Serum 25-hydroxyvitamin D is inversely associated with body mass index in cancer

Role of Vitamin D in Head and Neck Cancer-Immune Function, Anti-Tumour Effect, and Its Impact on Patient Prognosis

Head and neck squamous cell carcinoma (HNSCC) describes a heterogeneous group of human neoplasms of the head and neck with high rates of morbidity and mortality, constituting about 3% of all cancers and ~1.5% of all cancer deaths. HNSCC constituted the seventh most prevalent human malignancy and the most common human cancer in the world in 2020, according to multi-population observations conducted by the GLOBOCAN group. Since approximately 60-70% of patients present with stage III/IV neoplastic disease, HNSCC is still one of the leading causes of death in cancer patients worldwide, with an overall survival rate that is too low, not exceeding 40-60% of these patients. Despite the application of newer surgical techniques and the implementation of modern combined oncological treatment, the disease often follows a fatal course due to frequent nodal metastases and local neoplastic recurrences. The role of micronutrients in the initiation, development, and progression of HNSCC has been the subject of considerable research. Of particular interest has been vitamin D, the pleiotropic biologically active fat-soluble family of secosteroids (vitamin-D-like steroids), which constitutes a key regulator of bone, calcium, and phosphate homeostasis, as well as carcinogenesis and the further development of various neoplasms. Considerable evidence suggests that vitamin D plays a key role in cellular proliferation, angiogenesis, immunity, and cellular metabolism. A number of basic science, clinical, and epidemiological studies indicate that vitamin D has multidirectional biological effects and influences anti-cancer intracellular mechanisms and cancer risk, and that vitamin D dietary supplements have various prophylactic benefits. In the 20th century, it was reported that vitamin D may play various roles in the protection and regulation of normal cellular phenotypes and in cancer prevention and adjunctive therapy in various human neoplasms, including HNSCC, by regulating a number of intracellular mechanisms, including control of tumour cell expansion and differentiation, apoptosis, intercellular interactions, angio- and lymphogenesis, immune function, and tumour invasion. These regulatory properties mainly occur indirectly via epigenetic and transcriptional changes regulating the function of transcription factors, chromatin modifiers, non-coding RNA (ncRNAs), and microRNAs (miRs) through protein-protein interactions and signalling pathways. In this way, calcitriol enhances intercellular communication in cancer biology, restores the connection with the extracellular matrix, and promotes the epithelial phenotype; it thus counteracts the tumour-associated detachment from the extracellular matrix and inhibits the formation of metastases. Furthermore, the confirmation that the vitamin D receptor (VDR) is present in many human tissues confirmed the physiopathological significance of vitamin D in various human tumours. Recent studies indicate quantitative associations between exposure to vitamin D and the incidence of HNC, i.e., cancer risk assessment included circulating calcidiol plasma/serum concentrations, vitamin D intake, the presence of the VDR gene polymorphism, and genes involved in the vitamin D metabolism pathway. Moreover, the chemopreventive efficacy of vitamin D in precancerous lesions of the head and neck and their role as predictors of mortality, survival, and recurrence of head and neck cancer are also widely discussed. As such, it may be considered a promising potential anti-cancer agent for developing innovative methods of targeted therapy. The proposed review discusses in detail the mechanisms regulating the relationship between vitamin D and HNSCC. It also provides an overview of the current literature, including key opinion-forming systematic reviews as well as epidemiological, prospective, longitudinal, cross-sectional, and interventional studies based on in vitro and animal models of HNSCC, all of which are accessible via the PubMed/Medline/EMBASE/Cochrane Library databases. This article presents the data in line with increasing clinical credibility.

Obesity and Breast Cancer: Interaction or Interference with the Response to Therapy?

Background: Aromatase inhibitors (AI) are widely used for treating hormone-sensitive breast cancer (BC). Obesity, however, due to aromatase-mediated androgen conversion into estradiol in the peripheral adipose tissue, might impair AI inhibitory capacity. We aimed at identifying a cut-off of body mass index (BMI) with significant prognostic impact, in a cohort of stage I-II BC patients on systemic adjuvant therapy with AI. Methods: we retrospectively evaluated routinely collected baseline parameters. The optimal BMI cut-off affecting disease-free survival (DFS) in AI-treated BC patients was identified through maximally selected rank statistics; non-linear association between BMI and DFS in the AI cohort was assessed by hazard-ratio-smoothed curve analysis using BMI as continuous variable. The impact of the BMI cut-off on survival outcomes was estimated through Kaplan−Meier plots, with log-rank test and hazard ratio estimation comparing patient subgroups. Results: A total of 319 BC patients under adjuvant endocrine therapy and/or adjuvant chemotherapy were included. Curve-fitting analysis showed that for a BMI cut-off >29 in AI-treated BC patients (n = 172), DFS was increasingly deteriorating and that the impact of BMI on 2-year DFS identified a cut-off specific only for the cohort of postmenopausal BC patients under adjuvant therapy with AI. Conclusion: in radically resected hormone-sensitive BC patients undergoing neoadjuvant or adjuvant chemotherapy and treated with AI, obesity represents a risk factor for recurrence, with a significantly reduced 2-year DFS.

Cross-sectional observational study - Investigation of vitamin D concentration in Caucasian cancer patients. what is the adequate dose of vitamin D for these patients?

BACKGROUND & AIMS

Vitamin D impairs tumour-related transformation and supports the anticancer function of the immune system. Currently, there are no guidelines on vitamin D supplementation devoted solely to cancer patients. The primary objective of the study was to evaluate the frequency of vitamin D deficiency in Caucasian cancer patients and to characterize the clinical factors that predispose individuals to decreased vitamin D concentration. Secondly, the study aimed to estimate the dose of vitamin D supplementation that would prevent deficiencies in patients with cancer.

METHODS

In the presented cross-sectional study the population consisted of 500 consecutive Caucasian patients with a diagnosis of neoplastic disease, some of which declared long-term vitamin D supplementation in various doses. Serum vitamin D concentration was measured once in all patients and clinical data were obtained from the hospital database. The frequencies of vitamin D deficiency were compared to certain clinical variables by appropriate statistical tests. The dose of vitamin D substitution in cancer patients was estimated using the receiver operating characteristic (ROC) curve.

RESULTS

Vitamin D deficiency was diagnosed in 66.8% of patients with cancer and even in 31.6% who declared vitamin D supplementation. Older age, male gender, diagnosis of head and neck cancer or squamous cell carcinoma and body mass loss were identified as factors that predispose to vitamin D deficiency. The dose of vitamin D that would prevent deficiency in Caucasian patients with cancer was set at 2250 IU daily.

CONCLUSIONS

Vitamin D deficiency was very common in Caucasian patients with cancer, even in terms of vitamin D supplementation. The greatest predisposition was related to elder age, male gender, diagnosis of head and neck or squamous cell carcinoma and body mass loss. The dose of vitamin D supplementation in cancer patients should probably be higher than in the general population.

Serum Levels of Vitamin D in Diabetic Patients With and Without Retinopathy

Purpose

To evaluate the levels of vitamin D in the serum of diabetic patients with and without diabetic retinopathy (DR).

Methods

Thirty patients with DR and thirty diabetic patients without retinopathy were included in this cross-sectional study. Based on ophthalmic examination, patients with DR were categorized into having non-proliferative retinopathy (NPDR) and proliferative retinopathy (PDR). Patients were tested for fasting blood sugar (FBS), hemoglobin A1C (HbA1C), 25-hydroxy vitamin D (25 (OH) D), and creatinine levels in the serum, and for urine protein. Vitamin D deficiency was defined as a serum 25 (OH) D level < 20 ng/mL.

Results

We found that all diabetic patients had mild vitamin D deficiency (serum 25 (OH) D level = 10–20 ng/mL). The mean serum 25 (OH) D concentration in patients with DR was lower than in those without DR (12.10 ± 14.62 ng/mL vs 15.61 ± 9.40 ng/mL, respectively, P = 0.012). Trace or more proteinuria was frequently present in patients with DR than in those without DR (56% in DR vs 30% in non-DR; P = 0.037). There were no significant differences in the FBS, HbA1C, and serum creatinine levels between patients with or without retinopathy.

Conclusion

The present study demonstrated that patients with DR had lower levels of serum vitamin D compared with those without retinopathy.

A prospective, cross-sectional study on association of serum vitamin D level with musculoskeletal symptoms and blood pressure in adult population

Background:

Vitamin D is an important vitamin required to maintain an important physiological function of the body. The body should maintain an optimal level of vitamin D to maintain skeletal and metabolic functions. It was observed that inverse relationship is maintained by vitamin D level in the body with musculoskeletal symptoms and metabolic disorders.

Objective:

The study is conducted to associate between serum levels of vitamin D with self-reported symptoms (musculoskeletal) and blood pressure.

Material and Methods:

Venous blood sample was collected from 126 adults with musculoskeletal symptoms. The subjects were stratified based on their vitamin D levels. Groups were tested for the frequency of symptoms and the relationship of different parameters with vitamin D.

Results:

The frequency of subjects in the study was more in the deficient category (<20 ng/dL). In the study, vitamin D was found to have a significant association with “weakness.” Body mass index (BMI), systolic blood pressure (SBP), and diastolic blood pressure (DBP) were found to have an inverse relation with serum vitamin D level.

Conclusion:

The study showed the effect of vitamin D level in musculoskeletal symptoms and inverse association of vitamin D with BMI and blood pressure.

Does vitamin D status correlate with insulin resistance in obese prediabetic patients? An Egyptian multicenter study

BACKGROUND

The link between Vitamin-D deficiency and type 2 diabetes (T2D) is well-established. Since prediabetic obese populations have the greatest risk to develop to T2D, it was important in our study to examine serum 25(OH) D3 concentration among prediabetic obese patients and to evaluate the correlation between serum level of vitamin D and BMI, FBS, HOMA IR and HbA1c among prediabetes patients.

METHODS

A multicenter case control study was carried out among 101 prediabetic persons & 50 controls, after obtaining consent from subjects and clearance from institutional ethics committee. Serum vitamin D level, Plasma levels of glycosylated hemoglobin (HbA1c) and fasting insulin levels were measured by ELISA in both groups enrolled in the study.

RESULTS

The prevalence of vitamin-D deficiency/insufficiency was (73.3%) (n = 74) among 101 prediabetic obese individuals. Also, A significant inverse correlation was observed between vitamin D levels & body mass index(r = - 0.28, P = 0.004); fasting blood sugar (r = - 0.22, P = 0.002); HOMA insulin resistance (r = - 0.25 P = 0.01); HbA1C (r = - 0.2, P= 0.004).

CONCLUSIONS

High prevalence of vitamin D deficiency exists among obese prediabetic individuals and there is significant inverse correlation between BMI, FBS, HOMA IR, HbA1c and vitamin D level.

Association between serum 25-hydroxyvitamin D and global DNA methylation in visceral adipose tissue from colorectal cancer patients

Background

Visceral adipose tissue (VAT) has been identified as the essential fat depot for pathogenetic theories that associateobesity and colon cancer. LINE-1 hypomethylation has been mostly detected in tumor colon tissue, but less is known about the epigenetic pattern in surrounding tissues. The aim was to analyze for the first time the potential relationship between serum vitamin D, obesity and global methylation (LINE-1) in the visceral adipose tissue (VAT) from patients with and without colorectal cancer.

Methods

A total of 55 patients with colorectal cancer and 35 control subjects participated in the study. LINE-1 DNA methylation in VAT was measured by pyrosequencing. Serum 25(OH)D levels were determined by ELISA.

Results

Cancer patients had lower levels of LINE-1 methylation in VAT compared with the control group. In the subjects with colorectal cancer, LINE-1 DNA methylation levels were associated positively with vitamin D levels (r = 0,463; p < 0.001) and negatively with BMI (r = − 0.334, p = 0.01) and HOMA insulin resistance index (r = − 0.348, p = 0.01). Serum vitamin D was the main variable explaining the LINE-1% variance in the cancer group (β = 0.460, p < 0.001). In a multivariate analysis, subjects with higher LINE-1 methylation values had lower risk of developing colorectal cancer (OR = 0.53; IC95% =0.28–0.99) compared with the control group.

Conclusions

We showed for the first time an association between LINE-1 DNA methylation in VAT and vitamin D levels in subjects with colorectal cancer, highlighting the importance of VAT from cancer patients, which could be modified epigenetically compared to healthy subjects.

Vitamin D3 prevents cardiovascular diseases by lowering serum total homocysteine concentrations in overweight reproductive women: A randomized, placebo-controlled clinical trial

Obesity and overweight are associated with vitamin D deficiency and hyperhomocysteinemia, all of which are contributing factors for developing cardiovascular disease (CVD). Therefore, we hypothesized that improving serum 25-hydroxyvitamin D [25(OH)D] levels may decrease the body weight and total homocysteine concentrations among overweight reproductive women. To test our hypothesis, a randomized, double-blind placebo-controlled clinical trial, registered under ClinicalTrials.gov Identifier No. NCT03310307, was conducted on 100 overweight reproductive women that were allocated into two groups, namely, the treatment group (n = 50), which received 50 000 IU vitamin D₃ per week, and the placebo group (n = 50), and followed for 2 months. Participants' 25(OH)D, homocysteine, parathyroid hormone, calcium, phosphorus, body weight and body mass index (BMI) were measured and compared before and after treatment. The results showed that there was a significant decrease in homocysteine levels after the first and second months of vitamin D₃ intervention in the treatment group, and no significant changes were seen in the placebo group throughout the period of follow up. Statistically significant (P ≤ .05) reductions in homocysteine concentration, body weight, BMI, and parathyroid hormone levels were noticed in the treatment group compared to the placebo. Meanwhile, 25(OH)D, calcium and phosphorus levels were statistically significantly (P ≤ .05) increased in the treatment group. In conclusion, vitamin D₃ intervention with a treatment dose of 50 000 IU per week for at least 2 months can help decrease BMI and homocysteine levels, which in turn will help prevent or minimize the risk of CVD among overweight women of reproductive age.

Effect of Vitamin D Supplementation on Weight Loss, Glycemic Indices, and Lipid Profile in Obese and Overweight Women: A Clinical Trial Study

Introduction

Vitamin D (vit D) deficiency has defined as a health problem worldwide. World Health Organization (WHO) has declared that obesity is an epidemic of the 21^st century. Previous studies have shown that obesity may increase the risk of Vit D deficiency. Furthermore, other studies have demonstrated that vit D insufficiency was accompanied with higher risk of type 2 diabetes, cardiovascular diseases, hypertension, and obesity. The aim of this study was to survey the effect of vit D supplementation on weight loss among overweight and obese women aged 20-40 years in Isfahan.

Methods

This double-blind clinical trial was done on 50 overweight and obese women who were divided into two groups, in which one group received vit D supplements and the other group received placebo. Intervention group received vit D with dozes 50,000 IU/w for 6 weeks. The levels of total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-c), high-density lipoprotein cholesterol (HDL-c), fasting blood sugar (FBS), insulin (ins), homeostasis model assessment of ins resistance (IR), C-reactive protein (CRP), height, weight (WT), waist circumference (WC), hip circumference (HC), and blood pressure (BP) were measured before and after intervention.

Results

After using vit D supplementation for 6 weeks, WT, WC, and body mass index (BMI) were decreased significantly and serum vit D increased significantly compared to control group (P < 0.001). Other factors including TC, TG, LDL-c, HDL-c, FBS, CRP, ins, IR, and waist to hip ratio (WHR) did not change significantly (P > 0.05).

Conclusions

After 6 weeks of intervention, the means of WT, BMI, WC, and HC decreased significantly. Previous studies have shown that vit D deficiency was more prevalence in obese people and there was an inverse association among vit D with BMI and WC. The relationship between vit D and lipid profiles such as glycemic indexes, anthropometric indexes, CRP, and BP is not clear and needs more study in the future.

Prevalence and Predictors of Low Serum 25-Hydroxyvitamin D among Female African-American Breast Cancer Survivors

BACKGROUND

African-American breast cancer survivors commonly demonstrate low serum 25-hydroxyvitamin D (25(OH)D). Decreased cutaneous conversion, high levels of adiposity, and even breast cancer treatment may influence vitamin D status. Previous investigations have analyzed African-American women in aggregate with other breast cancer survivors and have not comprehensively addressed these influential factors.

OBJECTIVES

To determine the prevalence of low serum 25(OH)D in an exclusively African-American cohort of female breast cancer survivors with overweight/obesity and to evaluate the role of ultraviolet (UV) light exposure, body composition, and dietary sources of vitamin D on serum 25(OH)D levels.

DESIGN

Cross-sectional.

PARTICIPANTS

Pre- and postmenopausal African-American breast cancer survivors (n=244) were recruited from various neighborhoods in the city of Chicago, IL, between September 2011 and September 2014 for a larger weight loss trial.

MAIN OUTCOME MEASURES

Demographic, clinical, anthropometric (body mass index [calculated as kg/m²], waist circumference, and hip circumference), blood specimen, dietary intake (food frequency questionnaire), and sun behavior data were collected by trained study personnel before trial participation. Dual-energy x-ray absorptiometry was used to quantify adiposity (total, percentage, regional, visceral) and lean mass. Serum 25(OH)D was used as the biomarker reflective of vitamin D status.

STATISTICAL ANALYSES

Mean (±standard deviation), frequencies, and multivariate linear regression modeling.

RESULTS

The average participant was 57.4 years old (±10.0), 6.9 years (±5.2) from initial breast cancer diagnosis with a body mass index of 36.2 (±6.2). The majority of participants (60%) reported habitual oral vitamin D supplementation with mean intake of 327 IU (±169). Vitamin D deficiency was prevalent in 81% and 43%, when the cut points of the Endocrine Society (<30 ng/mL or <75 nmol/L) and the Institute of Medicine (<20 ng/mL or <50 nmol/L) were applied, respectively. A multivariate model adjusting for age, seasonality of blood draw, total energy intake, use of supplemental vitamin D, darker skin pigmentation, breast cancer stage, and waist-to-hip ratio was able to explain 28.8% of the observed variance in serum 25(OH)D concentrations. No significant associations were detected for body mass index or any dual-energy x-ray absorptiometry measures of body composition.

CONCLUSIONS

Considering the number of women who endorsed use of vitamin D supplementation, the prevalence of vitamin D deficiency among these African-American breast cancer survivors was high. Vitamin D supplementation, sun behavior, and waist-to-hip ratio may serve as future points of intervention to improve the vitamin D status of this minority survivor population.

Non-musculoskeletal benefits of vitamin D

The aim of this study is to determine and critically evaluate the plausible relationships of vitamin D with extra-skeletal tissues in humans. Severe vitamin D deficiency results in rickets in children and osteomalacia in adults; these beneficial effects in the musculoskeletal system and certain physiological functions are well understood. Nevertheless, mounting reports support additional beneficial effects of vitamin D, outside the musculoskeletal system. This review explores the recent advances in knowledge about the non-skeletal effects of vitamin D. Peer-reviewed papers were extracted from research databases using key words, to assess correlations between vitamin D and extra-skeletal diseases and conditions. As per the guidelines of the Preferred Reporting Items for Systematic Reviews (PRISMA); general interpretations of results are included; taking into consideration the broader evidence and implications. This review summarizes current knowledge of the effects of vitamin D status on extra-skeletal tissues with special attention given to relationships between vitamin D status and various diseases commonly affecting adults; the effects of intervention with vitamin D and exposure to sunlight. Evidence suggests that vitamin D facilitates the regulation of blood pressure; and cardiac; endothelial; and smooth muscle cell functions; playing an important role in cardiovascular protection. In addition; 1,25(OH)₂D improves immunity; subdues inflammation; and reduces the incidence and severity of common cancers; autoimmune diseases and infectious diseases. Almost all adequately powered; epidemiological and biological studies that use; adequate doses of vitamin D supplementation in D-deficient populations have reported favorable outcomes. These studies have concluded that optimizing 25(OH)D status improves the functionality of bodily systems; reduces comorbidities; improves the quality of life; and increases survival. Although accumulating evidence supports biological associations of vitamin D sufficiency with improved physical and mental functions; no definitive evidence exists from well-designed; statistically powered; randomized controlled clinical trials. Nevertheless, most studies point to significant protective effects of vitamin D in humans when the minimum 25(OH)D serum level exceeds 30ng/mL and is maintained throughout the year.

Inflammation Modifies the Association of Obesity with Circulating 25-Hydroxyvitamin D Levels in Cancer Survivors

OBJECTIVE

Obesity, inflammation, and circulating 25-hydroxyvitamin D (25-OHD) have distinct roles in cancer prognosis. The interplay of these factors was investigated by evaluating the associations of body mass index (BMI) with circulating 25-OHD levels in cancer survivors and determining whether associations were modified by inflammation, defined by C-reactive protein (CRP) levels.

METHODS

Data on cancer survivors were aggregated from the US National Health and Nutrition Examination Survey (2001-2010). Multivariable linear regression models were used to evaluate the associations of BMI with circulating 25-OHD. Analyses were stratified by CRP levels: low < 1.0 mg/L, moderate 1.0-3.0 mg/L, and high > 3.0-9.9 mg/L.

RESULTS

Among 1,305 cancer survivors (mean age = 60.8 years, mean BMI = 28.0 kg/m2 ), circulating 25-OHD levels were 8.74 nmol/L lower (95% CI: 4.71 to 12.77) in cancer survivors with BMI ≥ 30.0 kg/m2 compared with those with BMI < 25.0 kg/m2 . This association was, however, limited to those with moderate CRP (-9.90 nmol/L, 95% CI: -16.45 to -3.36) and high CRP (-11.61 nmol/L, 95% CI: -18.71 to -5.05), but not among those with low CRP levels (-5.31 nmol/L, 95% CI:-12.66 to 2.04).

CONCLUSIONS

A greater understanding of the interplay between 25-OHD and inflammation in cancer survivors with obesity should allow for targeted secondary prevention and help improve prognosis in these patients.

Leisure-time physical activity and circulating 25-hydroxyvitamin D levels in cancer survivors: a cross-sectional analysis using data from the US National Health and Nutrition Examination Survey

OBJECTIVES

Circulating 25-hydroxyvitamin D (25-OHD) is associated with improved cancer prognosis in some studies, yet it may be a surrogate marker for physical activity. We investigated the associations of leisure-time physical activity (LTPA) with circulating 25-OHD levels in cancer survivors, and determined whether associations differ by indoor and outdoor activity.

DESIGN

Cross-sectional study.

SETTING

The US National Health and Nutrition Examination Survey (NHANES).

PARTICIPANTS

Cancer survivors with available data on demographic information, measures of adiposity, smoking history, self-reported LTPA and circulating 25-OHD levels in five waves of NHANES (2001-2010).

MAIN OUTCOMES MEASURES

Circulating 25-OHD levels.

RESULTS

Multivariable linear regression and logistic regression models were used to evaluate the associations of self-reported LTPA with 25-OHD, adjusting for potential confounders. Due to the differences in LTPA measure, the analyses were conducted separately for 2001-2006 and 2007-2010 data. We further estimated associations by indoor and outdoor activity in the 2001-2006 data. There were 1530 cancer survivors (mean age=60.5 years, mean body mass index=28.6 kg/m2). The prevalent cancer sites were breast (19.3%), prostate (18.8%), cervix (10.4%) and colon (8.6%). Compared with inactive cancer survivors, being physically active was associated with higher circulating 25-OHD levels (8.07 nmol/L, 95% CI 4.63 to 11.52) for 2001-2006 data. In the mutually adjusted model, higher outdoor activity (5.83 nmol/L, 95% CI 1.64 to 10.01), but not indoor activity (2.93 nmol/L, 95% CI -1.80 to 7.66), was associated with statistically significantly higher 25-OHD levels. The interaction between indoor and outdoor activities was, however, not significant (p=0.29). The only statistically significant association seen in the 2007-2010 data was among obese cancer survivors.

CONCLUSION

Physical activity, particularly outdoor activity, is associated with higher 25-OHD levels in cancer survivors. In view of the possible beneficial effects of vitamin D on cancer prognosis, engaging in outdoor physical activity could provide clinically meaningful increases in 25-OHD levels among cancer survivors.

Circulating 25-hydroxyvitamin D level and prognosis of lung cancer patients: A systematic review and meta-analysis

BACKGROUND

Previous studies suggested a possible influence of circulating 25-hydroxyvitamin D [25(OH)D] level on the prognosis of lung cancer patients, but conflicting findings were reported. A systematic review and meta-analysis was thus conducted to comprehensively assess the influence of circulating 25(OH)D level on the prognosis of lung cancer patients.

METHODS

Prospective or retrospective cohort studies assessing the influence of circulating 25(OH)D level on the prognosis of lung cancer patients were considered eligible. Hazard Ratios (HR) were pooled using meta-analysis.

RESULTS

Eight studies with 2166 lung cancer patients were included. Meta-analysis of unadjusted HRs from four studies showed low circulating 25(OH)D level was significantly correlated with poor overall survival in lung cancer (HR=1.30, 95%CI 1.08-1.55, P=0.004). Meta-analysis of adjusted HRs from eight studies suggested that low circulating 25(OH)D level was not significantly correlated with poor overall survival (HR=1.25; P=0.13). However, sensitivity analysis suggested an obvious change in the pooled HRs when excluding single study by turns. When the study by Liu et al. was omitted, low circulating 25(OH)D level was significantly correlated with poor overall survival (HR=1.34; P=0.04).

CONCLUSION

The present systematic review and meta-analysis suggested a correlation between low circulating 25(OH)D level and poor overall survival in lung cancer. More studies are needed to further validate the finding above.

LOWER SERUM 25-HYDROXYVITAMIN D IS ASSOCIATED WITH OBESITY BUT NOT COMMON CHRONIC CONDITIONS: AN OBSERVATIONAL STUDY OF AFRICAN AMERICAN AND CAUCASIAN MALE VETERANS

OBJECTIVE

The study examined whether vitamin D insufficiency is a predictor of prevalent and/or incident common chronic conditions in African American men (AAM) and Caucasian American men (CAM).

METHODS

A total of 1,017 men were recruited at an urban VA medical center and followed prospectively for a mean of 5.4 years. Prevalent and incident chronic conditions evaluated were: obesity, type 2 diabetes, cancer, depression, dementia, and cardiovascular disease (CVD, including coronary artery disease [CAD], cerebrovascular accident [CVA], and congestive heart failure [CHF]). Univariate and multivariate regressions were performed to examine the association between 25-hydroxyvitamin D (25[OH]D) and these chronic illnesses.

RESULTS

This analysis was limited to 955 men (65.5% AAM, 27.2% CAM, 6.4% Hispanic) who had at least 1 year of follow-up (range, 1.0 to 7.1 years). Univariate analysis of the entire group showed that 25(OH)D correlated negatively with body mass index (BMI). There was no correlation between 25(OH)D and prevalent CVD (including separate analyses for CAD, CVA, and CHF), cancer, depression, dementia, all-cause mortality, or incident cancer, CAD, or CVA. Independent predictors of prevalent common conditions included increasing age, BMI, smoking, alcohol and polysubstance use, but not 25(OH)D levels.

CONCLUSION

The study does not support previously suggested associations of low vitamin D levels with prevalent common chronic conditions or increased risk for cancer, CAD, and CVA in a population of men with high burden of chronic disease. The finding that smoking and alcohol and polysubstance use are predictors of chronic conditions is an important reminder for addressing these risks during patient encounters.

ABBREVIATIONS

AAM = African American men BMI = body mass index CAD = coronary artery disease CAM = Caucasian American men CHF = congestive heart failure CI = confidence interval CVA = cerebrovascular accident CVD = cardiovascular disease HTN = hypertension OR = odds ratio T2DM = type 2 diabetes mellitus VAMC = Veteran Administration Medical Center 25(OH)D = 25-hydroxyvitamin D.

Vitamin D levels and their associations with survival and major disease outcomes in a large cohort of patients with chronic graft-vs-host disease

AIM

To identify the factors associated with vitamin D status in patients with chronic graft-vs-host disease (cGVHD) and evaluate the association between serum vitamin D (25(OH)D) levels and cGVHD characteristics and clinical outcomes defined by the National Institutes of Health (NIH) criteria.

METHODS

310 cGVHD patients enrolled in the NIH cGVHD natural history study (clinicaltrials.gov: NCT00092235) were analyzed. Univariate analysis and multiple logistic regression were used to determine the associations between various parameters and 25(OH)D levels, dichotomized into categorical variables: ≤20 and >20 ng/mL, and as a continuous parameter. Multiple logistic regression was used to develop a predictive model for low vitamin D. Survival analysis and association between cGVHD outcomes and 25(OH)D as a continuous as well as categorical variable: ≤20 and >20 ng/mL; <50 and ≥50 ng/mL, and among three ordered categories: ≤20, 20-50, and ≥50 ng/mL, was performed.

RESULTS

69 patients (22.3%) had serum 25(OH)D ≤20 ng/mL. Univariate analysis showed that supplement intake, nutritional status (severely malnourished, moderately malnourished, well-nourished), race (African-American, other), and estimated creatinine clearance (eCCr) were associated with 25(OH)D levels. A predictive model was developed based on supplement intake, nutritional status, race, and eCCr, accurately predicting 77.9% of patients with 25(OH)D ≤20 and 65.2% of those with 25(OH)D >20 ng/mL. No association was found between vitamin D and major cGVHD characteristics, but patients with 25(OH)D ≤20 ng/mL had somewhat decreased survival.

CONCLUSION

Nutritional status and adequate supplementation are important to maintain 25(OH)D >20 ng/mL in cGVHD patients. Intervention studies and more research is needed to reveal the underlying mechanism of vitamin D metabolism in cGVHD setting.

Economic Benefit of Calcium and Vitamin D Supplementation: Does It Outweigh the Cost of Nonunions?

OBJECTIVES

The purpose was to evaluate economic benefit of calcium and vitamin D supplementation in orthopaedic trauma patients. We hypothesized that reduced nonunion rates could justify the cost of supplementing every orthopaedic trauma patient.

DESIGN

Retrospective, economic model.

SETTING

Level 1 trauma center.

PATIENTS/PARTICIPANTS

Adult patients over 3 consecutive years presenting with acute fracture.

INTERVENTION

Operative or nonoperative fracture management.

MAIN OUTCOME MEASUREMENTS

Electronic medical records were queried for ICD-9 code for diagnosis of nonunion and for treatment records of nonunion for fractures initially treated within our institution.

RESULTS

In our hospital, a mean of 92 (3.9%) fractures develop nonunion annually. A 5% reduction in nonunion risk from 8 weeks of vitamin D supplementation would result in 4.6 fewer nonunions per year. The mean estimate of cost for nonunion care is $16,941. Thus, the projected reduction in nonunions after supplementation with vitamin D and calcium would save $78,030 in treatment costs per year. The resulting savings outweigh the $12,164 cost of supplementing all fracture patients during the first 8 weeks of fracture healing resulting in a net savings of $65,866 per year.

CONCLUSIONS

Vitamin D and calcium supplementation of orthopaedic trauma patients for 8 weeks after fracture seems to be cost effective. Supplementation may also reduce the number of subsequent fractures, enhance muscular strength, improve balance in the elderly, elevate mood leading to higher functional outcome scores, and diminish hospital tort liability by reducing the number of nonunions.

LEVEL OF EVIDENCE

Economic Level V. See Instructions for Authors for a complete description of levels of evidence.

The Incidence of and Factors Associated with Vitamin D Deficiency in Newly Diagnosed Children with Cancer

This retrospective chart review study aimed to assess vitamin D status and identify risk factors associated with vitamin D deficiency and bone parameters in children with cancer at admission. The data of 86 (50 males and 36 females) patients between April 2013 and June 2015 were analyzed. Calcium, phosphorus, alkaline phosphatase (ALP), 25(OH)D, age, gender, diagnostic category, body mass index, duration of complaints, and season of blood sampling were recorded. Median age was 7.17 years (range 0.31-17.40) in 29 hematological malignancy and 57 solid tumor patients. According to cut-off level of 20 ng/ml, 63% of children with cancer had vitamin D deficiency at diagnosis with a median 25(OH)D of 16.75 ng/ml. The mean vitamin D value of children >10 years was significantly low in comparison to that observed in younger children [11.83, 95% confidence interval (CI) = = 8.85-14.81 ng/ml vs. 19.81, 95% CI = = 17.02-22.60 ng/ml]. Vitamin D measurement between November and May was a risk factor for vitamin D deficiency (P < 0.05). The frequency of hypocalcemia and hypophosphatemia was not different between two groups of vitamin D. Further longitudinal studies are needed to investigate whether monitoring vitamin D status and supplementation in children with cancer might prevent future complications related to vitamin D deficiency.

The relationship between circulating 25-hydroxyvitamin D and survival in newly diagnosed advanced non-small-cell lung cancer

BACKGROUND

Serum 25-hydroxyvitamin D [25(OH)D], the major circulating form of vitamin D used for evaluating the vitamin D status of patients, has been associated with survival in a variety of cancers with conflicting evidence. We aimed to investigate this association in newly diagnosed advanced non-small-cell lung cancer (NSCLC) patients.

METHODS

This was a consecutive cohort of 359 newly diagnosed stages III-IV NSCLC patients who underwent a baseline serum 25(OH)D evaluation prior to receiving any treatment at our institution between January 2008 and December 2010. We used the vitamin D categories of "deficient (<20 ng/ml)" and "not deficient (> = 20 ng/ml)". Cox regression was used to evaluate the prognostic significance of serum 25(OH)D after adjusting for relevant confounders.

RESULTS

Mean age at diagnosis was 57.4 years. Of the 359 patients, 151 (42.1 %) were deficient in vitamin D at the time of diagnosis. The median survival in deficient and not deficient cohorts was 11.7 and 12.8 months respectively (p = 0.06). Season of diagnosis, performance status, smoking status and hospital location significantly predicted vitamin D status. On univariate Cox analysis, gender, stage of disease, hospital location, histologic subtype, subjective global assessment (SGA), performance status, smoking status, body mass index and serum albumin were significantly associated with survival (p <0.05 for all). On multivariate Cox analysis, six variables demonstrated statistically significant associations with survival: stage of disease, hospital location, histologic subtype, SGA, smoking status and serum albumin (p <0.05 for all). Serum vitamin D, which was borderline significant in univariate analysis, lost its significance in multivariate analysis.

CONCLUSIONS

We found season of diagnosis, performance status and smoking history to be predictive of vitamin D status. Consistent with previously published research in advanced NSCLC, we did not find any significant association between pre-treatment serum 25(OH)D and survival in our patients.

The association between pre-treatment serum 25-hydroxyvitamin D and survival in newly diagnosed stage IV prostate cancer

Background/Aims

Emerging evidence in the literature suggests a positive association between serum 25-hydroxyvitamin D [25(OH)D], a standard indicator of vitamin D status, and survival in certain types of cancer. We investigated this relationship in newly diagnosed stage IV prostate cancer patients.

Methods

A consecutive cohort of 125 newly diagnosed stage IV prostate cancer patients underwent a baseline serum 25(OH)D evaluation prior to receiving any treatment at our institution between January 2008 and December 2011. We used the vitamin D categories of “deficient (<20 ng/ml)”, “insufficient (20 to 32 ng/ml)”, and “sufficient (>32 ng/ml)”. Cox regression was used to evaluate the prognostic significance of serum 25(OH)D after adjusting for relevant confounders.

Results

Mean age at diagnosis was 60 years. Of the 125 patients, 32 (25.6%) were deficient, 49 (39.2%) were insufficient and 44 (35.2%) were sufficient in vitamin D at the time of diagnosis. The median survival in deficient, insufficient and sufficient cohorts was 47.8, 44.0 and 52.6 months respectively (p = 0.60). On univariate analysis, four variables demonstrated a statistically significant association with survival: nutritional status, bone metastasis, corrected serum calcium and serum albumin (p<0.05 for all). On multivariate analysis, five variables demonstrated statistically significant associations with survival: hospital location, age, bone metastasis, serum albumin and corrected serum calcium (p<0.05 for all). Serum vitamin D status was not significant on either univariate or multivariate analysis.

Conclusion

Contrary to previously published research, we found no significant association between pre-treatment serum 25(OH)D and survival in newly diagnosed stage IV prostate cancer patients. The lack of a significant association between serum vitamin D and survival in our study could perhaps be due to the fact that the disease was far too advanced in our patients for vitamin D levels to have any impact on prognosis.

Vitamin D status is inversely associated with obesity in a clinic-based sample in Puerto Rico

Studies show that vitamin D status is associated to obesity but data in Hispanic individuals is scarce. The aim of this study was to assess the association between vitamin D status and obesity in a clinic-based sample in Puerto Rico. We hypothesized that subjects with a higher adiposity would have a lower vitamin D status. We extracted the following data from medical records of a private clinic: age, gender, serum 25(OH)D levels, weight, height, and waist circumference. Body mass index (BMI) (kg/m(2)) and waist-to-height ratio were calculated and categorized according to standard guidelines. Statistical analyses included analysis of covariance, Pearson correlations and χ(2) test. From 797 individuals (mean age 53.7 ± 15.4 years; 63.5% females), 35.6% were overweight and 43.7% obese. Mean 25(OH)D levels were 24.7 ± 8.7 ng/mL; 5.3% had levels <12 ng/mL, 30.6% had levels 12 to 20 ng/mL, and 43.5% had levels 21 to 30 ng/mL. Mean 25(OH)D levels were significantly higher in normal weight and overweight males compared to obese males (P < .05) and in overweight females compared to obese females (P < .05). Levels were also higher in those with low risk compared to high risk of waist circumference and waist-to-height ratio (P < .001). BMI, waist circumference, and waist-to-height ratio were inversely correlated to 25(OH)D levels (P < .001). A greater proportion of obese individuals (41.4%) were vitamin D deficient or insufficient compared to the normal weight (33.9%) and overweight individuals (30.3%) (P < .05). In conclusion, in this clinic-based sample of Puerto Rican adults, those with higher BMI, waist circumference, and waist-to-height ratio had a significantly lower vitamin D status.

Serum 25-hydroxy vitamin D and survival in advanced colorectal cancer: a retrospective analysis

Higher serum 25-hydroxy vitamin D [25(OH)D] levels are associated with decreased colorectal cancer (CRC) incidence. In this retrospective study of Stage IV CRC patients, we evaluate whether 25(OH)D levels at diagnosis correlate with survival. Stored sera from carcinoembryonic antigen (CEA) measurements obtained between February 2005 and March 2006 were screened. The first 250 patients with CEA ± 30 days of Stage IV CRC diagnosis were included. Serum 25(OH)D levels were determined and categorized as adequate ≥ 30 ng/mL, or deficient <30 ng/mL. Multivariable Cox regression models controlling for albumin and Eastern Cooperative Oncology Group performance status were used to investigate whether higher 25(OH)D levels were associated with prolonged survival. A total of 207 patients (83%) were vitamin D-deficient (median = 21 ng/mL), with deficiencies significantly more likely among non-Hispanic black patients (P = 0.009). Higher levels were associated with prolonged survival in categorical variable analysis: adequate vs. deficient, hazard ratio = 0.61, 95% confidence interval = 0.38-0.98, P = 0.041. A majority of newly diagnosed Stage IV CRC patients are vitamin D-deficient. Our data suggest that higher 25(OH)D levels are associated with better overall survival. Clinical trials to determine whether aggressive vitamin D repletion would improve outcomes for vitamin D-deficient CRC patients are warranted.

Role of Vitamin D in Osteoarthritis: Molecular, Cellular, and Clinical Perspectives

Osteoarthritis is a debilitating and degenerative disease which affects millions of people worldwide. The causes and mechanisms of osteoarthritis remain to be fully understood. Vitamin D has been hypothesised to play essential roles in a number of diseases including osteoarthritis. Many cell types within osteoarthritic joints appear to experience negative effects often at increased sensitivity to vitamin D. These findings contrast clinical research which has identified vitamin D deficiency to have a worryingly high prevalence among osteoarthritis patients. Randomised-controlled trial is considered to be the most rigorous way of determining the effects of vitamin D supplementation on the development of osteoarthritis. Studies into the effects of low vitamin D levels on pain and joint function have to date yielded controversial results. Due to the apparent conflicting effects of vitamin D in knee osteoarthritis, further research is required to fully elucidate its role in the development and progression of the disease as well as assess the efficacy and safety of vitamin D supplementation as a therapeutic strategy.

Subclinical Vitamin D Insufficiency in Korean School-aged Children

PURPOSE

Recently, vitamin D insufficiency has increased and has been correlated to growth and puberty in children. This study was conducted to find the prevalence of subclinical vitamin D insufficiency and its influence on school-aged children in Korea.

METHODS

The subjects of this study were 397 children aged 7 to 15 years who had been tested for 25-OH vitamin D3 among the outpatients of the Department of Pediatrics in Eulji General Hospital from March 2007 to February 2011. Data for age, sex, comorbidities, serum 25-OH vitamin D3, height, weight, body mass index (BMI), and sunlight exposure time were collected before and after 3 months of vitamin D administration, retrospectively.

RESULTS

Vitamin D insufficiency was present in 343 (86%) of the subjects. In the vitamin D insufficient group, chronological age was 8.96±1.72 years, mean height (z-score [z]) was 0.51±1.26, mean BMI (z) was 0.81±2.20, and bone age was 10.26±1.75 years. In the vitamin D sufficient group, chronological age was 9.61±1.77 years, mean height (z) was-0.66±0.98, mean BMI (z) was-0.01±1.16, and bone age was 9.44±2.12 years. A paired t-test showed that three months after vitamin D administration, the mean 25-OH vitamin D3 level in the insufficient group increased to 24.38 ±10.03 ng/mL and mean BMI (z) decreased to 0.67±1.06.

CONCLUSION

In Korean school-aged children, vitamin D insufficiency were relatively higher and may be closely related with higher BMI. Insufficient rise of the level of vitamin D after supplementation suggest the new supplementation guidelines, especially for Korean children.

Circulating levels of 25-hydroxyvitamin D and prostate cancer prognosis

OBJECTIVES

Ecological, in vitro, and in vivo studies demonstrate a link between vitamin D and prostate tumor growth and aggressiveness. The goal of this study was to investigate whether plasma concentration of vitamin D is associated with survivorship and disease progression in men diagnosed with prostate cancer.

MATERIALS AND METHODS

We conducted a population-based cohort study of 1476 prostate cancer patients to assess disease recurrence/progression and prostate cancer-specific mortality (PCSM) risks associated with serum levels of 25(OH) vitamin D [25(OH)D].

RESULTS

There were 325 recurrence/progression and 95 PCSM events during an average of 10.8 years of follow-up. Serum levels of 25(OH)D were not associated with risk of recurrence/progression or mortality. Clinically deficient vitamin D levels were associated with an increased risk of death from other causes.

CONCLUSIONS

We did not find evidence that serum vitamin D levels measured after diagnosis affect prostate cancer prognosis. Lower levels of vitamin D were associated with risk of non-prostate cancer mortality.

Vitamin D deficiency impacts on expression of toll-like receptor-2 and cytokine profile: a pilot study

Background

Vitamin D is believed to play an important role outside the endocrine system in the regulation of the immune system, and in cellular proliferation and differentiation. The aim of the study was to investigate the impact of vitamin D levels on innate immunity.

Methods

Participants for this prospective, longitudinal study were recruited amongst otherwise healthy staff of a large hospital in Victoria, Australia. Those fulfilling the inclusion criteria, including a vitamin D level of <50 nmol/L, were supplemented. Using flow cytometry, expression of the innate immune receptors TLR2, TLR4 and CD86 was measured on peripheral blood mononuclear cells (PBMCs) collected prior to vitamin D treatment and then at 1 and 3 months. Additonally, PBMCs at each timepoint were stimulated with specific TLR ligands and resultant supernatants were assayed for the cytokines TNFα, IL-6, IFN-α and IP-10.

Results

In participants whose vitamin D level was >100 nmol/L post supplementation (n=11), TLR2 expression on PBMCs increased significantly, with no change noted in TLR4 or CD86 expression. Stimulation of vitamin D deficient samples with TLR ligands produced a number of proinflammatory cytokines, which were significantly reduced upon vitamin D normalisation. In patients whose levels returned to a deficient level at 3 months despite ongoing low-level supplementation, an increase in the pro-inflamamtory state returned. This suggests that vitamin D may play an important role in ensuring an appropriate baseline pro-inflammatory state.

Conclusions

This ex-vivo pilot study adds clinical evidence supporting a possibly important role for vitamin D in innate immunity. If confirmed, this unique clinical study has potentially significant implications for the treatment of a variety of inflammatory conditions, where achieving optimal vitamin D levels may help reduce inflammation.

The association between serum vitamin d levels with general and abdominal obesity among patients with migraine

BACKGROUND

Obesity is a common health problem around the world. Studies have shown inverse relationship between serum vitamin D levels with obesity among patients and healthy population. The aim of this present study is to examine the relationship between serum vitamin D levels with general and abdominal obesity among migraine patients.

METHODS

The present study is a cross-sectional and 66 migraine patients aged 19-61 years were included for analysis. Partial correlation was performed to assess association between serum 25-OH-D with general and abdominal obesity. Adjustments were performed for age, sex, and education.

RESULTS

No relationship was found between serum levels of vitamin D with general and abdominal obesity. However, a significant association was shown between waist circumferences (WC) with body mass index (BMI).

CONCLUSIONS

Serum levels of 25-OH-D were not associated with WC and BMI. Furthermore, after adjustment for confounder variables, no association was observed.

25-Hydroxyvitamin D Supplementation and BMI Change: A Meta-Analysis of Randomized Controlled Trials

The impact of 25-hydroxyvitamin D (25[OH]D) supplementation on weight change remains controversial. The objective of this study was to summarize the effects of 25[OH]D supplementation (cholecalciferol or ergocalciferol) on BMI change through a meta-analysis of published clinical trials. We completed a systematic review of English articles, using MEDLINE (Ovid, Pubmed) from January 1, 1998 through January 1, 2013. The articles selected focused on 25[OH]D supplementation and body mass index (BMI) in randomized controlled trials (RCT’s). The association between 25[OH]D and mean BMI change was estimated utilizing a random effects model. A total of 30 studies were reviewed and 9 were included in the meta-analysis. Total participants included 1651 adults (82.6% women and mean age 47.9 years) and mean follow-up ranged between 6 to 196 weeks and mean daily 25[OH]D dose ranged from 200 IU to 1,110 IU. Five of the 9 studies included calcium supplementation in both groups. Average baseline BMI was 30.7 and 30.4 kg/m² in the intervention and control groups, respectively. Five studies suggested a beneficial effect for 25[OH]D supplementation for BMI change whereas 3 studies showed no effect of 25[OH]D supplementation on BMI change, and one showed a non-perceptible change. Meta-analysis of BMI values at end of trial showed no statistically significant difference in BMI change by use of 25[OH]D supplementation. Based on existing published trials, oral 25[OH]D supplementation does not significantly impact BMI change.

Recruitment and results of a pilot trial of vitamin D supplementation in the general population of Australia

CONTEXT

The benefits of high serum levels of 25-hydroxyvitamin D [25(OH)D] are unclear. Trials are needed to establish an appropriate evidence base.

OBJECTIVE

We plan to conduct a large-scale trial of vitamin D supplementation for the reduction of cancer incidence and overall mortality and report here the methods and results of a pilot trial established to inform its design.

DESIGN

Pilot D-Health was a randomized trial carried out in a general community setting with 12 months intervention and follow-up.

PARTICIPANTS

Participants were 60- to 84-yr-old residents of one of the four eastern Australian states who did not have any vitamin D-related disorders and who were not taking more than 400 IU supplementary vitamin D per day. A total of 644 participants were randomized, and 615 completed the study (two persons withdrew because of nonserious adverse events).

INTERVENTIONS

The interventions were monthly doses of placebo or 30,000 or 60,000 IU vitamin D(3).

MAIN OUTCOMES

The main outcomes were the recruitment rate and changes in serum 25(OH)D.

RESULTS

Ten percent of those approached were recruited. At baseline, the mean 25(OH)D was 42 nmol/liter in all three study arms. The mean change in 25(OH)D in the placebo group was 0.12 nmol/liter, compared with changes of 22 and 36 nmol/liter in the 30,000- and 60,000-IU groups, respectively.

CONCLUSIONS

The D-Health pilot has shown that a large trial is feasible in Australia and that a dose of 2000 IU/d will be needed to ensure that a large proportion of the population reaches the target serum 25(OH)D level.

Decreasing 25-hydroxy-vitamin D levels account for portion of the effect of increasing body mass index on breast cancer mortality

SCOPE

Increased body mass index (BMI) and decreased serum vitamin D are both known to be associated with increased mortality from breast cancer. However, vitamin D levels are lower in obese individuals in general. Recent studies have sought to determine whether serum vitamin D levels can account for some of the association between higher BMI and increased risk for breast cancer and found that low vitamin D levels in the overweight and obese account for up to 40% of the BMI-attributable risk of developing breast cancer.

METHODS AND RESULTS

Here we reviewed the literature to determine if a similar relationship exists between vitamin D, BMI, and breast cancer mortality. Utilizing previously reported independent associations of low vitamin D and high BMI to increases in breast cancer mortality, as well as the known decrement in vitamin D per unit increase in BMI, we estimated that low vitamin D levels may be responsible for roughly 16% of the increased mortality from breast cancer in overweight and obese patients.

CONCLUSION

Although this is a relatively small proportion of the effect of obesity, supplements to increase serum vitamin D levels may represent a way to reduce obesity-associated disparities in breast cancer mortality.

Vitamin D insufficiency in diabetic retinopathy

OBJECTIVE

To assess the relationship between vitamin D status and diabetic retinopathy.

METHODS

A clinic-based, cross-sectional study was conducted at Emory University, Atlanta, Georgia. Overall, 221 patients were classified into 5 groups based on diabetes status and retinopathy findings: no diabetes or ocular disease (n = 47), no diabetes with ocular disease (n = 51), diabetes with no background diabetic retinopathy (n = 41), nonproliferative diabetic retinopathy (n = 40), and proliferative diabetic retinopathy (PDR) (n = 42). Patients with type 1 diabetes and those taking >1,000 IU of vitamin D daily were excluded from the analyses. Study subjects underwent dilated funduscopic examination and were tested for hemoglobin A1c, serum creatinine, and 25-hydroxyvitamin D [25(OH)D] levels between December 2009 and March 2010.

RESULTS

Among the study groups, there was no statistically significant difference in age, race, sex, or multivitamin use. Patients with diabetes had lower 25(OH)D levels than did those without diabetes (22.9 ng/mL versus 30.3 ng/mL, respectively; P<.001). The mean 25(OH)D levels, stratified by group, were as follows: no diabetes or ocular disease = 31.9 ng/mL; no diabetes with ocular disease = 28.8 ng/mL; no background diabetic retinopathy = 24.3 ng/mL; nonproliferative diabetic retinopathy = 23.6 ng/mL; and PDR = 21.1 ng/mL. Univariate analysis of the 25(OH)D levels demonstrated statistically significant differences on the basis of study groups, race, body mass index, multivitamin use, hemoglobin A1c, serum creatinine level, and estimated glomerular filtration rate. In a multivariate linear regression model with all potential confounders, only multivitamin use remained significant (P<.001).

CONCLUSION

This study suggests that patients with diabetes, especially those with PDR, have lower 25(OH)D levels than those without diabetes.

Calcium and vitamin D in obesity

New and more effective nutritional measures are urgently needed for the prevention of obesity. The role of Ca and vitamin D in obesity has been recently implicated. Low Ca intake and low vitamin D status have been linked with an increased risk of obesity in epidemiological studies; however, clinical intervention trials designed to test this association have produced controversial results. The suggested anti-obesity mechanisms of Ca and vitamin D include the regulation of adipocyte death (apoptosis), adipogenesis and lipid metabolism. Dietary Ca has been also shown to increase faecal fat excretion. The potential role of Ca and vitamin D in shifting energy balance towards a more negative state is an area of considerable interest. Ultimately, a review of recent research findings does not allow the reaching of a definitive conclusion that increasing Ca intake and rising vitamin D status will influence fat mass and body weight or decrease the risk of obesity and overweight.

Prospective association of vitamin D concentrations with mortality in postmenopausal women: results from the Women's Health Initiative (WHI)

BACKGROUND

Prospective epidemiologic data on the association between vitamin D and all-cause and cause-specific mortality are limited.

OBJECTIVE

This study aimed to determine whether 25-hydroxyvitamin D [25(OH)D] concentrations were prospectively and independently associated with cardiovascular disease (CVD), cancer, and all-cause mortality in postmenopausal women.

DESIGN

A substudy in 2429 postmenopausal women within the Women's Health Initiative (WHI) with measured baseline 25(OH)D concentrations were followed for 10 y for death from CVD, cancer, and all-cause mortality. Proportional hazards models were performed to evaluate quartiles of month-adjusted 25(OH)D concentrations, with adjustment for potential confounders. Sequential model building and analysis for multiplicative interaction were performed to evaluate the effects of central adiposity on the association of low 25(OH)D with all-cause mortality.

RESULTS

Of the 2429 women, 224 deaths occurred, with 79 deaths from CVD and 62 deaths from cancer. Multivariate-adjusted HRs that compared quartiles 1 (lowest) to 4 (highest) of 25(OH)D for all-cause mortality (HR: 1.25; 95% CI: 0.80, 1.95), CVD mortality (HR: 1.27; 95% CI: 0.81, 1.99), and cancer mortality (HR: 1.39; 95% CI: 0.88, 2.19) were not significant. There was a potential interaction (P = 0.08) between abdominal obesity and low 25(OH)D concentrations that showed an increased risk of the lowest quartile of 25(OH)D concentrations (HR: 1.85; 95% CI: 1.00, 3.44) with increased mortality in women with a normal waist circumference but no increased risk in women with abdominal obesity (HR: 0.96; 95% CI: 0.52, 1.76).

CONCLUSION

Body fat distribution may play an important role in the modulation of the effect of low vitamin D concentrations on health. This trial was registered at clinicaltrials.gov as NCT 00000611.