to investigate their relation with disease activity, disability, quality of life, and possibly to construct a new Patient Reported Outcome (PRO) questionnaire in order to self-estimate if they are at risk for vitamin D insufficiency/deficiency-related clinical implications (D-PRO).

METHODS

This was a European League Against Rheumatism (EULAR) supported cross-sectional study (project No CLI064) which involved 625 RA patients (mean age 55±11years, mean disease duration 11±9years), 276 age and sex matched healthy subjects, and rheumatologists working in academic institutions or hospital centres, as well as PARE organizations (patient representatives) from 13 European countries. Serum samples for 25(OH)D level measurement were collected during winter time and analyzed in a central laboratory using chemiluminescence immunoassay (DiaSorin). Patient past medical history was recorded. RA patients were provided with three questionnaires: the Rheumatoid Arthritis Impact Diseases score (RAID), the Health Assessment Questionnaire (HAQ), and the new D-PRO questionnaire at the time of 25(OH)D serum sampling. D-PRO questionnaire consisted of three domains, Symptom Risk Score (SRS), Habitus Risk Score (HRS) and Global Risk Score (SRS+HRS=GRS), constructed with items possibly related to vitamin D deficiency. D-PRO was correlated with both clinical and PRO scores. DAS28-CRP was also evaluated. Statistical analysis was performed by non parametric tests.

RESULTS

Mean serum concentration of 25(OH)D in RA patients (17.62±9.76ng/ml) was found significantly lower if compared to the levels obtained in matched controls (18.95±9.45ng/ml) (p=0.01), with statistically significant differences among several European countries. Negative correlations were found between 25(OH)D serum levels and DAS28-CRP (p<0.001), RAID (p=0.05) and HAQ (p=0.04) scores in the RA patients group. Negative correlations were also found in the cohort of enrolled RA patients between 25(OH)D serum concentrations and SRS (p=0.04), HRS (p=0.02) and GRS (p=0.02) domains of the D-PRO questionnaire.

CONCLUSIONS

This first multicentre European survey add new evidences that vitamin D insufficiency/deficiency is frequent in RA patients with statistically significant differences among several countries. Vitamin D serum concentrations seem to correlate negatively and significantly with the D-PRO Global Risk Score, clinimetric indexes for quality of life, disease activity and disability in present cohort of RA European patients.

Association of arthritis and vitamin D insufficiency with physical disability in Mexican older adults: findings from the Mexican Health and Aging Study

Arthritis and vitamin D insufficiency are prevalent in older adults and are risk factors for disability. The objective of this study was to examine the effect of co-occurring arthritis and vitamin D deficiency on upper-lower extremity functional limitations and disability in older adults. We examined 1533 participants aged ≥50 years from a subsample of the Mexican Health and Aging Study. Measures included sociodemographics, body mass index, comorbid conditions, falls, physical activity, physical function tests, functional limitations, activities of daily living (ADL), and vitamin D. Participants were categorized into four groups according to arthritis and vitamin D status: no vitamin D insufficiency and no arthritis (58.80%), vitamin D insufficiency only (27.49%), arthritis only (8.47%), and arthritis and vitamin D insufficiency (5.24%). Fourteen percent reported arthritis, and 31.2% had vitamin D insufficiency. The arthritis and vitamin D insufficiency group was associated with upper-lower extremity functional limitations [odds ratio (OR) 1.82, 95% confidence interval (CI) 1.06-3.15, and OR 1.90, 95% CI 1.00-3.62, respectively] and ADL disability (OR 3.00, 95% CI 1.63-5.51) when compared with the no vitamin D insufficiency and no arthritis group (reference group). The arthritis only group was three times more likely to report upper-lower extremity functional limitations and ADL disability. The vitamin D insufficiency only group was not significantly associated with functional limitations nor ADL disability. Arthritis and vitamin D insufficiency increased the risk of ADL disability in this population. However, the effect of arthritis and vitamin D insufficiency on upper-lower extremity functional limitations was not higher than the effect of arthritis only, but higher than the effect on vitamin D insufficiency alone.

Association of circulating 25-hydroxyvitamin D with mental well-being in a population-based, nationally representative sample of German adolescents

OBJECTIVE

Numerous studies have linked vitamin D to health-related quality of life (hrQoL) in chronically ill adults or elderly subjects. The aim of this study was to evaluate the association between 25-hydroxyvitamin D (25(OH)D) and hrQoL in a population-based sample of German adolescents.

METHODS

A total of n = 5066 study participants from the nationwide, representative German Health Interview and Examination Survey for Children and Adolescents (Kinder- und Jugendgesundheitssurvey) aged 11-17 years were included in this post hoc analysis. HrQoL was measured using the well-validated self- and parent-rated Children's Quality of Life questionnaires (KINDL-R), while the level of distress was assessed using the self- and proxy version of the Strengths and Difficulties Questionnaire (SDQ). Serum 25(OH)D concentrations were determined using a commercially available chemiluminescence immunoassay.

RESULTS

Bivariate analyses demonstrated a significant positive association between 25(OH)D and hrQoL for both self- [estimate (E) = 0.82, 95 % confidence interval (95 % CI) 0.35-1.30, p = 0.001] and parent ratings (E = 1.33, 95 % CI 0.83-1.83, p < 0.001). In addition, we found negative correlations between 25(OH)D and self- (E = -0.34, 95 % CI -0.58 to -0.11, p = 0.005) and parent-reported total SDQ scores (E = -0.70, 95 % CI -1.03 to -0.37, p < 0.001). Generalized linear models adjusted for age, sex, body mass index, systolic blood pressure, migration background, socio-economic status, and sedentary screen time confirmed that 25(OH)D independently and significantly predicted better hrQoL (p ≤ 0.004).

CONCLUSIONS

These findings linking 25(OH)D to better well-being in a nationally representative sample of German children and adolescents suggest beneficial effects of vitamin D on mental health. However, recommendations for vitamin supplementation in healthy children and adolescents are not warranted from our data.

Serum Vitamin D Level and Rheumatoid Arthritis Disease Activity: Review and Meta-Analysis

Background

The evidence from epidemiological studies concerning the relationship between serum vitamin D concentrations and rheumatoid arthritis (RA) is inconsistent. This meta-analysis is aimed at determining the magnitude of the correlation between this common autoimmune disease and vitamin D, an important nutrient known to dampen adaptive immune responses.

Methods

Through multiple search strategies, relevant literature was identified and evaluated for quality before May 16 2015. Data extracted from eligible studies was synthesized to calculate pooled correlation coefficient (r), mean difference (MD) and odds ratio (OR). The Venice criteria were applied to assess the credibility of the evidence for each statistically significant association.

Results

A total of 24 reports involving 3489 patients were selected for analysis. RA patients had lower vitamin D levels than healthy controls (MD:-16.52 nmol/L, 95% confidence intervals [CI]:-18.85 to -14.19 nmol/L). There existed a negative relationship between serum 25-hydroxyvitamin D (25OHD) level and disease activity index, e.g. 25OHD vs. Disease Activity Score in 28 joints (DAS28): r = -0.13, 95% CI -0.16 to -0.09; 25OHD vs. C-reactive protein: r = -0.12, 95% CI -0.23 to -0.00. Additionally, latitude-stratified subgroup analysis yielded a relatively stronger negative correlation between 25OHD and DAS28 in low-latitude areas. This inverse relationship also appeared more significant in developing countries than in developed countries. No publication bias was detected.

Conclusion

RA patients had lower vitamin D values than healthy controls. There was a negative association between serum vitamin D and RA disease activity. However, more strictly controlled studies are needed to validate these findings.

Low vitamin D levels are associated with higher opioid dose in palliative cancer patients--results from an observational study in Sweden

Background

Vitamin D deficiency is common among palliative cancer patients and has been connected to an increased risk for pain, depressions and infections. Therefore we wanted to test the hypothesis that low 25-hydroxyvitamin D (25OHD) levels are associated with higher opioid dose, higher infectious burden and impaired quality of life in palliative cancer patients. The secondary aim was to investigate the association between 25OHD-levels and survival time.

Method

In this prospective, observational study in palliative cancer-patients (n = 100) we performed univariate and multiple linear regression analysis to assess the association of 25OHD levels with opioid dose, infectious burden (antibiotic consumption), quality of life (Edmonton Symptom Assessment Scale, ESAS) and survival time, controlling for potential confounding factors.

Results

The median 25OHD level was 40 nmol/L (range 8-154 nmol/L). There was a significant association between 25OHD levels and opioid dose, beta coefficient -0.67; p=0.02; i.e. a low 25OHD level was associated with a higher opioid dose. This association remained significant after adjustment for stage of the cancer disease in a multivariate analysis, beta coefficient -0.66; p = 0.04. There was no association between 25OHD levels and antibiotic use or quality of life. Univariate cox regression analysis showed a weak correlation between survival time and 25OHD levels (p<0.05). However, decreased albumin levels and increased CRP levels were superior markers to predict survival time; p<0.001 for both analyses.

Conclusion

Low 25OHD-levels are associated with increased opioid consumption in palliative cancer patients. Future interventional studies are needed to investigate if pain can be reduced by vitamin D supplementation in these patients. In addition, this study confirms previous findings that low albumin and increased CRP levels are useful markers for survival time in palliative cancer patients.