Assessment of Vitamin D Status in Slovenian Premenopausal and Postmenopausal Women,Using Total,Free, and Bioavailable 25-Hydroxyvitamin D (25(OH)D)

The objective of our study was to evaluate vitamin D status and its predictors in Slovenian premenopausal and postmenopausal women. A cross-sectional study was carried out between 1 March 2021 and 31 May 2021. A total of 319 healthy women from the Central Slovenian region aged between 44 and 65 were recruited; 176 were included in the final analysis. The vitamin D status was determined by measuring the total 25-Hydroxycholecalciferol (25(OH)D) concentration, vitamin D binding protein (DBP), and albumin and calculating the bioavailable 25(OH)D and free 25(OH)D. For the calculation of bioavailable and free 25(OH)D, we developed a new online calculator. The Endocrine Society’s thresholds for vitamin D deficiency and insufficiency were used; 29.0% of premenopausal and 24.4% of postmenopausal subjects were found to be vitamin D deficient (total 25(OH)D < 50 nmol/L); 76.8% of the premenopausal and 61.7% of postmenopausal subjects were found to have insufficient levels (total 25(OH)D < 75 nmol/L). Premenopausal women had 11.8% lower total 25(OH)D, 32.2% lower bioavailable 25(OH)D, and 25.2% higher DBP than postmenopausal women. The most important predictors of vitamin D status were vitamin D supplementation and time spent in the sun. Contrary to similar studies, the vitamin D status in Slovenian postmenopausal women was significantly better than in premenopausal women. In postmenopausal women, the measurement of free or bioavailable 25(OH)D instead of the total 25(OH)D could be advantageous.     

Vitamin D Supplementation Regulates Postoperative Serum Levels of PD-L1 in Patients with Digestive Tract Cancer and Improves Survivals in the Highest Quintile of PD-L1: A Post Hoc Analysis of the AMATERASU Randomized Controlled Trial

Because vitamin D responsive elements have been found to be located in the PD-L1 gene, vitamin D supplementation was hypothesized to regulate serum PD-L1 levels and thus alter survival time of cancer patients. A post hoc analysis of the AMATERASU randomized, double-blind, placebo-controlled trial of postoperative vitamin D3 supplementation (2000 IU/day) in 417 patients with stage I to stage III digestive tract cancer from the esophagus to the rectum was conducted. Postoperative serum PD-L1 levels were measured by ELISA and divided into quintiles (Q1–Q5). Serum samples were available for 396 (95.0%) of the original trial. Vitamin D supplementation significantly (p = 0.0008) up-regulated serum PD-L1 levels in the lowest quintile (Q1), whereas it significantly (p = 0.0001) down-regulated them in the highest quintile (Q5), and it did not either up- or down-regulate them in the middle quintiles (Q2–Q4). Significant effects of vitamin D supplementation, compared with placebo on death (HR, 0.34; 95% CI, 0.12–0.92) and relapse/death (HR, 0.37; 95% CI, 0.15–0.89) were observed in the highest quintile (Q5) of serum PD-L1, whereas significant effects were not observed in other quintiles (P_interaction = 0.02 for death, P_interaction = 0.04 for relapse/death). Vitamin D supplementation significantly reduced the risk of relapse/death to approximately one-third in the highest quintile of serum PD-L1.     

Low 25(OH)D Level Is Associated with Severe Course and Poor Prognosis in COVID-19

We evaluated associations between serum 25-hydroxyvitamin D [25(OH)D] level and severity of new coronavirus infection (COVID-19) in hospitalized patients. We assessed serum 25(OH)D level in 133 patients aged 21–93 years. Twenty-five (19%) patients had severe disease, 108 patients (81%) had moderate disease, and 18 (14%) patients died. 25(OH)D level ranged from 3.0 to 97.0 ng/mL (median, 13.5 [25%; 75%, 9.6; 23.3] ng/mL). Vitamin D deficiency was diagnosed in 90 patients, including 37 with severe deficiency. In patients with severe course of disease, 25(OH)D level was lower (median, 9.7 [25%; 75%, 6.0; 14.9] ng/mL), and vitamin D deficiency was more common than in patients with moderate course (median, 14.6 [25%; 75%, 10.6; 24.4] ng/mL, p = 0.003). In patients who died, 25(OH)D was 9.6 [25%; 75%, 6.0; 11.5] ng/mL, compared with 14.8 [25%; 75%, 10.1; 24.3] ng/mL in discharged patients (p = 0.001). Severe vitamin D deficiency was associated with increased risk of COVID-19 severity and fatal outcome. The threshold for 25(OH)D level associated with increased risk of severe course was 11.7 ng/mL. Approximately the same 25(OH)D level, 10.9 ng/mL, was associated with increased risk of mortality. Thus, most COVID-19 patients have vitamin D deficiency; severe vitamin D deficiency is associated with increased risk of COVID-19 severity and fatal outcome.     

Variants in the VDR Gene May Influence 25(OH)D Levels in Type 1 Diabetes Mellitus in a Brazilian Population

Vitamin D has been considered a strong contributing factor to type 1 diabetes mellitus (T1DM). Many studies have investigated polymorphisms in the VDR gene in association with T1DM in different populations, but there are still conflicting findings. This study aimed to evaluate the association of four variants in the VDR gene (rs7975232, rs1544410, rs731236, and rs2228570) with T1DM risk and vitamin D levels within a population from North Region, Brazil, as well as the influence of genomic ancestry on T1DM. A total of 65 T1DM patients and 83 non-T1DM patients were enrolled in this study. VDR gene polymorphisms were assessed using Sanger sequencing analysis. Genomic ancestry was analyzed using a set of 61 ancestry-informative markers. T1DM patients showed higher European genomic contribution and lower Native American genomic contribution when compared to non-T1DM patients. T1DM patients with AA genotype in rs1544410 or CC genotype in rs731236 had significantly lower 25(OH)D levels compared to the other two genotypes (p = 0.013 and p = 0.02, respectively), while T1DM with TT genotype in rs2228570 had higher 25(OH)D levels compared to CC + TC in the same polymorphism (p = 0.011). Our findings suggest that the association between 25(OH)D and T1DM may be modified by VDR variants, possibly influencing the development of this autoimmune disease.     

血清离子钙、25-羟基维生素D与社区居民肥胖的相关性研究

目的探索社区居民血清中离子钙及25-羟基维生素D[25-(OH)D]水平与肥胖的相关性研究。方法在横断面研究的基础上,采用1∶1配对病例-对照的方法,选取肥胖组169人:男性92人,平均年龄(37.76±17.56)岁,女性77人,平均年龄(38.79±17.40)岁;对照组169人:男性92人,平均年龄(36.24±17.28)岁,女性77人,平均年龄(32.32±13.07)岁,用火焰原子吸收分光光度法测定血清中离子钙的浓度,ELISA测定血清中25-羟基维生素D;采用Logistic回归分析法分析全血钙及25-羟基维生素D水平与肥胖的相关性。结果①肥胖组的血清离子钙浓度为(46.9±20.7)mg/L,对照组血清离子钙浓度为(63.2±19.5)mg/L,肥胖组的血清离子钙浓度明显低于对照组(t=5.146,P=0.000);②肥胖组血清中25-羟基维生素D浓度为(48.3±16.7)nmmol/L,对照组血清中25-羟基维生素D浓度为(63.8±35.4)nmmol/L,肥胖组血清中25-羟基维生素D浓度明显低于对照组(t=7.434,P=0.000);③血清离子钙及25-羟基维生素D与肥胖的发生均呈现负相关关系(OR=0.959,95%CI 0.945～0.973;OR=0.435,95%CI 0.329～0.575)。结论维生素D可能是肥胖发生的独立危险因素。     

Plasma 25(OH)D Concentrations and Gestational Diabetes Mellitus among Pregnant Women in Taiwan

Vitamin D’s function in the development of gestational diabetes mellitus (GDM) is not consistent in the literature. We examined the association between maternal plasma 25(OH)D concentration and GDM risk. A national cross-sectional study (1497 pregnant women) was conducted between 2017 and 2019 across Taiwan. Blood samples were drawn at recruitment to assess 25(OH)D concentrations, including vitamin D deficiency (VDD) (<20 ng/mL), insufficiency (<32 ng/mL), and sufficiency (≥32 ng/mL). GDM was detected from 24 to 28 weeks of gestation with the results extracted from the antenatal visit records. The prevalence of GDM was 2.9%. Logistic model analysis showed that 25(OH)D concentrations were not significantly associated with the risk of GDM (adjusted odds ratio (AOR) = 0.97, p = 0.144). However, subjects with VDD had a significantly greater risk of GDM (AOR = 2.26, p = 0.041), but not in those with vitamin D insufficiency (AOR = 1.20, p = 0.655). Furthermore, cubic piecewise spline regression was used to explore the relationship between five-unit intervals of 25(OH)D and the predicted probability of GDM. As the proportion of GDM increased for low 25(OH)D concentrations, it decreased at moderate concentrations and increased again at higher concentrations. These findings revealed a nonlinear relationship between 25(OH)D and GDM risk. VDD would be risky for GDM occurrence.     

Relationship between Serum 25(OH)D and Depression: Causal Evidence from a Bi-Directional Mendelian Randomization Study

The relationship between depression and vitamin D deficiency is complex, with evidence mostly from studies affected by confounding and reverse causality. We examined the causality and direction of the relationship between 25-hydroxyvitamin D (25(OH)D) and depression in bi-directional Mendelian randomization (MR) analyses using information from up to 307,618 white British participants from the UK Biobank and summary results from the SUNLIGHT (n = 79,366) and Psychiatric Genomics consortia (PGC 113,154 cases and 218,523 controls). In observational analysis, the odds of depression decreased with higher 25(OH)D concentrations (adjusted odds ratio (OR) per 50% increase 0.95, 95%CI 0.94–0.96). In MR inverse variance weighted (IVW) using the UK Biobank, there was no association between genetically determined serum 25(OH)D and depression (OR per 50% higher 0.97, 95%CI 0.90–1.05) with consistent null association across all MR approaches and in data from PGC consortium. In contrast, genetic liability to depression was associated with lower 25(OH)D concentrations (MR IVW −3.26%, −4.94%–−1.55%), with the estimates remaining generally consistent after meta-analysing with the consortia. In conclusion, we found genetic evidence for a causal effect of depression on lower 25(OH)D concentrations, however we could not confirm a beneficial effect of nutritional vitamin D status on depression risk.     

A Phase II Multicenter Trial on High-Dose Vitamin D Supplementation for the Correction of Vitamin D Insufficiency in Patients with Breast Cancer Receiving Adjuvant Chemotherapy

Breast cancer (BC) treatments induce vitamin D (VD) insufficiency and bone metabolism changes, resulting in osteoporosis and skeletal morbidity risk. We report the results of a bicentric phase II trial (ClinicalTrials.gov Identifier: {"type":"clinical-trial","attrs":{"text":"NCT04091178","term_id":"NCT04091178"}}NCT04091178) on the safety and efficacy of high-dose oral VD supplementation for VD deficiency correction in 44 patients with early BC treated with adjuvant chemotherapies. Patients received one dose of 100,000 IU 25-OH VD every 3 weeks from day 1 of cycle 1 to day 1 of cycle 5. The primary endpoint was the percentage of patients achieving serum 25-OH VD concentration normalization on day 1 of cycle 6 (D1C6). Secondary endpoints were safety, VD and calcium parameters at baseline and during chemotherapy, and identification of predictive biomarkers of VD normalization on D1C6. On D1C6, 21 patients (47.7%, 95% CI: 33.0–62.8) achieved VD normalization. No VD-related clinical toxicity was reported. However, 13 patients (29.5%) presented asymptomatic grade 1 hypercalciuria, leading to interruption of the high-dose oral VD supplementation in 10, followed by a rapid reduction in serum VD concentration. No baseline clinical factor was predictive of VD normalization on D1C6. This high-dose VD supplementation appears safe and efficient in patients with early BC receiving adjuvant chemotherapy.     

血清总IgE与25羟维生素D在小儿支气管哮喘病情变化中的意义

目的探讨血清总IgE与25羟维生素D在小儿支气管哮喘病情变化中的意义。方法随机选取我院2009年1月至2012年10月诊治的支气管哮喘患儿85例,其中缓解组40例,急性发作组45例,另选取40例同期体检健康儿童为对照组。采用放射免疫法检测各组患儿血清总IgE与25羟维生素D水平,并分析两者与患儿病情的相关性。结果与健康对照组比较,哮喘急性发作组和哮喘缓解组血清总IgE明显升高,其中急性发作组水平最高,三组间比较具有统计学差异(P<0.05)。哮喘急性发作组和哮喘缓解组血清25羟维生素D水平均低于健康对照组,具有统计学差异(P<0.05),而急性发作组和哮喘缓解组间比较无统计学差异(P>0.05)。血清总IgE在哮喘急性期轻、中、重组间存在统计学差异,随着病情的加重IgE水平升高,具有正相关性(r=0.714,P<0.05),血清25羟维生素在哮喘急性期三组间无统计学差异(P>0.05)。结论 IgE参与了支气管哮喘患儿急性发作过程,而25羟维生素缺乏可能是引起小儿哮喘发作的一个重要原因。     

Association of Dietary Vitamin D Intake,Serum 25(OH)D3, 25(OH)D2 with Cognitive Performance in the Elderly

Background: As life expectancy increases, cognitive performance decline in the elderly has become one of the major global challenges. We aimed to evaluate the association of dietary vitamin D (VD), serum 25-hydroxyvitamin D3 (25(OH)D₃), 25-hydroxyvitamin D2 (25(OH)D₂), and total 25-hydroxyvitamin (25(OH)D) concentration with cognitive performance in older Americans. Methods: The data from the National Health and Nutrition Examination Survey (NHANES), 2011–2014 was used. The cognitive performance was assessed by the Consortium to Establish a Registry for Alzheimer’s Disease (CERAD) Word Learning sub-test, Animal Fluency test, and Digit Symbol Substitution Test (DSST). A binary logistic regression model was applied to evaluate the association between VD and cognitive performance, and restricted cubic spline model was adopted to evaluate the dose–response relationship. Results: While comparing to the lowest dietary VD intake group, the multivariate adjusted odds ratios (ORs) and 95% confidence intervals (CIs) of the highest dietary VD intake group were 0.51 (0.36–0.72) for the Animal Fluency test score and 0.45 (0.31–0.66) for DSST score, respectively; and those of serum total 25(OH)D and 25(OH)D₃ concentration were 0.68 (0.47–0.97) and 0.62 (0.44–0.86) for DSST score. L-shaped relationships were identified for dietary VD intake, serum total 25(OH)D and 25(OH)D₃ concentration with cognition performance. The associations between dietary VD intake, serum total 25(OH)D and cognitive performance were non-significant when stratified by gender. Conclusions: The study indicates that dietary VD intake, serum total 25(OH)D and 25(OH)D₃ concentration were positively associated with cognitive performance. Further studies are needed to clarify the possible effects of dietary VD intake and serum 25(OH)D₂, 25(OH)D₃ on cognitive performance.     

HPLC-MS/MS法检测吉林省427例儿童血浆25(OH)D的水平

目的:了解吉林省保健体检儿童血浆25(OH)D的水平,探讨高效液相色谱-串联质谱法(HPLC-MS/MS法)诊断维生素D缺乏性佝偻病的临床意义。方法:采用HPLC-MS/MS法检测并分析了427例体检儿童血浆25(OH)D的水平。结果:①血浆25(OH)D属于正常参考值范围的检出率为41.69%(178/427);低于正常参考值范围的检出率为58.31%(249/427),其中血浆25(OH)D处于缺乏水平的检出率为28.34%(121/427),处于不足水平的检出率为29.98%(128/427);高于正常参考值的检出率为0.00%(0/427)。②255例0～3岁研究对象中,1岁以内婴儿25(OH)D缺乏的发病率为39.34%(24/61),13个月～3岁幼儿25(OH)D缺乏的发病率为15.46%(30/194),二者相比有统计学差异(χ2=15.854 9,P=6.84E-5)。③临床诊断为佝偻病的121例儿童血浆25(OH)D检测结果占全部低于正常参考值儿童的48.59%(121/249),而血浆25(OH)D检测值低于正常参考值但临床尚未诊断佝偻病的儿童占全部低于正常参考值儿童的51.41%(128/249)。结论:①维生素D不足在吉林省的发病率高(58.31%),尤其1岁内婴儿更容易罹患维生素D缺乏,必须进一步加强和规范吉林省佝偻病的防治工作。②目前临床诊断佝偻病与经HPLC-MS/MS法检测25(OH)D诊断佝偻病符合率约50%,应尽快广泛普及此法,提高诊断的敏感性和特异性。     

The Evidence That 25(OH)D3 and VK2 MK-7 Vitamins Influence the Proliferative Potential and Gene Expression Profiles of Multiple Myeloma Cells and the Development of Resistance to Bortezomib

Multiple myeloma (MM) remains an incurable hematological malignancy. Bortezomib (BTZ) is a proteasome inhibitor widely used in MM therapy whose potent activity is often hampered by the development of resistance. The immune system is vital in the pathophysiology of BTZ resistance. Vitamins D (VD) and K (VK) modulate the immune system; therefore, they are potentially beneficial in MM. The aim of the study was to evaluate the effect of BTZ therapy and VD and VK supplementation on the proliferation potential and gene expression profiles of MM cells in terms of the development of BTZ resistance. The U266 MM cell line was incubated three times with BTZ, VD and VK at different timepoints. Then, proliferation assays, RNA sequencing and bioinformatics analysis were performed. We showed BTZ resistance to be mediated by processes related to ATP metabolism and oxidative phosphorylation. The upregulation of genes from the SNORDs family suggests the involvement of epigenetic mechanisms. Supplementation with VD and VK reduced the proliferation of MM cells in both the non-BTZ-resistant and BTZ-resistant phenotypes. VD and VK, by restoring proper metabolism, may have overcome resistance to BTZ in vitro. This observation forms the basis for further clinical trials evaluating VD and VK as potential adjuvant therapies for MM patients.     

Smoking Exposure Is Associated with Serum Vitamin D Deficiency in Children: Evidence from the Japan Environment and Children’s Study

Tobacco smoke exposure is known to lower serum 25-hydroxyvitamin D (25(OH)D) concentrations. This study evaluated the association between passive smoking and vitamin D deficiency (VDD) in young children using data from the Japan Environment and Children’s Study (JECS), the largest birth cohort study in Japan. Information on parental smoking status was extracted from a survey of JECS for children aged 1.5 years and data for serum 25(OH)D concentrations were obtained from blood tests in the Sub-Cohort Study of JECS performed at age 2 years. Logistic regression and linear models were fitted to evaluate the association between these variables. Data were analyzed for 4593 children. After adjusting for covariates, smoke exposure was significantly associated with increased incidence of VDD (OR 1.35; 95% CI, 1.14–1.59) according to the logistic model. The linear model indicated that passive smoking negatively predicted de-seasonalized serum 25(OH)D concentrations (β −0.5; 95% CI −0.95 to −0.08) in children aged 2 years. The results suggest that smoke exposure is a risk factor for VDD in children. Given that VD plays a crucial role in bone metabolism and the immune system, our findings are significant for clinical and public health.     

Associations between Pregnancy-Related Symptoms,Serum 25(OH)D,and Physical Quality of Life in Pregnant Women

Vitamin D deficiency has been associated with pregnancy-related symptoms including fatigue, poor sleep quality, and musculoskeletal pain. Pregnant Black and Hispanic women are more likely to have vitamin D deficiency compared with pregnant non-Hispanic White women. Data are limited on the association of vitamin D deficiency with quality of life (QOL) among pregnant women. This study examined the association of serum 25(OH)D and pregnancy-related symptoms with QOL among pregnant predominantly minority women. Using a cross-sectional design, 119 pregnant Black and Hispanic women completed surveys and had blood drawn for serum 25(OH)D levels between 24–32 weeks gestation. Hierarchical regression analysis indicated that total pregnancy-related symptoms and serum 25(OH)D level were significant predictors of QOL, while controlling for covariates. Higher total pregnancy-related symptoms and lower serum 25(OH)D predicted poorer physical QOL. Screening for pregnancy-related symptoms and vitamin D levels among childbearing women might be important nursing interventions to improve physical QOL.     

Safety Data in Patients with Autoimmune Diseases during Treatment with High Doses of Vitamin D3 According to the “Coimbra Protocol”

Background: In 2013, the group of Cicero Coimbra, Brazil, reported the clinical efficacy of high doses of vitamin D3 in patients suffering from autoimmune skin disorders (“Coimbra protocol”, CP). However, hypercalcemia and the subsequent impaired renal function may be major concerns raised against this protocol. Methods: We report for the first time for a broad spectrum of autoimmune diseases in 319 patients (mean age (±SD) 43.3 ± 14.6 years, 65.5% female, 34.5% male) safety data for high doses of orally applied vitamin D3 (treatment period: up to 3.5 years) accompanied by a strict low-calcium diet and regular daily fluid intake of at least 2.5 L. Results: Mean vitamin D3 dose was 35,291 ± 21,791 IU per day. The measurement of more than 6100 single relevant laboratory parameters showed all mean values (±SD) within the normal range for total serum calcium (2.4 ± 0.1 mmol/L), serum creatinine (0.8 ± 0.2 mg/dL), serum creatinine associated estimated GFR (92.5 ± 17.3 mL/min), serum cystatin C (0.88 ± 0.19 mg/L), serum TSH (1.8 ± 1 mIU/L), and for 24 h urinary calcium secretion (6.9 ± 3.3 mmol/24 h). We found a very weak relationship between the dosage of oral vitamin D3 and the subsequent calcium levels, both in serum and in urinary excretion over 24 h, respectively. Conclusions: Our data show the reliable safety of the CP in autoimmune patients under appropriate supervision by experienced physicians.     

A descriptive cross-sectional study of the prevalence of 25-hydroxyvitamin D deficiency and association with bone markers in a hospitalized population

Patients with gastrointestinal disease may be in particular risk of hypovitaminosis D because of reduced intestinal uptake or metabolism in the liver. The aim of the present study was to evaluate the prevalence of vitamin D deficiency in several groups of patients with various gastroenterologic diseases compared with patients without any chronic disease. We tested the hypothesis that persons with a gastrointestinal disease are at higher risk of hypovitaminosis D than persons with no chronic disease and whether this group needs special attention regarding their nutrition. We included patients admitted to our department of gastroenterology. The concentration of 25-hydroxyvitamin D (25(OH)D2+D3) was defined as insufficient when less than 50 nmol/L, deficient when less than 25 nmol/L, and severely deficient when less than 12.5 nmol/L. We included 146 patients with a mean age of 55 years (range, 16-93 years). 25(OH)D was sufficient in 47%, insufficient in 29%, deficient in 12%, and severely deficient in 11% of the population. Participants without chronic disease had a significantly higher mean level of 25(OH)D (57 nmol/L) compared to participants with cirrhosis (15 nmol/L, P = .002) and alcoholism (31 nmol/L, P = .003). A linear relationship between 25(OH)D and alkaline phosphatase could be demonstrated (Spearman ρ, −0.299; P < .001). Participants with severe 25(OH)D deficiency had higher levels of total alkaline phosphatase (149.5 vs 76 U/L, P = .001) and parathyroid hormone (5.1 vs 2.8 pmol/L; P = .001). We recommend measuring the level of 25(OH)D and parathyroid hormone in patients with chronic diseases, especially alcoholism and cirrhosis.     

育龄期多囊卵巢综合征妇女25(OH)D3水平与超重及胰岛素抵抗的相关性分析

目的 探讨育龄期妇女多囊卵巢综合征(PCOS)患者中25羟基维生素D3[25(OH)D3]水平与超重和胰岛素抵抗的相关性。方法 选择2017年3月至2019年12月在徐州市肿瘤医院就诊的育龄期PCOS患者265例,测量患者的一般体征、25(OH)D3水平及血清学资料。结果 随着25(OH)D3的升高,超重人群所占比例逐渐下降(P趋势＜0.001);随着25(OH)D3的升高,超重的风险逐渐降低(P趋势＜0.001),校正年龄、血压等指标后,负向关联依然存在(P趋势＜0.001)。Pearson相关显示,25(OH)D3与空腹胰岛素、空腹血糖和HOMAIR指数呈负相关(r=-0.289,P＜0.001, r=-0.113,P＜0.001, r=-0.273,P＜0.001 ),控制年龄、BMI、甘油三酯和总胆固醇后,负相关关系仍然存在(r=-0.271,P＜0.001, r=-0.096,P=0.024, r=-0.255,P＜0.001);校正代谢因素的多因素线性回归分析显示,25(OH)D3水平与HOMAIR存在负相关(P＜0.001)。结论 PCOS患者补充25(OH)D3可减少肥胖和胰岛素抵抗的发生,预防肥胖和糖尿病疾病。     

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.