Alterations in vitamin D status and anti-microbial peptide levels in patients in the intensive care unit with sepsis

Vitamin D Deficiency Treatment Patterns in Academic Urban Medical Center

OBJECTIVE

Assess racial/ethnic and sex differences in treatment of vitamin D deficiency with high dose ergocalciferol ('vitamin D2') or other forms of vitamin D in a northeastern U.S. ambulatory clinic of an academic urban medical center.

STUDY DESIGN

Cross-sectional observational review of electronic medication prescribing records of patients with 25-hydroxyvitamin D (25OHD) deficiency (25OHD < 20 ng/ml) from 2004-2008.

METHODS

Using multivariable logistic regression adjusting for patients' demographics, and Elixhauser comorbidity score, we examined the association of sex and race/ethnicity with prescription for at least one dose of vitamin D.

RESULTS

Among 2,140 patients without renal disease and tested for 25OHD deficiency (25OHD < 20 ng/ml), 66.2% received no vitamin D prescription for vitamin D deficiency. Blacks and Hispanics received vitamin D prescriptions at a higher frequency than whites, 37.8% 38.4% and 30.9%, respectively, p=0.003. The vitamin D prescription rate for women versus men was 26.3% and 7.5%, respectively, p=0.04. In a fully adjusted model, no difference in prescription likelihood for blacks and whites [OR=1.18 95% CI, 0.88-1.58; p=0.29] or Hispanics and whites was noted [OR=1.01 95% CI, 0.70-1.45;p=0.73]. Similarly, fully adjusted model showed no difference in prescription likelihood for females and males [OR=1.23 95% CI, 0.93-1.63; p=0.12].

CONCLUSIONS

Among primary care patients with vitamin D deficiency, vitamin D supplementation was low and white patients were less likely to receive vitamin D treatment than blacks or Hispanics. Interventions to correct the high prevalence of vitamin D deficiency should address the markedly low rate of vitamin D prescribing when 25OHD levels are measured.

Is vitamin d insufficiency associated with mortality of critically ill patients?

Objective. To evaluate the vitamin D status of our critically ill patients and its relevance to mortality. Patients and Methods. We performed a prospective observational study in the medical intensive care unit of a university hospital between October 2009 and March 2011. Vitamin D levels were measured and insufficiency was defined as <20 ng/mL. Results. Two hundred and one patients were included in the study. The median age was 66 (56–77) and the majority of patients were male (56%). The median serum level of vitamin D was 14,9 ng/mL and 139 (69%) patients were vitamin D insufficient on admission. While we grouped the ICU patients as vitamin D insufficient and sufficient, vitamin D insufficient patients had more severe acute diseases and worse laboratory values on admission. These patients had more morbidities and were exposed to more invasive therapies during stay. The mortality rate was significantly higher in the vitamin D insufficient group compared to the vitamin D sufficient group (43% versus 26%, P = 0,027). However, logistic regression analysis demonstrated that vitamin D insufficiency was not an independent risk factor for mortality. Conclusion. Vitamin D insufficiency is common in our critically ill patients (69%), but it is not an independent risk factor for mortality.

The role of vitamin D in critical illness

The role of vitamin D in critical illness is under investigation. Recent data indicate declining levels of serum vitamin D in multiple adult populations. Deficiencies have been strongly linked to infectious processes and certain chronic disorders. Vitamin D deficiency that is present at the onset of critical illness may impact the severity of illness and contribute to less-than-optimal outcomes. This article describes the function of vitamin D, the effects that deficiencies have on body systems, and the emerging role of vitamin D deficiency for critically ill patients.

Principles and pitfalls of free hormone measurements

The free hormone hypothesis states that a hormone's physiological effects depend on the free hormone concentration, not the total hormone concentration. Although the in vivo relationship between free hormone and protein-bound hormone is complex, most experts have applied this view to the design of assays used to assess the free hormone concentration in the blood sampled for testing in vitro. The history of the measurement of free thyroxine, probably the most frequently requested free hormone determination, offers a good example of the approaches that have been taken. Methods that require physical separation of the free hormone from the protein-bound hormone must address both the potential disturbance in the equilibrium between the two, as well as the challenge of quantifying small levels of hormone accurately and precisely. The implementation of mass spectrometry in the clinical laboratory has helped to develop proposed reference measurement procedures. These must be utilized to standardize the variety of immunoassay approaches that currently represent options commercially available to the routine clinical laboratory. Practicing endocrinologists should discuss the details of the free hormone assays offered by the clinical laboratory they utilize for patient result reporting, and clinical laboratories should implement the recommendations of published guidelines to ensure that free hormone results using commercially available immunoassays are as accurate and precise as possible.

Dysregulated mineral metabolism in patients with acute kidney injury and risk of adverse outcomes

OBJECTIVE

Numerous studies have evaluated the prevalence and importance of vitamin D deficiency among patients with chronic kidney disease and end-stage renal disease; however, little is known about vitamin D levels in acute kidney injury (AKI). We evaluated the association between vitamin D metabolites and clinical outcomes among patients with AKI.

DESIGN

Prospective cohort study.

PATIENTS

A total of 30 participants with AKI and 30 controls from general hospital wards and intensive care units at a tertiary care hospital were recruited for the study.

MEASUREMENTS

Plasma levels of 25-hydroxyvitamin D [25(OH)D], 1,25-dihydroxyvitamin D [1,25(OH)2 D], 24R,25-dihydroxyvitamin D3 , vitamin D binding protein (VDBP) and fibroblast growth factor 23 (FGF23) were measured within 24 hours of AKI onset and 5 days later. Bioavailable 25(OH)D and 1,25(OH)2 D levels, defined as the sum of free- and albumin-bound 25(OH)D and 1,25(OH)2 D, were estimated using equations.

RESULTS

Compared to controls, participants with AKI had lower levels of 1,25(OH)2 D [17 (10-22) vs 25 (15-35) pg/ml, P = 0·01], lower levels of VDBP [23 (15-31) vs 29 (25-36) mg/dl, P = 0·003] and similar levels of bioavailable 25(OH)D and 1,25(OH)2 D at enrolment. Levels of bioavailable 25(OH)D were inversely associated with severity of sepsis in the overall sample (P < 0·001). Among participants with AKI, bioavailable 25(OH)D, but not other vitamin D metabolites, was significantly associated with mortality after adjusting for age and serum creatinine (adjusted odds ratio per 1 SD ln [bioavailable 25(OH)D] = 0·16, 95% confidence interval = 0·03-0·85).

CONCLUSIONS

Bioavailable 25(OH)D could have a role as a biomarker or mediator of adverse outcomes among patients with established AKI.

Novel Gemini vitamin D3 analogs: large structure/function analysis and ability to induce antimicrobial peptide

We have synthesized 39 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] analogs having two side chains attached to carbon-20 (Gemini) with various modifications and compared their anticancer activities. Five structure-function rules emerged to identify analogs with enhanced anticancer activity. One of these active analogs, BXL-01-0126, was more potent than 1,25(OH)2D3 in mediating 50% clonal inhibition of cancer cell growth. Murine studies found that BXL-01-0126 and 1,25(OH)2D3 had nearly the same potency to raise serum calcium levels. Taken together, BXL-01-0126 when compared to 1,25(OH)2D3 has greater anticancer potency, but similar toxicity causing hypercalcemia. We focused on the effect of these compounds on the stimulation of expression of human cathelicidin antimicrobial peptide (CAMP) whose gene has a vitamin D response element in its promoter. Expression of CAMP mRNA and protein increased in a dose-response fashion after exposure of acute myeloid leukemia (AML) cells to the Gemini analog, BXL-01-126, in vitro. A xenograft model of AML was developed using U937 AML cells injected into NSG-immunodeficient mice. Administration of vitamin D3 compounds to these mice resulted in substantial levels of CAMP in the systemic circulation. This suggests a unique prophylactic treatment at diagnosis or during induction chemotherapy for AML patients to provide them with protection against various microbial infections through CAMP induction.

Vitamin D and immune function

Vitamin D metabolizing enzymes and vitamin D receptors are present in many cell types including various immune cells such as antigen-presenting-cells, T cells, B cells and monocytes. In vitro data show that, in addition to modulating innate immune cells, vitamin D also promotes a more tolerogenic immunological status. In vivo data from animals and from human vitamin D supplementation studies have shown beneficial effects of vitamin D on immune function, in particular in the context of autoimmunity. In this review, currently available data are summarized to give an overview of the effects of vitamin D on the immune system in general and on the regulation of inflammatory responses, as well as regulatory mechanisms connected to autoimmune diseases particularly in type 1 diabetes mellitus.

Vitamin D deficiency in surgical congenital heart disease: prevalence and relevance

Vitamin D is a pleiotropic hormone important for the proper functioning of multiple organ systems. An emerging body of adult and pediatric critical care literature strongly suggests that vitamin D deficiency contributes to secondary organ pathophysiology, prolongs ICU stay, and worsens outcome in critically ill populations. Recent clinical studies suggest that a significant number of children with congenital heart disease (CHD) have post-operative vitamin D deficiency which appears to be associated with greater cardiovascular dysfunction. Altogether the cumulative body of literature suggests that peri-operative optimization of vitamin D status has the potential to speed recovery and/or improve outcome. This review describes the epidemiological and basic science research linking vitamin D deficiency to post-operative organ dysfunction. Furthermore, the available supplementation approaches are reviewed in the context of prevention of post-operative vitamin D deficiency and avoidance of toxicity in the majority of CHD patients. Finally, knowledge gaps regarding vitamin D supplementation are identified and the next stages for research are outlined.

Serum 1,25-dihydroxyvitamin D: an outcome prognosticator in human sepsis

In sepsis, the vitamin D active metabolite 1,25-dihydroxyvitamin D (1,25(OH)₂D) may play a crucial role by its action to produce cathelicidin and improve endothelial barrier function, such that a deficiency in 1,25(OH)₂D is associated with poor outcome. To test our hypothesis, we performed analysis of stored plasma samples from a prospective observational study in 91 patients with sepsis, age of 59.1+/−2.0 years, 52.7% females, and 11.0% deaths at 30 days. Vitamin D status, including 25-hydroxyvitamin D (25(OH)D), 1,25(OH)₂D, 24,25-dihydroxyvitamin D (24,25(OH)₂D), and parathyroid hormone (PTH), were measured daily over 3 days after hospital admission. At baseline, 1,25(OH)₂D was significantly different between survivors vs. non-survivors. But there was no significant difference in 25(OH)D, 24,25(OH)₂D, and PTH. In a multivariable binomial logistic regression model, age, total calcium and 1,25(OH)₂D were significant predictors of 30-day mortality. Kaplan Meier analysis showed that patients with mean 1,25(OH)₂D measured over 3 days of < = 13.6 pg/mL had 57.1% 30-day survival compared to 91.7% in patients with 1,25 (OH)₂D level >13.6 pg/mL (p<0.01). From repeated measures regression analysis, there was significant increase in 1,25(OH)₂D for increases in 25(OH)D in both survivors and non-survivors. However, compared to survivors, the low 25(OH)D in non-survivors was insufficient to account for the larger decrease in 1,25(OH)₂D, indicating a dysfunctional 1α-hydroxylase. Additionally, there was a significant negative correlation between PTH and 1,25(OH)₂D in both survivors and non-survivors, suggesting a severe impairment in the effect of PTH to increase renal 1α-hydroxylase activity. In conclusion, low 1,25(OH)₂D levels are associated with increased 30-day mortality in sepsis patients, likely due to impaired 25(OH)D hydroxylation and PTH insensitivity. Our data also suggest that the active metabolite 1,25(OH)₂D may be an important therapeutic target in the design of sepsis clinical trials.

Vitamin D to prevent acute lung injury following oesophagectomy (VINDALOO): study protocol for a randomised placebo controlled trial

Background

Acute lung injury occurs in approximately 25% to 30% of subjects undergoing oesophagectomy. Experimental studies suggest that treatment with vitamin D may prevent the development of acute lung injury by decreasing inflammatory cytokine release, enhancing lung epithelial repair and protecting alveolar capillary barrier function.

Methods/Design

The ‘Vitamin D to prevent lung injury following oesophagectomy trial’ is a multi-centre, randomised, double-blind, placebo-controlled trial. The aim of the trial is to determine in patients undergoing elective transthoracic oesophagectomy, if pre-treatment with a single oral dose of vitamin D₃ (300,000 IU (7.5 mg) cholecalciferol in oily solution administered seven days pre-operatively) compared to placebo affects biomarkers of early acute lung injury and other clinical outcomes. The primary outcome will be change in extravascular lung water index measured by PiCCO® transpulmonary thermodilution catheter at the end of the oesophagectomy. The trial secondary outcomes are clinical markers indicative of lung injury: PaO₂:FiO₂ ratio, oxygenation index; development of acute lung injury to day 28; duration of ventilation and organ failure; survival; safety and tolerability of vitamin D supplementation; plasma indices of endothelial and alveolar epithelial function/injury, plasma inflammatory response and plasma vitamin D status. The study aims to recruit 80 patients from three UK centres.

Discussion

This study will ascertain whether vitamin D replacement alters biomarkers of lung damage following oesophagectomy.

Trial registration

Current Controlled Trials ISRCTN27673620

Effects of high-dose cholecalciferol on serum markers of inflammation and immunity in patients with early chronic kidney disease

BACKGROUND/OBJECTIVES

Vitamin D has anti-inflammatory and immune-regulating properties. We aimed to determine if high-dose cholecalciferol supplementation for 1 year in subjects with early chronic kidney disease (CKD) improved circulating markers of inflammation and immunity.

SUBJECTS/METHODS

In this double-blind, randomized, placebo-controlled trial, 46 subjects with early CKD (stages 2 and 3) were supplemented with oral cholecalciferol (50 000 IU weekly for 12 weeks followed by 50 000 IU every other week for 40 weeks) or a matching placebo for 1 year. Serum tumor necrosis factor-α, interleukin-6, monocyte chemoattractant protein-1 (MCP-1), interferon gamma-induced protein-10 and neutrophil gelatinase-associated lipocalin were measured at baseline, 12 weeks and 1 year. Serum cathelicidin (LL-37) was measured at baseline and 12 weeks. An in vitro experiment was performed to investigate the effect of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) treatment on MCP-1 secretion in THP-1 monocytes activated with lipopolysaccharide (LPS) and Pseudomonas aeruginosa.

RESULTS

By 12 weeks, serum MCP-1 decreased in the cholecalciferol group (66.2±2.5 to 60.8±2.6 pg/ml, group-by-time interaction P=0.02) but was not different from baseline at 1 year. Other markers of inflammation and immunity did not change. In vitro, LPS- and Pseudomonas-activated monocytes treated with 1,25(OH)2D3 had significantly less MCP-1 secretion compared with untreated cells.

CONCLUSIONS

High-dose cholecalciferol decreased serum MCP-1 concentrations by 12 weeks in patients with early CKD, although the decrease was not maintained for the remainder of the year. In vitro results confirm an MCP-1-lowering effect of vitamin D. Future studies should determine if vitamin D-mediated reductions in MCP-1 concentrations reflect improved clinical outcomes.

Vitamin D in a northern Canadian first nation population: dietary intake, serum concentrations and functional gene polymorphisms

The wide spectrum of vitamin D activity has focused attention on its potential role in the elevated burden of disease in a northern Canadian First Nations (Dené) cohort. Vitamin D insufficiency, and gene polymorphisms in the vitamin D receptor (VDR) and vitamin D binding protein (VDBP) have been implicated in susceptibility to infectious and chronic diseases. The objectives of this study were to determine the contribution of vitamin D from food, and measure the serum concentrations of 25-hydroxyvitamin D(3) (25-OHD(3)) and VDBP in Dené participants. Single nucleotide polymorphisms (SNPs) associated with the dysregulation of the innate immune response were typed and counted. Potential correlations between the SNPs and serum concentrations of 25-OHD(3) and VDBP were evaluated. Venous blood was collected in summer and winter over a one-year period and analyzed for 25-OHD(3) and VDBP concentrations (N = 46). A questionnaire was administered to determine the amount of dietary vitamin D consumed. Sixty-one percent and 30% of the participants had 25-OHD(3) serum concentrations <75 nmol/L in the winter and summer respectively. Mean vitamin D binding protein concentrations were within the normal range in the winter but below normal in the summer. VDBP and VDR gene polymorphisms affect the bioavailability and regulation of 25-OHD(3). The Dené had a high frequency of the VDBP D432E-G allele (71%) and the Gc1 genotype (90%), associated with high concentrations of VDBP and a high binding affinity to 25-OHD(3). The Dené had a high frequency of VDR Fok1-f allele (82%), which has been associated with a down-regulated Th1 immune response. VDBP and VDR polymorphisms, and low winter 25-OHD(3) serum concentrations may be risk factors for infectious diseases and chronic conditions related to the dysregulation of the vitamin D pathway.

Correction of vitamin D deficiency in critically ill patients - VITdAL@ICU study protocol of a double-blind, placebo-controlled randomized clinical trial

BACKGROUND

Vitamin D deficiency is associated with multiple adverse health outcomes including increased morbidity and mortality in the general population and in critically ill patients. However, no randomized controlled trial has evaluated so far whether treatment with sufficiently large doses of vitamin D can improve clinical outcome of patients in an intensive care setting.

METHODS/DESIGN

The VITdAL@ICU trial is an investigator-initiated, non-commercial, double-blind, placebo-controlled randomized clinical trial. This study compares high-dose oral cholecalciferol (vitamin D3) versus placebo treatment in a mixed population of 480 critically ill patients with low 25-hydroxyvitamin-D levels at study enrollment (≤ 20ng/ml). Following an initial loading dose of 540,000 IU of vitamin D3, patients receive 90,000 IU of vitamin D3 on a monthly basis for 5 months. The study is designed to compare clinical outcome in the two study arms with the primary endpoint being length of hospital stay. Secondary endpoints include among others length of ICU stay, the percentage of patients with 25(OH)D levels > 30 ng/ml at day 7, ICU and hospital mortality and duration of mechanical ventilation. We describe here the VITdAL@ICU study protocol for the primary report.

DISCUSSION

This trial is designed to evaluate whether high-dose vitamin D3 is able to improve morbidity and mortality in a mixed population of adult critically ill patients and correct vitamin D deficiency safely.

TRIAL REGISTRATION

ClinicalTrials: NCT01130181.

Vitamin D in acute stress and critical illness

PURPOSE OF REVIEW

The pleotropic effects of vitamin D on chronic diseases have received significant attention; however, its role in acute illness is less understood. The purpose of this review is to summarize the current evidence regarding the role of vitamin D in acute stress and critical illness.

RECENT FINDINGS

25-Hydroxyvitamin D levels may affect risk of developing acute illnesses (e.g. respiratory infections), and low concentrations are associated with unfavorable outcomes during critical care. Inflammatory changes alone do not explain the observed deterioration in vitamin D status following acute stress. Hemodilution, interstitial extravasation, decreased synthesis of binding proteins, and renal wasting of 25-hydroxyvitamin D, all appear to play a more significant role in the regulation of vitamin D status during critical illness.

SUMMARY

Single-point assessments of 25-hydroxyvitamin D following acute stress may provide an inaccurate assessment of vitamin D status. In such cases, measurement of binding proteins and free vitamin D metabolites may be essential to create a more realistic approximation of vitamin D status. Variations in patient responses to acute stress and critical illness may depend not only on the degree of systemic vitamin D insufficiency, but also on the individual tissue requirements.

Positive correlation between circulating cathelicidin antimicrobial peptide (hCAP18/LL-37) and 25-hydroxyvitamin D levels in healthy adults

Background

Transcription of the cathelicidin antimicrobial peptide (CAMP) gene is induced by binding of the bioactive form of vitamin D, 1,25-dihydroxyvitamin D, to the vitamin D receptor. Significant levels of the protein hCAP18/LL-37 are found in the blood and may protect against infection and/or sepsis. We hypothesized that serum vitamin D levels may modulate the circulating levels of hCAP18. Only three studies have shown a positive correlation between circulating 25-hydroxyvitamin D and hCAP18 levels. Here we provide additional evidence for such a correlation in healthy, middle-aged adults.

Findings

Serum levels of 25-hydroxyvitamin D [25(OH)D] and plasma levels of hCAP18 were determined in 19 healthy middle-aged (mean of 50.1 years) adult men and women. Plasma hCAP18 concentrations correlated with serum 25(OH)D concentrations in subjects with 25(OH)D levels ≤ 32 ng/ml (r = 0.81, p < 0.005) but not in subjects with concentrations > 32 ng/ml (r = 0.19, p = 0.63).

Conclusions

We conclude that plasma hCAP18 levels correlate with serum 25(OH)D levels in subjects with concentrations of 25(OH)D ≤ 32 ng/ml as opposed to those with concentrations > 32 ng/ml and that vitamin D status may regulate systemic levels of hCAP18/LL-37.

Significant perturbation of vitamin D-parathyroid-calcium axis and adverse clinical outcomes in critically ill patients

PURPOSE

A prospective multicentre cohort study was conducted to determine the prevalence of hypovitaminosis D in adult critically ill patients, to characterize alterations in the parathyroid hormone (PTH)-vitamin D-calcium axis and to explore associations between hypovitaminosis D and adverse clinical outcomes.

METHODS

Demographic, disease severity scores and clinical outcome data were collected in 100 consecutive patients with expected intensive care unit (ICU) admission of at least 2 days. Levels of 25-hydroxyvitamin D (25-OH-D), 1,25-dihydroxyvitamin D (1,25-(OH)(2)-D), PTH and ionized calcium were measured on days 1, 3 and on day 7 or ICU discharge.

RESULTS

The prevalence of vitamin D insufficiency (25 nmol/L ≤ 25-OH-D ≤ 50 nmol/L) and deficiency (25-OH-D < 25 nmol/L) were 54 and 24 %, respectively, and levels did not recover during ICU stay. Admission 25-OH-D levels correlated with 1,25-(OH)(2)-D (R = 0.61, p = 0.001), Simplified Acute Physiology Score (SAPS-II) (R = -0.3, p = 0.01), Acute Physiology and Chronic Health Evaluation (APACHE-II) scores (R = -0.2, p = 0.05), but not calcium (R = 0.16, p = 0.11) or PTH (R = -0.11, p = 0.31) levels. Vitamin D deficiency was associated with fewer hospital-free days, OR 3.15 (1.18-8.43) in univariate analysis. Secondary hyperparathyroidism (PTH > 7 pmol/L) was observed in 37.5 % of hypocalcaemic and 32.5 % of vitamin D insufficient/deficient patients, and was associated with higher SAPS-II [43 (31.3-60) vs. 36 (30-43), p = 0.03].

CONCLUSIONS

Hypovitaminosis D and secondary hyperparathyroidism are highly prevalent in critically ill patients. Low vitamin D status persists during ICU stay and is associated with worse disease severity and fewer hospital-free days.

Vitamin D's potential to reduce the risk of hospital-acquired infections

Health care–associated and hospital-acquired infections are two entities associated with increased morbidity and mortality. They are highly costly and constitute a great burden to the health care system. Vitamin D deficiency (< 20 ng/ml) is prevalent and may be a key contributor to both acute and chronic ill health. Vitamin D deficiency is associated with decreased innate immunity and increased risk for infections. Vitamin D can positively influence a wide variety of microbial infections.

Herein we discuss hospital-acquired infections, such as pneumonia, bacteremias, urinary tract and surgical site infections, and the potential role vitamin D may play in ameliorating them. We also discuss how vitamin D might positively influence these infections and help contain health care costs. Pending further studies, we think it is prudent to check vitamin D status at hospital admission and to take immediate steps to address existing insufficient 25-hydroxyvitamin D levels.

Vitamin D and sepsis: An emerging relationship

Vitamin D insufficiency and sepsis are both highly prevalent worldwide problems and this article reviews the emerging science that is defining the intersections of these conditions. The importance of vitamin D’s role in skeletal health has long been understood but recent evidence is beginning to highlight its role in the functioning of other physiologic systems of the body. Basic science data reveal its integral role in local immune responses to pathogens and the systemic inflammatory pathways of sepsis. Furthermore, clinical scientists have found associations with respiratory infections, critical illness and sepsis but the causal relationship and its clinical impact have yet to be clearly defined. The article ends with speculations on the connections between racial disparities and seasonal differences in sepsis and vitamin D insufficiency.

Differences in vitamin D status may account for unexplained disparities in cancer survival rates between African and white Americans

Considerable disparities in cancer survival rates exist between African Americans (AAs) and white Americans (WAs). Various factors such as differences in socioeconomic status (SES), cancer stage at time of diagnosis, and treatment—which this analysis considers primary explanatory factors—have accounted for many of these differences. An additional factor not usually considered is vitamin D. Previous studies have inversely correlated higher solar ultraviolet-B (UVB) doses and serum 25-hydroxyvitamin D (25(OH)D) concentrations with incidence and/or mortality rates for about 20 types of cancer and improved survival rates for eight types of cancer. Because of darker skin pigmentation, AAs have 40% lower serum 25(OH)D concentrations than WAs. This study reviews the literature on disparities in cancer survival between AAs and WAs. The journal literature indicates that there are disparities for 13 types of cancer after consideration of SES, stage at diagnosis and treatment: bladder, breast, colon, endometrial, lung, ovarian, pancreatic, prostate, rectal, testicular, and vaginal cancer; Hodgkin lymphoma and melanoma. Solar UVB doses and/or serum 25(OH)D concentrations have been reported inversely correlated with incidence and/or mortality rates for all of these cancers. This finding suggests that future studies should consider serum 25(OH)D concentrations in addressing cancer survival disparities through both measurements of serum 25(OH)D concentrations and increasing serum 25(OH)D concentrations of those diagnosed with cancer, leading to improved survival rates and reduced disparities.

Vitamin D status in critically ill children

BACKGROUND

Hypovitaminosis D is an independent risk factor for cardiovascular disease, muscle weakness, impaired metabolism, immune dysfunction, and compromised lung function. Hypovitaminosis D is common in critically ill adults and has been associated with adverse outcomes. The prevalence of hypovitaminosis D and its significance in critically ill children are unclear.

METHODS

We performed a prospective study to determine the prevalence of hypovitaminosis D in 316 critically ill children, and examined its association with physiological and biochemical variables, length of pediatric intensive care unit (PICU) stay, and hospital mortality.

RESULTS

The prevalence of hypovitaminosis D [25(OH)D(3) <50 nmol/L] was 34.5 %. Hypovitaminosis D was more common in postoperative cardiac patients than in general medical ICU patients (40.5 versus 22.6 %, p = 0.002), and the cardiac patients had a higher inotrope score [2.5 (1.9-3.3) versus 1.4 (1.1-1.9), p = 0.006]. Additionally, ionized calcium within the first 24 h was lower in patients with 25(OH)D(3) <50 nmol/L [1.07 (0.99-1.14) mmol/L] compared with patients with normal vitamin D(3) [1.17 (1.14-1.19) mmol/L, p = 0.02]. Hypovitaminosis D was not associated with longer PICU stay or increased hospital mortality.

CONCLUSIONS

Hypovitaminosis D is common in critically ill children, and is associated with higher inotropes in the postoperative cardiac population, but not with PICU length of stay or hospital survival.

Vitamin D deficiency in critically ill children

OBJECTIVE

Vitamin D influences cardiovascular and immune function. We aimed to establish the prevalence of vitamin D deficiency in critically ill children and identify factors influencing admission 25-hydroxy vitamin D (25(OH)D) levels. We hypothesized that levels would be lower with increased illness severity and in children with serious infections.

METHODS

Participants were 511 severely or critically ill children admitted to the PICU from November 2009 to November 2010. Blood was collected near PICU admission and analyzed for 25(OH)D concentration by using Diasorin radioimmunoassay.

RESULTS

We enrolled 511 of 818 (62.5%) eligible children. The median 25(OH)D level was 22.5 ng/mL; 40.1% were 25(OH)D deficient (level <20 ng/mL). In multivariate analysis, age and race were associated with 25(OH)D deficiency; summer season, vitamin D supplementation, and formula intake were protective; 25(OH)D levels were not lower in the 238 children (46.6%) admitted with a life-threatening infection, unless they had septic shock (n = 51, 10.0%) (median 25(OH)D level 19.2 ng/mL; P = .0008). After adjusting for factors associated with deficiency, lower levels were associated with higher admission day illness severity (odds ratio 1.19 for a 1-quartile increase in Pediatric Risk of Mortality III score per 5 ng/mL decrease in 25(OH)D, 95% confidence interval 1.10-1.28; P < .0001).

CONCLUSIONS

We found a high rate of vitamin D deficiency in critically ill children. Given the roles of vitamin D in bone development and immunity, we recommend screening of those critically ill children with risk factors for vitamin D deficiency and implementation of effective repletion strategies.

The association of vitamin D status with pediatric critical illness

OBJECTIVES

Vitamin D is a pleiotropic hormone important for the proper functioning of multiple organ systems. It has been hypothesized that vitamin D deficiency could contribute to or worsen outcomes in critical illness. The study objective was to determine the prevalence of vitamin D deficiency, risk factors for its presence, and potential association with clinically relevant outcomes in critically ill children.

METHODS

A prospective cohort study, conducted from 2005 to 2008 in 6 tertiary-care PICUs in Canada. Data and biological samples from 326 critically ill children up to 17 years of age were available for analysis. Total serum 25 hydroxyvitamin D or 25(OH)D was measured by using liquid chromatography-mass spectrometry.

RESULTS

The prevalence of 25(OH)D <50 nmol/L was 69% (95% confidence interval, 64-74), and 23% (95% confidence interval, 19-28) for 25(OH)D between 50 to 75 nmol/L. Lower levels were associated with hypocalcemia, catecholamine utilization, and significant fluid bolus administration. Vitamin D deficiency was independently associated with a longer PICU length of stay (+1.92 days, P = .03) and increasing severity of illness as determined by the Pediatric Risk of Mortality score with every additional point increasing the likelihood of being vitamin D deficient by 8% (P = .005).

CONCLUSIONS

This study provides evidence that vitamin D deficiency is both common among critically ill children and associated with greater severity of critical illness. Further research will determine whether targeted vitamin D supplementation or rapid restoration will improve outcome.

Review article: vitamin D and inflammatory bowel disease--established concepts and future directions

BACKGROUND

Understanding of the role of vitamin D in health and disease has increased markedly in the past decade, with its involvement extending well beyond traditional roles in calcium and phosphate homeostasis and musculoskeletal health. This conceptual expansion has been underpinned by identification and exploration of components of this axis including vitamin D-binding protein, key enzymes and receptors in multiple cell types, and a greater recognition of nonclassical autocrine and paracrine effects. Its influence in IBD remains uncertain.

AIM

To review the role of vitamin D in bone health, immune regulation and cancer prevention in IBD, and to outline practical issues and limitations of its use.

METHODS

An extensive online literature review including PubMed and Medline.

RESULTS

In patients with IBD, the vitamin D axis provides an important and often underutilised pathway to preserving bone health. Furthermore, an exciting body of clinical and basic science research demonstrates that these pathways may have an integral part to play in regulation of the immune response in IBD, through effects on the intestinal barrier, antigen presenting cells and adaptive T cells. The possibility of chemoprevention requires further study. The optimal target level of 25-hydroxy vitamin D in patients with IBD is currently uncertain, as is the best therapeutic modality.

CONCLUSIONS

Study of vitamin D pathways may result in the development of relatively inexpensive therapeutic options to optimise patient outcomes. Further prospective clinical research is required to address efficacy and long-term safety.

Vitamin D in sepsis: from basic science to clinical impact

The growing basic and clinical investigations into the extraskeletal effects of vitamin D have revealed roles in the functioning of the immune system, generating interesting questions about this nutrient's connections to sepsis. This article briefly reviews the current science of the function of vitamin D in the immune system as well as the emerging clinical literature regarding its associations with respiratory infections, sepsis, and critical illness. Finally, we offer views on the potential future directions for research in the field by outlining potential relevant scenarios and outcomes.

Regulation of antimicrobial peptide gene expression by nutrients and by-products of microbial metabolism

BACKGROUND

Antimicrobial peptides (AMPs) are synthesized and secreted by immune and epithelial cells that are constantly exposed to environmental microbes. AMPs are essential for barrier defense, and deficiencies lead to increased susceptibility to infection. In addition to their ability to disrupt the integrity of bacterial, viral and fungal membranes, AMPs bind lipopolysaccharides, act as chemoattractants for immune cells and bind to cellular receptors and modulate the expression of cytokines and chemokines. These additional biological activities may explain the role of AMPs in inflammatory diseases and cancer. Modulating the endogenous expression of AMPs offers potential therapeutic treatments for infection and disease.

METHODS

The present review examines the published data from both in vitro and in vivo studies reporting the effects of nutrients and by-products of microbial metabolism on the expression of antimicrobial peptide genes in order to highlight an emerging appreciation for the role of dietary compounds in modulating the innate immune response.

RESULTS

Vitamins A and D, dietary histone deacetylases and by-products of intestinal microbial metabolism (butyrate and secondary bile acids) have been found to regulate the expression of AMPs in humans. Vitamin D deficiency correlates with increased susceptibility to infection, and supplementation studies indicate an improvement in defense against infection. Animal and human clinical studies with butyrate indicate that increasing expression of AMPs in the colon protects against infection.

CONCLUSION

These findings suggest that diet and/or consumption of nutritional supplements may be used to improve and/or modulate immune function. In addition, by-products of gut microbe metabolism could be important for communicating with intestinal epithelial and immune cells, thus affecting the expression of AMPs. This interaction may help establish a mucosal barrier to prevent invasion of the intestinal epithelium by either mutualistic or pathogenic microorganisms.

Osteoporosis self-assessment tool for Asians as a simple risk index of identifying a poor prognosis in women surgically treated for colorectal cancer

BACKGROUND

Osteoporosis and colorectal cancer (CRC) in older women are considered enormous public health burdens. The effects of osteoporosis on the oncologic outcome of CRC surgery are poorly understood. We evaluated the use of the Osteoporosis Self-assessment Tool for Asians (OSTA) for predicting postoperative outcome in older women after receiving surgical treatment of CRC.

MATERIALS AND METHODS

The present single-institution retrospective study analyzed patients who had undergone surgery for CRC in 2002-2008. To characterize the major population of women with osteoporosis, which consists of postmenopausal women, only patients aged 50 years and older were analyzed. Their OSTA scores were evaluated for correlations with cancer-specific survival after surgery for CRC by performing univariate, multivariate, and survival analyses.

RESULTS

During a 7-year period, 440 women were studied. The cancer-specific mortality and overall mortality rate was 28.4% and 33.4%, respectively. The univariate analyses revealed that significant predictors of cancer-specific mortality after CRC surgery were the International Union Against Cancer (UICC) stage, OSTA category, histologic grading, lymph node metastases, and tumor invasion depth. After risk adjustment, the UICC stage and OSTA risk index were independent predictors of mortality. A comparison of OSTA risk index among patients with different UICC stages showed that the accuracy of the index in predicting cancer-specific survival after CRC surgery was greatest for patients with stage II and III disease.

CONCLUSIONS

The UICC stage and OSTA risk status showed independent positive associations with postoperative mortality in aged female patients with CRC. Moreover, the OSTA index had a particularly strong association with cancer-specific mortality in patients with UICC stage II and III.

Vitamin D and chronic rhinitis

PURPOSE OF REVIEW

To discuss the role of vitamin D in chronic rhinitis and chronic rhinosinusitis (CRS).

RECENT FINDINGS

Vitamin D has been shown to have an immunomodulatory effect with a significant impact on immune function. Specifically, vitamin D regulates the mechanisms which suppress the inflammatory response and direct the differentiation fate of immune cells. Vitamin D has been shown to play an important role in asthma, and the concept of the unified airway model allows the extrapolation of vitamin D as a critical player in chronic rhinitis and rhinosinusitis.

SUMMARY

Recent findings on the function of vitamin D may explain aspects of the pathophysiology of chronic rhinitis and CRS, and may help direct future treatment of these diseases.

Invasive pneumonia and septic shock in infants as a presentation of cystic fibrosis with vitamin-deficiency

Herein we describe three infants with the rare presentation of pneumonia with septic shock as their initial medical encounter leading to the diagnosis of cystic fibrosis (CF). At the time of their presentation all three children had significant nutritional deficiency. We initiated an aggressive treatment regimen including nutritional supplementation which resulted in improvement in their pulmonary status and no further recurrences. This series highlights the possible presentation of CF in infancy as a life-threatening invasive infection of Staphylococcus aureus or Pseudomonas aeruginosa. It also supports neonatal screening and emphasizes the role of early attention to nutritional status and vitamin supplementation.

Clinical review: Early treatment of acute lung injury--paradigm shift toward prevention and treatment prior to respiratory failure

Acute lung injury (ALI) remains a major cause of morbidity and mortality in critically ill patients. Despite improved understanding of the pathogenesis of ALI, supportive care with a lung protective strategy of mechanical ventilation remains the only treatment with a proven survival advantage. Most clinical trials in ALI have targeted mechanically ventilated patients. Past trials of pharmacologic agents may have failed to demonstrate efficacy in part due to the resultant delay in initiation of therapy until several days after the onset of lung injury. Improved early identification of at-risk patients provides new opportunities for risk factor modification to prevent the development of ALI and novel patient groups to target for early treatment of ALI before progression to the need for mechanical ventilation. This review will discuss current strategies that target prevention of ALI and some of the most promising pharmacologic agents for early treatment of ALI prior to the onset of respiratory failure that requires mechanical ventilation.

Statins in the critically ill

The use or misuse of statins in critically ill patients recently attracted the attention of intensive care clinicians. Indeed, statins are probably the most common chronic treatment before critical illness and some recent experimental and clinical data demonstrated their beneficial effects during sepsis, acute lung injury (ALI)/acute respiratory distress syndrome (ARDS), or after aneurismal subarachnoidal hemorrhage (aSAH). Due to the heterogeneity of current studies and the lack of well-designed prospective studies, definitive conclusions for systematic and large-scale utilization in intensive care units cannot be drawn from the published evidence. Furthermore, the extent of statins side effects in critically ill patients is still unknown. For the intensive care clinician, it is a matter of individually identifying the patient who can benefit from this therapy according to the current literature. The purpose of this review is to describe the mechanisms of actions of statins and to synthesize the clinical data that underline the relevant effects of statins in the particular setting of critical care, in an attempt to guide the clinician through his daily practice.

The immunoregulatory function of vitamin D: implications in chronic kidney disease

Cardiovascular and infectious diseases remain the most common causes of death among patients with chronic kidney disease (CKD) and end-stage renal disease (ESRD). Basic science and epidemiological studies indicate that vitamin D has importance not only for cardiovascular health, but also for the immune response. Vitamin D signaling pathways regulate both innate and adaptive immunity, maintaining the associated inflammatory response within physiological limits. Levels of both the inactive as well as active form of vitamin D (25-hydroxyvitamin D and 1,25-dihydroxyvitamin D, respectively) are decreased in patients with CKD and ESRD. It is reasonable to hypothesize, therefore, that the immune dysfunction associated with vitamin D deficiency in patients with CKD and ESRD in part explains the misdirected inflammatory response and increased susceptibility to infection seen in this population. Indeed, observational studies show that vitamin D deficiency in patients with ESRD is associated with increased mortality, and treatment with vitamin D is associated with a decreased risk of infection, as well as reduced all-cause mortality. However, whether different vitamin D preparations have differential effects on physiological function and clinical outcomes is still unclear. A proper understanding of the immune regulatory function of vitamin D is important for the development of future therapeutic strategies.

Relationship of vitamin D deficiency to clinical outcomes in critically ill patients

BACKGROUND

Despite the numerous disease conditions associated with vitamin D deficiency in the general population, the relationship of this deficiency to outcome in critically ill patients remains unclear. The objective of this study is to determine the burden of vitamin D deficiency in intensive care unit (ICU) patients and determine if it is associated with poor patient outcomes.

METHODS

The authors conducted an analysis of samples collected from a prospective study of 196 patients admitted to a medical/surgical ICU in a tertiary care hospital. They measured serum 25-hydroxyvitamin D at admission and up to 10 days following admission and followed patients prospectively for 28-day outcomes.

RESULTS

Of analyzable patients, 50 (26%) were deficient (≤30 nmol/L) and 109 (56%) were insufficient (>30 and ≤60 nmol/L). Baseline 25(OH)D levels decreased significantly in all patients after 3 days in the ICU and remained significantly lower through 10 days (P < .001). 25(OH)D status was not significantly associated with 28-day all-cause mortality (hazard ratio [HR], 0.89; 95% confidence interval, [CI] 0.37-2.24). Higher levels of 25(OH)D were associated with a shorter time-to-alive ICU discharge (HR, 2.11; 95% CI, 1.27-3.51). 25(OH)D-deficient patients showed a nonstatistically significant trend toward a higher infection rate (odds ratio [OR], 3.20; 95% CI, 0.784-13.07; P = .11) compared with patients with sufficient levels of 25(OH)D.

CONCLUSIONS

This study demonstrates significant decreases in vitamin D status over the duration of the patient's ICU stay. Low levels of vitamin D are associated with longer time to ICU discharge alive and a trend toward increased risk of ICU-acquired infection.

Cationic host defence peptides: multifaceted role in immune modulation and inflammation

Host defence peptides (HDPs) are innate immune effector molecules found in diverse species. HDPs exhibit a wide range of functions ranging from direct antimicrobial properties to immunomodulatory effects. Research in the last decade has demonstrated that HDPs are critical effectors of both innate and adaptive immunity. Various studies have hypothesized that the antimicrobial property of certain HDPs may be largely due to their immunomodulatory functions. Mechanistic studies revealed that the role of HDPs in immunity is very complex and involves various receptors, signalling pathways and transcription factors. This review will focus on the multiple functions of HDPs in immunity and inflammation, with special reference to cathelicidins, e.g. LL-37, certain defensins and novel synthetic innate defence regulator peptides. We also discuss emerging concepts of specific HDPs in immune-mediated inflammatory diseases, including the potential use of cationic peptides as therapeutics for immune-mediated inflammatory disorders.

An update on vitamin D and human immunity

In the last 5 years, there has been a remarkable change in our understanding of the health benefits of vitamin D. The classical actions of vitamin D as a determinant of mineral metabolism and rachitic bone disease have been expanded to include a broader role in skeletal homoeostasis and prevalent bone disorders such as osteoporosis. However, it is the nonskeletal function of vitamin D that has attracted most attention. Although pluripotent responses to vitamin D have been recognized for many years, our new perspective on nonclassical vitamin D function stems from two more recent concepts. The first is that impaired, vitamin D status is common to many populations across the globe. This has prompted studies to explore the health impact of suboptimal circulating levels of vitamin D, with association studies linking vitamin D 'insufficiency' to several chronic health problems including autoimmune and cardiovascular disease, hypertension and common cancers. In support of a broader role for vitamin D in human health, studies in vitro and using animal models have highlighted immunomodulatory and anticancer effects of vitamin D that appear to depend on localized activation of vitamin D. The conclusion from these reports is that many nonclassical actions of vitamin D are independent of conventional vitamin D endocrinology and are therefore more sensitive to variations in vitamin D status. The current review summarizes these developments, with specific reference to the newly identified effects of vitamin D on the immune system, but also highlights the challenges in translating these observations to clinical practice.

Accuracy of 6 Routine 25-Hydroxyvitamin D Assays: Influence of Vitamin D Binding Protein Concentration

BACKGROUND

Recent recognition of its broad pathophysiological importance has triggered an increased interest in 25-hydroxyvitamin D [25(OH)D]. By consequence, throughput in 25(OH)D testing has become an issue for clinical laboratories, and several automated assays for measurement of 25(OH)D are now available. The aim of this study was to test the accuracy and robustness of these assays by comparing their results to those of an isotope dilution/online solid-phase extraction liquid chromatography/tandem mass spectrometry (ID-XLC-MS/MS) method. We put specific focus on the influence of vitamin D–binding protein (DBP) by using samples with various concentrations of DBP.

METHODS

We used 5 automated assays (Architect, Centaur, iSYS, Liaison, and Elecsys), 1 RIA (Diasorin) preceded by extraction, and an ID-XLC-MS/MS method to measure 25(OH)D concentrations in plasma samples of 51 healthy individuals, 52 pregnant women, 50 hemodialysis patients, and 50 intensive care patients. Using ELISA, we also measured DBP concentrations in these samples.

RESULTS

Most of the examined 25(OH)D assays showed significant deviations in 25(OH)D concentrations from those of the ID-XLC-MS/MS method. As expected, DBP concentrations were higher in samples of pregnant women and lower in samples of IC patients compared to healthy controls. In 4 of the 5 fully automated 25(OH)D assays, we observed an inverse relationship between DBP concentrations and deviations from the ID-XLC-MS/MS results.

CONCLUSIONS

25(OH)D measurements performed with most immunoassays suffer from inaccuracies that are DBP concentration dependent. Therefore, when interpreting results of 25(OH)D measurements, careful consideration of the measurement method is necessary.

Vitamin D and the critically ill patient

PURPOSE OF REVIEW

To summarize the current knowledge on vitamin D with a special focus on critically ill patients.

RECENT FINDINGS

Vitamin D deficiency is associated with adverse health outcomes including increased risk of cardiovascular disease, morbidity and mortality in the general population. In critically ill patients, the pleiotropic effects of vitamin D including its role in immune function are of great interest.

SUMMARY

To date, it is not clear whether vitamin D deficiency is a surrogate marker for increased morbidity or whether treatment with sufficiently large doses of vitamin D may improve patient outcome in an intensive care setting.

Hypocalcemia and hypovitaminosis D in dogs with induced endotoxemia

BACKGROUND

Hypocalcemia is a documented electrolyte disturbance in people and animals with sepsis, but its mechanism is poorly understood.

OBJECTIVE

To investigate mechanisms of hypocalcemia in dogs with experimentally induced endotoxemia.

ANIMALS

Six healthy mixed breed dogs were included in this nonrandomized, placebo-controlled, crossover study.

METHODS

Dogs initially were injected with placebo (0.9% NaCl; 1 mL, IV) and then lipopolysaccharide (LPS; 2 μg/kg, IV) after a 5-day washout period. Blood and urine samples were collected for measurement of serum total calcium (tCa), ionized calcium (iCa), total magnesium (tMg), ionized magnesium (iMg), parathyroid hormone (PTH), 25-hydroxyvitamin D (vitamin D), venous blood gases, and fractional excretion (FE) of calcium.

RESULTS

After LPS administration, body temperature increased and blood pressure decreased. Both iCa and tCa decreased (P < .01), but iMg was not significantly different between control and LPS treatments. PTH concentrations increased (P < .01) and vitamin D concentrations decreased (P < .01). Venous pH, bicarbonate, base excess, and blood glucose also decreased (P < .01). Urine tCa concentration was below the limit of detection for all dogs after LPS administration.

CONCLUSIONS

Hypocalcemia occurs during endotoxemia in dogs and is associated with hypovitaminosis D. Hypomagnesemia, hypoparathyroidism, alkalosis, and increased calciuresis are not associated with hypocalcemia in endotoxemic dogs.

Age and low levels of circulating vitamin D are associated with impaired innate immune function

This study investigated in vivo the influence of age and vitamin D status on innate immune function in HC. Serum 25OHD was measured in 71 HC. TLR expression on various subpopulations of PBMCs, as well as TLR function by stimulating PBMCs with specific ligands, was assessed by flow cytometry. Circulating cathelicidin levels were determined by ELISA. Serum 25OHD levels decreased with age, and there was a significant inverse correlation between 25OHD levels and age. There was a negative correlation between serum 25OHD levels and MFI expression of TLR7 on B cells, T cells, and monocytes. TLR7 function, addressed by in vitro stimulation with a specific agonist, was significantly correlated with serum 25OHD levels, and this was especially a result of the results in HC older than 60 years. MFI expression of TLR5 on T cells and TLR2 on monocytes was also negatively correlated with serum 25OHD levels. TLR1 (monocytes) and TLR2 (monocytes) expression was positively correlated with age. Furthermore, TLR4 and TLR8 function was negatively correlated with age. Circulating cathelicidin levels decreased with age and were positively correlated with 25OHD levels. Aging is accompanied by changes in expression and function of several TLRs. Serum 25OHD levels decrease with age and are also associated with a change in expression and defective function of certain TLRs, especially those involved in viral response.

Low serum 25-hydroxyvitamin D at critical care initiation is associated with increased mortality

OBJECTIVE

We hypothesized that deficiency in 25-hydroxyvitamin D at critical care initiation would be associated with all-cause mortalities.

DESIGN

Two-center observational study.

SETTING

Two teaching hospitals in Boston, MA.

PATIENTS

The study included 1,325 patients, age ≥ 18 yrs, in whom 25-hydroxyvitamin D was measured 7 days before or after critical care initiation between 1998 and 2009.

MEASUREMENTS

25-hydroxyvitamin D was categorized as deficiency in 25-hydroxyvitamin D (≤ 15 ng/mL), insufficiency (16-29 ng/mL), and sufficiency (≥ 30 ng/mL). Logistic regression examined death by days 30, 90, and 365 postcritical care initiation and in-hospital mortality. Adjusted odds ratios were estimated by multivariable logistic regression models.

INTERVENTIONS

None.

KEY RESULTS

25-hydroxyvitamin D deficiency is predictive for short-term and long-term mortality. Thirty days following critical care initiation, patients with 25-hydroxyvitamin D deficiency have an odds ratio for mortality of 1.85 (95% confidence interval 1.15-2.98; p = .01) relative to patients with 25-hydroxyvitamin D sufficiency. 25-hydroxyvitamin D deficiency remains a significant predictor of mortality at 30 days following critical care initiation following multivariable adjustment for age, gender, race, Deyo-Charlson index, sepsis, season, and surgical vs. medical patient type (adjusted odds ratio 1.94; 95% confidence interval 1.18-3.20; p = .01). Results were similarly significant at 90 and 365 days following critical care initiation and for in-hospital mortality. The association between vitamin D and mortality was not modified by sepsis, race, or neighborhood poverty rate, a proxy for socioeconomic status.

CONCLUSION

Deficiency of 25-hydroxyvitamin D at the time of critical care initiation is a significant predictor of all-cause patient mortality in a critically ill patient population.

Worsening severity of vitamin D deficiency is associated with increased length of stay, surgical intensive care unit cost, and mortality rate in surgical intensive care unit patients

BACKGROUND

Vitamin D deficiency is the most common nutritional deficiency in the United States. It is seldom measured or recognized, and rarely is treated, particularly in critically ill patients. The purpose of this study was to investigate the prevalence and impact of vitamin D deficiency in surgical intensive care unit patients. We hypothesized that severe vitamin D deficiency increases the length of stay, mortality rate, and cost in critically ill patients admitted to surgical intensive care units.

METHODS

We performed a prospective observational study of vitamin D status on 258 consecutive patients admitted to the Surgical Intensive Care Unit at Grady Memorial Hospital between August 2009 and January 2010. Vitamin D levels (25 [OH]2 vitamin-D3) were measured by high-pressure liquid chromatography and tandem mass spectrometry. Vitamin D deficiency was defined as follows: severe deficiency was categorized as less than 13 ng/mL; moderate deficiency was categorized as 14 to 26 ng/mL; mild deficiency was categorized as 27 to 39 ng/mL; and normal levels were categorized as greater than 40 ng/mL.

RESULTS

Of the 258 patients evaluated, 70.2% (181) were men, and 29.8% (77) were women; 57.6% (148) were African American and 32.4% (109) were Caucasian. A total of 138 (53.5%) patients had severe vitamin D deficiency, 96 (37.2%) had moderate deficiency, 18 (7.0%) had mild deficiency, and 3 (1.2%) of the patients had normal vitamin D levels. The mean length of stay in the Surgical Intensive Care Unit for the severe vitamin D-deficient group was 13.33 ± 19.5 days versus 7.29 ± 15.3 days and 5.17 ± 6.5 days for the moderate and mild vitamin D-deficient groups, respectively, which was clinically significant (P = .002). The mean treatment cost during the patient stay in the surgical intensive care unit was $51,413.33 ± $75,123.00 for the severe vitamin D-deficient group, $28,123.65 ± $59,752.00 for the moderate group, and $20,414.11 ± $25,714.30 for the mild vitamin D-deficient group, which also was clinically significant (P = .027). More importantly, the mortality rate for the severe vitamin D-deficient group was 17 (12.3%) versus 11 (11.5%) in the moderate group (P = .125). Because no deaths occurred in the mildly or normal vitamin D-deficient groups, we compared the mortality rate between severe/moderate and mild/normal vitamin D groups (P = .047).

CONCLUSIONS

In univariate analysis, severe and moderate vitamin D deficiency was related inversely to the length of stay in the surgical intensive care unit (r = .194; P = .001), related inversely to surgical intensive care unit treatment cost (r = .194; P = .001) and mortality (r = .125; P = .023), compared with the mild vitamin D-deficient group, after adjusting for age, sex, race, and comorbidities (myocardial infarctions, acute renal failure, and pneumonia); the length of stay, surgical intensive care unit cost, and mortality remained significantly associated with vitamin D deficiency.

Translating the role of vitamin D3 in infectious diseases

Vitamin D(3) affects both the innate as well as adaptive immune responses. Epidemiological studies have established that vitamin D(3) deficiency plays an important role in tuberculosis (TB) and viral influenza prevalence as well as susceptibility to active disease in TB. Vitamin D(3) status has been associated with the clinical course of HIV infection and drug interaction with anti-retroviral therapy. This article reviews the immunomodulatory capacity of vitamin D(3) and examines the impact of vitamin D(3) supplementation as a preventive or therapeutic intervention with the intent to uncover its potential therapeutic application in infectious diseases and to identify novel areas for future research. We present a review of randomized, controlled clinical studies conducted in humans which included assessment of the immune function or clinical outcome as study end points. Current data support vitamin D(3) supplementation as risk-modifying intervention in tuberculosis and viral respiratory tract infection, but the optimal dosage regimen remains to be determined. However, to date the knowledge on its role in fungal infection and sepsis is limited although a potential benefit could be harnessed from its ability to curtail the unrestrained pro-inflammatory response and therefore prevent excessive collateral tissue damage.