25‐Hydroxyvitamin D Concentrations and Clostridium difficile Infection: A Meta‐Analysis

Background: Well‐known risk factors for Clostridium difficile infection (CDI) are exposure to antibiotics and gastric acid suppressants. Recent studies have provided some evidence of an association between hypovitaminosis D and the risk of CDI. Therefore, this meta‐analysis aimed to pool all the existing evidence to investigate the association between 25‐hydroxyvitamin D (25[OH]D) and CDI. Methods: A systematic search was conducted in 3 databases (PubMed, Embase, and Web of Sciences) for epidemiological studies that examined the association between mean 25(OH)D concentrations and CDI as well as between 25(OH)D status and CDI severity or recurrence. 25(OH)D status was defined as “lower” or “higher” at a threshold concentration of <20 or ≥20 ng/mL, respectively. Pooled effect sizes were computed using the inverse variance heterogeneity model of meta‐analysis. Results: Eight publications (n = 4479 patients) were included in the meta‐analysis. The mean concentration of 25(OH)D in patients with CDI was 3.54 ng/mL (95% confidence interval [CI], 0.39–6.89 ng/mL) lower than in patients without CDI. Patients with lower 25(OH)D status had a higher odds (odds ratio [OR], 1.61; 95% CI, 1.02–2.53) of developing severe CDI compared with those with a higher 25(OH)D status. No significant association was found between 25(OH)D status and CDI recurrence. Conclusion: The results of this meta‐analysis suggest that lower mean concentrations of 25(OH)D were associated with CDI. A lower 25(OH)D status increased the odds of severe CDI but not of CDI recurrence.     

Association Between Serum 25(OH)D Level and Nonspecific Musculoskeletal Pain in Acute Rehabilitation Unit Patients

Objective: Nonspecific musculoskeletal pain can be difficult to manage in acute rehabilitation unit (ARU) patients. We investigated whether vitamin D status is a potential modifiable risk factor for nonspecific musculoskeletal pain in ARU patients. Materials and Methods: This cross‐sectional study focused on 414 adults from an inpatient ARU in Mission Viejo, California, between July 2011 and June 2012. On ARU admission, all patients had serum 25‐hydroxyvitamin D (25(OH)D) levels measured and were assessed for nonspecific musculoskeletal pain. We performed multivariable logistic regression to test the association of serum 25(OH)D level with nonspecific musculoskeletal pain while adjusting for clinically relevant covariates. Results: Among these 414 patients, mean (SD) 25(OH)D level was 29 (12) ng/mL, and 30% had nonspecific musculoskeletal pain. After adjustment for age, sex, race, body mass index, Functional Independence Measure score, Deyo‐Charlson Comorbidity Index, fractures, steroid use, history of osteoporosis/osteomalacia, and patient type (orthopedic, cardiac, neurological, spinal cord injury, or traumatic brain injury), serum 25(OH)D level was inversely associated with nonspecific musculoskeletal pain (odds ratio [OR] per 10 ng/mL, 0.67; 95% confidence interval [CI], 0.48–0.82). When 25(OH)D level was dichotomized, patients with levels <20 ng/mL had higher odds of nonspecific musculoskeletal pain (OR, 2.33; 95% CI, 1.23–4.17) compared with patients with levels ≥20 ng/mL. Conclusions: In adult patients, serum 25(OH)D level on admission to ARU was inversely associated with nonspecific musculoskeletal pain. These data support the need for randomized, controlled trials to test the role of vitamin D supplementation to improve nonspecific musculoskeletal pain in ARU patients.     

Vitamin D Status and Severity of Clostridium difficile Infections

Background: Clostridium difficile is the most common cause of nosocomial diarrhea, affecting up to 10% of hospitalized patients. Preliminary studies suggest an association between vitamin D status and C difficile infections (CDIs). Our goal was to investigate whether serum 25‐hydroxyvitamin D (25(OH)D) levels are associated with CDI severity. Methods: We prospectively enrolled patients diagnosed with CDI and divided them into 2 severity groups: group A (positive toxin A/B enzyme immunoassay only) and group B (positive toxin A/B enzyme immunoassay with abdominal computed tomography scan findings consistent with colitis). Serum 25(OH)D levels (25(OH)D₃, 25(OH)D₂, and total 25(OH)D) were measured on all patients after diagnosis of CDI. We performed multivariable logistic regression analyses to investigate the association between 25(OH)D levels and CDI severity, while adjusting for age, Deyo‐Charlson Comorbidity Index, recent hospitalization, and vitamin D supplementation. Results: One hundred patients were enrolled between July 2011 and February 2013. The mean (standard deviation) cohort age and Deyo‐Charlson Comorbidity Index were 62 (19) years and 4 (3), respectively; 54% of patients were male. Mean serum total 25(OH)D level was 22 (10) ng/mL. Mean 25(OH)D₃ level was significantly higher in group A (n = 71) than in group B (n = 29): 21 (1) vs 15 (2) ng/mL, respectively (P = .005). There was no observed difference in mean 25(OH)D₂ levels and total 25(OH)D levels between the 2 groups. Multivariable logistic regression analysis demonstrated an association between 25(OH)D₃ levels and CDI severity (adjusted odds ratio, 0.92; 95% confidence interval, 0.87–0.98). Conclusions: We found a significant inverse association between 25(OH)D₃ levels and CDI severity. Further studies are needed to determine whether vitamin D supplementation can improve outcomes in patients with CDI.     

Low 25-Hydroxyvitamin D Concentrations and Risk of Incident Cognitive Impairment in Black and White Older Adults: The Health ABC Study

Using data from the Health, Aging, and Body Composition study, we examined whether low 25-hydroxyvitamin D (25[OH]D) concentrations were associated with prevalent or incident cognitive impairment. Serum 25(OH)D concentrations were measured in 2,786 older adults and categorized as <20?ng/mL, 20 to <30?ng/mL, or ≥30?ng/mL. Cognitive impairment was defined as a score >1.5 standard deviations below race and education specific means on either digit symbol substitution test or modified mini-mental state test. Logistic regression determined the odds of cognitive impairment at baseline and year 5 by 25(OH)D category. 25(OH)D concentrations were <30?ng/mL in 57.3% of whites and 84.6% of blacks. After excluding participants with baseline cognitive impairment (n?=?340), 13% of whites and 13% of blacks developed cognitive impairment by year 5. In whites, 25(OH)D concentrations <30?ng/mL were not associated with prevalent or incident cognitive impairment. Black participants with 25(OH)D concentrations <20?ng/mL had a higher odds of prevalent, but not incident cognitive impairment (OR (95% CI): 2.05 (1.08–3.91), p?=?0.03) compared to participants with 25(OH)D concentrations ≥30?ng/mL. Low 25(OH)D concentrations were associated with twofold higher odds of prevalent cognitive impairment in blacks.     

Pretreatment 25‐Hydroxyvitamin D Levels and Durability of Anti–Tumor Necrosis Factor–α Therapy in Inflammatory Bowel Diseases

Introduction: Emerging evidence supports an immunologic role for 25‐hydroxyvitamin D (25(OH)D) in inflammatory bowel disease (IBD). Here we examined if pretreatment vitamin D status influences durability of anti–tumor necrosis factor (TNF)–α therapy in patients with Crohn's disease (CD) or ulcerative colitis (UC). Methods: All IBD patients who had plasma 25(OH)D level checked <3 months prior to initiating anti–TNF‐α therapy were included in this retrospective single‐center cohort study. Our main predictor variable was insufficient plasma 25(OH)D (<30 ng/mL). Cox proportional hazards model adjusting for potential confounders was used to identify the independent effect of pretreatment vitamin D on biologic treatment cessation. Results: Our study included 101 IBD patients (74 CD; median disease duration 9 years). The median index 25(OH)D level was 27 ng/mL (interquartile range, 20–33 ng/mL). One‐third of the patients had prior exposure to anti–TNF‐α therapy. On multivariate analysis, patients with insufficient vitamin D demonstrated earlier cessation of anti–TNF‐α therapy (hazard ratio [HR], 2.13; 95% confidence interval [CI], 1.03–4.39; P = .04). This effect was significant in patients who stopped treatment for loss of response (HR, 3.49; 95% CI, 1.34–9.09) and stronger for CD (HR, 2.38; 95% CI, 0.95–5.99) than UC (P = NS). Conclusions: Our findings suggest that vitamin D levels may influence durability of anti–TNF‐α induction and maintenance therapy. Larger cohort studies and clinical trials of supplemental vitamin D use with disease activity as an end point may be warranted.     

A comprehensive genetic and epidemiological association analysis of vitamin D with common diseases/traits in the UK Biobank

Vitamin D has been intensively studied for its association with human health, but the scope of such association and the causal role of vitamin D remain controversial. We aim to comprehensively investigate the links between vitamin D and human health through both epidemiological and Mendelian randomization (MR) analyses. We examined the epidemiological associations between serum 25‐hydroxyvitamin D (25(OH)D) concentration and 90 diseases/traits in 326,409 UK Biobank (UKBB) Europeans. The causal relations between 25(OH)D and 106 diseases/traits were investigated by performing MR analysis using genome‐wide significant 25(OH)D‐associated variants (N = 143) from the largest UKBB GWAS to date. In epidemiological analysis, we found 25(OH)D was associated with 45 diseases/traits across cardiovascular/metabolic diseases, psychiatric/neurological diseases, autoimmune/inflammatory diseases, cancer, musculoskeletal diseases, and quantitative traits. In MR‐analysis, we presented evidence suggesting potential causal role of 25(OH)D in increasing height (β = .064, 95% confidence interval [CI] = 0.019–0.11) and preventing the risk of ovarian cancer (odds ratio [OR] = 0.96, 95% CI = 0.93–0.99), multiple sclerosis (OR = 0.96, 95% CI = 0.94–0.98), leg fracture (OR = 0.60, 95% CI = 0.45–0.80) and femur fracture (OR = 0.53, 95% CI = 0.32–0.84). These findings confirmed associations of vitamin D with a broad spectrum of diseases/traits and supported the potential causal role of vitamin D in promoting health.     

Vitamin D Status in Pediatric and Young Adult Cystic Fibrosis Patients. Are the New Recommendations Effective?

Introduction: In recent years, guidelines for vitamin D supplementation have been updated and prophylactic recommended doses have been increased in patients with cystic fibrosis (CF). Objective: To evaluate safety and efficacy of these new recommendations. Results: Two cohorts of pancreatic insufficient CF patients were compared before (cohort 1: 179 patients) and after (cohort 2: 71 patients) American CF Foundation and European CF Society recommendations were published. Cohort 2 patients received higher Vitamin D doses: 1509 (1306–1711 95% CI) vs 1084 (983–1184 95% CI) IU/Day (p < 0.001), had higher 25 OH vitamin D levels: 30.6 (27.9–33.26 95% CI) vs. 27.4 (25.9–28.8 95% CI) ng/mL (p = 0.028), and had a lower prevalence of insufficient vitamin D levels (<30 ng/mL): 48% vs 65% (p = 0.011). Adjusted by confounding factors, patients in cohort 1 had a higher risk of vitamin D insufficiency: OR 2.23 (1.09–4.57 95% CI) (p = 0.028). Conclusion: After the implementation of new guidelines, CF patients received higher doses of vitamin D and a risk of vitamin D insufficiency decreased. Despite this, almost a third of CF patients still do not reach sufficient serum calcidiol levels.     

Serum 25-hydroxyvitamin D levels and the risk of depression: A systematic review and meta-analysis

Objective

No quantitative systematic review or meta-analysis of population-based epidemiological studies has been conducted to assess the association between serum 25-hydroxyvitamin D (25(OH)D) levels and the risk of depression. This study aimed to summarize the current evidence from cross-sectional and prospective cohort studies that have evaluated the association between 25(OH)D levels and the risk of depression.

Methods

Relevant studies were identified by systematically searching the PubMed, EMBASE, Web of Science, and PsycINFO databases through April 2012. Cross-sectional and cohort studies that reported adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for the association of interest were included. The reported risk estimates for 25(OH)D categories were recalculated, employing a comprehensive trend estimation from summarized dose-response data. A pooled OR was calculated separately for cross-sectional and cohort studies using random-effects models.

Results

In the meta-analysis, 25(OH)D levels were significantly inversely associated with depression in 5 of 11 case-control studies and 2 of 5 cohort studies. The pooled estimate of the adjusted OR of depression in 11 cross-sectional studies (n = 43,137) was 0.96 (95% CI = 0.94–0.99, I² = 63%) for a 10 ng/ml increase in 25(OH)D levels. The 5 included cohort studies comprised 12,648 participants, primarily elderly individuals, whose serum 25(OH)D levels were measured, and 2,663 experienced depression events during follow-up. The pooled adjusted OR of depression was 0.92 (95% CI = 0.87–0.98, I² = 50%) for a 10 ng/ml increase in 25(OH)D levels.

Conclusions

Our results indicate an inverse association between serum 25(OH)D levels and the risk of depression. Further studies are warranted to establish whether this association is causal.     

Low 25-Hydroxyvitamin D and Myofascial Pain: Association of Cancer,Colon Polyps,and Tendon Rupture

Background: Myofascial pain that has been associated with cancer and increased risk of morbidity and mortality in cancer patients is intrinsically associated with low magnesium and low 25-hydroxyvitamin D (25(OH)D). Therefore, this physical finding was used as a clinical diagnostic proxy.

Objective: The objective of this study was to assess the association and prevalence of disease in individuals with myofascial pain and low 25(OH)D in a county with low magnesium in the drinking water.

Design: This is a retrospective cross-sectional study of a chart review of 269 subjects to assess subjects presenting with myofascial pain (assessed by tender trigger points) and 25(OH)D concentrations below 30 ng/mL or a history of 25(OH)D deficiency compared to those without these exposures.

Results: The association between the exposure of low 25(OH)D levels and myofascial pain was compared to all cancers, colon polyps, and tendon ruptures. The odds of having cancer with the combined exposures was 10.14 times the odds of not having either exposure (95% confidence interval [CI], 5.08, 20.25, p < 0.001). For adenomatous colon polyps, the odds ratio (OR) was 7.24 (95% CI, 3.83, 13.69, p < 0.001), and for tendon rupture, the OR was 8.65 (95% CI, 3.76, 19.94, p < 0.001). Of 80 subjects who had both myofascial pain and 25(OH)D less than 30 ng/mL, 74 were tested for red blood cell (RBC) magnesium. Half of those subjects had RBC magnesium concentrations < 4.6 mg/dL, and 23% had levels below the reference range (4.0–6.4 mg/dL).

Conclusion: Myofascial pain as assessed by tender trigger points and 25(OH)D deficiency showed a significant association with cancer, adenomatous colon polyps, and tendon rupture. Further studies to verify these results are needed, especially in areas where there is low magnesium in the drinking water.     

Vitamin D Deficiency Is Widespread in Cancer Patients and Correlates With Advanced Stage Disease: A Community Oncology Experience

The purpose of this study was to correlate serum vitamin D levels with potential clinical variables and to determine the extent of vitamin D deficiency in a large, outpatient oncology practice. One hundred ninety-five consecutive patients referred for consultation at a community radiation oncology center from October 8, 2008 to March 17, 2010 had vitamin D levels ordered. Patients who were deficient in vitamin D were treated with replacement therapy. Demographic and medical data were collected prospectively and subsequently analyzed. Pretreatment baseline patient and tumor characteristics were evaluated with respect to vitamin D concentrations. One hundred and sixty patients were analyzed. A total of 74% of patients had 25-hydroxyvitamin D concentrations considered either deficient (<20 ng/mL) or suboptimal (20–30 ng/mL). Replacement therapy raised serum vitamin D levels by an average of 15 ng/mL (95% CI = 11–18, P < 0.01). Lower than median serum vitamin D levels were associated with stage III disease in univariate analysis [OR = 2.6 (95% CI = 1.1–6.2), p = 0.04] as well as multivariate analysis adjusted for age, sex, body mass index, and season of draw [OR = 3.3 (95% CI = 1.1–9.7), P = 0.03]. Three-quarters of patients in our series had suboptimal or deficient circulating concentrations of 25-hydroxyvitamin D. Low serum vitamin D levels, independent of age, sex, and body mass index, predicted advanced stage disease.     

Association between Vitamin D Status and Premenstrual Symptoms

Background

Premenstrual symptoms are experienced by up to 95% of women, and few treatments are available. Previous studies suggest that 25-hydroxyvitamin D (25(OH)D) may be associated with the severity of premenstrual symptoms, but the findings have been inconclusive.

Vitamin D Level and Risk of Community-Acquired Pneumonia and Sepsis

Previous research has reported reduced serum 25-hydroxyvitamin D (25(OH)D) levels is associated with acute infectious illness. The relationship between vitamin D status, measured prior to acute infectious illness, with risk of community-acquired pneumonia (CAP) and sepsis has not been examined. Community-living individuals hospitalized with CAP or sepsis were age-, sex-, race-, and season-matched with controls. ICD-9 codes identified CAP and sepsis; chest radiograph confirmed CAP. Serum 25(OH)D levels were measured up to 15 months prior to hospitalization. Regression models adjusted for diabetes, renal disease, and peripheral vascular disease evaluated the association of 25(OH)D levels with CAP or sepsis risk. A total of 132 CAP patients and controls were 60 ± 17 years, 71% female, and 86% Caucasian. The 25(OH)D levels <37 nmol/L (adjusted odds ratio (OR) 2.57, 95% CI 1.08–6.08) were strongly associated with increased odds of CAP hospitalization. A total of 422 sepsis patients and controls were 65 ± 14 years, 59% female, and 91% Caucasian. The 25(OH)D levels <37 nmol/L (adjusted OR 1.75, 95% CI 1.11–2.77) were associated with increased odds of sepsis hospitalization. Vitamin D status was inversely associated with risk of CAP and sepsis hospitalization in a community-living adult population. Further clinical trials are needed to evaluate whether vitamin D supplementation can reduce risk of infections, including CAP and sepsis.     

Association of racial disparities in the prevalence of insulin resistance with racial disparities in vitamin D levels: National Health and Nutrition Examination Survey (2001-2006)

We tested the hypothesis that racial differences in vitamin D levels are associated with racial disparities in insulin resistance between blacks and whites. Among 3628 non-Hispanic black and white adults in the National Health and Nutrition Examination Survey from 2001 to 2006, we examined the association between race and insulin resistance using the homeostasis assessment model for insulin resistance. We conducted analyses with and without serum 25-hydroxyvitamin D (25[OH]D). We adjusted for age, sex, educational level, body mass index, waist circumference, physical activity, alcohol intake, smoking, estimated glomerular filtration rate, and urinary albumin/creatinine ratio. Blacks had a lower mean serum 25(OH)D level compared with whites (14.6 [0.3] ng/mL vs 25.6 [0.4] ng/mL, respectively; P < .0001). Blacks had a higher odds ratio (OR) for insulin resistance without controlling for serum 25(OH)D levels (OR, 1.67; 95% confidence interval, 1.26-2.20). The association was not significant (OR, 1.28; 95% confidence interval, 0.90-1.82) after accounting for serum 25(OH)D levels. The higher burden of insulin resistance in blacks compared with whites may be partially mediated by the disparity in serum 25(OH)D levels.     

Residential Greenness Alters Serum 25(OH)D Concentrations: A Longitudinal Cohort of Chinese Older Adults

ObjectivesVitamin D deficiency is prevalent among older adults. We aimed to study whether residential greenness could alter serum 25(OH)D concentrations as a possible mechanism of residential greenness's positive health effects.DesignA longitudinal cohort study.Setting and ParticipantsWe included older adults aged ≥65 years from the Chinese Longitudinal Healthy Longevity Survey (CLHLS) with follow-up between 2012 and 2014.MethodsWe measured residential greenness by calculating annual average Normalized Difference Vegetation Index (NDVI) in a 500 m radius by using satellite images around each participant's residential address. Serum 25-hydroxyvitamin D (25(OH)D) concentration was dichotomized into 2 categories: nondeficiency (≥50 nmol/L) and deficiency (<50 nmol/L). We used the generalized estimating equation to examine the relationship between annual average NDVI and serum 25(OH)D.ResultsWe included 1336 participants in our analysis. The annual average NDVI was 0.49, and mean serum 25(OH)D was 43 nmol/L at baseline. Each 0.1-unit increase in annual average NDVI was associated with a 13% higher odds of vitamin D nondeficiency [95% confidence interval (CI): 1.01, 1.26]. The association was stronger among men [odds ratio (OR): 1.17, 95% CI: 1.02, 1.35] than women (OR: 1.08, 95% CI: 0.91, 1.29) and also stronger among those who were free of activities of daily living (ADL) disability at baseline (OR: 1.12, 95% CI: 1.00, 1.25). During the follow-up period, the participants who lived in greener areas were more likely to have an improved, rather than stable or deteriorated, vitamin D status (OR: 1.94, 95% CI: 1.51, 2.51).Conclusions and ImplicationsOur study suggests that higher levels of residential greenness are associated with higher serum 25(OH)D concentrations, which has implications for prevention of vitamin D deficiency among older adults.     

Vitamin D Status and Acute Respiratory Infection: Cross Sectional Results from the United States National Health and Nutrition Examination Survey, 2001–2006

Vitamin D is a promising, though under-explored, potential modifiable risk factor for acute respiratory infections (ARIs). We sought to investigate the association of vitamin D status with ARI in a large, nationally-representative sample of non-institutionalized individuals from the United States. We analyzed 14,108 individuals over 16 years of age in the National Health and Nutrition Survey (NHANES) 2001–2006 in this cross-sectional study. We used locally weighted scatterplot smoothing (LOWESS) to depict the relationship between increasing 25-hydroxyvitamin D (25OHD) levels and ARI. We then performed a multivariable regression analysis to investigate the association of 25OHD levels with ARI, while adjusting for known confounders. The median serum 25OHD level was 21 (IQR 15–27) ng/mL. Overall, 4.8% (95% CI: 4.5–5.2) of participants reported an ARI within 30 days before their participation in the national survey. LOWESS analysis revealed a near-linear relationship between vitamin D status and the cumulative frequency of ARI up to 25OHD levels around 30 ng/mL. After adjusting for season, demographic factors, and clinical data, 25OHD levels <30 ng/mL were associated with 58% higher odds of ARI (OR 1.58; 95% CI: 1.07–2.33) compared to levels ≥30 ng/mL. Among the 14,108 participants in NHANES 2001–2006, 25OHD levels were inversely associated with ARI. Carefully designed, randomized, controlled trials are warranted to determine the effect of optimizing vitamin D status on the risk of ARI.     

Vitamin D status and risk of dementia and Alzheimer’s disease: A meta-analysis of dose-response†

Objective: We aimed to test the dose-response association of serum 25(OH)D and risk of dementia and Alzheimer’s disease (AD).

Methods: We performed a systematic search of PubMed and Scopus from database inception up to September 2017. Longitudinal cohort studies reporting risk estimates of incident dementia or AD in the general population, and for three or more quantitative categories of serum 25(OH)D were included. Pooled hazard ratios (HRs) were calculated using fixed-effects/random-effects models.

Results: Seven prospective cohort studies and one retrospective cohort study (total n?=?28,354) involving 1953 cases of dementia and 1607 cases of AD were included. The pooled HRs of dementia and AD were 1.09 (95%CI: 0.95, 1.24) and 1.19 (95%CI: 0.96, 1.41) for vitamin D insufficiency (10–20?ng/ml), and 1.33 (95%CI: 1.08, 1.58) and 1.31 (95%CI: 0.98, 1.65) for deficiency (<10?ng/ml), respectively. The lower risk of dementia was observed at serum 25(OH)D of ～25?ng/ml, whereas the risk of AD decreased continuously along with the increase of serum 25(OH)D up to ～35?ng/ml.

Conclusion: Higher levels of serum 25(OH)D was associated with a lower risk of dementia and AD, but we have no conclusive evidence regarding serum 25(OH)D levels of >35?ng/ml.     

Vitamin D Deficiency Increases the Risk for Moderate to Severe Disease Activity in Crohn's Disease Patients in South Africa,Measured by the Harvey Bradshaw Index

Objective: Vitamin D has immunoregulatory properties and appears to influence disease outcomes in patients with Crohn's disease (CD). The primary aim of this study was to evaluate the association between vitamin D status and CD activity in South Africa.

Methods: In a cross-sectional study performed between September 2011 and January 2013, serum 25-hydroxyvitamin D (25(OH)D) was measured in 186 consecutive patients with CD seen at 2 inflammatory bowel disease (IBD) centers and 199 healthy controls in the Western Cape, South Africa. Lifestyle and clinical variables were identified using an investigator-administered questionnaire, as well as clinical examination and patient case notes. Vitamin D status was evaluated in 2 ways: ≤20 ng/mL vs ≥21 ng/mL and ≤29 ng/mL vs ≥30 ng/mL. Disease activity was measured by the Harvey Bradshaw Index (HBI). Various 25(OH)D threshold concentrations for predicting a higher HBI score were also investigated.

Results: On multiple log-binomial regression analysis, higher HBI scores and not having taken vitamin D supplementation in the 6 months prior to enrollment were identified as risk factors for vitamin D deficiency in patients with CD, defined either as ≤20 ng/mL or as ≤29 ng/mL (p < 0.03). Compared to patients with HBI < 5, those with HBI ≥ 8 were 2.5 times more likely to have 25(OH)D concentrations ≤21 ng/mL (prevalence risk [PR] = 2.5; 95% confidence interval [CI], 1.21–6.30). The risk was similar, though not as high, when defined as ≤29 ng/mL (PR = 2.0; 95% CI, 1.13–3.51). When vitamin D deficiency was defined as <20, <30, <40, and <50 ng/mL, the sensitivity and specificity obtained were 44.9% and 78.8%; 75.5% and 62.4%; 86.7% and 44.7%; and 92.9% and 23.5%, respectively (area under the curve = 0.71; p < 0.0001).

Conclusion: Low serum 25(OH)D was associated with increased CD activity in a South African cohort.     

Vitamin D Status and SARS-CoV-2 Infection in a Cohort of Kidney Transplanted Patients

Background: Recently the protective role of 25-hydroxyvitamin D (25(OH)D) against viral infections has been hypothesized. We evaluated the association between vitamin D status and SARS-CoV-2 infection susceptibility and severity in a cohort of kidney transplanted patients (KTxp). Methods: A total of 61 KTxp with SARS-CoV-2 infection (COV+) were matched with 122 healthy KTxp controls (COV−). Main biochemical parameters at 1, 6, and 12 months before SARS-CoV-2 infection were recorded. Vitamin D status was considered as the mean of two 25(OH)D measures obtained 6 ± 2 months apart during the last year. The severity of SARS-CoV-2 infection was based on the need for hospitalization (HOSP+) and death (D+). Results: 25(OH)D levels were lower in COV+ than in controls [19(12–26) vs. 23(17–31) ng/mL, p = 0.01]. No differences among the other biochemical parameters were found. The SARS-CoV-2 infection discriminative power of 25(OH)D was evaluated by ROC-curve (AUC 0.61, 95% CI 0.5–0.7, p = 0.01). 25(OH)D was not significantly different between HOSP+ and HOSP− [17(8–25) vs. 20(15–26) ng/mL, p = 0.19] and between D+ and D− [14(6–23) vs. 20(14–26) ng/mL, p = 0.22] and had no significant correlation with disease length. Conclusions: During the year preceding the infection, 25(OH)D levels were lower in COV+ KTxp in comparison with controls matched for demographic features and comorbidities. No significant association between vitamin D status and SARS-CoV-2 infection related outcomes was found.     

Serum Vitamin D Concentrations,Time to Pregnancy,and Pregnancy Outcomes among Preconception Couples: A Cohort Study in Shanghai,China

Background: The role of vitamin D in reproductive health is still unclear. This study aimed to assess the effect of serum 25-hydroxyvitamin D (25(OH)D), among preconception couples, on fecundity, and the associations between 25(OH)D concentrations before and during pregnancy, and pregnancy outcomes. Methods: 200 preconception couples attempting to conceive were recruited and were followed-up until childbirth. Time to pregnancy was collected via telephone every two months or obtained via a questionnaire during pregnancy. Blood samples were collected to measure serum 25(OH)D levels from both partners at enrollment and from women during the second and third trimester of pregnancy. Results: Couples had higher conception rates within six months (adjusted odds ratio (aOR): 3.72, 95% CI: 1.16, 11.9) and reduced time to pregnancy (adjusted fecundability ratio (aFR): 1.50, 95% CI: 1.01, 2.23) if male partners had sufficient 25(OH)D compared with insufficient 25(OH)D. Compared to pregnant women with insufficient 25(OH)D in the third trimester of pregnancy, sufficient 25(OH)D was associated with reduced odds of anemia (OR: 0.22, 95% CI: 0.06, 0.82), longer gestational age (β: 0.53, 95% CI: 0.04, 1.01) and newborns’ higher ponderal index (β: 0.10, 95% CI: 0.01, 0.19). Conclusions: Sufficient serum 25(OH)D levels among preconception men or during pregnancy were associated with better reproductive health.     

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.