Violation of the Constant Genetic Effect Assumption Can Result in Biased Estimates for Non-Linear Mendelian Randomization.

INTRODUCTION: Non-linear Mendelian randomization is an extension of conventional Mendelian randomization that performs separate instrumental variable analyses in strata of the study population with different average levels of the exposure. The approach estimates a localized average causal effect function, representing the average causal effect of the exposure on the outcome at different levels of the exposure. The commonly used residual method for dividing the population into strata works under the assumption that the effect of the genetic instrument on the exposure is linear and constant in the study population. However, this assumption may not hold in practice. METHODS: We use the recently developed doubly ranked method to re-analyse various datasets previously analysed using the residual method. In particular, we consider a genetic score for 25-hydroxyvitamin D (25[OH]D) used in a recent non-linear Mendelian randomization analysis to assess the potential effect of vitamin D supplementation on all-cause mortality. RESULTS: The effect of the genetic score on 25(OH)D concentrations varies strongly, with a five-fold difference in the estimated genetic association with the exposure in the lowest and highest decile groups. Evidence for a protective causal effect of vitamin D supplementation on all-cause mortality in low vitamin D individuals is evident for the residual method but not for the doubly ranked method. We show that the constant genetic effect assumption is more reasonable for some exposures and less reasonable for others. If the doubly ranked method indicates that this assumption is violated, then estimates from both the residual and doubly ranked methods can be biased, although bias was smaller on average in the doubly ranked method. CONCLUSION: Analysts wanting to perform non-linear Mendelian randomization should compare results from both the residual and doubly ranked methods, as well as consider transforming the exposure for the residual method to reduce heterogeneity in the genetic effect on the exposure.

Vitamin D supplementation prior to or during COVID-19 associated with better 3-month survival in geriatric patients: Extension phase of the GERIA-COVID study.

BACKGROUND: The objective of this extension phase of the quasi-experimental GERIA-COVID study was to determine whether vitamin D3 supplementation taken prior to or during COVID-19 was associated with better 3-month survival in geriatric patients hospitalized for COVID-19. METHODS: Intervention group was defined as all participants supplemented with vitamin D3 prior to or during COVID-19 (n = 67). Supplements were either bolus vitamin D3 (ie, 50,000 IU per month, or 80,000 IU or 100,000 IU or 200,000 IU every 2-3 months), or daily supplementation with 800 IU. Comparator group involved those without vitamin D supplements (n = 28). Outcome was 3-month mortality. Covariables were age, sex, functional abilities, history of malignancies, cardiomyopathy, undernutrition, number of acute health issues, antibiotics use, systemic corticosteroids use, and 25(OH)D concentration. RESULTS: 76.1 % (n = 51) of participants survived at 3 months in Intervention group, compared to only 53.6 % (n = 15) in Comparator group (P = 0.03). The fully-adjusted hazard ratio for 3-month mortality was HR = 0.23 [95 %CI: 0.09;0.58](P = 0.002) in Intervention group compared to Comparator group. Intervention group had also longer survival time (log-rank P = 0.008). CONCLUSIONS: Vitamin D3 supplementation was associated with better 3-month survival in older COVID-19 patients.

Therapeutic and prognostic role of vitamin D for COVID-19 infection: A systematic review and meta-analysis of 43 observational studies.

Vitamin D modulates the systemic inflammatory response through interaction with immune system. As such, it has a possible protective role against the risk of respiratory tract infections and other diseases. It may be useful in particular, during COVID-19 pandemic. PubMed, the Cochrane Library, and EMBASE were searched from inception until January 31, 2021, for observational or clinical studies reporting the prognosis (and therapeutic effect) of COVID-19 infection in patients with deficient vitamin D levels. The infection rate, severity, and death from COVID-19 infection were pooled to provide an odds ratio with a 95 % confidence interval (OR 95 % CI). An OR > 1 was associated with the worst outcome in deficient compared with nondeficient patients. We assessed the association between vitamin D and risk, severity, and mortality for COVID-19 infection, through a review of 43 observational studies. Among subjects with deficient vitamin D values, risk of COVID-19 infection was higher compared to those with replete values (OR = 1.26; 95 % CI, 1.19-1.34; P < .01). Vitamin D deficiency was also associated with worse severity and higher mortality than in nondeficient patients (OR = 2.6; 95 % CI, 1.84-3.67; P < .01 and OR = 1.22; 95 % CI, 1.04-1.43; P < .01, respectively). Reduced vitamin D values resulted in a higher infection risk, mortality and severity COVID-19 infection. Supplementation may be considered as preventive and therapeutic measure.

Vitamin D Deficiency and Low Serum Calcium as Predictors of Poor Prognosis in Patients with Severe COVID-19.

BACKGROUND: The severity of Coronavirus Disease 2019 (COVID-19) is a multifactorial condition. An increasing body of evidence argues for a direct implication of vitamin D deficiency, low serum calcium on poor outcomes in COVID-19 patients. This study was designed to investigate the relationship between these two factors and COVID-19 in-hospital mortality. MATERIALS: This is a prospective study, including 120 severe cases of COVID-19, admitted at the department of Reanimation-Anesthesia. Vitamin D was assessed by an immuno-fluoroassay method. Total serum calcium by a colorimetric method, then, corrected for serum albumin levels. The association with in-hospital mortality was assessed using the Kaplan-Meier survival curve, proportional Cox regression analyses and the receiver operating characteristic curve. RESULTS: Hypovitaminosis D and hypocalcemia were very common, occurring in 75% and 35.8% of patients. When analyzing survival, both were significantly associated with in-hospital mortality in a dose-effect manner (pLog-Rank = 0.009 and 0.001 respectively). A cutoff value of 39 nmol/l for vitamin D and 2.05 mmol/l for corrected calcemia could predict poor prognosis with a sensitivity of 76% and 84%, and a specificity of 69% and 60% respectively. Hazard ratios were (HR = 6.9, 95% CI [2.0-24.1], p = 0.002 and HR = 6.2, 95% CI [2.1-18.3], p = 0.001) respectively. CONCLUSION: This study demonstrates the high frequency of hypocalcemia and hypovitaminosis D in severe COVID-19 patients and provides further evidence of their potential link to poor short-term prognosis. It is, therefore, possible that the correction of hypocalcemia, as well as supplementation with vitamin D, may improve the vital prognosis.

Association Between Vitamin D Deficiency and COVID-19 Incidence, Complications, and Mortality in 46 Countries: An Ecological Study.

Each patient's immune defenses play a major role in mitigating the impact (ie, morbidity and mortality) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for coronavirus disease 2019 (COVID-19). Vitamin D is an important modulator of the immune system. Although serum 25-hydroxyvitamin D levels can be raised through diet or supplements, most vitamin D in the body is the result of dermal synthesis from ultraviolet radiation. The production of vitamin D in the skin, however, can be limited by latitude, skin-covering clothes, the use of sunblock, and skin pigmentation. Vitamin D deficiency affects a high percentage of the world population. Serum 25-hydroxyvitamin D levels are suboptimal, not only in specific risk groups but also in adults from many countries. Low vitamin D levels, therefore, represent a risk factor for several different pathologies, including SAR-CoV-2. This study used an ecological design to assess the association between vitamin D deficiency and COVID-19 incidence, complications, and mortality across 46 countries. All data were obtained from published sources. The results of the study suggest an association at the population level between the prevalence of vitamin D deficiency and the risk of being infected with COVID-19, severity of the disease, and risk of dying from it.

Vitamin D Status in Hospitalized Patients with SARS-CoV-2 Infection.

BACKGROUND: The role of vitamin D status in COVID-19 patients is a matter of debate. OBJECTIVES: To assess serum 25-hydroxyvitamin D (25OHD) levels in hospitalized patients with COVID-19 and to analyze the possible influence of vitamin D status on disease severity. METHODS: Retrospective case-control study of 216 COVID-19 patients and 197 population-based controls. Serum 25OHD levels were measured in both groups. The association of serum 25OHD levels with COVID-19 severity (admission to the intensive care unit, requirements for mechanical ventilation, or mortality) was also evaluated. RESULTS: Of the 216 patients, 19 were on vitamin D supplements and were analyzed separately. In COVID-19 patients, mean ±â€…standard deviation 25OHD levels were 13.8 ±â€…7.2 ng/mL, compared with 20.9 ±â€…7.4 ng/mL in controls (P < .0001). 25OHD values were lower in men than in women. Vitamin D deficiency was found in 82.2% of COVID-19 cases and 47.2% of population-based controls (P < .0001). 25OHD inversely correlates with serum ferritin (P = .013) and D-dimer levels (P = .027). Vitamin D-deficient COVID-19 patients had a greater prevalence of hypertension and cardiovascular diseases, raised serum ferritin and troponin levels, as well as a longer length of hospital stay than those with serum 25OHD levels ≥20 ng/mL. No causal relationship was found between vitamin D deficiency and COVID-19 severity as a combined endpoint or as its separate components. CONCLUSIONS: 25OHD levels are lower in hospitalized COVID-19 patients than in population-based controls and these patients had a higher prevalence of deficiency. We did not find any relationship between vitamin D concentrations or vitamin deficiency and the severity of the disease.

Is There a Crucial Link Between Vitamin D Status and Inflammatory Response in Patients With COVID-19?

Background: Hypovitaminosis D has been suggested to play a possible role in coronavirus disease 2019 (COVID-19) infection. Methods: The aim of this study is to analyze the relationship between vitamin D status and a biochemical panel of inflammatory markers in a cohort of patients with COVID-19. A secondary endpoint was to evaluate the correlation between 25OHD levels and the severity of the disease. Ninety-three consecutive patients with COVID-19-related pneumonia were evaluated from March to May 2020 in two hospital units in Pisa, in whom biochemical inflammatory markers, 25OHD levels, P/F ratio at nadir during hospitalization, and complete clinical data were available. Results: Sixty-five percent of patients presented hypovitaminosis D (25OHD ≤ 20 ng/ml) and showed significantly higher IL-6 [20.8 (10.9-45.6) vs. 12.9 (8.7-21.1) pg/ml, p = 0.02], CRP [10.7 (4.2-19.2) vs. 5.9 (1.6-8.1) mg/dl, p = 0.003], TNF-α [8.9 (6.0-14.8) vs. 4.4 (1.5-10.6) pg/ml, p = 0.01], D-dimer [0.53 (0.25-0.72) vs. 0.22 (0.17-0.35) mg/l, p = 0.002], and IL-10 [3.7 (1.8-6.9) vs. 2.3 (0.5-5.8) pg/ml, p = 0.03]. A significant inverse correlation was found between 25OHD and all these markers, even adjusted for age and sex. Hypovitaminosis D was prevalent in patients with severe ARDS, compared with the other groups (75% vs. 68% vs. 55%, p < 0.001), and 25OHD levels were lower in non-survivor patients. Conclusions: The relationship between 25OHD levels and inflammatory markers suggests that vitamin D status needs to be taken into account in the management of these patients. If vitamin D is a marker of poor prognosis or a possible risk factor with beneficial effects from supplementation, this still needs to be elucidated.

Outcomes of Clostridioides difficile in Patients with Vitamin D Deficiency: A Propensity-Matched National Inpatient Sample Analysis.

OBJECTIVES: We aimed to determine in-hospital outcomes, length of hospital stay, and resource utilization in a contemporary cohort of Clostridioides difficile infection (CDI) and vitamin D deficiency (VDD). METHODS: The National Inpatient Sample database for 2016 and 2017 was used for data analysis using International Classification of Diseases, Tenth Revision, Clinical Modification/Procedure Coding System (ICD-10-CM/PCS) codes to identify the patients with the principal diagnosis of CDI and VDD. We assessed the all-cause in-hospital mortality, morbidity, length of hospital stay (LOS), and total costs between propensity-matched groups of CDI without VDD versus CDI with VDD. RESULTS: We identified 202,234 patients with CDI, 4515 of whom were patients with VDD and 197,719 of whom were without VDD. After propensity matching, there was no difference in the in-hospital mortality between the two groups (odds ratio [OR] 1.5, 95% confidence interval [CI] 0.58-4.3; P = 0.90). CDI with VDD has a higher odds of sepsis (OR 1.6, 95% CI 1.3-1.9; P = 0.0), and peritonitis (OR 1.6, 95% CI 1.4-3.8; P = 0.01). Mean LOS (5.9 ± 1.8 vs 5.4 ± 2, P < 0.01) and mean total charges ($11,500 vs $9971, P < 0.04) were higher in CDI with VDD. The factors affecting the LOS were acute coronary syndrome (P = 0.04), mechanical ventilation (P = 0.03), obesity (P = 0.004), acute kidney injury (P = 0.04), and sepsis (P = 0.05). CONCLUSIONS: In this large cohort in a propensity-matched analysis, VDD does not increase the in-hospital mortality in CDI. VDD increases the odds of complications with a higher LOS and resource utilization. These findings may be clinically relevant to guide clinicians to routinely monitor vitamin D status and supplement in patients at risk of CDI.

Vitamin D Deficiency and Outcome of COVID-19 Patients.

Infection with the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) poses an enormous challenge to health care systems throughout the world. Without causal treatment, identification of modifiable prognostic factors may help to improve outcomes. To explore possible associations of vitamin D (VitD) status with disease severity and survival, we studied 185 patients diagnosed with coronavirus disease 2019 (COVID-19) and treated at our center. VitD status at first presentation was assessed retrospectively using accredited laboratory methods. VitD deficiency was defined as serum total 25-hydroxyvitamin D level < 12 ng/mL (<30 nM). Primary endpoint was severe course of disease (i.e., need for invasive mechanical ventilation and/or death, IMV/D). Within a median observation period of 66 days (range 2-92), 23 patients required IMV. A total of 28 patients had IMV/D, including 16 deaths. Ninety-three (50%) patients required hospitalization (inpatient subgroup). A total of 41 (22%) patients were VitD deficient. When adjusted for age, gender, and comorbidities, VitD deficiency was associated with higher risk of IMV/D and death (HR 6.12, 95% CI 2.79-13.42, p < 0.001 and HR 14.73, 95% CI 4.16-52.19, p < 0.001, respectively). Similar correlations were observed in the inpatient subgroup. Our study demonstrates an association between VitD deficiency and severity/mortality of COVID-19, highlighting the need for interventional studies on VitD supplementation in SARS-CoV-2 infected individuals.

Vitamin D levels condition the outcome benefits of renin-angiotensin system inhibitors (RASI) among patients undergoing percutaneous coronary intervention.

BACKGROUND: Vitamin D deficiency is estimated as the most common medical condition worldwide, with severe implications on survival and on several inflammatory, immune-mediated and thrombotic disorders, and especially for cardiovascular disease. Recent studies have suggested that vitamin D could directly regulate the Renin-Angiotensin System (RAS) activity, therefore potentially interfering with the pharmacological effects of RAS Inhibitors (RASI), an issue that has seldom been explored. Therefore, the aim of the present study was to evaluate the prognostic impact of the use of RASI according to vitamin D levels among patients with coronary artery disease (CAD) undergoing percutaneous coronary intervention (PCI). METHODS: Consecutive patients undergoing PCI were included. Main clinical features and chemistry parameters were assessed at admission. Vitamin D levels were measured by chemiluminescence immunoassay kit LIAISON® Vitamin D assay (Diasorin Inc). Severe deficiency was defined for 25(OH)D < 10 ng/mL. The primary study endpoint was defined as the occurrence of major cardiovascular events (MACE, a composite of death, recurrent Myocardial Infarction (MI) and target vessel revascularization) at the longest available follow-up. RESULTS: We included a total of 705 patients, that were divided according to vitamin D tertiles (< 12.7 ng/mL; 12.7-21.59 ng/mL; ≥21.6 ng/mL) and use of RASI. RASI therapy was significantly associated to arterial hypertension, creatinine, lower 25(OH)D, use of statins, diuretics, ASA and ticagrelor across vitamin D tertiles. At a median follow-up of 996 [377-1552] days, MACE occurred in 174 (24.7 %) patients. Severe hypovitaminosis D was significantly associated with a higher rate of MACE (HR[95 %CI] = 0.75[0.62-0.91], p = 0.004). The use of RASI significantly lowered the rate of MACE in patients with lower vitamin D (I tertile: 41.3 % vs 25.9 %, adjusted HR[95 %CI] = 0.43[0.26-0.73], p = 0.002); whilst a non-significant effect was observed for II and III tertiles values (18.6 %vs 29.5 %, adjusted HR[95 %CI] = 1.16[0.57-2.34], p = 0.69, and 21.2 % vs 12.6 %, adjusted HR[95 %CI] = 1.1[0.46-2.62], p = 0.83) (p int = 0.04). A similar prognostic interaction for RASI and vitamin D was observed for cardiovascular mortality and MI (p int = 0.03). CONCLUSION: Among patients undergoing PCI, the use of RASI was associated with lower risk of MACE only among patients with lower levels of vitamin D. Future larger studies are certainly warranted in order to define the prognostic implications of vitamin D supplementation on the RAS system modulation, especially among patients treated with RASI.

Vitamin D Insufficiency and Deficiency and Mortality from Respiratory Diseases in a Cohort of Older Adults: Potential for Limiting the Death Toll during and beyond the COVID-19 Pandemic?

The COVID-19 pandemic goes along with increased mortality from acute respiratory disease. It has been suggested that vitamin D3 supplementation might help to reduce respiratory disease mortality. We assessed the prevalence of vitamin D insufficiency and deficiency, defined by 25-hydroxyvitamin D (25(OH)D) blood levels of 30-50 and <30 nmol/L, respectively, and their association with mortality from respiratory diseases during 15 years of follow-up in a cohort of 9548 adults aged 50-75 years from Saarland, Germany. Vitamin D insufficiency and deficiency were common (44% and 15%, respectively). Compared to those with sufficient vitamin D status, participants with vitamin D insufficiency and deficiency had strongly increased respiratory mortality, with adjusted hazard ratios (95% confidence intervals) of 2.1 (1.3-3.2) and 3.0 (1.8-5.2) overall, 4.3 (1.3-14.4) and 8.5 (2.4-30.1) among women, and 1.9 (1.1-3.2) and 2.3 (1.1-4.4) among men. Overall, 41% (95% confidence interval: 20-58%) of respiratory disease mortality was statistically attributable to vitamin D insufficiency or deficiency. Vitamin D insufficiency and deficiency are common and account for a large proportion of respiratory disease mortality in older adults, supporting the hypothesis that vitamin D3 supplementation could be helpful to limit the burden of the COVID-19 pandemic, particularly among women.

COVID-19 fatalities, latitude, sunlight, and vitamin D.

BACKGROUND: Since Vitamin D is known to be vital in regulating the immune system, and sunlight UV radiation exposure on the skin produces Vitamin D and UV intensity is highest nearest the equator, a study was done to examine the correlation between the latitude and COVID-19 fatality rates for countries. METHODS: Eighty-eight countries were selected based on their likelihood of providing reliable data. Using death rates/million for each country from the "worldometer" website, a correlation analysis was done between death rates and a country's latitude. RESULTS: A highly significant, positive correlation was found between lower death rates and a country's proximity to the equator (Pearson r = 0.40 P < .0001, 2-tailed t test). The R squared of 0.16 means that 16% of the variation in death rates among nations is accounted for by the latitude of the country. Evidence is presented suggesting a direct correlation between sunlight exposure and reduced mortality. DISCUSSION: This study is the first to document a statistically significant correlation between a country's latitude and its COVID-19 mortality and is consistent with other research regarding latitude, Vitamin D deficiency, and COVID-19 fatalities. Limitations of this study are noted. CONCLUSIONS: Further research is needed to confirm the correlation between latitude and COVID-19 fatalities, and to determine the optimum amounts of safe sunlight exposure and/or vitamin D oral supplementation to reduce COVID-19 fatalities in populations that are at high risk for vitamin D deficiency.

Low Vitamin D Levels Predict Mortality in Ankylosing Spondylitis Patients: A Nationwide Population-Based Cohort Study.

In this study, we aimed to examine the effect of vitamin D deficiency on all-cause mortality in ankylosing spondylitis (AS) patients and in the general population. This is a retrospective-cohort study based on the electronic database of the largest health-maintenance organization in Israel. AS patients who were first diagnosed between 2002-2007 were included. Controls were matched by age, gender and enrollment-time. Follow-up continued until death or end of study follow-up on 1 July 2019. Laboratory measures of serum 25-hydroxyvitamin-D levels during the entire follow-up period were obtained. A total of 919 AS patients and 4519 controls with a mean time of follow-up of 14.3 years were included. The mean age at the time of enrollment was 52 years, and 22% of them were females. AS was associated with a higher proportion of vitamin D deficiency (odds ratio 1.27 [95% confidence-interval (CI) 1.03-1.58]). In AS patients, insufficient levels of vitamin D (< 30 ng/mL) were significantly associated with increased incidence of all-cause mortality (hazard ratio (HR) 1.59 [95% CI 1.02-2.50]). This association was more prominent with the decrease in vitamin D levels (< 20 ng/mL, HR 1.63 [95% CI 1.03-2.60]; <10 ng/mL, HR 1.79 [95% CI 1.01-3.20]) and among male patients (< 30 ng/mL, HR 2.11 [95% CI 1.20-3.72]; <20 ng/mL, HR 2.12 [95% CI 1.19-3.80]; <10 ng/mL, HR 2.23 [95% CI 1.12-4.43]). However, inadequate levels of vitamin D among controls were not associated with an increased all-cause mortality. Our study has shown that vitamin D deficiency is more common in AS patients than controls and is linked to an increased risk for all-cause mortality. These results emphasize the need for randomized-controlled trials to evaluate the benefits of vitamin D supplementation as a secondary prevention of mortality in patients with chronic inflammatory rheumatic disease.

The effect of physical activity on dose-relationship between serum 25-hydroxyvitamin D and cardiovascular health events in older adults.

BACKGROUND AND AIMS: Reverse J- or U-shaped associations between serum 25-hydroxyvitamin D (25[OH]D) concentrations and cardiovascular outcomes have been reported, which need clarifications in older adults. Physical activity, correlating with both serum 25[OH]D concentration and cardiovascular health, may have an effect on the dose-relationships. METHODS AND RESULTS: At baseline, 2790 participants aged 65 years and over, free of vitamin D supplementation use, had assays for serum 25[OH]D concentrations and health related characteristics and measurements, were followed up for cardiovascular events and death by up to 7 and 15 years, respectively. The dose-response associations of serum 25[OH]D concentrations with cardiovascular events and mortality risk were examined using Cox regression models. After adjusting for physical activity and other covariates, serum 25[OH]D concentration was non-linearly associated with cardiovascular mortality risk (U-shaped, P = 0.009). According to the Institute of Medicine categories, the HR(95% CI) of cardiovascular mortality risk separately in deficient (<25 nmol/L), inadequate (25 to < 50 nmol/L) and potentially harmful (≥125 nmol/L) level was 1.67 (0.23, 12.01), 1.66 (1.25, 2.20) and 2.21 (0.30, 16.37), respectively. The risk of 25[OH]D inadequacy for cardiovascular mortality was significantly attenuated by increased physical activity, especially leisure activity (P for trend = 0.008 and 0.021, respectively). No significant finding was observed for incident cardiovascular events. CONCLUSION: Both lower and higher serum 25[OH]D concentrations were associated with risk of cardiovascular mortality in Chinese community-dwelling older adults. Physical activity may attenuate the cardiovascular mortality risk of vitamin D inadequacy, but its role in individuals with higher 25[OH]D concentrations remains unclear.

Vitamin D Deficiency Is Highly Prevalent in Critically Ill Patients and a Risk Factor for Mortality: A Prospective Observational Study Comparing Noncirrhotic Patients and Patients With Cirrhosis.

INTRODUCTION: A 25-hydroxyvitamin D, 25(OH)D, deficiency is common among critically ill patients and correlated with increased mortality. Furthermore, deficiency is associated with advanced liver disease. However, there are no studies available comparing the dimensions and consequences of a 25(OH)D deficiency between patients with and without liver cirrhosis in the setting of intensive care units (ICUs). This study focuses on differences in 25(OH)D status between critically ill noncirrhosis patients and patients with cirrhosis (primary end point), hypothesizing that deficiency and its impact on mortality risk are even more pronounced in patients with cirrhosis. METHODS: We performed a prospective observational study of 176 patients (noncirrhosis patients, N = 114; patients with cirrhosis, N = 62) with a laboratory assessment of 25(OH)D on ICU admission and survival analyses after 180 days. RESULTS: On admission, 55% of patients showed a severe deficiency, 25(OH)D <10 ng/mL, and a further 23% moderate deficiency (10-19 ng/mL). The overall median level of 25(OH)D was 8.0 (5.0-18.0) ng/mL (10.5 [6.0-21.3] in noncirrhosis patients vs 7.0 [4.8-10.0] in patients with cirrhosis; P < .001). We found extremely low levels particularly in patients without prior vitamin D supplementation (6.0 [4.0-7.5] in patients with cirrhosis vs 8.0 [5.0-12.0] ng/mL in noncirrhosis patients; P = .004). Vitamin D status correlated inversely with the sequential organ failure assessment, acute and physiology chronic health evaluation, model of end-stage liver disease, and Child-Pugh scores. Survival analyses categorized 25(OH)D levels <10 ng/mL as a high-risk factor for mortality 180 days after admission (hazard ratio [HR]: 2.45, 95% confidence interval [CI] = 1.60-3.70; P < .001). In patients with cirrhosis, a severe deficiency (<10 ng/mL) involved a significantly higher mortality risk than in noncirrhosis patients (HR: 2.30, 95% CI = 1.39-3.82; P = .001). In cases of admission levels ≥10 ng/mL, however, mortality risk was similar between patients with cirrhosis and noncirrhosis patients (HR: 1.08, 95% CI = 0.43-2.73; P = .873). CONCLUSIONS: Hypovitaminosis D is a highly frequent disorder in critically ill patients admitted to ICU. A severe deficiency with levels <10 ng/mL is a high risk factor for increased mortality, especially in patients with cirrhosis.

Vitamin D deficiency is highly prevalent in malnourished inpatients and associated with higher mortality: A prospective cohort study.

The impact of vitamin D deficiency on the recovery of patients with malnutrition remains undefined. Our aim was to study the prevalence of vitamin D deficiency in a well-characterized cohort of patients with malnutrition and its association with outcomes.Within this secondary analysis of a randomized controlled trial, we examined the association of vitamin D deficiency and adverse clinical outcomes over a follow-up of 180 days in hospitalized patients at risk for malnutrition. We measured 25-hydroxyvitamin D levels upon admission and defined Vitamin D deficiency when levels were <50nmol/l. The primary endpoint was 180-day mortality.The prevalence of vitamin D deficiency in our cohort of 828 patients was 58.2% (n = 482). Patients with vitamin D deficiency had increased 180-day mortality rates from 23.1% to 29.9% (odds ratio 1.42, 95% confidence interval [CI] 1.03-1.94, P = .03). When adjusting the analysis for demographics, comorbidities, and randomization, this association remained significant for the subgroup of patients not receiving vitamin D treatment (adjusted odds ratio 1.63, 95% CI 1.01-2.62, P = .04). There was no significantly lower risk for mortality in the subgroup of vitamin D deficient patients receiving vitamin D treatment compared to not receiving treatment (adjusted odds ratio 0.74, 95% CI 0.48-1.13, P = .15).Vitamin D deficiency is highly prevalent in the population of malnourished inpatients and is negatively associated with long-term mortality particularly when patients are not receiving vitamin D treatment. Our findings suggest that malnourished patients might benefit from vitamin D screening and treatment in case of deficiency.

Vitamin D as a Biomarker of Ill Health among the Over-50s: A Systematic Review of Cohort Studies.

BACKGROUND: The association between circulating levels of vitamin D and the incidence of chronic diseases is known. The identification of vitamin D as a biomarker of physiological/pathological ageing could contribute to expanding current knowledge of its involvement in healthy ageing. METHODS: According to PRISMA guidelines, a systematic review was conducted on cohorts studying the role of 25OH-Vitamin D [25(OH)D] and 1,25(OH)2-Vitamin D [1,25(OH)2D] concentrations as biomarkers of healthy ageing. We consulted MedLine, Scopus, and Web of Science to search for studies on the association between vitamin D status in populations of originally healthy adults, and outcomes of longevity, illness, and physical and cognitive functionality. The quality of the studies was assessed using the Newcastle Ottawa scale. RESULTS: Twenty cohorts from 24 articles were selected for this review. Inverse associations were found between low 25(OH)D levels and all-cause mortality, respiratory and cardiovascular events, as well as markers relating to hip and non-vertebral fractures. Associations between 1,25(OH)2D and healthy ageing outcomes gave similar results, although of lower clinical significance. CONCLUSIONS: This systematic review pinpoints peculiar aspects of vitamin D as a multidimensional predictor of ill health in the ageing process. Further well-designed controlled trials to investigate whether vitamin D supplement results in superior outcomes are warranted in the future.

Type 2 Diabetes Mellitus, Insulin Resistance, and Vitamin D.

PURPOSE OF REVIEW: There is a growing, largely inconsistent, literature on the role of vitamin D in association with type 2 diabetes, insulin resistance/insulin secretion, glycemic indices, and complications of type 2 diabetes. Pathophysiologic, bystander, preventive, and treatment roles of vitamin D have all been proposed. In this focused review, we attempt to organize and clarify our current information in this area. RECENT FINDINGS: Clinical study interpretation is difficult because of variability in dosage, dosage form, study duration, and populations studied, as well as recently reported normal human polymorphisms in vitamin D synthesis and catabolism, vitamin D-binding protein, and vitamin D receptors in addition to a host of potential epigenetic confounders. Low vitamin D status appears to be associated with type 2 diabetes and most other insulin resistance disorders reported to date. The extraskeletal benefits of supplementation/repletion in these disorders in our species, with a few highlighted exceptions, remain to be established. This focused review attempts to summarize our current knowledge in this burgeoning area through a review of key meta-analyses, observational studies, randomized control trials, and Mendelian randomization studies and will hopefully serve as a guide to indicate future research directions and current best practice.

Trying to identify who may benefit most from future vitamin D intervention trials: a post hoc analysis from the VITDAL-ICU study excluding the early deaths.

BACKGROUND: Vitamin D supplementation has shown promise for reducing mortality in the intensive care setting. As a steroid prohormone with pleiotropic effects, there may be a lag between administration and observing clinical benefit. This secondary analysis of the VITdAL-ICU study sought to explore whether the effect size of vitamin D on mortality was different when study participants who died or were discharged early were excluded. METHODS: The VITdAL-ICU study was a randomized, placebo-controlled trial in critically ill adults who received placebo or 540,000 IU cholecalciferol followed by monthly supplementation. The effect of vitamin D on 28-day mortality was evaluated after exclusion of participants who died or were discharged within 7 days from study drug administration, according to vitamin D concentrations on day 3, using a bivariate analysis adjusted for confounders and in a stepwise multiple analysis. RESULTS: Of 475 study participants, 65 died or were discharged within the first 7 days. In the remaining 410 patients, vitamin D supplementation was associated with a reduction in 28-day mortality [OR 0.58 (95% CI 0.35-0.97) p value = 0.035]. The effect on mortality was not significant after adjusting for age, severity scores, female gender, chronic liver and kidney disease, COPD, diagnosis of the tumor, mechanical ventilation, and vasopressors at enrollment (all p > 0.05). In a multiple model, the mortality reduction by vitamin D supplementation did not remain independently significant [OR 0.61 (95% CI 0.35-1.05) p = 0.075]. Vitamin D metabolite response, in the treatment group, demonstrated that survivors at 28 days, had higher levels of 25-hydroxyvitamin D (34.4 vs 25.4 ng/ml, p = 0.010) and 1,25-dihydroxyvitamin D (107.6 vs 70.3 pg/ml, p = 0.049) on day 3. The increase of plasma metabolites after vitamin D oral supplementation, independent of the baseline value, was associated with lower odds of death [OR 0.48 (95% CI 0.27-0.87) p value = 0.016]. CONCLUSIONS: High-dose vitamin D3 supplementation was associated with a reduction of 28-day mortality in a mixed population of critically ill adults with vitamin D deficiency when excluding patients who died or were discharged within 7 days after study inclusion. However, this survival benefit was not independently confirmed when adjusted for other factors strongly associated with mortality.