Nonclassic actions of vitamin D

Vitamin D status and supplementation in adult patients receiving extracorporeal membrane oxygenation

The prevalence of vitamin D deficiency in critical illness is known to be high and associated with adverse clinical outcomes. Patients receiving extracorporeal membrane oxygenation (ECMO) may be at increased risk of vitamin D deficiency due to high severity of acute illness. Challenges with drug dosing in ECMO patients are recognised due to increased volume of distribution and drug absorption to circuit components. To describe the prevalence of vitamin D deficiency in ECMO patients and the effect of intramuscular dosing of cholecalciferol on levels of vitamin D metabolites, and to compare these data with intensive care unit (ICU) patients not receiving ECMO, two prospective studies were performed sequentially: an observational study of 100 consecutive ICU patients and an interventional study assessing effects of intramuscular cholecalciferol in 50 ICU patients. The subgroup of patients who required ECMO support in each of these studies was analysed and compared to patients who did not receive ECMO. Twenty-four ECMO patients, 12 from the observational study and 12 from the interventional study (who received intramuscular cholecalciferol) were studied-21/24 (88%) ECMO patients were vitamin D deficient at baseline compared to 65/126 (52%) of non-ECMO patients (<i>P</i>=0.006). Of the 12 ECMO patients who received cholecalciferol, six patients (50%) achieved correction of deficiency compared to 36/38 (95%) non-ECMO patients (<i>P</i>=0.001). The prevalence of vitamin D deficiency is higher in ECMO patients compared to other critically ill adults. Correction of deficiency with single dose cholecalciferol is not reliable; higher or repeated doses should be considered to correct deficiency.

The impact of sunlight exposure on mortality of patients with end stage renal disease

Recent data suggest that reduced sunlight exposure is associated with increased mortality in the general population. To date, the association between sunlight exposure and mortality in dialysis patients has not been examined. Among 134,478 dialysis patients in the Korean end-stage renal disease (ESRD) cohort from 2001 to 2014, 31,291 patients were enrolled from seven metropolitan cities, and data were analyzed using bi-directional case-crossover design. We examined the association between short-term sunlight exposure and mortality in ESRD patients. We adjusted for temperature, humidity, and daily concentrations of nitrogen dioxide (NO₂), sulfur dioxide (SO₂), ozone (O₃), carbon monoxide (CO), and particle matter (PM₁₀) as confounders. The characteristics of the study population included age (65.6 ± 12.26 (mean ± standard deviation [SD]) years), sex (male, 59.96%; female, 41.04%), comorbidity (diabetes, 53.58%; hypertension, 40.5%), and kidney dialysis type (hemodialysis, 73.02%; peritoneal dialysis, 26.98%). The mean ± SD follow-up time was 4.68 ± 4.37 years. The daily sunlight exposure was significantly decreased in the case group compared with the control group (P = 0.004). Sunlight exposure was associated with all-cause death overall (ORs [95% CI]: 0.99 [0.98-0.99], P = 0.042) in a fully adjusted model. Patients with diabetes (ORs [95% CI]: 0.98 [0.97-0.99], P = 0.016) or aged higher than 75 years (ORs [95% CI]; 0.97 [0.96-0.99], P = 0.020) had higher risks of mortality than patients without diabetes or aged below 75 years, respectively. These findings suggest that sunlight exposure is inversely correlated with all-cause mortality in dialysis patients.

Nutritional Issues and Positive Living in Human Immunodeficiency Virus/AIDS

Nutritional counseling has been shown to improve dietary intake in individuals with human immunodeficiency virus (HIV)/AIDS. Registered dietitians/nutritionists can individualize diet interventions to optimize effectiveness in treating metabolic consequences of the HIV infection or highly active antiretroviral therapy. Nutrition management for individuals infected with HIV can be helpful in maintaining lean body weight, combating oxidative stress, reducing complications from hyperglycemia and hyperlipidemia, and managing gastrointestinal function. Consideration should be given to including the expertise of a registered dietitian/nutritionist.

Synthesis of 1α,25-dihydroxyvitamin D3 analogues with α,α-difluorocycloketone at the CD-ring side chains and their biological properties in ovariectomized rats

Two novel 1α,25-dihydroxyvitamin D₃ derivatives containing a α,α-difluorocyclopentanone (3) or α,α-difluorocyclohexanone (4) moiety at the CD-ring side chains were designed, synthesized, and evaluated for their biological properties on restoring bone mass in ovariectomized (OVX) rats with established osteopenia. The synthesis of compounds 3 and 4 utilized the Wittig-Horner coupling to build up the vitamin D conjugated triene system, followed by the introduction of the cycloketone fragments at the side chain, and subsequent α,α-difluorination of the ketone by the treatment of the derived silyl enol ether with Selectfluor, as the key synthetic steps. In comparison with the natural 1α,25-dihydroxyvitamin D₃ (calcitriol; 200 ng/kg/day), oral administration of compounds 3 and 4 at the dose of 25 ng/kg/day for 6 weeks led to much improved bone mass and bone density related parameters, while maintaining normal serum calcium and serum phosphorus levels. The immunohistochemistry results showed that both compounds remarkably decreased in osteoclast number and moderately decreased in osteoblast number on trabecular bone surface. Therefore, our findings suggested that compounds 3 and 4 successfully rescue bone loss by suppression on bone turnover in OVX rat models.

Vitamin-D2 treatment-associated decrease in 25(OH)D3 level is a reciprocal phenomenon: a randomized controlled trial

BACKGROUND

Vitamin-D2 (D2) treatment has been associated with a decrease in 25-hydroxy (25(OH)) vitamin-D3 (D3) level, suggesting that D3 treatment would be preferred to raise total 25(OH) vitamin-D (D) level. We postulated that D2 treatment-associated decrease in 25(OH)D3 level is related to the increase in 25(OH)D level rather than being D2-specific, and thus there would be a similar D3 treatment-associated decrease in 25(OH)D2 level.

METHODS

Fifty volunteers were block-randomized to 50,000 IU D2 or placebo orally once (study-1) and fifty volunteers received 50,000 IU D2 orally once and 4 days later block-randomized to 50,000 IU D3 or placebo orally once (study-2). Interventions were concealed from volunteers and research coordinators and blindly-administered. Serum 25(OH)D2 and 25(OH)D3 levels were blindly-determined at baseline and days 14, 28, 42, and 56, post-randomization by high performance liquid chromatography assay. Results of 97 participants were analyzed. Primary outcome measure was day-28 D2-associated change in 25(OH)D3 level in study-1 and D3-associated change in 25(OH)D2 level in study-2, adjusted for baseline levels.

RESULTS

Mean (95% confidence interval) difference between the active and placebo arms in the decrease in day-28 25(OH)D3 (study-1) and 25(OH)D2 (study-2) levels was 13.2 (9.7 to 16.6) and 9.8 (5.2 to 14.4) nmol/L, respectively. Corresponding differences at day-56 were 10.8 (6.8 to 14.8) and 1.7 (- 7.6 to 11.1) nmol/L, respectively. The difference between the placebo and active arms in area-under-the-curve at day-28 (AUC₂₈) and day-56 (AUC₅₆) were 262.3 (197.8 to 326.7) and 605.1 (446.3 to 784.0) for 25(OH)D3 (study-1) and 282.2 (111.2 to 453.3) and 431.2 (179.3 to 683.2) nmol.d/L for 25(OH)D2 (study-2), respectively. There were significant correlations between day-28 changes in 25(OH)D2 and 25(OH)D3 levels in study-1 (rho = - 0.79, p < 0.001) and study-2 (rho = - 0.36, p = 0.01), and between day-28 changes in 25(OH)D2 level and baseline 25(OH)D level in study-2 (rho = - 0.42, p = 0.003).

CONCLUSIONS

Compared to placebo, D3 treatment is associated with a decrease in 25(OH)D2 level similar in magnitude to D2-treatment associated decrease in 25(OH)D3 level; however, the D3-placebo difference in 25(OH)D2 level is shorter-lasting. Changes in 25(OH)D2 and 25(OH)D3 levels are correlated with each other and with baseline 25 (OH) D levels, suggesting a common regulatory mechanism.

TRIAL REGISTRATION

ClinicalTrial.gov identifier: NCT03035084 (registered January 27, 2017).

Evaluation of nasal mucociliary clearance time in patients with Vitamin-D deficiency

OBJECTIVES

The main purpose of the current study was to investigate nasal mucociliary clearance time (NMC) in patients with Vitamin-D deficiency.

METHODS

A total of 55 patients with Vitamin-D deficiency and 32 controls were evaluated. NMC time was measured with subjective saccharine test and compared between study and control groups. In addition, NMC time was re-evaluated after Vitamin-D replacement protocol in patients with Vitamin-D deficiency.

RESULTS

The mean 25(HO)Vitamin-D levels were 14.32 ± 4.23 ng/mL (7-24.6) and 29.38 ± 7.05 ng/mL (25-53.8) in study and control groups, respectively (p < 0.001). The mean NMC time was 11.15 ± 3.05 (6.3-17.6) and 8.40 ± 2.33 (6-13.2) in study and control groups, respectively (p < 0.001). The mean 25(HO)Vitamin-D level after the replacement protocol was 33.38 ± 10.03 and the mean NMC time was 9.56 ± 2.54 (p < 0.001).

CONCLUSION

The mean NMC time was significantly increased in patients with Vitamin-D deficiency which can be corrected after Vitamin-D replacement protocols. The prolonged mucociliary clearance might be one of the pathophysiologic pathways at increased upper respiratory tract infections, and sinonasal and ear infections in patients with Vitamin-D deficiency.

The interplay between vitamin D and viral infections

The pleiotropic role of vitamin D has been explored over the past decades and there is compelling evidence for an epidemiological association between poor vitamin D status and a variety of diseases. While the potential anti-viral effect of vitamin D has recently been described, the underlying mechanisms by which vitamin D deficiency could contribute to viral disease development remain poorly understood. The possible interactions between viral infections and vitamin D appear to be more complex than previously thought. Recent findings indicate a complex interplay between viral infections and vitamin D, including the induction of anti-viral state, functional immunoregulatory features, interaction with cellular and viral factors, induction of autophagy and apoptosis, and genetic and epigenetic alterations. While crosstalk between vitamin D and intracellular signalling pathways may provide an essential modulatory effect on viral gene transcription, the immunomodulatory effect of vitamin D on viral infections appears to be transient. The interplay between viral infections and vitamin D remains an intriguing concept, and the global imprint that vitamin D can have on the immune signature in the context of viral infections is an area of growing interest.

The Role of Vitamin D Binding Protein, Total and Free 25-Hydroxyvitamin D in Diabetes

Vitamin D is important for bone health, but may also have extra-skeletal effects. Vitamin D and its binding protein DBP have immunological effects and may therefore be important in the development of type 1 diabetes (T1DM), and low serum levels of 25-hydroxyvitamin D (25(OH)D) are associated with later development of type 2 diabetes (T2DM). However, it has so far been difficult to convincingly show an effect of vitamin D supplementation on prevention or treatment of diabetes. The serum level of 25(OH)D has traditionally been used as a marker of a subject's vitamin D status. This measurement includes both 25(OH)D bound to DBP and albumin as well as the free from of 25(OH)D. However, according to the free hormone hypothesis, the free form is the biologically active. Previously the free form of 25(OH)D had to be calculated based on measurements of 25(OH)D, DBP, and albumin, but recently a method for direct measurement of free 25(OH)D has become commercially available. This is important in clinical conditions where the amount of DBP is affected, and has caused a renewed interest in which vitamin D metabolite to measure in clinical situations. In the present review the relations between DBP, total and free 25(OH)D in T1DM and T2DM are described.

Vitamin D, Inflammation and Immunity: Review of Literature and Considerations on Recent Translational and Clinical Research Developments

The most relevant and recent literature findings linking exposure to sunlight, Vitamin D (VD), inflammation and immune system in health and disease, are reviewed.

Reduced sunlight exposure determined hypo-vitaminosis D to be common among patients or even healthy subjects, especially at higher latitudes. Numerous studies support the hypothesis that VD insufficiency could contribute to the higher autoimmune diseases incidence in the same geographic areas.

In the present review, the ways in which VD was reported to influence immune system, contributing to organism homeostasis or disease development are addressed. In fact, some of the hormone activities were recognised to determine stimulation or inhibition of immune system components.

Several diseases, where an association with VD deficiency was studied, are summarised. Finally, the rationale for optimization of substitutive/additive therapy with VD analogues and the last innovations regarding these drugs are mentioned.

Low wintertime pre-diagnostic vitamin D status is associated with an increased risk of internal malignancies in kidney transplant recipients

Low serum 25-hydroxyvitamin D (25OHD) concentrations have been associated with increased cancer risk, but the relative importance of seasonality, i.e. high summer concentrations versus low winter concentrations, is unclear. We investigated this issue in a high risk group: kidney transplant recipients with known increased risk of cancer and low vitamin D statuses. We examined the relationship between registered concentrations of 25OHD binned by quarter and subsequent risk of internal malignancy or cutaneous squamous cell carcinoma in 1112 kidney transplant recipients. Hazard ratios for internal malignancies were significantly increased with lower pre-diagnostic 25OHD concentrations in the first quarter of the year (January-March); a 1.4 fold increase (95%CI 1.1;1.7) per 10 nmol L-1 decrease in 25OHD. Except for women in April-June (1.3 (1.01;1.7) per 10 nmol L-1 decrease) pre-diagnostic 25OHD concentrations in the other quarters were not statistically significantly associated with internal malignancies. Higher 25OHD concentrations tended to be associated with the development of cutaneous squamous cell carcinomas, independent of the time of the year. Our study indicates that low wintertime 25OHD concentrations are associated with an increased risk of internal malignancies and that transplant recipients may benefit from wintertime vitamin D supplementation. Our findings need further corroboration, but suggest that the lowest concentrations of vitamin D, which occur in winter, are important for the risk of internal malignancies.

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

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

Vitamin D protection from rat diabetic nephropathy is partly mediated through Klotho expression and renin-angiotensin inhibition

OBJECTIVE

We hypothesised that vitamin D has a beneficial renal protective effect from diabetic nephropathy (DN).

METHODS

Four rat groups were included: normal control (control), type 2 diabetes for eight weeks (DM), treated group with angiotensin receptor blocker losartan (DM + L), and vitamin D-treated group started from the onset of diabetes (DM + Vit D).

RESULTS

In the both treated groups, we found a significant (p < .05) reduction in the renal pro-inflammatory and profibrotic markers induced by diabetes. Vitamin D caused more reduction in monocyte chemoattractant protein-1 (MCP-1), transforming growth factor (TGFβ-1), and renin-angiotensin levels that gave better kidney function compared to the DM + L group.

CONCLUSION

Vitamin D may have a valuable role in the renal protective effect from DN, this may occur via expression of its VDR, Klotho and blocking renin-angiotensin activation, so vitamin D should be considered as a target in renal prophylactic measures against DN.

In Silico Model of Vitamin D3 Dependent NADPH Oxidase Complex Activation During Mycobacterium Infection

Mycobacterium tuberculosis (Mtb) is a highly infectious aerosolizable bacterium, which causes upward of 1.5 million deaths per year. Alveolar macrophages, the primary defense cell of the lung, are the preferred host cell of this intracellular bacterium. Vitamin D₃ is a known transcription factor, modulating the transcription of pro- and anti-inflammatory cytokines and immunologically relevant proteins. In a vitamin D₃ deficient host, the immune systems response to infection is greatly impaired. We used a quantitative systems biology approach to model the impact of long-term vitamin D₃ deficiency on macrophage effector response. We then compared our simulation output to our in vitro model of mycobacterium infection of macrophages from vitamin D₃ supplemented hosts. Our in silico model results agreed with in vitro levels of hydrogen peroxide (H₂O₂) production, an antimicrobial effector molecule produced by the host's macrophage, known to be modulated indirectly by vitamin D₃. The current model will provide a foundation for further studies into the effects of micronutrient deficiency on immune response.

Vitamin D insufficiency, hemoglobin, and anemia in children with chronic kidney disease

BACKGROUND

25-Hydroxyvitamin D (25OHD) deficiency is common in children with chronic kidney disease (CKD). It has been associated with an increased risk for anemia in both healthy US children and in adults with CKD. This association has not been explored in children with CKD.

METHODS

Children aged 1-16 enrolled in the Chronic Kidney Disease in Children (CKiD) study with mild to moderate kidney dysfunction, and with 25OHD measured at baseline (n = 580), were included in the analysis. The cross-sectional associations between 25OHD and hemoglobin (g/dL) and anemia were assessed. Anemia was defined as hemoglobin < 5th percentile for age and sex.

RESULTS

Overall 334 (57.59%) children were vitamin D insufficient/deficient and 137 (23.62%) were anemic. Of those who were vitamin D insufficient/deficient, 95 (28.44%) were anemic. In the overall cohort, the odds of being anemic was 1.9 times higher (95% CI, 1.22-3.04, p < 0.01) in vitamin D insufficient/deficient vs sufficient children, when adjusting for covariates (age, sex, race [black, white, or other], body mass index (BMI), iohexol GFR (iGFR), erythropoietin stimulation agent (ESA) use, iron supplementation use, and underlying cause of CKD). Stratified by race, the odds of being anemic was 2.39 times higher (95% CI, 1.41-4.05, p = 0.001) in vitamin D insufficient/deficient vs vitamin D sufficient white children. The association between vitamin D status and anemia was not significant in black children.

CONCLUSIONS

The data support our hypothesis that vitamin D insufficiency/deficiency increases the odds of anemia in children with CKD. The effect was strong and significant among white, but not black, children.

Preoperative Serum 25-Hydroxyvitamin D Level, a Risk Factor for Postoperative Cognitive Dysfunction in Elderly Subjects Undergoing Total Joint Arthroplasty

BACKGROUND

Postoperative cognitive dysfunction (POCD) is a very common postoperative complication occurring mainly after high-risk surgery, especially in the elderly individuals. This study aimed to investigate potential risk factors for POCD in elderly patients after total joint arthroplasty (TJA).

MATERIALS AND METHODS

A total of 257 eligible elderly patients (≥65 years) who were scheduled for elective TJA for osteoarthritis with general anesthesia were enrolled. An experienced psychiatrist was invited to evaluate the cognitive function at baseline (1 day before the surgery) and at day 7 after the surgery. Univariate and multiple logistic regression analyses were performed to screen risk factors associated with POCD. Receiver-operating characteristic curve analysis was performed to assess the predictive value of serum 25-hydroxyvitamin D [25(OH)D] expression for POCD.

RESULTS

Of all the 257 enrolled patients, 55 (21.4%) developed POCD within 7 days after the surgery. Serum 25(OH)D level was the only independent risk factor associated with POCD (odds ratio: 1.77, 95% confidence interval: 1.13-2.78, P = 0.016) by multiple logistic regression analysis. The area under the curve of 25(OH)D for POCD was 0.687, with the cut-off value of 11.2 ng/mL, sensitivity of 41.82% and specificity of 78.71% respectively (95% confidence interval: 0.617-0.757, P < 0.001).

CONCLUSIONS

Our results revealed that preoperative serum 25(OH)D level was an independent risk factor for POCD in elderly subjects after TJA.

Vitamin D deficiency and supplementation in critical illness-the known knowns and known unknowns

The burgeoning literature on vitamin D deficiency and supplementation over the past decade or so has generated a greater understanding of some areas but also an appreciation of the many areas of equipoise. This is particularly relevant in the field of critical care with the heterogeneous patient populations, the severity and duration of illness and the frequency of comorbid conditions.

This review aims to summarise the current knowledge base of vitamin D deficiency within the context of critical illness—“the known knowns”—and also highlight the areas of recognised uncertainty—“the known unknowns”. It acknowledges the fact that there may well be other knowledge gaps of clinical relevance of which we are currently unaware—“the unknown unknowns”.

Low vitamin D at ICU admission is associated with cancer, infections, acute respiratory insufficiency, and liver failure

OBJECTIVES

Vitamin D deficiency may be associated with comorbidities and poor prognosis. However, this association in patients in the intensive care unit (ICU) has not been fully elucidated. The aim of this study was to investigate whether the serum concentrations of 25-hydroxyvitamin D (25[OH]D) within the first 48 h after ICU admission are associated with prognostic indicators (Acute Physiology and Chronic Health Evaluation [APACHE] II, Sequential Organ Failure Assessment [SOFA] score, Charlson comorbidity index [CCI]), clinical complications, serum C-reactive protein (CRP) concentrations, mechanical ventilation duration, and mortality.

METHODS

Seventy-one patients were admitted to the ICU, and their concentrations of 25(OH)D in the first 48 h were analyzed. To evaluate the prognostic factors in the ICU, APACHE II scores, SOFA scores, CCI questionnaires, mechanical ventilation time, CRP, and mortality were used.

RESULTS

The mean concentration of 25(OH)D was 17.7 ± 8.27 ng/mL (range 3.5-37.5 ng/mL), with 91.6% presenting with deficiency at admission. Although no associations were found between serum 25(OH)D concentrations with mechanical ventilation time, CRP, mortality, and APACHE II and SOFA severity scores, we found associations with the CCI when adjusted by age (model 1: odds ratio [OR], 1.64; 95% confidence interval [CI], 1.14-2.34) and by age, sex and body mass index (model 2: OR, 1.59; 95% CI, 1.10-2.34). In addition, among the comorbidities present, 25(OH)D concentrations were inversely associated with cancer (crude model OR, 3.42; 95% CI, 1.21-9.64) and liver disease (crude model OR, 9.64; 95% CI, 2.28-40.60).

CONCLUSION

We found a strong association between 25(OH)D concentrations and the prognostic indicator CCI and clinical complications (acute respiratory insufficiency, acute liver failure, and infections), but no associations with the prognostic indicators APACHE II and SOFA score, CRP, mechanical ventilation duration, or mortality. The main comorbidities associated with low 25(OH)D were cancer and liver disease, suggesting that the determination of 25(OH)vitamin D is relevant during the ICU stay.

Serum Vitamin D Status in a Group of Migraine Patients Compared With Healthy Controls: A Case-Control Study

OBJECTIVE

The association between serum vitamin D and migraine is investigated in this research.s BACKGROUND: Although the pathogenesis of migraine headache is not fully understood, the possible role of inflammation and disturbed immune system has been proposed; thus, higher levels of vitamin D might reduce the risk of migraine. However, the results of related studies have been inconclusive.

METHODS

Seventy healthy individuals and 70 age- and sex-matched migraineurs (34 chronic and 36 episodic migraineurs), diagnosed according to the International Headache Society criteria (ICHD-IIIβ), were recruited. After obtaining baseline data and assessing migraine disability, a 30-day headache diary was given to the participants. Blood samples were obtained and 25(OH)D serum concentrations were determined using ELISA techniques. Serum 25(OH)D under 20, 20-29, and 30-100 ng/mL were considered deficient, insufficient, and sufficient, respectively. The applied statistical tests for between-group comparisons include independent-sample t-test, chi-square, and analysis of variance. Multiple regression analysis was also performed to identify the possible risk factors of migraine headache.

RESULTS

Migraine patients had significantly lower mean (SD) of serum VitD (30 (16) ng/mL) than healthy subjects (43 (19) ng/mL) (P < .001). The number (%) of subjects with VitD deficiency and insufficiency was significantly higher among the migraineurs (36 (53.7%)) than the controls (18 (26.1%)) (P < .0001). A significant negative association between migraine headache and serum VitD was detected in the fully adjusted multiple regression models when comparing the third and the highest serum 25(OH)D quartiles with the lowest (OR = 0.20; 95% CI = 0.05-0.77; OR = 0.17; 95% CI = 0.04-0.64, respectively, P for trend = .009). For each 5 ng/mL increase in serum 25(OH)D, there was a 22% odds decrease in the odds of migraine (OR = 0.78; 95% CI = 0.68-0.90; P = .001).

CONCLUSION

We have found that a higher level of serum VitD (between 50 to less than 100 ng/mL) among a sample of the Iranian population is associated with 80-83% lower odds of migraine headache than those with serum 25(OH)D levels below 20 ng/mL. However, there is a need for well-designed clinical trials to investigate beneficial effects of increased serum 25(OH)D on lower risk of migraine.

Updates on the Status of Vitamin D as a Risk Factor for Respiratory Distress Syndrome

To update the guidelines regarding vitamin D status in respiratory distress syndrome, we reviewed recent human and animal studies on the benefits of vitamin D in respiratory distress. We searched PubMed and ProQuest for studies on the use of vitamin D from 2009 to 2017. The common parameters in these studies included the use of lung tissue, phospholipids, blood, and plasma to assess the effects of vitamin D on respiratory syndrome. The metabolized form of vitamin D used in these studies was 1,25(OH)₂D₃ in animal studies and 25(OH)D in human studies. Vitamin D supplementation decreases the risk of respiratory distress syndrome, improves the quality of life, and is relatively effective and safe for preterm neonates as well as during lung maturation. However, although vitamin D supplementation may offer benefits for respiratory distress syndrome, the optimal dosing strategies for specific types of risk factors in the lungs must be clarified to confirm the therapeutic efficacy.

Vitamin D deficiency and infection risk in kidney transplant recipients: A single-center cohort study

BACKGROUND

Recent studies have reported an increased susceptibility to infection among vitamin D-deficient kidney transplant (KT) recipients, although methodological concerns remain.

METHODS

Serum 25-hydroxyvitamin D (25(OH)D) levels were measured in 246 KT recipients at post-transplant months 1, 3, 6 and 12. Vitamin D status was analysed in terms of deficiency (Endocrine Society [<20 ng/mL] and Institute of Medicine [IoM, <12 ng/mL] criteria) and as a continuous variable. Cox models for overall, bacterial and opportunistic infection were adjusted for nutritional status and immunosuppression-related covariates.

RESULTS

Median serum 25(OH)D increased from month 1 (10.5 ng/mL) to month 6 (16.3 ng/mL; P-value = 0.001). Prevalence of vitamin D deficiency at month 1 ranged from 87.0% to 61.0% (depending on the diagnostic criteria) and significantly decreased over the next months. After adjustment for age and nutritional status, vitamin D deficiency (serum 25(OH)D < 12 ng/mL) at month 1 was an independent risk factor for overall (hazard ratio [HR]: 1.70; 95% confidence interval [CI]: 1.08-2.69; P-value = 0.023) and opportunistic infection (HR: 4.05; 95% CI: 1.57-10.46; P-value = 0.004), but not for bacterial infection. A protective effect for overall (adjusted HR: 0.76; 95% CI: 0.63-0.93; P-value = 0.007) and opportunistic infection (adjusted HR: 0.62; 95% CI: 0.45-0.86; P-value = 0.004) was observed when 25(OH)D levels were analyzed per one-quartile increases.

CONCLUSIONS

Vitamin D status influences the risk of infection among KT recipients, with the association being particularly evident for opportunistic events and mainly restricted to the early post-transplant period.

Vitamin D Deficiency, Skin Phototype, Sun Index, and Metabolic Risk Among Patients with High Rates of Sun Exposure Living in the Tropics

Objective: We sought to evaluate serum 25-hydroxycholecalciferol (vitamin D [25-OHD]) levels, skin phototype, and sun index in a sample of patients to determine the association between these factors and metabolic risk. Design: This was a cross-sectional study involving 729 adults (50.2% male). Mean age was 65.13±9.18 years, sun index 5.71±5.06, body mass index (BMI) 27.60±5.34 kg/m2, and waist circumference 97.29±12.08cm. Hypertension, metabolic syndrome, and Type 2 diabetes were reported in 77.8, 74.5, and 38.9 percent, respectively; Fitzpatrick Skin Types III and IV were reported in 60.6 percent. Results: Mean serum 25-OHD was 25.72±10.91ng/mL; 31 percent of subjects had serum 25-OHD below 20ng/mL, and 63.1 percent had serum 25-OHD below 30ng/mL. Although there were no significant differences between the vitamin D deficient and sufficient groups regarding age, BMI, waist circumference, or presence of diabetes, in the group with 25-OHD less than 20ng/mL (sun index of 4.5±4.08), higher serum triglycerides and lower high-density lipoprotein cholesterol (HDL-C) levels were measured: triglycerides 179.14±103.53 versus 161.63±90.23mg/dL (p=0.029) and HDL-C 43.48±12.38 versus 45.94±14.14mg/dL (p=0.018) compared to the group with 25-OHD levels of 20ng/mL or higher (sun index: 6.25±5.36). Considering less than 25th percentile (25-OHD: 18.7ng/mL) and 75th percentile or higher (25-OHD: 30.8 ng/mL), the differences in serum triglycerides remained significant: 176.63±103.79 versus 157.47±80.49 (p=0.039). Conclusion: We found a high prevalence of vitamin D deficiency in individuals with high sun exposure, regardless of age, BMI, and waist circumference. This deficiency was associated with increased serum triglycerides and decreased HDL-C levels.

Association between serum vitamin D deficiency and age-related macular degeneration in Koreans: Clinical case-control pilot study

The objective of this study was to evaluate the association between serum vitamin D deficiency and age-related macular degeneration (AMD) in Koreans through a clinical case-control pilot study. The study included 96 patients: 30 with late AMD, 32 with early AMD, and 34 normal controls. The patients with late AMD were divided into 2 subgroups based on the presence or absence of subretinal fibrosis on optical coherence tomography (OCT) images. We measured 25-hydroxyvitamin D levels in the serum of all patients during the same season to rule out seasonal variation of serum vitamin D level. Serum vitamin D deficiency was defined as a serum 25-hydroxyvitamin D level below 20 ng/mL. Serum vitamin D deficiency had a tendency to increase the risk of early AMD, although with borderline significance [odds ratio (OR) = 3.59; 95% confidence interval (95% CI) 0.95-13.58; P = .060]. It was significantly associated with a greater risk of late AMD (OR = 3.61; 95%CI 1.04-12.51; P = .043). Among the 2 subgroups of patients with late AMD, those with subretinal fibrosis present on the OCT images showed a greater risk of serum vitamin D deficiency than the normal controls (OR = 7.54; 95% CI 1.34-42.51). However, there was no significant association between serum vitamin D deficiency and late AMD without subretinal fibrosis (OR = 1.89; 95% CI 0.40-8.92). Serum vitamin D deficiency may increase the risk of early and late AMD in Koreans, and may also be associated with subretinal fibrosis in this population.

Serum 25-Hydroxyvitamin D Concentrations Are Inversely Correlated with Hepatic Lipid Content in Male Collegiate Football Athletes

Lower serum 25-hydroxyvitamin D (25(OH)D) concentrations are associated with more weight and fat mass gain in adults in the general population, but it is unknown whether this is the case in collegiate football athletes with greater body weight. This study aimed to investigate associations of serum 25(OH)D concentrations with body fat and ectopic fat accumulation, and to determine which fat indicators are closely related to serum 25(OH)D in male collegiate football athletes. Thirty-four collegiate athletes aged 21 years were recruited. Serum 25(OH)D concentrations and the levels of visceral fat area (VFA), vastus lateralis intramyocellular lipid (IMCL), extramyocellular lipid (EMCL), and intrahepatic lipid (IHCL) were measured. Serum 25(OH)D concentrations were negatively associated with the IHCL values (r = −0.372, p = 0.030), and the relationship remained after adjustment for several factors (r = −0.378, p = 0.047). Additionally, multiple stepwise regression analysis of IHCL content as the dependent variable indicated that 25(OH)D concentrations were a stronger predictor of IHCL content (β = −0.363, p = 0.030) than % body fat and VO₂peak_FFM. Higher serum 25(OH)D concentrations are more closely related to lower IHCL content rather than any other fat indicators, suggesting that increasing serum 25(OH)D concentrations may have some effect that inhibits lipid accumulation in hepatic tissue, especially in heavy athletes.

Vitamin D Supplementation and Survival of Patients with Non-small Cell Lung Cancer: A Randomized, Double-Blind, Placebo-Controlled Trial

Purpose: Higher serum 25-hydroxyvitamin D (25(OH)D) levels are reportedly associated with better survival in early-stage non-small cell lung cancer (NSCLC). Therefore, whether vitamin D supplementation can improve the prognosis of patients with NSCLC was examined (UMIN000001869).Patients and Methods: A randomized, double-blind trial comparing vitamin D supplements (1,200 IU/day) with placebo for 1 year after operation was conducted. The primary and secondary outcomes were relapse-free survival (RFS) and overall survival (OS), respectively. Prespecified subgroup analyses were performed with stratification by stage (early vs. advanced), pathology (adenocarcinoma vs. others), and 25(OH)D levels (low, <20 ng/mL vs. high, ≥20 ng/mL). Polymorphisms of vitamin D receptor (VDR) and vitamin D-binding protein (DBP) and survival were also examined.Results: Patients with NSCLC (n = 155) were randomly assigned to receive vitamin D (n = 77) or placebo (n = 78) and followed for a median of 3.3 years. Relapse and death occurred in 40 (28%) and 24 (17%) patients, respectively. In the total study population, no significant difference in either RFS or OS was seen with vitamin D compared with the placebo group. However, by restricting the analysis to the subgroup with early-stage adenocarcinoma with low 25(OH)D, the vitamin D group showed significantly better 5-year RFS (86% vs. 50%, P = 0.04) and OS (91% vs. 48%, P = 0.02) than the placebo group. Among the examined polymorphisms, DBP1 (rs7041) TT and CDX2 (rs11568820) AA/AG genotypes were markers of better prognosis, even with multivariate adjustment.Conclusions: In patients with NSCLC, vitamin D supplementation may improve survival of patients with early-stage lung adenocarcinoma with lower 25(OH)D levels. Clin Cancer Res; 24(17); 4089-97. ©2018 AACR.

Vitamin D deficiency and mild to moderate anemia in young North Indian children: A secondary data analysis

OBJECTIVES

The aim of this study was to examine the association between vitamin D deficiency and anemia status among young children in the resource-poor setting of northern urban India.

METHODS

We used data from a randomized controlled trial of daily supplementation with folic acid, vitamin B₁₂, or both for 6 mo in children 6 to 30 mo of age conducted in Delhi, India. We measured serum vitamin D status, hemoglobin, plasma vitamin B₁₂, folate, soluble transferrin receptor, and homocysteine levels at baseline. Children with severe anemia (hemoglobin [Hgb] <7 g/dL) were excluded from enrollment. Multivariable logistic and multinomial logistic regressions were used to examine the association between vitamin D and anemia status at baseline.

RESULTS

25-Hydroxyvitamin-D (25 OHD) concentration was measured for 960 (96%) children. Of the children, 331 (34.5%) were vitamin-D deficient (<10 ng/mL). Approximately 70% of the enrolled children were anemic, with ∼46% having moderate (Hgb 7-9.9 g/dL) and 24% mild (Hgb 10-10.9 g/dL) anemia. There was no association between vitamin D and anemia status after adjusting for confounders; however, the risk for moderate anemia was significantly higher among vitamin D-deficient children than those who were vitamin-D replete (relative risk, 1.58; 95% confidence interval, 1.09-2.31).

CONCLUSIONS

Vitamin D deficiency was associated with moderate anemia among young children and the effect was independent of iron deficiency. The causal association of vitamin D deficiency with anemia risk remains debatable. The role of vitamin D in risk for anemia needs to be examined in further studies.

Evidence of a significant vitamin D deficiency among 9-13-year-old Polish children: results of a multicentre study

PURPOSE

To evaluate the extent to which the population of Polish preadolescents is vitamin D deficient and to assess seasonal variations in vitamin D status.

PARTICIPANTS AND METHODS

A total of 720 healthy children aged 9-13 years (409 girls, 311 boys) residing in 6 representative geographical locations in Poland were studied. A parental-assisted questionnaire provided data on nutritional habits, vitamin D supplements and sun exposure. Serum concentration of 25-hydroxyvitamin was determined twice, after the winter in March and after the summer in October.

RESULTS

In March, vitamin D deficiency (25-50 nmol/L) was found in 64%, and severe deficiency (< 25 nmol/L) in 20.2% of children. In October, the deficiency and severe deficiency were still noticed in 25.9 and 0.1% of children, respectively. The mean serum concentration of 25-OHD was 52% higher in October (55.4 ± 14.0 nmol/L) than in March (36.4 ± 13.5 nmol/L), (p < 0.01). In children with 25-OHD < 50 nmol/L in March, their 25-OHD concentration increased by 64% through March to October (32.5 ± 8.2 vs. 53.2 ± 7.9 nmol/L, p < 0.01). An association was found between 25-OHD concentration and regular consumption of vitamin D supplements, cod-liver oil and fish.

CONCLUSIONS

The majority of preadolescent Polish boys and girls show vitamin D deficiency after the winter period, although a distinct amelioration over summertime is found in this age group. There is a need to implement effective prevention and intervention strategies in the management of vitamin D deficiency among schoolchildren in Poland, with the supplementation throughout the entire year.

Seasonal Variation of Vitamin D Status in Long-Term Kidney Transplant Recipients

BACKGROUND

There is little information about circannual rhythm of vitamin D level in kidney transplantation (KTx) patients.

MATERIAL AND METHODS

In 71 patients (27 females; 44 males) in the long term after KTx (5.5 ± 2.6 years) during the winter and summer months plasma concentration of 25-hydroxyvitamin D (25(OH)D), 1,25-hydroxyvitamin D, parathormone (PTH), fibroblast growth factor 23 (FGF-23), calcium, and phosphorus were assessed. Vitamin D status was classified according to 25(OH)D level (ie, insufficiency, ≤30 ng/mL; deficiency, <15 ng/mL).

RESULTS

In this study, 96% of KTx patients had vitamin D insufficiency including 37% deficiency during winter and 89% of KTx patients had vitamin D insufficiency and 24% had vitamin D deficiency, respectively, during summer. Mean 25(OH)D level during winter was lower than in summer (17.4 ± 7.1 vs 20.2 ± 7.2 ng/mL; P = .02), similar to calcitriol (163.6 ± 37.4 vs 284.5 ± 77.8 pmol/L; P = .001). There were no significant differences in winter and summer levels of calcium, phosphorus, and PTH. The 25(OH)D level was significantly higher in patients with estimated glomerular filtration rate (eGFR) ≥45 mL/min/1.73 m² compared with those with lower eGFR (21.6 ± 7.5 vs 17.6 ± 6.0; P = .02) only in the summer time.

CONCLUSIONS

Most of the KTx patients have vitamin D insufficiency during both winter and summer with higher concentration of vitamin D metabolites in summer. Other factors than graft function may have an impact on vitamin D levels in KTx patients.

The association of VDR polymorphisms and type 2 diabetes in older people living in community in Santiago de Chile

INTRODUCTION

Several polymorphisms have been associated with obesity and type 2 diabetes in different populations.

OBJECTIVE

To investigate the frequencies of a genetic polymorphism of vitamin D receptor (FokI and BsmI) in patients with T2D.

METHODS

The case-control study was conducted in 138 patients with T2D and 172 control subjects, men and women (60-79 years old). The genotype and allele frequency determination of VDR polymorphisms were determined in these subjects.

RESULTS

The frequency of the C allele of the FokI polymorphism was significantly higher in the T2D group than in healthy subjects (p = 0.025). The frequencies of the BsmI variant were similar in subjects with and without T2D (p = 0.747). Consistent with these data, there was an association of the C allele with T2D (OR = 1.74, 95% CI = 1.003-3.084, p = 0.036), but not the AG + GG variants for BsmI (OR = 1.02, 95% CI = 0.635-1.649, p = 0.916). We can observe a significant association between carrier of the T > C variant of FokI and type 2 diabetes, adjusted for vitamin D, age, obesity (overweight and obesity), seasonality, sex and Homa-IR. Here, we show a significant association between the FokI polymorphisms (TC + CC) and T2D with an odds ratio of 1.9001 (95% CI (1.0970-3.6838), p = 0.041).

CONCLUSION

Our study suggests that the C allele (TC + CC) of the VDR-FokI gene is a possible risk factor for T2D in older people living in a community in Santiago de Chile.

Parameters of the Immune System and Vitamin D Levels in Old Individuals

Aim

The increased number of individuals older than 80 years, centenarians, and supercentenarians is not a synonym for healthy aging, since severe infections, hospitalization, and disability are frequently observed. In this context, a possible strategy is to preserve the main characteristics/functions of the immune system with the aim to cause less damage to the organism during the aging process. Vitamin D acts on bone marrow, brain, breast, malignant cells, and immune system and has been recommended as a supplement. We aimed to evaluate whether immune parameters and vitamin D serum levels are correlated.

Methods

We evaluated some features of the immune system using the peripheral blood of individuals older than 80 years (n = 12) compared to young subjects (n = 10). In addition, we correlated these findings with vitamin D serum levels.

Results

Old individuals presented metabolic parameters of healthy aging and maintained preserved some features of immunity such as CD4/CD8 ratio, and low production of pro-inflammatory cytokines after stimulus. On the other hand, we observed increase in the frequency of myeloid-derived suppressor cells, reduction in circulating leukocytes, in the percentage of total CD8+, and in CD8+ Naïve T cells, in addition to increase in the percentage of CD8+ effector memory re-expressing CD45RA (EMRA) T cells. We found seropositivity for CMV in 97.7%, which was correlated with the decrease of CD8+ Naïve T cells and increase in CD8+ EMRA T cells. Vitamin D levels were insufficient in 50% of old individuals and correlated positively with total CD8+ T cells and negatively with CD8+ EMRA T cells.

Conclusion

In the studied population, longevity was correlated to maintenance of some immune parameters. Considering the limitations of the study as size of the sample and lack of functional assays, it was found that vitamin D in old individuals was correlated to some features of the immune system, mainly in the CD8 compartment.

Antibody Formation in Transfusion Therapy

The production of antibodies following blood transfusions is a complex process that involves many recipient and donor factors. Inflammation in the recipient is one important factor. As knowledge of the immune system, of oxygen, carbon dioxide, and nitric oxide pathways, and of hemostasis grows, more specific therapies will allow precise manipulation of the immune system and safer transfusions. Communication of patients' transfusion and immunotherapy histories with the laboratory, attention to detail in labeling pretransfusion specimens, checking patient and blood product identification before administration, and closely monitoring patients during transfusions remain critical to minimizing risks during transfusion therapy.

Relationship of vitamin D and parathyroid hormone with the nocturnal blood pressure decline in hypertension

OBJECTIVES

Vitamin D deficiency and high parathyroid hormone (PTH) levels have been linked with hypertension. Nondipper hypertension is associated with increased morbidity and mortality. We aimed to investigate the relationship of vitamin D and PTH levels with nondipper hypertension and nocturnal decline in untreated hypertensive patients.

PATIENTS AND METHODS

This cross-sectional study included a total of 73 hypertensive and 34 normotensive participants. Each patient underwent 24-hour ambulatory blood pressure monitoring, routine biochemical tests, vitamin D, and PTH analysis.

RESULTS

The study population was divided into three groups according to ambulatory blood pressure monitoring records: 40 nondippers (mean age; 59.8±10.8 years, 24 women and 16 men), 33 dipper hypertensives (mean age; 58±11.8 years, 13 women and 20 men), and 34 normotensives (mean age; 56.9±11.7 years, 19 women and 15 men). Nondipper hypertensives showed lower levels of vitamin D than dippers and normotensives (9.7±6.1 vs. 14.9±10.1 vs. 16.4±9.5 ng/ml, P=0.001, for both) and higher levels of PTH than dippers (74.8±34.7 vs. 53.3±19.9 ng/ml, P=0.001). A significant positive correlation was observed between vitamin D and nocturnal decline (r=0.34, P=0.001), whereas a significant negative correlation was present between PTH and nocturnal decline(r=-0.26, P=0.006). In multivariate analysis, PTH level was correlated independently with nocturnal decline (β=-0.07, 95% confidence interval: -0.114-0.025, P=0.003).

CONCLUSION

In this study, vitamin D levels were significantly lower and PTH levels were significantly higher in nondippers. The vitamin D level was correlated positively and the PTH level was correlated negatively with nocturnal decline. In addition, PTH level was associated independently with nocturnal decline in hypertension.

The dynamic immunomodulatory effects of vitamin D3 during Mycobacterium infection

Mycobacterium tuberculosis ( Mtb), is a highly infectious airborne bacterium. Previous studies have found vitamin D₃ to be a key factor in the defense against Mtb infection, through its regulation of the production of immune-related cytokines, chemokines and effector molecules. Mycobacterium smegmatis was used in our study as a surrogate of Mtb. We hypothesized that the continuous presence of vitamin D₃, as well as the level of severity of infection would differentially modulate host cell immune response in comparison with control and the vehicle, ethanol. We found that vitamin D₃ conditioning promotes increased bacterial clearance during low-level infection, intracellular containment during high-level infection, and minimizes host cytotoxicity. In the presence of vitamin D₃ host cell production of cytokines and effector molecules was infection-level dependent, most notably IL-12, which increased during high-level infection and decreased during low-level infection, and NO, which had a rate of change positively correlated to IL-12. Our study provides evidence that vitamin D₃ modulation is context-dependent and time-variant, as well as highly correlated to level of infection. This study furthers our mechanistic understanding of the dual role of vitamin D₃ as a regulator of bactericidal molecules and protective agent against host cell damage.

The When, What & How of Measuring Vitamin D Metabolism in Clinical Medicine

We now have the ability to measure a number of different vitamin D metabolites with very accurate methods. The most abundant vitamin D metabolite, 25-hydroxyvitamin D, is currently the best marker for overall vitamin D status and is therefore most commonly measured in clinical medicine. The added value of measuring metabolites beyond 25-hydroxyvitamin D, like 1,25-, and 24,25-dihydroxyvitamin D is not broadly appreciated. Yet, in some more complicated cases, these metabolites may provide just the information needed for a legitimate diagnosis. The problem at present, is knowing when to measure, what to measure and how to measure. For 25-hydroxyvitamin D, the most frequently used automated immunoassays do not meet the requirements of today’s standards for certain patient groups and liquid chromatography-tandem mass spectrometry is the desired method of choice in these individuals. The less frequently measured 1,25-dihydroxyvitamin D metabolite enables us to identify a number of conditions, including 1α-hydroxylase deficiency, hereditary vitamin D-resistant rickets and a number of granulomatous diseases or lymphoproliferative diseases accompanied by hypercalcaemia. Furthermore, it discriminates between the FGF23-mediated and non-FGF23-mediated hypophosphatemic syndromes. The 24,25-dihydroxyvitamin D metabolite has proven its value in the diagnosis of idiopathic infantile hypercalcaemia and has the potential of having value in identifying other diseases. For both metabolites, the understanding of the origin of differences between assays is limited and requires further attention. Nonetheless, in every way, appropriate measurement of vitamin D metabolism in the clinical laboratory hinges eminently on the comprehension of the value of the different metabolites, and the importance of the choice of method.

Influence of Vitamin D Receptor Gene Polymorphisms on Response to Pegylated Interferon in Chronic Hepatitis B Egyptian Patients

BACKGROUND

We explored the effect of vitamin D receptor gene (VDR) polymorphisms in response to PEG-IFN treatment in Egyptian chronic hepatitis B (CHB) patients.

METHODS

Two hundred hepatitis B virus (HBV) patients (42.3±10.7 years) on PEG-IFN α-2a (180 µg /kg for 48 weeks) and one hundred control subjects (37.3 ±12 years) were enrolled in the study. Vitamin D levels and hepatitis B surface antigen (HBsAg) expression were assessed by ELISA. VDR polymorphisms FokI T>C (rs 10735810), BsmI A>G (rs 1544410), ApaI (rs7975253), and TaqI C>T (rs 731236), were genotyped using real-time PCR.

RESULTS

Hepatitis B virus patients expressed significantly greater AST (p=< 0.00001) and ALT (P=< 0.00001), and significantly less vitamin D (P=0.01), than control subjects. Patients with Ff or ff alleles of the FokI single-nucleotide polymorphism (SNP), bb alleles of BsmI SNP, or TT alleles of the Taq1 single nucleotide polymorphisms (SNP) showed greater response to PEG-IFN therapy than those with the FF (P=0.02 and P=0.0002), Bb (P=0.023), or Tt/tt alleles (P=0.01 and P=0.004 respectively). Logistic stepwise regression showed that HBV DNA (r: 0.910, P< .00001), FokI SNP polymorphism (r: 0.919, (P=0.037) and bAt haplotype (r: .926, (P=0.043) are independent factors that determine PEG-IFN treatment response in the HBV-infected patients.

CONCLUSION

VDR gene polymorphisms may be used as treatment response predictors in HBV patients receiving PEG-IFN. FokI SNP and bAt haplotype are independent factors that that can be used to determine PEG-IFN treatment responses in HBV-infected patients.

Measurement of Vitamin D for Epidemiologic and Clinical Research: Shining Light on a Complex Decision

Vitamin D is a fat-soluble vitamin that is synthesized in the skin with exposure to sunlight or is ingested from dietary supplements or food. There has been a dramatic increase in research on vitamin D, linking it with health outcomes as varied as reproductive function, infection, cardiovascular disease, and cancer. The study of vitamin D has generated much excitement, partly because there is an ideal intervention: Low levels may be common and can be remedied with widely available supplements. Determination of vitamin D status is complex and has advanced dramatically in the past 5 years. In this paper, we begin by describing important considerations for measurement of total 25-hydroxyvitamin D (25(OH)D), the biomarker traditionally assessed in epidemiologic studies. While 25(OH)D remains the most commonly measured biomarker, emerging evidence suggests that other related analytes may contribute to the characterization of an individual's vitamin D status (e.g., vitamin D-binding protein, bioavailable and free 25(OH)D, the C-3 epimer of 25(OH)D, 1,25-dihydroxyvitamin D, and 24,25-dihydroxyvitamin D). The measurement of these analytes is also complex, and there are important considerations for deciding whether their measurement is warranted in new research studies. Herein we discuss these issues and provide the reader with an up-to-date synthesis of research on vitamin D measurement options and considerations.

Vitamin D, obesity and leptin in relation to bladder cancer incidence and survival: prospective protocol study

INTRODUCTION

Bladder cancer (BC) (including renal pelvis, ureter and urethra) is one of the most common urogenital cancers and the fourth most frequent cancer in men in the USA. In Norway, the incidence of BC has increased over the last decades. The age-standardised incidence rates per 100 000 for 2011-2015 were 53.7 in men and 16.5 in women. Compared to the 5-year period 2006-2010, the percentage increase in incidence was 6.1% in men and 12.3% in women. The recurrence rate of BC is over 50%, the highest recurrence rate of any malignancy. Smoking and occupational exposure to aromatic amines are recognised as the major risk factors. Recently, low-serum level of 25-hydroxy vitamin D (25(OH)D) and obesity have been suggested to increase the BC risk, and leptin, which is important in weight regulation, may be involved in bladder carcinogenesis. More knowledge on potential risk factors for BC is necessary for planning and implementing primary prevention measures.

METHODS AND ANALYSES

Cohort and nested case-control studies will be carried out using the population-based Janus Serum Bank Cohort consisting of prediagnostic sera, clinical measurement data (body height and weight, body surface area and weight change over time, blood pressure, cholesterol and triglycerides) and self-reported information on lifestyle factors (smoking, physical activity). Participants were followed from cohort inclusion (1972-2003) through 2014. The cohort will be linked to the Cancer Registry of Norway (cancer data), the National Cause of Death Registry (date and cause of death), National Population Registry (vital status) and Statistic Norway (education and occupation). Serum samples will be analysed for 25(OH)D, vitamin D binding protein, leptin, albumin, calcium and parathyroid hormone. Cox regression and conditional logistic regression models and mediation analysis will be used to estimate association between the exposures and BC.

ETHICS AND DISSEMINATION

The study has been approved by the Regional Committee for Medical Research Ethics and is funded by the Norwegian Cancer Society. Results will be published in peer-reviewed journals, at scientific conferences and through press releases.

Can Supplementation of Vitamin D Improve Aerobic Capacity in Well Trained Youth Soccer Players?

There is no clear evidence that vitamin D effectively improves physical capacity in high-level athletes. The aim of this study was to confirm that vitamin D supplementation of soccer players during eight-week high-intensity training would have a significant effect on their aerobic capacity. The subjects were divided into two groups: the experimental one that was supplemented with vitamin D (SG, n = 20), and the placebo group (PG, n = 16), not supplemented with vitamin D. All the players were subjected to the same soccer training described as High-Intensity Interval Training (HIIT). The data of the vitamin D level, PWC170, lactate threshold (LT) were collected just before and after the intervention. A significant increase in vitamin D concentration (119%) was observed in the supplemented group, while the non-supplemented group showed a decrease of 8.4%. The studied subjects improved VO2max results by 20% in the SG, and by 13% in the PG. The improvement in velocity at the LT was similar in both groups. Results of this study show that vitamin D can have a positive, though moderate, effect on aerobic performance in players subjected to high-intensity training in the form of small-sided games for 8 weeks.

Dysregulated 1,25-dihydroxyvitamin D levels in high-fat diet-induced obesity can be restored by changing to a lower-fat diet in mice

Altered regulation of vitamin D metabolites, 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D (1,25[OH]₂D), was observed in high-fat diet (HFD)-induced obesity. We hypothesized that these HFD-induced changes in vitamin D metabolism would be reversed by decreasing fat mass through dietary intervention. Four-week-old C57BL/6J mice were assigned to 1 of 3 experimental diet groups: (1) the LL group was fed a control diet for 31 weeks, (2) the HH group was fed an HFD for 31 weeks, and (3) the HL group was fed HFD for 15 weeks then switched to the control diet for the remaining 16 weeks. The fat mass of the HL group decreased by 15% from the 14th to the 30th week. Serum 1,25(OH)₂D level was significantly higher in the HH group than the LL group, whereas that of the HL group was intermediate to the 2 groups. Serum parathyroid hormone and renal 1-hydroxylase (Cyp27b1) mRNA levels, which are known to stimulate renal 1,25(OH)₂D production, were significantly higher in the HH group than the LL group. After losing fat mass, the HL group had significantly lower renal Cyp27b1 mRNA levels than the HH group. No differences were found in serum 25-hydroxyvitamin D levels and mRNA levels of hepatic 25-hydroxylases. In adipose tissue, mRNA levels of 25-hydroxylase and vitamin D receptor were elevated in parallel to the adiposity. In conclusion, serum 1,25(OH)₂D levels were closely associated with body adiposity, and reducing fat mass by changing to a lower-fat diet can reverse this obesity-associated increase in circulating 1,25(OH)₂D levels.

Association of vitamin D receptor gene TaqI, FokI and ApaI variants with arteriovenous fistula failure in hemodialysis patients

PURPOSE

We investigated the influence of the vitamin D receptor gene TaqI (rs731236), ApaI (rs7975232), and FokI (rs2228570) polymorphisms in arteriovenous fistula failure in hemodialysis patients.

METHODS

This study was carried out with 54 patients who experienced two or more fistula failures in the late period after arteriovenous fistula operation and 58 control patients with no history of arteriovenous fistula failure in 3 years or longer. The polymerase chain reaction-restriction fragment length polymorphism method was used to determine the vitamin D receptor TaqI, FokI, and ApaI polymorphisms.

RESULTS

For vitamin D receptor gene TaqI and Fok1 polymorphisms, no significant association was found between the two groups ( p > 0.05). However, a statistically significant association was determined for ApaI polymorphism between the two groups ( p = 0.02). In patients, ApaI AA, AC, and CC genotype frequencies were found as 21 (38.9%), 32 (59.3%), and 1 (1.8%), respectively. However, genotype frequencies of AA, AC, and CC in the control group were 29 (50%), 22 (37.9%), and 7 (12.1%), respectively. In all three polymorphisms, no significant difference was found between the two groups in terms of allele frequencies ( p > 0.05).

CONCLUSION

Vitamin D receptor ApaI AC genotype may be a possible cardiovascular risk factor for the development of arteriovenous fistula failure.

Vitamin D Receptor Expression in Dogs

Background

There is growing evidence linking low blood vitamin D concentration to numerous diseases in people and in dogs. Vitamin D influences cellular function by signaling through the vitamin D receptor (VDR). Little is known about which non‐skeletal tissues express the VDR or how inflammation influences its expression in the dog.

Objectives

To define which non‐skeletal canine tissues express the VDR and to investigate expression in inflamed small intestine.

Animals

Thirteen non‐skeletal tissues were collected prospectively from 6 control dogs. Thirty‐five dogs diagnosed with a chronic enteropathy (CE) and 24 control dogs were prospectively enrolled and duodenal biopsies were evaluated for VDR expression.

Methods

Prospective; blinded assessment of canine intestinal VDR. Dogs with CE were included once other identifiable causes of intestinal disease were excluded. Age matched controls were included with no intestinal clinical signs. VDR expression was assessed immunohistochemically in all samples, using a Rat IgG VDR monoclonal antibody. Quantitative real‐time polymerase chain reaction (qPCR) was also used for duodenal biopsies.

Results

VDR expression as assessed by immunohistochemistry (IHC) was highest in the kidney, duodenum, skin, ileum and spleen, and weak in the colon, heart, lymph node, liver, lung, and ovary. Gastric and testicular tissue did not express the VDR. There was no statistical difference in duodenal VDR expression between the 24 healthy dogs and 34 dogs with CE when quantified by either qPCR (P = 0.87) or IHC (P = 0.099).

Conclusions and Clinical Importance

The lack of down regulation of VDR expression in inflamed intestine contrasts with previous studies in humans. Our findings support future studies to investigate whether vitamin D and its analogues can be used to modulate intestinal inflammation in the dog.

Prevalence of vitamin D deficiency and its associated factors among the urban elderly population in Hyderabad metropolitan city, South India

BACKGROUND

Deficiency of vitamin D has been associated with various health conditions. However, vitamin D deficiency (VDD) and factors associated with VDD are not well studied, especially among the urban elderly population of India.

AIM

To assess the prevalence of VDD and its associated factors among the urban free-living elderly population in Hyderabad.

SUBJECTS AND METHODS

A community-based cross-sectional study was conducted among 298 urban elderly (≥60 years) by adapting a random sampling procedure. Demographic particulars were collected. Blood pressure and anthropometric measurements were recorded using standard equipment. Fasting glucose, lipid profile and 25-hydroxy vitamin D [25(OH) D] were estimated in plasma samples.

RESULTS

The mean ± SE plasma vitamin D and the prevalence of VDD among the urban elderly population were 19.3 ± 0.54 (ng/ml) and 56.3%, respectively. The prevalence of VDD was significantly associated with education, high body mass index (BMI), hypertension (HT) and metabolic syndrome (MS). Multiple logistic regression analysis revealed HT as a significant predictor of vitamin D deficiency and the risk of VDD was double among the elderly with hypertension.

CONCLUSIONS

The prevalence of VDD was high among the urban elderly population in the south Indian city of Hyderabad. High BMI, MS, HT and education are significant associated factors of VDD.

Clinical role of vitamin D in prognosis of otitis media with effusion

OBJECTIVE

To investigate the clinical role of Vitamin D in prognosis of Otitis media with effusion.

METHODS

This prospective-controlled study was conducted at otolaryngology department in Duzce University, Turkey. The study group comprised children who were diagnosed with Otitis media with effusion between September 2016 and February 2017. Control group was conducted with children underwent circumcision or inguinal hernia repair operations that confirmed with ENT examination they do not have any sign of otitis media. After 3 months of follow-up without any treatment, unresolved cases who were accepted as chronic otitis media with effusion were operated under general anesthesia for ventilation tube application. Study and control groups were assessed depending on the serum 25(OH)Vitamin D levels at the end of 3 months; < 15 ng/mL was accepted as vitamin D deficiency. The results were compared with the control group in terms of vitamin D levels. Also, subgroup analysis was performed addressing to the complete recovery otitis media with effusion and chronic otitis media with effusion.

RESULTS

One-hundred-seventy-four children with otitis media with effusion and 80 control patients were included to the study. One-hundred-eight (62%) out of 174 patients with otitis media with effusion was completely recovered after a 3-months follow up. Of those 66 out of 174 children, they had persistent diseases, underwent ventilation tube insertion after a 3-months follow-up. The mean 25(OH)Vitamin D level was 18.98 ± 10.60 in otitis media with effusion group and 28.07 ± 14.10 in control group and the difference was statistically significant between the study and control group (p < 0.001). Vitamin D deficiency was observed in 33 out of 66 patients (50.0%) in chronic otitis media with effusion group whilst 35 out of 108 patients (32.4%) in complete recovery otitis media with effusion group (p = 0.021). The rate of 25(OH)Vitamin D deficiency was 25% in control group which was statistically different from chronic otitis media with effusion and recovery chronic otitis media with effusion groups (p = 0.006).

CONCLUSIONS

This study not only shows the relationship between Vitamin D and otitis media with effusion development, but also demonstrates the effects of Vitamin D on otitis media with effusion prognosis. There is a significant association between 25(OH)Vitamin D deficiency and follow-up outcomes of otitis media with effusion.

Vitamin D deficiency and hepatitis viruses-associated liver diseases: A literature review

The secosteroid hormone vitamin D has, in addition to its effects in bone metabolism also functions in the modulation of immune responses against infectious agents and in inhibiting tumorigenesis. Thus, deficiency of vitamin D is associated with several malignancies, but also with a plethora of infectious diseases. Among other communicable diseases, vitamin D deficiency is involved in the pathogenesis of chronic liver diseases caused by hepatitis B and C viruses (HBV, HCV) and high prevalence of vitamin D deficiency with serum levels below 20 mg/mL in patients with HBV and HCV infection are found worldwide. Several studies have assessed the effects of vitamin D supplementation on the sustained virological response (SVR) to interferon (IFN) plus ribavirin (RBV) therapy in HBV and HCV infection. In these studies, inconsistent results were reported. This review addresses general aspects of vitamin D deficiency and, in particular, the significance of vitamin D hypovitaminosis in the outcome of HBV- and HCV-related chronic liver diseases. Furthermore, current literature was reviewed in order to understand the effects of vitamin D supplementation in combination with IFN-based therapy on the virological response in HBV and HCV infected patients.