Evaluation, treatment, and prevention of vitamin D deficiency: an Endocrine Society clinical practice guideline

Vitamin D: What role in obesity-related cancer?

Obesity is an important risk factor for incidence and death for many types of cancer. Vitamin D reduces risk of incidence and death for many types of cancer. This review outlines the mechanisms by which obesity increases risk of cancer, how vitamin D reduces risk of cancer, and the extent to which vitamin D counters the effects of obesity in cancer. Vitamin D is a partial ally against some of obesity's pro-carcinogenic effects, notably by reducing inflammation and regulating sex hormone receptors, leptin resistance, cellular energy metabolism, the microbiome, and hypoxia. However, it can act stronger in against the renin-angiotensin system, insulin resistance, and oxidative stress in cancer. Additionally, excess fat tissue sequesters vitamin D and, along with its dilution in increased body volume, further reduces its bioavailability and serum concentration, limiting its protective effects against cancer. In conclusion, while vitamin D cannot reverse obesity, it plays a significant role in mitigating its pro-carcinogenic effects by targeting several mechanisms.

Analytical performance evaluation and optimization of serum 25(OH)D LC-MS/MS measurement

OBJECTIVES

Measuring serum 25-hydroxyvitamin D is key in clinical labs, but inter-laboratory variations risk diagnostic errors. This study evaluates the performance of current in-house liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods used in top Chinese clinical laboratories and proposes an optimized method for improving serum 25(OH)D measurement accuracy and reliability.

METHODS

Seven serum pools with different concentrations of 25(OH)D were prepared and sent to 12 participating laboratories for multiple repeat analysis with their current in-house LC-MS/MS methods and then an optimized LC-MS/MS method. Precision was assessed in terms of coefficient of variance (CV), and trueness was assessed in terms of bias referring to the U.S. National Institute of Standards and Technology (NIST) reference measurement procedure (RMP). The analytical performances of the two methods were compared and evaluated.

RESULTS

Eighty percent and 90 % of the laboratories achieved the defined performance criteria (CV, <12.5 %; mean bias, <8.3 %) with the optimized method for the measurement of 25(OH)D2 and 25(OH)D3, compared with 43 % and 57 % of the laboratories meeting the criteria with their in-house methods, respectively. Precision and trueness improved after applying the optimized method. Although the optimized method didn't not ensure that all laboratory samples meet the measurement uncertainty (MU) criteria (MU<13.6 %), particularly for low-concentration samples, it significantly reduced the MU compared to the in-house method.

CONCLUSIONS

Precision, trueness and MU improved after applying the optimized method. Nonetheless, more efforts are needed to ensure the reliability and accuracy of 25(OH)D measurements in clinical laboratories in China.

Effect of vitamin D supplementation on glycemic control in children and adolescents with type 1 diabetes mellitus: Data from a controlled clinical trial

AIM

To evaluate the effect of vitamin D supplementation on vitamin D deficiency (VDD) and glycemic control in children and adolescents with type 1 diabetes mellitus (T1DM).

METHODS

This controlled clinical trial involved children and adolescents with T1DM for at least one year. Participants with VDD (25(OH)D < 30 ng/mL) were allocated to the intervention group and oral supplementation with cholecalciferol was prescribed at a dose of 2000 IU/day for 12 weeks. Sociodemographic, clinical, laboratory, lifestyle,anthropometric data and the Fok-I polymorphism (rs2228570) vitamin D receptor were collected. The effect of the intervention was assessed using Glass's Delta.

RESULTS

Of the 133 participants, 77.4 % were assigned to the intervention group (n = 103). Serum 25(OH)D concentration increased from 19.2 ± 6.2 to 30.9 ± 10.1 ng/mL (Glass's Delta = 1.2; CI 0.8/-1.4).A minimal effect was showed on glycemic control (Glass's Delta = 0.1; CI -0.2/0.4). A higher dose of insulin (β = -4.6; CI -8.1/-1.1; p = 0.010) and a high BMI (β = -0.3; CI - 0.6/-0.01; p = 0.059) were associated with lower serum 25(OH)D concentration, and sedentary (β = 0.20; CI - 0.1/0.7; p = 0.004) associated with higher HbA1C after 12 weeks of supplementation.

CONCLUSION

Oral cholecalciferol supplementation was effective in correcting VDD. This study identified the minimal effect of this intervention on glycemic control.

Vitamin D deficiency and its potential associations on the health status of older patients with chronic obstructive pulmonary disease in rural Crete, Greece: A cross-sectional study

BACKGROUND & AIMS

While low vitamin D levels are common in Chronic Obstructive Pulmonary Disease (COPD) and have been associated with various adverse COPD-related outcomes, data on vitamin D status in rural COPD cohorts is limited. Therefore, the present study aimed to assess the prevalence of Vitamin D deficiency among patients with COPD living in rural areas and explore its potential association on the overall health status.

METHODS

This cross-sectional study included 138 participants >40 years with COPD from the prospective "COlaborative care vs usual CARE in primary care patients with COPD" (COCARE) study. Sociodemographic characteristics, medical history, patient's health-related quality of life (HRQoL) with the COPD Assessment Test (CAT), fatigue with the Fatigue Severity Scale (FSS), phycological parameters with Patient Health Questionnaire-9 (PHQ-9) and General Anxiety Disorder-7 (GAD-7), sleep disorders with the COPD and Asthma Sleep Impact Scale (CASIS), Athens Insomnia Scale (AIS) and the Epworth Sleepiness Scale (ESS) were collected. Vitamin D deficiency was defined as levels of 25-hydroxy (OH)-Vitamin D below 20 ng/mL. Multiple logistic regression analysis was conducted to test for associations of Vitamin D deficiency with CAT, FSS, PHQ-9, GAD-7, CASIS, AIS, and ESS, adjusting for age, gender, smoking status, comorbidities, and seasonality.

RESULTS

Most of the participants were male (70 %) with a mean age of 68 ± 9 years and a mean Body Mass Index (BMI) of 30 ± 6 kg/m2. Moreover, 33 % of the participants had Vitamin D deficiency. Vitamin D deficiency increased the odds for worse HRQoL (CAT≥10 OR: 2.3, CI: 0.9-6.4, p = 0.008), greater fatigue severity (FSS, OR: 1.2, CI: 0.4-3.1, p = 0.756), more depressive (PHQ-9≥5, OR: 2.9, CI: 1.1-7.4, p = 0.024), anxiety (GAD-7, OR: 0.8, CI: 0.3-2.1, p = 0.592) and insomnia symptoms (AIS score OR: 1.1, CI: 0.7-5, p = 0.29), excessive daytime sleepiness (ESS, OR: 1.1, CI: 0.7-5, p = 0.29), and lower sleep quality (CASIS OR: 2.5, CI: 0.9-6.5, p = 0.006).

CONCLUSION

In conclusion, our findings indicate that Vitamin D deficiency is positively associated with numerous negative health outcomes of patients with COPD, including worse HRQoL, fatigue, depression, anxiety and sleep disorders. However, further research is needed to determine the role of Vitamin D in the health status of these patients.

Synergistic impact of 25-hydroxyvitamin D and physical activity on incident depression: Evidence from a prospective cohort and genome-wide data

BACKGROUND

The relationship between 25-hydroxyvitamin D [25(OH)D] levels, physical activity (PA), and depression risk remains underexplored. This study examines how combinations of 25(OH)D and PA influence depression.

METHODS

We conducted a longitudinal analysis using data from the English Longitudinal Study of Ageing, including cognitively healthy adults aged 50 years and older at baseline. Baseline measurements of PA and 25(OH)D were taken, with depression as the primary outcome. Multivariate Cox proportional hazards models were used, with and without interaction terms. Furthermore, two-sample Mendelian randomization (MR) analyses were performed.

RESULTS

A total of 4146 participants (mean age: 66.0 years; 52.1 % female) were followed for eight years. Multivariate-adjusted hazard ratios (HRs) for depression were 0.71 (95 % CI: 0.61-0.83) for those with high 25(OH)D and PA (P = 0.005), 0.79 (95 % CI: 0.63-0.99) for those younger than 65 (P = 0.042), and 0.65 (95 % CI: 0.53-0.80) for those 65 and older (P = 0.041). A significant interaction between low 25(OH)D and PA was found in the younger group (HR: 1.43, 95 % CI: 1.03-1.99, P = 0.034). High 25(OH)D and PA independently reduced depression risk by 7.2 % and 7.7 %, respectively, with a 23.1 % reduction when combined. Mendelian randomization confirmed these findings.

CONCLUSIONS

High 25(OH)D levels are linked to lower depression risk. The combination of high 25(OH)D and PA provides synergistic protection, particularly in older adults, emphasizing the need for vitamin D supplementation and PA in depression prevention.

Hypoparathyroidism: diagnosis, management and emerging therapies

Hypoparathyroidism is characterized by inadequate parathyroid hormone (PTH) secretion or action and results in hypocalcaemia, and can lead to hyperphosphataemia and hypercalciuria. Most cases of hypoparathyroidism occur as a complication of surgery, with the remainder due to causes including autoimmune disease, genetic causes, infiltrative diseases, mineral deposition or due to abnormalities in serum levels of magnesium. Hypoparathyroidism can cause multisystem disease, with long-term complications resulting from ectopic calcification as well as renal complications with nephrocalcinosis, nephrolithiasis and renal impairment in addition to respiratory, cardiac or neurological manifestations. Conventional therapy consists of oral calcium salts and active vitamin D but it has limitations, including fluctuations in serum levels of calcium and a high pill burden, and can increase the risk of long-term complications. By contrast, PTH replacement therapy can effectively achieve normal serum levels of calcium, and lower serum levels of phosphate. The long-acting PTH analogue, palopegteriparatide, has been shown to normalize urine levels of calcium. In addition, PTH replacement therapy reduces the pill burden. Palopegteriparatide is also associated with improved quality of life in comparison to conventional therapy. This Review summarizes current recommendations regarding the pathophysiology, evaluation and management of hypoparathyroidism and also references the 2022 international hypoparathyroidism guidelines. Palopegteriparatide has now been approved as PTH replacement therapy for hypoparathyroidism. Emerging therapies will also be presented in this Review.

Threshold-dependent risk of postoperative hypocalcemia in vitamin D-deficient patients undergoing total thyroidectomy: A meta-analysis

BACKGROUND

Vitamin D deficiency is common and asymptomatic in many populations, and research reveals an association between vitamin D levels and postoperative hypocalcemia after total thyroidectomy. However, the definition of vitamin D deficiency has varied, and the threshold used might have a major impact on clinical results. The purpose of this study was to investigate the threshold effect in the relationship between vitamin D deficiency and the incidence of postoperative hypocalcemia.

METHODS

A meta-analysis was done following Preferred Reporting Items for Systematic reviews and Meta-Analyses recommendations. Studies that examined preoperative vitamin D levels and assessed postoperative hypocalcemia in total thyroidectomy patients were included. The investigation explored 3 vitamin D insufficiency thresholds: 15, 20, and 30 ng/mL. Odds ratios for biochemical and clinical hypocalcemia were determined, and sensitivity analyses were conducted to ensure the findings were robust. The methodologic quality was assessed using the Quality In Prognosis Studies technique.

RESULTS

Twenty-eight studies were included, with 4,944 patients, 80.4% of whom were female. The risk of having postoperative biochemical hypocalcemia was highest at the 15 ng/mL threshold (odds ratio 3.22, 95% confidence interval 1.69-6.12), and reduced as the threshold increased to 20 ng/mL (odds ratio 1.69, 95% confidence interval 1.17-2.45) and 30 ng/mL (odds ratio 1.87, 95% confidence interval 1.20-2.91). Similar patterns were seen in clinical hypocalcemia.

CONCLUSION

This investigation demonstrates the existence of a threshold effect in the relationship between vitamin D deficiency and postoperative hypocalcemia after total thyroidectomy. The classification of vitamin D deficiency has a substantial impact on clinical outcomes, highlighting the significance of standardizing criteria to enhance preoperative treatment and patient care.

Effects of vitamin D supplementation on symptoms and clinical outcomes in adults with different baseline vitamin D levels: an interventional study

BACKGROUND

Hypovitaminosis D or vitamin D deficiency is a significant public health issue. Several vitamin D preparations are currently available. However, there is no consensus on the optimal dose and duration of vitamin D supplementation. This study aimed to evaluate the effects of vitamin D supplementation on symptoms and clinical outcomes in adults with insufficient or deficient baseline vitamin D levels.

METHOD

A pre-post two-month intervention with 50,000 IU vitamin D3 supplementation for adults with documented insufficient or deficient baseline vitamin D levels, presented at Jazan University Hospital from August to December 2022.

RESULTS

Of the 204 participants, 65.1% had baseline vitamin D levels < 30 nmol/L. Vitamin D insufficiency is more prevalent among females, older adults, married individuals, and those with low income. However, these differences were not statistically significant (p > 0.5). The symptoms and clinical outcomes were significantly improved after 2 months of vitamin D3 supplementation for the participants who achieved vitamin D levels > 50 nmol/L (p = 0.000). After adjusting for multiple confounders, the significant determinants of symptom improvement and clinical outcomes post-supplementation included education level, income, smoking status, and baseline vitamin D level.

CONCLUSIONS

Hypovitaminosis D or vitamin D deficiency was observed in study participants. The use of a 50,000 IU cholecalciferol (vitamin D3) orally once per week for two months is sufficient to improve the symptoms and clinical outcomes of vitamin D deficiency. However, long-term follow-up could better assess the sustainability of benefits and explore long-term outcomes, such as the risk of deficiency recurrence.

CLINICAL TRIAL NUMBER

Not applicable.

Mild to moderate COPD, vitamin D deficiency, and longitudinal bone loss: The MESA study

OBJECTIVE

Despite the established association between chronic obstructive pulmonary disease (COPD) severity and risk of osteoporosis, even after accounting for the known shared confounding variables (e.g., age, smoking, history of exacerbations, steroid use), there is paucity of data on bone loss among mild to moderate COPD, which is more prevalent in the general population.

METHODS

We conducted a longitudinal analysis using data from the Multi-Ethnic Study of Atherosclerosis. Participants with chest CT at Exam 5 (2010-2012) and Exam 6 (2016-2018) were included. Mild to moderate COPD was defined as forced expiratory volume in 1 s (FEV1) to forced vital capacity ratio of <0.70 and FEV1 of 50 % or higher. Vitamin D deficiency was defined as serum vitamin D < 20 ng/mL. We utilized a validated deep learning algorithm to perform automated multilevel segmentation of vertebral bodies (T1-T10) from chest CT and derive 3D volumetric thoracic vertebral BMD measurements at Exam 5 and 6.

RESULTS

Of the 1226 participants, 173 had known mild to moderate COPD at baseline, while 1053 had no known COPD. After adjusting for age, race/ethnicity, sex, body mass, index, bisphosphonate use, alcohol consumption, smoking, diabetes, physical activity, C-reactive protein and vitamin D deficiency, mild to moderate COPD was associated with faster decline in BMD (estimated difference, β = -0.38 g/cm3/year; 95 % CI: -0.74, -0.02). A significant interaction between COPD and vitamin D deficiency (p = 0.001) prompted stratified analyses. Among participants with vitamin D deficiency (47 % of participants), COPD was associated with faster decline in BMD (-0.64 g/cm3/year; 95 % CI: -1.17 to -0.12), whereas no significant association was observed among those with normal vitamin D in both crude and adjusted models.

CONCLUSIONS

Mild to moderate COPD is associated with longitudinal declines in vertebral BMD exclusively in participants with vitamin D deficiency over 6-year follow-up. Vitamin D deficiency may play a crucial role in bone loss among patients with mild to moderate COPD.

Acute Management of Hypercalcemia of Malignancy - A Review of Pathophysiology, Diagnosis, and Treatment

PURPOSE OF REVIEW

Hypercalcemia of malignancy is one of the most common metabolic disorders in patients with cancer and is associated with significant morbidity and mortality. This narrative review summarizes pathophysiology, clinical presentation, diagnostic strategies, and therapies available for the management of hypercalcemia of malignancy in acutely ill adult patients.

RECENT FINDINGS

We reviewed both classic and recent literature to provide practical recommendations for managing cancer-related hypercalcemia. Our findings are presented in the context of recently published societal guidelines. Timely identification and treatment of acute hypercalcemia of malignancy is vital. Understanding of the underlying disease processes and available therapies is needed to optimize patient care and healthcare resource utilization.

Vitamin D-related risk factors for preterm and full-term infants at birth: a retrospective study

BACKGROUND

Preterm birth affects a child's development and health. Vitamin D may influence the health of neonates. Our objective was to evaluate vitamin D levels and contributing factors in preterm and full-term newborns in Wuxi, China.

METHODS

A retrospective study was performed on neonates at the Affiliated Women's Hospital of Jiangnan University from May 2020 to May 2022. The neonates were classified into three categories: very preterm (< 32+ 0 weeks, n = 167), preterm (32+ 0-36+ 6 weeks, n = 454), and full-term (≥ 37+ 0 weeks, n = 192). Serum concentrations of 25-hydroxyvitamin D were assessed. We employed the Kruskal-Wallis test, Mann-Whitney U tests, or chi-squared tests to compare categorical variables. The binary logistic regression study aimed to identify potential risk variables.

RESULTS

The median blood 25-hydroxyvitamin D concentration was 35.9 nmol/L, with roughly 82.7% categorized as vitamin D deficiency. However, the frequency of vitamin D insufficiency did not vary significantly across the three groups. Serum 25-hydroxyvitamin D levels at birth in full-term, preterm, and very preterm children exhibit substantial differences when mother body mass index exceeds 30 kg/m² (P < 0.001). Newborn vitamin D levels shown considerable variations among three groups categorized by maternal body mass index, maternal age, and season of birth. In terms of the preterm birth phenotypes, deficiency was significantly associated with fetal growth restriction, fetal distress, and neonatal infections. No significant differences in vitamin D levels were observed among the three groups for mode of conception, number of gestations, or maternal gestational age. Furthermore, the deficiency rates of vitamin D were not markedly different among full-term, preterm, and very preterm newborns.

CONCLUSION

Vitamin D levels in newborns were correlated with maternal obesity, maternal age, season of birth, preeclampsia, fetal growth restriction, neonatal infection, and fetal distress. At delivery, full-term infants born to women with a BMI exceeding 30 kg/m² or those delivered in winter exhibit significantly elevated levels of 25-hydroxyvitamin D compared to preterm and very preterm newborns.

Vitamin D Deficiency and Interleukin-6: Risk Factors for Preterm Birth in Black Women: A Retrospective cross-sectional study

BACKGROUND

Non-Hispanic Black women have a 1.5 times greater rate of preterm birth (PTB, any birth occurring at <37 weeks' gestation) than non-Hispanic White women. Black women are also more likely to have vitamin D deficiency (VDD; 25[OH]D <20 ng/ml) than White women. Vitamin D has anti-inflammatory effects, which may help explain the association of VDD with PTB in Black women.

OBJECTIVE

To examine associations between inflammatory biomarkers and VDD with PTB as an outcome.

METHODS

We used an exploratory retrospective cross-sectional design utilizing data collected as part of the larger Biosocial Impact on Black Births (BIBB) study. A case-control subsample was selected from the BIBB participants who had stored blood plasma available at 8-25 weeks gestation (n = 172). Fifty-nine PTB cases were included in the current study, with a set of matched controls based on maternal age controls at a 1:2 ratio of PTB to term birth (n = 113, 65.6%). Total 25(OH)D and cytokine levels were measured in the plasma.

RESULTS

Seventy percent of women with PTB had VDD compared with 50% of women with term birth who had VDD. Other inflammatory biomarkers were not associated with PTB except for Interleukin-6 (IL-6). The PTB group had higher IL-6 and lower 25(OH)D levels compared to term birth. In adjusted models controlling for IL-6 and other covariates, odds ratios for VDD remained significant for predicting PTB (OR: 2.45; 95% CI 1.18-5.06; p = .016).

CONCLUSIONS

Increased VDD was associated with increased risk of PTB among Black women after controlling for IL-6 and other factors. Achieving adequate vitamin D status in early pregnancy may have an important role in PTB prevention as it is a significant predictor of risk after inflammation and other factors are considered. Further investigation is warranted.

Exposure to seasonal PM2.5 derived from biomass burning increased the risk of vitamin D deficiency in healthy perimenopausal women

OBJECTIVE

Southeast Asia faces problems with seasonal air pollution from biomass burning. Data regarding vitamin D deficiency and seasonal air pollution is limited. Therefore, this study aimed to determine the effects of seasonal air pollutants on vitamin D deficiency and the predictors of vitamin D deficiency during haze periods.

METHODS

This prospective cohort study included 77 peri-menopausal women. All participants were enrolled and followed at the peak and low pollutant periods, respectively. Serum 25-hydroxyvitamin D (25(OH)D) was measured at both points. Data regarding 24 h particulate matter with a diameter less than 2.5 µm (PM2.5) was obtained from the database of the Pollution Control Department of Thailand.

RESULTS

The ambient 24 h PM2.5 was higher (46.9 ± 4.7 µg/m3 vs. 11.2 ± 5.1 µg/m3, P < 0.001) at the peak pollutant period. In contrast, serum 25(OH)D level was 18.8% lower, and the incidence of vitamin D deficiency was 45.4% higher at the peak pollutant period compared to those at the low pollutant period. Seasonal air pollutants were associated with an increased risk of vitamin D deficiency by 3.5 folds [OR 3.5 (95% CI 1.1-14.6)]. The ambient 24 h PM2.5 during the peak pollutant periods was an independent predictor of vitamin D deficiency. Its threshold of 20 µg/m3 demonstrated sensitivity, specificity, and accuracy of 75.0%, 85.7%, and 78.0%, respectively, to predict the occurrence of vitamin D deficiency.

CONCLUSION

Seasonal air pollutants increase the risk of vitamin D deficiency. The ambient 24 h PM2.5 at 20 µg/m3 demonstrated high diagnostic performance for vitamin D deficiency.

The Impact of Minimal Sunlight Exposure on Bone Health: Insights From a Cohort Study in Erythropoietic Protoporphyria

CONTEXT

Erythropoietic protoporphyria (EPP) is a rare inherited metabolic disease, causing lifelong painful phototoxic reactions, minimal sunlight exposure, and vitamin D deficiency. Previous studies reported a high osteoporosis prevalence in EPP patients.

OBJECTIVE

To identify those at risk for low bone mineral density (BMD) and assess which factors, including treatment with cholecalciferol and afamelanotide, improve BMD in EPP.

METHODS

A longitudinal ambispective single-center cohort study. Data from patient files and two-time questionnaires from adult patients with EPP who underwent at least one dual-energy x-ray absorptiometry (DXA) scan between 2012 and 2023 were used.

RESULTS

BMD is low in EPP patients, with 82.7% of the 139 patients having a Z-score below 0 SD at baseline. Low BMD classified as osteopenia was found in 39.5%, and osteoporosis in 15.3%. There were 50 osteoporosis-related fractures in 34.2% of patients. Aging (odds ratio [OR] 1.08; CI, 1.03-1.12), persistent vitamin D deficiency (OR 1.11; 95% CI, 1.00-1.23) and a low body mass index (OR 0.91; 95% CI, 0.82-0.99) increased the odds of low BMD. Patients with a vitamin D deficiency (OR 5.51; 95% CI, 1.69-17.92) and no cholecalciferol at baseline (OR 0.22; 95% CI, 0.04-1.34) had the highest odds of improving their BMD. Afamelanotide did not improve BMD.

CONCLUSION

25-hydroxyvitamin D (25(OH)D) status plays a crucial role in both preventing low BMD and improving BMD. EPP is a natural model for lack of sunlight exposure and vitamin D deficiency, underlining the importance of lifelong adequate vitamin D status for bone health in the general population.

Transcriptomic profiling of immune modulation induced by vitamin D3 in the VitDPAS and VitDHiD cohort studies

The VitDPAS study (NCT06104111) was designed as a medical experiment to assess the in vivo effects of vitamin D on immune responses. This study enrolled 45 healthy individuals from Olsztyn, Poland, who received a body weight-adjusted bolus dose of vitamin D3 (1,000 IU/kg). Transcriptome-wide differential gene expression analysis of peripheral blood mononuclear cells, collected before and 24 h after supplementation, identified 758 significantly responsive genes (p < 0.05). By correlating individual gene expression changes with alterations in vitamin D status, participants were categorized into three response groups: 17 high responders, 19 mid responders, and 9 low responders. A comparative analysis with the VitDHiD study (NCT03537027), conducted on a Finnish cohort of 25 healthy participants, revealed 232 overlapping target genes, enabling an integrated assessment of vitamin D responsiveness across all 70 individuals. Applying a more stringent statistical threshold (false discovery rate < 0.05) highlighted 26 shared target genes, demonstrating a consistent in vivo response to vitamin D3 across both cohorts. The modulation of inflammatory processes, mediated primarily via tumor necrosis factor and nuclear factor κB signaling pathways, emerged as a shared effect, highlightening the immunomodulatory potential of vitamin D as a key function of the vitamin in healthy individuals.

Serial Changes in Vitamin D Status in Patients During Severe Acute Respiratory Distress Syndrome and Extracorporeal Membrane Oxygenation

Background and Objectives: Therapeutic interventions, such as extracorporeal membrane oxygenation (ECMO) therapy, in patients suffering from severe acute respiratory distress syndrome (ARDS) may reduce their vitamin D levels. Many observational studies have shown associations between poor outcomes and low vitamin D levels in critically ill patients. This retrospective study primarily aimed to investigate the time-dependent changes in vitamin D levels and the correlation of vitamin D levels with disease severity and inflammatory markers in patients suffering from ARDS receiving ECMO therapy. Materials and Methods: This study used a longitudinal approach to assess the serial changes and the correlations of vitamin D levels (25-hydroxyvitamin D (25(OH)D) and 1,25-dihydroxyvitamin D (1,25(OH)2D)) with disease severity and inflammatory markers in 24 invasively mechanically ventilated (IMV) patients treated using ECMO over a period of 17 days. Most of the patients in this study were suffering from severe coronavirus disease 2019 (COVID-19) (n = 19; 79%). Serial blood samples collected during routine blood draws were retrospectively analyzed to assess the dynamics of their vitamin D levels over 17 days of ICU therapy. Results: Hypovitaminosis D (25(OH)D ≤ 50 nmol/L) was prevalent in 18 (75%) patients, while values of 25(OH)D lower than 30 nmol/L were measured in 5 patients (21%), indicating severe deficiency. Additionally, 1,25(OH)2D showed a significant decrease within the first 11 days of intensive care unit (ICU) treatment (these levels dropped by 28%; p = 0.03) and then remained at similar levels throughout the observational period; 25(OH)D levels remained largely unchanged during the observation period. We observed that 25(OH)D showed a significant negative correlation with C-reactive protein (CRP) (p = 0.04), and that 25(OH)D and 1,25(OH)2D levels did not show correlations with disease severity. Conclusions: Patients suffering from severe COVID-19 ARDS showed a significant decrease in their 1,25(OH)2D levels from day 0 to day 11 in the ICU. Therefore, routine vitamin D substitution and monitoring in critically ill patients, especially for patients suffering from ARDS treated with ECMO, should be carried out to prevent hypovitaminosis D. In addition, vitamin D may be associated with inflammation. Further studies are necessary to elucidate the mechanisms behind these retrospective observations.

Vitamin D deficiency in relation to different phenotypes of prediabetes: a population-based study

PURPOSE

Vitamin D deficiency is implicated in the development of prediabetes. However, it is unclear whether vitamin D deficiency showed any relationship with different phenotypes of prediabetes. This study was designed to address this issue.

METHODS

We included participants from the National Health and Nutrition Examination Survey 2011-2016. Prediabetes is classified into the following phenotypes: an isolated defect (that is, impaired fasting glucose [IFG], impaired glucose tolerance [IGT], or impaired hemoglobin A1c[IA1c]), two defects (that is, IFG+IGT, IFG+IA1c, or IGT+IA1c), or three defects (that is, IFG+IGT+IA1c). Multivariate logistic regression analysis was used to obtain the odds ratio (OR) and 95% confidence intervals (CIs).

RESULTS

A total of 4126 participants (2332 with prediabetes and 1794 with normal glycemia) were included in this study. Multivariate logistic regression analysis showed that prediabetes was associated with an increased odds of vitamin D deficiency than normal glycemia (OR 1.216, 95% CI 1.023-1.444). Further analysis showed that prediabetes phenotypes of IGT+IFG (OR 1.549, 95% CI 1.050-2.283) and IFG+IGT + IA1c (OR 1.507, 95% CI 1.062-2.138) had an increased odds of vitamin D deficiency. The odds of vitamin D deficiency was higher in individuals with glucose-defined prediabetes, but not in those with HbA1c-defined prediabetes when compared with individuals with normal glycemia.

CONCLUSION

Prediabetes was associated with an increased odds of vitamin D deficiency, and glucose-defined prediabetes might be a better predictor of vitamin D deficiency.

CT-Based Evaluation of Hounsfield Units-A Novel Screening Tool for Undiagnosed Osteoporosis in Patients with Fragility Fractures of the Pelvis

Background: This institutional, register-based analysis aimed to evaluate the feasibility of using CT-based sacral Hounsfield units (HUs) for assessing bone density in pelvic fragility fractures and to explore their potential correlation with DEXA measurements and osteological laboratory diagnostics. Methods: Patients aged > 80 years, admitted between 2003 and 2019 with pelvic ring fractures, were analyzed in this retrospective single-center study. CT scans were evaluated according to the classification of fragility fractures of the pelvis (FFPs), which guided treatment decisions (conservative or surgical). The diagnosis of a fragility fracture was based on both fracture morphology and patient history, including the presence of low-energy trauma. Bone health was assessed using standardized laboratory diagnostics including serum calcium, phosphate, alkaline phosphatase, and 25(OH)-vitamin D, in addition to DEXA scans and CT-derived Hounsfield units. Vitamin D levels and bone density evaluations were analyzed to identify possible correlations among these factors and with fracture patterns. Results: A total of 456 patients (mean age 87.3 years, 79.6% female) were included. The CT-based FFP classification identified Type II as the most common fracture type (66.7%). Conservative treatment was the predominant approach (84.9%). Serum 25(OH)-vitamin D deficiency was observed in 62.7% of the patients, while osteopenia and osteoporosis were found in 34.3% and 46.5% of cases, respectively. HU values at S1 showed significant correlation with femoral neck T-scores, highlighting the utility of CT scans for bone density assessment. Conclusions: This study emphasizes the complementary roles of CT-derived HU values and DEXA T-scores in evaluating bone quality and fracture severity in geriatric patients with FFP. While DEXA remains the gold standard, CT imaging offers valuable early insights, supporting the timely initiation of osteoporosis therapy. Given the high prevalence of fragility fractures in this age group, early CT-based screening may facilitate earlier initiation of osteoporosis-specific therapy, including anabolic agents where indicated. Further research is needed to explore the relationships between vitamin D levels, bone density assessments, and fracture types.

Vitamin D status, vitamin D receptor polymorphisms, and risk of cardiometabolic multimorbidity

BACKGROUND

The prevalence of cardiometabolic multimorbidity (CMM) has increased substantially in recent years. Previous studies have established the associations between vitamin D, vitamin D receptor (VDR) polymorphisms, and the risk of individual cardiometabolic disease (CMD). However, the role of these factors in the progression of CMD to CMM or mortality remains unclear. This study aimed to investigate the associations between vitamin D, VDR polymorphisms, and the dynamic progression of CMM, as well as to explore the potential modification effect of VDR polymorphisms.

METHODS

Data for this cohort study were extracted from the UK Biobank. CMM was defined as the coexistence of at least two CMDs, including type 2 diabetes (T2D), coronary heart disease (CHD), and stroke. A multi-state model was used to analyze associations between serum 25(OH)D, VDR polymorphisms and the dynamic progression of CMM.

RESULTS

The sample included 396,192 participants. Over a median follow-up of 13.8 years, 55,772 individuals experienced at least one CMD and 28,624 died. Compared to participants with 25(OH)D < 25 nmol/L, those with 25(OH)D ≥ 75 nmol/L had HRs of 0.70 (95% CI, 0.67, 0.72) for baseline to first CMD (FCMD), 0.74 (95% CI, 0.67, 0.82) for FCMD to CMM, 0.66 (95% CI, 0.62, 0.70) for baseline to death, 0.84 (95% CI, 0.77, 0.92) for FCMD to death, and 0.85 (95% CI, 0.70, 1.03) for CMM to death. L-shaped relationships of these associations were noted, with a threshold around 45 nmol/L. The rs1544410 (BsmI) T alleles may have a detrimental effect, while the rs11568820 (Cdx2) T alleles may exert a protective effect in the early stages of CMM progression. Additionally, VDR polymorphisms significantly modified the association between serum 25(OH)D and certain stages of CMM progression.

CONCLUSIONS

Maintaining adequate vitamin D levels, as a readily implementable intervention strategy, not only reduces the risk of initial CMD but also delays the progression to CMM or death. Risk stratification based on VDR polymorphisms provides further insights for developing personalized prevention strategies.

Type 1 Diabetes Mellitus and Vitamin D

Type 1 diabetes mellitus (T1DM) is a multifactorial disease in which environmental factors and genetic predisposition interact to induce an autoimmune response against pancreatic β-cells. Vitamin D promotes immune tolerance through immunomodulatory and anti-inflammatory functions. The aim of this study is to provide a narrative review about the association between vitamin D status in the pathogenesis of T1DM and the role of vitamin D supplementation in the prevention and treatment of T1DM. Although vitamin D deficiency is more prevalent in children/adolescents with new-onset T1DM than in healthy individuals, there does not appear to be an association between vitamin D status before diagnosis and the onset of T1DMD later in life. The results of vitamin D as adjuvant therapy have, at best, a positive short-term effect in newly diagnosed T1DM patients. Intervention studies have been conducted in the clinical phase of T1DM, but it would be desirable to do so in the early stages of the autoimmune process (pre-diabetes).

(-)-Epigallocatechin-3-gallate and chlorogenic acid in combination with vitamin D as a therapeutic approach for letrozole-induced polycystic ovary syndrome (PCOS) rats: Biochemical and hormonal modulation

Treatment with phytochemicals have shown promising results in managing various diseases including Polycystic ovary syndrome (PCOS) which is an endocrine gynecological disorder affecting reproductive aged women. This study has demonstrated that Epigallocatechin-3-gallate (EGCG) and chlorogenic acid (CGA) in combination with vitamin D can significantly reduce PCOS like characteristics including ovarian cysts, hyperandrogenism, fasting blood glucose level, insulin resistance, hyperlipidaemia, ROS formation, oxidative stress, DNA damage, and ovarian histomorphology in letrozole induced PCOS rats. PCOS was induced in female Wistar rats by giving 1 mg/kg/day letrozole for 21 days through oral gavage. EGCG (100 mg/kg/day) and CGA (120 mg/kg/day) in combination with vitamin D (25 mcg/kg/day) was given orally for 15 days, from day 21-35. Metformin treatment was used as a positive control. Histological, microscopic analysis, and chemiluminescent immunoassays were performed to evaluate decrement in PCOS like symptoms. Nitric oxide (RNS) production, antioxidant status, and the generation of reactive oxygen species (ROS) were also assessed. Ovary homogenates and plasma samples of rats were also examined for markers of protein, lipid, and DNA oxidation. Activities of enzymatic antioxidants (superoxide dismutase, catalase, glutathione reductase, Paraoxonase-1 status) were also evaluated. EGCG + vitamin D and CGA + vitamin D has been found to restore hormonal balance by modulating steroidogenic enzymes, they also improved antioxidant enzyme activity including SOD, catalase, glutathione reductase, PON-1 arylesterase, PON-1 CMPAase, etc. Similarly, EGCG + vitamin D and CGA + vitamin D treatment have shown efficacy in normalizing the estrus cycle, reducing ovarian cysts, and improving ovarian histomorphology. They also assisted in alleviating triglycerides and cholesterol levels and maintained liver function enzymes level. However, EGCG + vitamin D proves to have better therapeutic potential modulates glucose metabolic pathways, by reducing blood glucose levels, advanced glycation end product formation, decreasing ROS generation and oxidative stress; consequently, lowers hyperandrogenism and insulin resistance. Overall, EGCG + vitamin D treatment offers a comprehensive approach in managing PCOS by targeting multiple pathways associated with this disorder, making it a potential alternative to conventional therapies.

Vitamin D status and the adequacy of its supplementation during the first year of life in preterm infants in northern Japan

BACKGROUND

Vitamin D (VD) deficiency (VDD) is a major concern in preterm infants. The prevalence of VDD in mothers and infants varies between countries and is affected by a range of factors, such as geography and lifestyle. Thus, strategies aimed at preventing VDD must consider the status of each region. However, few reports have explored VDD in preterm infants in Japan and the safety and efficacy of VD supplementation in addressing VDD remain unclear.

METHODS

This study was conducted between September 2019 and October 2022. The participants were 108 preterm infants who were divided into three groups based on their gestational age: <28 weeks (Group 1), 28-33 weeks (Group 2), and 34-36 weeks (Group 3). VD status at birth was assessed, and 25-hydroxyvitamin D (25OHD) levels and biochemical markers were monitored during supplementation with 400 IU/day of VD over the first year of life.

RESULTS

Levels of 25OHD at birth were 10.0 (10.0-16.1), 10.5 (10.0-18.0), and 13.0 (10.0-19.0) nmol/L in Groups 1, 2, and 3, respectively. Infants in all three groups exhibited marked VDD. Their 25OHD levels gradually increased with VD supplementation before plateauing at 6 months. Nevertheless, VDD persisted in the majority of infants at 1 month of age. Serum intact parathyroid hormone levels peaked at 1 month of age and declined thereafter, negatively correlating with 25OHD levels. None of the infants exhibited symptoms of VD toxicity.

CONCLUSION

Preterm infants in northern Japan exhibited substantial VDD, regardless of gestational age. In our cohort, VD supplementation at 400 IU/day safely increased 25OHD levels. However, VD levels improved gradually over the months, and several of these infants developed secondary hyperparathyroidism. Further studies are warranted to determine the optimal VD supplementation dose for preterm infants in this region.

Nonlinear associations of serum vitamin D levels with advanced liver disease and mortality: a US Cohort Study

Background

Vitamin D deficiency is prevalent and linked to chronic diseases; its association with advanced liver disease progression requires clarification.

Objectives

To investigate the association between vitamin D levels and risks of liver cirrhosis, hepatocellular carcinoma (HCC), and mortality, and assess risk changes after achieving sufficiency post-supplementation.

Design

This was a retrospective cohort study.

Methods

Utilized TriNetX US data (3,905,594 patients, 2000-2024). Adults with vitamin D deficiency (20.00-30.00 ng/mL) were compared with those with sufficient levels (30.01-80.00 ng/mL). Follow-up was initiated from the first vitamin D test or start of supplementation to minimize immortal time bias. Propensity score matching (1:1) balanced >20 baseline confounders.

Results

After matching, 1,204,760 patients with vitamin D deficiency and 1,204,760 with sufficient vitamin D levels were included. Vitamin D deficiency was associated with an increased risk of liver cirrhosis (hazard ratio (HR), 1.30; 95% confidence interval (CI), 1.25-1.36), HCC (HR, 1.22; 95% CI, 1.08-1.37), and all-cause mortality (HR, 1.14; 95% CI, 1.13-1.16). Achieving sufficient vitamin D levels reduced the risk of all-cause mortality (HR, 0.93; 95% CI, 0.88-0.99) and aligned HCC outcomes (HR, 1.16; 95% CI, 0.68-2.00). However, it did not significantly reduce the risk of liver cirrhosis (HR, 2.05; 95% CI, 1.69-2.50). Dose-response analysis showed a U-shaped relationship for liver cirrhosis and HCC, with the lowest risks at 40-60 ng/mL.

Conclusion

Serum vitamin D levels showed a nonlinear association with liver cirrhosis and HCC risk; deficiency independently increased the risks for cirrhosis, HCC, and mortality. Supplementation achieving sufficiency reduced mortality and normalized HCC risk but not cirrhosis risk, potentially reflecting limitations in reversing established disease. The lowest liver disease risk was associated with vitamin D levels of 40-60 ng/mL in this cohort, although causality and the clinical benefit of targeting this specific range require confirmation.

Gene Expression Differences Based on Low Total 25(OH)D and Low VDBP Status with a Preterm Birth

Preterm birth (PTB; <37 weeks' gestation) is a persistent problem in the United States that affects non-Hispanic Black women at much higher rates than White women. Several biomarkers have been associated with PTB, including vitamin D deficiency (VDD) and low levels of vitamin D-binding protein (VDBP). However, no biomarker has been found to predict PTB. To identify a predictive biomarker of PTB, gene expression differences were determined in Black women with PTB and full-term births and between women with high and low levels of plasma vitamin D and high and low VDBP levels. In this pilot study of 19 pregnant women from the Biosocial Impact on Black Births (BIBB) study, we found that 47 genes were upregulated and 16 genes were downregulated in women with PTB as compared with women who had a full-term birth, 361 genes were downregulated and 61 genes were upregulated in women with VDD as compared with those that had vitamin D sufficiency, and 44 genes were upregulated and 295 were downregulated in women with low VDBP. Several genes expressed by neutrophils were downregulated in the PTB, VDD, and low VDBP groups. These findings support the idea that vitamin D and VDBP status may be important clinical markers influencing the gene expression of genes associated with PTB.

Association of calcium supplement with risk of incident arrhythmia

BACKGROUND AND AIMS

Calcium plays a crucial role in cardiac electrophysiology, but the association between calcium supplement and the risk of incident arrhythmia remains unclear.

OBJECTIVE

To investigate the relationship between habitual calcium supplement and incident risk of cardiac arrhythmia.

METHODS

We conducted a prospective study of 480,972 participants from the UK Biobank. Habitual calcium supplement was treated as the main exposure. The primary outcome was the incidence of arrhythmias, including atrial fibrillation/flutter (AF/AFL), ventricular arrhythmia (VA), and bradyarrhythmia. Cox proportional hazards regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

After a median follow-up of 11.69 years, 46,609 incident arrhythmia cases were documented, including 36,406 AF/AFL, 5,370 VA, and 14,226 bradyarrhythmia. After multivariable adjustment, calcium supplement was associated with an increased risk of total arrhythmias (HR 1.11, 95% CI 1.05-1.19), AF/AFL (HR 1.20, 95% CI 1.12-1.28), VA (HR 1.14, 95% CI 1.07-1.21), and bradyarrhythmia (HR 1.18, 95% CI 1.11-1.26). Significant interactions were observed between calcium supplement and estimated glomerular filtration rate, diabetes, cardiovascular disease, and polygenic risk score for AF (all p for interaction < 0.05).

CONCLUSIONS

Calcium supplement was associated with an increased risk of incident arrhythmia. Careful evaluation of the potential arrhythmic risk is warranted when considering calcium supplement in individuals with clinical indications.

Effect of Vitamin D Deficiency on Development of Slipped Capital Femoral Epiphysis

OBJECTIVE

Slipped capital femoral epiphysis (SCFE) is one of the most common hip disorders in adolescents, often linked to obesity. However, other factors, such as vitamin D deficiency, may also contribute to SCFE development. This study investigates the impact of vitamin D deficiency on SCFE development in a large cohort.

METHODS

We utilized the TriNetX national database to query pediatric patients with documented calcidiol levels. Patients with a recorded visit below the age of 9 and subsequent documented calcidiol levels were followed until SCFE occurrence or age 18. Patients were categorized into vitamin D adequate (≥ 30 ng/mL) and deficient (< 30 ng/mL) groups. Propensity score matching was performed using a multivariable logistic regression model to adjust for baseline characteristics, including age, sex, race, and body mass index percentile. Significance testing was conducted using the Fisher exact test and χ 2 tests to compare SCFE risk between the cohorts, with a significance level set at P <0.05.

RESULTS

On preliminary analysis, 98,045 patients met the inclusion criteria. After matching, 34,552 individuals in both vitamin D deficient and adequate groups were included, with an average age of 8.4 years at the time of their first visit and 50% females. SCFE occurred in 136 (0.39%) and 48 (0.14%) patients in the vitamin D deficient and adequate groups, respectively ( P < 0.0001). Vitamin D deficiency significantly increased SCFE risk, with a relative risk of 2.8 (95% CI: 2-3.9; P < 0.0001) and a hazard ratio of 1.6 (95% CI: 1.1-2.2; P < 0.0001).

CONCLUSION

This study, one of the largest to date, establishes a significant association between vitamin D deficiency and SCFE development. After controlling for potential confounding variables, including body mass index, individuals with vitamin D deficiency were ∼2.83 times more likely to develop SCFE. The study findings highlight the need for further research to evaluate whether supplementation could mitigate this risk of developing SCFE.

LEVEL OF EVIDENCE

Level III.

Daily or intermittent vitamin D supplementation in patients with or at risk of osteoporosis: Position statement from the GRIO

Advantages and disadvantages of intermittent versus daily vitamin D supplementation especially in adults with or at risk of osteoporosis are discussed by the Osteoporosis Research and Information Group (GRIO). The analysis of the literature suggests that intermittent long-term high doses vitamin D supplementation (such as 60,000IU/month or more), may increase the risk of falls, fracture and premature death in certain populations, while daily doses of 800-1000IU with calcium decrease falls and non-vertebral fractures in the elderly with vitamin D deficiency. In patients with or at risk of osteoporosis we hence recommend measuring the 25(OH)D concentration prior to supplementation and to provide vitamin D supplementation (with optimization of calcium intake if needed) to obtain a concentration between 30 and 60ng/mL. We recommend the use of an initial loading dose, especially in those who need a quick repletion of vitamin D store (symptoms of osteomalacia and/or 25(OH)D concentration <12ng/mL, patients eligible for treatment with potent antiresorptive therapy), followed by a maintenance dose. A daily supplementation should be the rule when possible. When daily forms are however not available or not reimbursed, we recommend, like other experts, to continue using intermittent dosing with the smallest available dose (≤50,000IU) and the shortest interval between doses as a stopgap until reimbursement or adequate daily pharmaceutical forms (pills or soft capsules of 1000, 2000IU) are available.

Sex-specific associations of vitamin D and bone biomarkers with bone density and physical function during recovery from hip fracture: the Baltimore Hip Studies

Less is known about recovery from hip fracture in men. We found differences in 25-hydroxyvitamin D and bone biomarkers between men and women during the year after hip fracture, underscoring the importance of vitamin D assessment in older men and pharmaceutical treatment to reduce bone resorption after hip fracture.

PURPOSE

Less is known about recovery from hip fracture in men compared to women. We examined differences between men and women in 25-hydroxyvitamin D (25OHD) and bone turnover markers, and associations with bone mineral density (BMD) and physical function, during the year after a hip fracture.

METHODS

Community-dwelling, ambulatory adults aged 65 years and over (157 men and 154 women) enrolled in the Baltimore Hip Studies 7th cohort were included. We analyzed 25OHD, C-terminal telopeptide (β-CTX-I), procollagen type I N-terminal propeptide (PINP), PTH, and femoral neck BMD at baseline, 2, 6, and 12 months after hip fracture, and short physical performance battery (SPPB) at 2, 6, and 12 months.

RESULTS

During admission for hip fracture, median 25OHD levels were 15.2 ng/mL (IQR 10.0) in men compared with 23.9 ng/mL (IQR 13.4) in women and remained lower in men at 2, 6, and 12 months (all p < 0.001). β-CTX-I was higher in men on admission, and at 2 and 6 months (all p < 0.05), and PINP was higher in men at 6 months (p = 0.04), with no significant differences between men and women in PTH. Higher 25OHD and PINP concentrations in women only and lower β-CTX-I and PTH concentrations in both sexes were associated with greater BMD. Higher 25OHD concentrations were associated with higher SPPB scores in both sexes.

CONCLUSIONS

These findings underscore the importance of vitamin D assessment in older men and missed opportunities in both sexes for vitamin D supplementation and pharmaceutical treatment to reduce bone resorption after hip fracture.

Associations between serum and seminal vitamin D levels and sperm parameters

AIM

To examine the association between serum/seminal plasma vitamin D levels and sperm parameters, the possible effects of serum/seminal vitamin D on sperm motility via seminal intracellular calcium measurement, and the antioxidant effect via malondialdehyde (MDA) measurement.

METHODS

This prospective study was conducted on 87 male patients. Serum vitamin D levels of patients were evaluated and grouped based on their serum vitamin D levels: low (<50 nmol/L), normal (50-75 nmol/L), and high (>75 nmol/L). Sperm characteristics were evaluated. Seminal plasma vitamin D, intracellular calcium, and MDA concentrations were measured using Liquid Chromatography Mass Spectrometry (LC-MS/MS), High-performance liquid chromatography (HPLC), and fluorescence plate reader methods, respectively.

RESULTS

Patients with normal serum vitamin D levels had higher total progressive motile sperm concentrations (14.0 vs. 8.5 vs. 4 million/mL, p = 0.037) and higher normal sperm morphology (6% vs. 4% vs. 3%, p = 0.020) compared to those with low and high levels. No correlations were found between serum vitamin D levels and seminal vitamin D (r = 0.052, p = 0.468), MDA (r = -0.048, p = 0.791), and intracellular calcium levels (r = 0.064, p = 0.929). Seminal intracellular calcium levels were significantly correlated with total (r = 0.241, p = 0.024) and progressive (r = 0.217, p = 0.043) sperm motility.

CONCLUSIONS

There were positive correlations between serum vitamin D levels, total progressive motile sperm concentration, and normal sperm morphology. However, serum vitamin D levels were not correlated with seminal vitamin D levels and showed no correlations with potential mechanisms of action, reflected by intracellular calcium and MDA concentrations. Conversely, intracellular calcium levels were positively correlated with both total and progressive sperm motility, suggesting that intracellular calcium plays an essential role in sperm motility.

Association Between Vitamin D Level and Clinical Outcomes of Assisted Reproductive Treatment: A Systematic Review and Dose-Response Meta-Analysis

The investigation about association between vitamin D level and clinical outcomes of assisted reproductive treatment showed various outcomes. This study aimed to review the correlation between vitamin D and outcomes of assisted reproductive treatment. The search was registered on the PROSPERO database (CRD42023458040). PubMed, Embase, Medline, ClinicalTrials.gov, and Cochrane databases were searched up to July 2023. Twenty-three observational studies were selected for meta-analysis. Comparing groups with deficient and 'insufficient + sufficient' vitamin D level, meta-analysis showed positive correlation between clinical pregnancy rate and vitamin D (OR 0.81, 95%CI: 0.70, 0.95, P = 0.0001). Comparing groups with 'deficient + insufficient' and sufficient vitamin D level, meta-analysis showed positive correlation between vitamin D and clinical pregnancy rate (OR 0.71, 95%CI: 0.55, 0.91, P = 0.006), vitamin D and live birth rate (OR 0.69, 95%CI: 0.54, 0.89, P = 0.003). Subgroup analysis did not show the source of high heterogeneity. No correlation was found in biochemical pregnancy rate, ongoing pregnancy rate, miscarriage rate and implantation rate. In dose-response meta-analysis, a nonlinear association was found between vitamin D levels and outcomes when levels are below approximately 24 ng/L. The study shows that vitamin D level is associated with clinical pregnancy rate and live birth rate. Low vitamin D level does not influence biochemical pregnancy rate, ongoing pregnancy rate, miscarriage rate and implantation rate. Furthermore, 24 ng/L may be a possible threshold of vitamin D concentration in assisted reproduction therapy.

Association between dyslipidemia and vitamin D deficiency: a cross-sectional study in Chinese healthy population

Background

Given the global prevalence of vitamin D deficiency, this study examines the association between serum 25-hydroxyvitamin D (25(OH)D) levels and lipid profiles, including total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides (TG).

Methods

In a cross-sectional analysis at the Yuhuan People's Hospital Physical Examination Center, 1535 asymptomatic individuals underwent anthropometric assessment and blood sampling. Serum 25(OH)D levels were quantified by a chemiluminescent immunoassay, while lipid parameters were evaluated by an enzymatic method on a fully automated analyzer.

Results

The mean serum 25(OH)D level of the participants was 49.6 ± 15.3 nmol/L, with 54.7% demonstrating vitamin D deficiency. Female participants had significantly lower mean 25(OH)D levels (46.2 ± 13.7 nmol/L) than males (54.1 ± 16.0 nmol/L, P < 0.001). After adjustment for age and BMI, multivariate ordinal logistic analysis revealed a 1.71-fold higher dyslipidemia-associated risk of vitamin D deficiency in the population (OR=1.71, 95% CI=1.07-2.79), more pronounced in females(OR=2.84, 95% CI=1.17-8.09) compared to males (OR=1.44, 95% CI=0.82-2.58). Notably, vitamin D deficiency was significantly associated with elevated LDL-C levels in females (OR=5.17, 95% CI=1.47-32.96), in contrast to males.

Conclusion

This study highlights a significant association between 25(OH)D deficiency and an increased risk of dyslipidemia, especially in females, highlighting the importance of considering gender-specific risk factors in the management of 25(OH)D deficiency.

Vitamin D supplementation in critically ill patients: a meta-analysis

Background

Vitamin D is commonly used in clinical practice, while its clinical significance in critically ill patients remains controversial. Therefore, we aimed to perform a systemic review and meta-analysis to investigate the effect of vitamin D on this patient population.

Methods

We searched for randomized controlled trials (RCTs) in PubMed, Embase, and the Cochrane Library databases from inception until August 15, 2024. Studies evaluating critically ill adult patients who received vitamin D compared to controls were included. The primary outcome was short-term mortality. We used the Cochrane risk of bias tool and GRADE system to evaluate the study quality and evidence. Secondary outcomes were changes in serum 25-hydroxyvitamin D levels, mechanical ventilation (MV) duration, and length of stay (LOS) in the ICU or hospital. We also conducted meta-regression, subgroup analyses, and trial sequential analysis (TSA) to explore the potential heterogeneity among the included trials.

Results

Nineteen RCTs with 2,754 patients were eligible. Overall, vitamin D significantly increased serum 25-hydroxyvitamin D levels and significantly reduced the short-term mortality (risk ratio [RR] = 0.83; 95%CI, 0.70-0.98; p = 0.03, I 2 = 13%), duration of MV (MD = -2.96 days; 95% CI, -5.39 to -0.52; I 2 = 77%; p = 0.02) and ICU LOS (MD = -2.66 days; 95% CI, -4.04 to -1.29, I 2 = 70%; p = 0.0001) but not hospital LOS (MD = -0.48 days; 95% CI, -2.37 to 1.40; I 2 = 31%; p = 0.61). The meta-regression analysis revealed that the proportion of MV (MV%) accounted for the source of heterogeneity, and the subgroup analyses based on MV% suggested that the MV group was more likely to benefit from vitamin D applications than the partly MV group in all the predefined outcomes (all p values<0.05). TSA for short-term mortality suggested that more data is required to confirm our main conclusion.

Conclusion

Vitamin D supplementation increased serum 25-hydroxyvitamin D levels and significantly benefited critically ill patients, especially those with MV.

Systematic review registration

https://inplasy.com/inplasy-2022-10-0074/, INPLASY2022100074.

Placental and cord serum inflammatory cytokines and children's domain-specific neurodevelopment at 18 months: effect modification by maternal vitamin D status

BACKGROUND

Epidemiological studies that have simultaneously explored the effects of placental and cord blood inflammatory cytokine levels on neurodevelopment in offspring, as well as the role of maternal vitamin D in these associations, are lacking. To investigate the associations of placental and cord blood inflammatory cytokine levels with neurodevelopment in 18-month-old children, and the potential modification effect by maternal vitamin D.

METHODS

Based on the Ma'anshan birth cohort, the current study involved 1241 mother-child pairs. The placental inflammatory cytokine mRNA expression levels, cord serum inflammatory cytokine concentrations, and maternal serum vitamin D concentrations were determined. Children's neurodevelopmental outcomes were defined as the Chinese version of the Ages and Stages Questionnaire (Third Edition) subdomain scores below the established cutoff scores. Generalized linear models were utilized to assess the effects of placental and cord serum inflammatory cytokines on neurodevelopmental outcomes and to examine the modification effects of maternal vitamin D.

RESULTS

After adjusting for confounders, each one-unit increase in placental IL-6 (OR = 1.30, 95% CI: 1.09, 1.55, P-FDR = 0.024), IL-8 (OR = 1.25, 95% CI: 1.05, 1.49, P-FDR = 0.036), and IFN-γ level in the cord serum (OR = 1.74, 95% CI: 1.16, 2.61, P-FDR = 0.042) was associated with an increased risk of fine motor delay. Elevated levels of placental TNF-α (OR = 1.38, 95% CI: 1.12, 1.69, P-FDR = 0.012), IL-6 (OR = 1.29, 95% CI: 1.04, 1.61, P-FDR = 0.042), and IL-8 (OR = 1.31, 95% CI: 1.06, 1.62, P-FDR = 0.036) were associated with an increased risk of personal-social delay. Stratified analyses showed that lower maternal vitamin D levels (< 20 ng/mL) moderated the associations between inflammatory markers and delays in fine motor, gross motor, and personal-social subdomains.

CONCLUSIONS

Elevated levels of specific inflammatory cytokines in the placenta and umbilical cord blood were associated with developmental delays on a parental-reported screening tool. Maternal vitamin D status can modify the adverse effects of the intrauterine pro-inflammatory milieu on the neurodevelopment of children.

Unveiling the Link Between Vitamin D, Hashimoto's Thyroiditis, and Thyroid Functions: A Retrospective Study

BACKGROUND/OBJECTIVES

Hashimoto's thyroiditis (HT) is an autoimmune disease influenced by genetic factors and environmental triggers that affect immune system function. Data suggest that vitamin D may also play a role in the etiopathogenesis of HT.

METHODS

This retrospective study included patients admitted to the Endocrinology and Metabolic Diseases Outpatient Clinic. Data from individuals aged 18 years and older were analyzed, including serum levels of thyroid-stimulating hormone (TSH), free triiodothyronine (fT3), free thyroxine (fT4), anti-thyroid peroxidase (anti-TPO), anti-thyroglobulin (anti-TG), and vitamin D. HT was diagnosed based on the presence of anti-TPO and/or anti-TG antibodies, while individuals with negative results for both were classified as non-HT. Thyroid function was categorized as euthyroid if TSH levels were between 0.55 mU/L and 4.78 mU/L and fT4 levels were between 0.89 ng/dL and 1.76 ng/dL; hypothyroid status was defined as TSH > 4.78 mU/L. Vitamin D levels were classified as deficient (<50 nmol/L), insufficient (50-74.9 nmol/L), or sufficient (≥75 nmol/L).

RESULTS

Of the total participants, 25,018 did not have HT, while 27,800 were diagnosed with HT. Vitamin D level was significantly higher in the HT group than the non-HT group (41.43 nmol/L and 39.44 nmol/L, p < 0.001). Vitamin D deficiency was present in 65.5% of the non-HT group and 62.1% of the HT group (p < 0.001). Subgroup analyses based on thyroid function showed that vitamin D levels were highest in the euthyroid HT group and similar in the euthyroid non-HT, hypothyroid non-HT, and hypothyroid HT groups (p < 0.001).

CONCLUSIONS

In conclusion, while vitamin D levels were higher in the HT group compared to the non-HT group, no clinically significant association between vitamin D levels and HT or autoantibody positivity was observed. Vitamin D deficiency was more prevalent in the hypothyroid group compared to the euthyroid group. This study suggests that although vitamin D deficiency may not be directly involved in the pathogenesis of HT, it may still play a role in modulating immune activity or influencing the disease phenotype..

Role of vitamin D in the development and progression of diabetic kidney disease: an overview of meta-analyses

Background

The effectiveness of vitamin D supplementation in the progression of diabetic kidney disease (DKD) remains controversial. Our review tries to provide a comprehensive summary of all the relevant articles in the area to assess the association of vitamin D deficiency with the development of DKD and the effect of vitamin D supplementation on the progression of DKD.

Methods

PubMed, Embase, Scopus, Cochrane Library and Web of Science were accessed from inception till June 2024 to obtain all the relevant meta-analyses assessing the function of vitamin D in the onset and prognosis of DKD. The summary data were extracted by two independent reviewers. A Measurement Tool to Assess Systematic Reviews (AMSTAR) 2 tool was used for the assessment of the methodological quality of the included meta-analyses.

Results

A total of 4579 articles were obtained from 5 databases in the initial search, of which 8 meta-analyses were included for the evidence synthesis. The methodological quality of the retrieved articles ranged from critically low to high. Serum vitamin D levels were significantly correlated with the prevalence of DKD. The review suggested that vitamin D supplementation could help in reducing proteinuria. However, no such changes were observed in other renal function parameters of DKD patients following vitamin D supplementation.

Conclusion

The current evidence indicates that vitamin D supplementation could be beneficial in reducing proteinuria among DKD patients.PROSPERO registration number: CRD42022375194.

25(OH)D3 and F-25(OH)D as indicators of chronic kidney disease progression in patients with rheumatoid arthritis

Vitamin D (VitD) deficiency has been associated with the development of rheumatoid arthritis (RA) and chronic kidney disease (CKD), but its exact role in patients with RA and CKD remains unclear. This cross-sectional study explored the relationship of 25(OH)D2, 25(OH)D3, and Free 25(OH)D [F-25(OH)D] with CKD progression in patients with RA. Patients with RA (n = 1514) were enrolled and divided into the mild, moderate, and severe CKD groups. Total 25(OH)D, 25(OH)D3, and F-25(OH)D in the moderate and severe CKD groups were lower than in the mild CKD group (all P < 0.05), while there were no differences in 25(OH)D2 levels (P = 0.095). As the severity of CKD progressed, total 25(OH)D, 25(OH)D3, and F-25(OH)D decreased (all Padj.<0.05). When progressing from moderate to severe CKD, only 25(OH)D3 decreased significantly (Padj.=0.014). Partial correlation and multiple logistic regression analyses revealed a significant association between 25(OH)D3 and the progression of CKD deterioration, as did F-25(OH)D (all P < 0.05). Further seasonal stratified analysis showed that this correlation existed only in spring, summer, and autumn for 25(OH)D3 and only in spring and summer for F-25(OH)D (P < 0.05). In conclusion, the serum 25(OH)D3 and F-25(OH)D levels may be indicators of CKD progression in patients with RA to plan for timely intervention and management.

Consequences of vitamin D deficiency or overdosage on follicular development and steroidogenesis in Normo and hypo calcemic mouse models

Vitamin D deficiency (VDD) is a widespread situation, linked to patients' dietary habits and/or geographical origins. On the other hand, hypervitaminosis D (VDO) is also a worldwide problem, mainly associated with uncontrolled self-administration. In this study, we investigated the effects of VDD and VDO on sex steroid production and ovarian histology in mice. In addition to addressing the rarely explored situation of VDO, the originality of our approach is to disconnect VDD/VDO situations from the well-known calciotrophic effect of vitamin D (VitD). Our data indicate that VDD led to a significant decrease in serum LH and FSH levels, independently of serum calcium levels. VDD was also associated with increased testosterone and reduced oestradiol levels. VDO animals showed increased LH and reduced testosterone levels. Hormonal changes in the VDO animal groups were correlated with a lower accumulation of transcripts of steroidogenic genes such as CYP11A1 and 3ß-HSD, whereas these transcripts were higher in the VDD groups. CYP19A1 transcripts were lower in VDD animals than in controls. This study highlights the complex interaction between vitamin D status, the regulation of reproductive hormones and, consequently, reproductive performance. It underlines the need for caution when oral vitamin D supplementation is chosen as a therapeutic action to boost female reproductive performance, as VDO can be as detrimental as VDD.

The Lebanese GRADE-based vitamin D guidelines: a paradigm for the MENA region

BACKGROUND

The Middle East and North Africa region are traditionally known as regions with a high prevalence of vitamin D deficiency. However, serum 25-hydroxyvitamin D (25OHD) levels seem to be increasing lately. We developed guidelines on the screening and supplementation of adult Lebanese patients with vitamin D. These guidelines address community-dwelling and institutionalized individuals.

METHODS

Our guideline panel consisted of clinical and methodology experts that formulated the guidelines questions. We conducted a systematic review to gather global data on fracture (CRD42019129540), regional data on vitamin D trials (CRD42014010488), and on patients' values and preferences (CRD42022320022). We also complemented the latter with results from a cross-sectional local study. We followed the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology to assess the quality and certainty of evidence, and to develop recommendations.

RESULTS

For community-dwelling and institutionalized Lebanese adult population, the panel suggests no screening for vitamin D deficiency, over screening for vitamin D deficiency (conditional recommendation, based on very low certainty evidence). For community-dwelling Lebanese adult population, the panel suggests no supplementation with calcium and vitamin D, over supplementation (conditional recommendation, based on moderate certainty evidence). For institutionalized Lebanese adult population, the panel suggests supplementation with calcium and vitamin D, over no supplementation (conditional recommendation, based on moderate certainty evidence). The guidelines also identify high-risk subgroups, more likely to benefit from screening and supplementation. In community dwelling and institutionalized Lebanese adult individuals, for whom there is a decision to supplement with calcium and vitamin D, the panel suggests supplementation with a daily vitamin D equivalent of 600-2000 IU, as compared to doses higher than 2000 IU (conditional recommendation, very low certainty evidence).

CONCLUSION

The Lebanese GRADE-based vitamin D guidelines recommend against population screening and vitamin D supplementation. Subgroups at high risk are identified. The guidelines take into account contextual factors, and allow their adoption or adaptation in countries in the region.

Associations of Gestational Exposure to Air Pollution With Maternal Vitamin D Levels: A Meta-Analysis

CONTEXT

Maternal vitamin D level is an important determinant of pregnancy and child health outcomes. Exposure to air pollution is suspected to increase the risk of vitamin D deficiency, but the evidence is scarce.

OBJECTIVE

We investigated the association between air pollution during pregnancy and maternal vitamin D levels.

METHODS

A total of 15 935 pregnant women from 5 birth cohorts in Europe and the United States were included. Averaged concentrations of nitrogen oxides, fine and coarse particles, and composition of fine particles from conception until vitamin D measurement were estimated at participants' residential addresses using land-use regression or other spatiotemporal models. Cohorts measured vitamin D as 25(OH)D or 25(OH)D3 levels in serum or plasma at early or mid-pregnancy. We defined suboptimal vitamin D levels as levels below 20 ng/mL. We performed logistic regression models for each cohort to estimate the association between air pollution exposure and suboptimal vitamin D levels and pooled cohort-specific estimates in a random-effect meta-analysis. Models were adjusted for sociodemographic and lifestyle characteristics and month of conception.

RESULTS

We found an association between particulate matter (PM)2.5 and higher odds of suboptimal vitamin D levels (ie, below 20 ng/mL) (odds ratio per 5 μg/m3 increase in PM2.5, 1.43; 95% CI: 1.02, 1.99). There was no association between other air pollutant exposure and vitamin D levels.

CONCLUSION

PM2.5 exposure might contribute to suboptimal levels of vitamin D in pregnancy. Reducing air pollution exposure should be a priority because vitamin D deficiency may adversely influence offspring development.

Development and validation of prediction model for vitamin D deficiency in Chinese college students (a dynamic online nomogram predicting vitamin D deficiency for Chinese college students)

OBJECTIVE

This study aims to develop a model for predicting vitamin D deficiency in Chinese college students using easily accessible clinical characteristics.

METHODS

Data were derived from a cross-section study of the Vitamin D status in Chinese college students in September, 2020. Totally 1,667 freshmen from 26 provinces, autonomous districts or municipalities were analyzed. A LASSO regression model was used to select predictors and the significant factors were used to construct the logistic regression model expression and the nomogram. The prediction model was subjected to100 bootstrap resamples for internal validation to assess its predictive accuracy. Calibration and discrimination were used to assess the performance of the model. A dynamic online nomogram was conducted to make the model easy to use. The clinical use was evaluated by a decision curve analysis.

RESULTS

Gender, region of original residence, milk and yogurt intake, puffed foods intake, outdoor activity duration, UV protection index and "taken calcium or vitamin D supplements within 3 months" were identified as significant predictors of vitamin D deficiency among Chinese college students. The model demonstrated good calibration with a 100 bootstraps analysis. The C-index was 0.677 and the bias-adjusted C-index was 0.668 in internal validation with 100 bootstrap resamples. The decision curve analysis showed a threshold probability between 0.5 and 0.8, using the model added more benefit than considering all patients are deficient or not deficient.

CONCLUSIONS

The performance of this vitamin D deficiency prediction model is commendable, and the dynamic online nomogram was proved to be a user-friendly screening tool for identifying high-risk subjects among Chinese college students. However, external validation is imperative to ensure the model's generalizability.

Vitamin D for primary dysmenorrhea and endometriosis-related pain - A systematic review of registered RCTs

OBJECTIVE

This systematic review investigates the potential role of vitamin D supplement in alleviating pain associated with primary dysmenorrhea or endometriosis by analysing registered randomised controlled trials (RCTs).

METHODS

We comprehensively searched the WHO International Clinical Trials Registry Platform to identify registered RCTs that assessed the effects of vitamin D supplement on pain outcomes in people with primary dysmenorrhea or endometriosis. The primary outcomes of interest were pain severity/intensity, pain duration, pain medication usage and pain-related outcome measurements.

RESULTS

Seven registered RCTs were included in this systematic review. These RCTs had diverse doses and treatment durations of vitamin D supplement used as intervention. They also had either high or some concerns of risk of bias, according to Cochrane risk of bias version 2 assessment. Substantial heterogeneities were generally observed across the seven RCTs. When measured using a validated tool visual analogue scale (VAS), pain severity was significantly lower at the end of treatment when compared with placebo (mean difference MD -1.12, 95% confidence interval [-2.16, -0.07], I2=81%, 5 studies, n = 308). This significant difference was observed in the primary dysmenorrhea RCTs, but not the endometriosis RCTs.

CONCLUSION

This systematic review identified vitamin D may reduce pain associated with primary dysmenorrhea, though a low certainty of evidence was available. Future studies that use standardised doses and treatment duration in accordance with the latest clinical practice guidelines are needed to explore any potential benefits vitamin D may have for people with these conditions.

Antioxidant Supplementation in Childhood Obesity: A Path to Improved Metabolic Health?

Childhood obesity is linked to heightened oxidative stress, a key driver of endothelial dysfunction, inflammation, and metabolic complications. Antioxidants, including Vitamins C and E, are vital in neutralizing free radicals and mitigating oxidative damage. This non-systematic review examines the potential advantages of antioxidant supplementation in pediatric obesity, focusing on its effects on vascular health, insulin sensitivity, and inflammatory processes. Emerging data suggest that antioxidants may improve endothelial function, reduce blood pressure, and enhance metabolic homeostasis in obese children. However, the long-term efficacy and safety of antioxidant supplementation remain uncertain, necessitating further rigorous randomized controlled trials. A deeper understanding of antioxidants' role in pediatric obesity could unlock novel therapeutic approaches for managing obesity-related complications and improving children's overall health outcomes.

Influence of Vitamin D on Developmental Defects of Enamel (DDE) in Children and Adolescents: A Systematic Review

Background/Objectives: This systematic review aims to investigate the potential association between vitamin D levels and the occurrence of developmental enamel defects (DDE) in children, including conditions like molar-incisor hypomineralization (MIH) and hypomineralized second primary molars (HSPMs). DDEs, which occur during tooth development, can result in significant aesthetic and functional issues, and their exact etiology remains unclear, with both genetic and environmental factors contributing. Among environmental factors, vitamin D deficiency has been proposed as a possible risk factor, given its role in enamel mineralization. Methods: A thorough literature search was conducted in PubMed, Scopus, and Embase. The search strategy included terms such as "vitamin D", "vitamin D deficiency", "developmental defects of enamel", "enamel hypoplasia", "molar-incisor hypomineralization", and "hypomineralized second primary molars". Studies were included if they were original human observational research (cohort, case-control, or cross-sectional) conducted in children under 18 years of age or involving maternal-child cohorts. Ten studies were included in the analysis, with a total of 15,891 participants. The primary data extracted from the selected studies included the following: study design, participants' age, sample size, vitamin D status in relation to developmental defects of enamel, and statistical significance Results: The findings were mixed, with only a few studies suggesting a significant association between low vitamin D levels and the presence of DDEs. Specifically, one study found a link between insufficient maternal vitamin D levels during pregnancy and an increased number of teeth affected by MIH in children. However, the majority of the studies did not report a significant association. Conclusions: This review concludes that while there is some evidence to suggest a possible relationship between vitamin D and DDEs, more research is needed to confirm these findings and better understand the underlying mechanisms.

A case-control study on vitamin D receptor gene polymorphisms in patients with Parkinson's disease in Bangladesh

Parkinson's disease (PD) is a neurodegenerative disorder with a multifactorial etiology. This study aimed to investigate the association between vitamin D receptor (VDR) gene polymorphisms (ApaI, BsmI, FokI and TaqI) and the risk of PD in a Bangladeshi population. A case-control study was conducted with 100 PD patients and 100 age- and sex-matched healthy controls. Serum vitamin D levels were measured using a chemiluminescent immunoassay, and VDR gene polymorphisms were genotyped using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. Genetic models (allele, dominant, recessive and additive models) were used to assess the association between each polymorphism and PD risk. The mean age of the patients with PD was 63 years, with 65% being male, while the control group had a mean age of 54.5 years and 60% were male. In genetic models, the T allele of the ApaI gene demonstrated a significant association with PD (OR 1.92, 95% CI 1.20-3.13, p-value 0.007). This significant association persisted across both recessive and additive models (for recessive model: OR 2.17, 95% CI 1.10-4.55, p-value 0.027 and for additive model: OR 2.78, 95% CI 1.22-6.67, p-value 0.015). Similarly, the T allele of the FokI gene was found to be significantly associated with PD (OR 2.27, 95% CI 1.43-3.57, p-value 0.001). This association was also evident in both dominant and additive models (for dominant model: OR 2.56, 95% CI 1.45-4.55, p-value 0.001 and for additive model: OR 3.03, 95% CI 1.67-5.56, p-value 0.001). Conversely, no significant associations were observed for the genetic polymorphisms of the BsmI and TaqI genes across any of the genetic models examined. The findings suggest that specific VDR gene polymorphisms, particularly ApaI and FokI, are significantly associated with the risk of PD in the Bangladeshi population.

The Quantification of Vitamin D in Humans: A Promising, Non-Invasive and Cost-Effective Method to Measure 25-Hydroxyvitamin D

BACKGROUND

Vitamin D intake and synthesis are essential. Vitamin D deficiency is increasing across all age groups, raising concerns regarding public health. Serum 25(OH)D is measured to define vitamin D deficiency. However, its quantification in non-invasively collected biological matrices is still poorly studied. This study aimed to assess 25(OH)D levels in unconventional matrices using cost-effective analytical methods.

METHODS

Serum, urine, and saliva were collected from 62 healthy, non-smoking volunteers, 25-44 years of age. Biological samples were analysed using the Enzyme-Linked Immunosorbent Assay (ELISA). The serum was additionally analysed via the chemiluminescent microparticle immunoassay (CMIA), which was used as a benchmark.

RESULTS

We observed a linear correlation (Pearson r = 0.44; p = 0.05) between the benchmark and ELISA-measured 25(OH)D urinary levels. After stratification by sex, the correlation was stronger and significant only in females (Pearson r = 0.62; p = 0.04). Salivary 25(OH)D levels did not correlate with serum levels for both ELISA and CMIA measures. Subjects with a CMIA serum-based deficiency showed lower urinary 25(OH)D levels (p = 0.04).

CONCLUSION

Our study opens up the possibility of using urinary 25(OH)D levels as a proxy measurement of vitamin D. Such an approach may allow future investigations on the association between environmental factors and vitamin D assessed in non-invasively collected biological matrices via cost-effective analytical methods.

The Optimal Protective 25-Hydroxyvitamin D Level for Different Health Outcomes in Adults: A Brief Summary of Dose-Response Meta-Analyses

Vitamin D is very important for bone metabolism as well as for the prevention of various diseases, such as type 2 diabetes, cardiovascular disease and different types of cancer. Although vitamin D deficiency is widespread and an important public health problem, there exists controversy in the scientific community, with no established standard definition of adequate and deficient vitamin D status. To add new information on this topic, the aim of this brief opinion paper is to identify and discuss the optimal 25(OH)D concentration (range) for a reduction in the risk of various disease outcomes by summarizing dose-response reporting meta-analyses.

The Impact of Vitamin D in the Prevention of Influenza, COVID-19, and Dengue: A Review

Since its discovery, vitamin D (VD) has been known for its implications in maintaining bone homeostasis. However, in recent years it has been discovered that the vitamin D receptor is expressed on different cells of the immune system and that these cells can locally produce the active form of this molecule, calcitriol, strongly suggesting that this vitamin might play a key role in both branches of the immune system, innate and adaptive. Recent evidence has demonstrated that VD participates in the different protective phases of the immune system against invading microorganisms, including in the activation and production of antimicrobial peptides, in the inactivation of replication of infectious agents, in the prevention of the exposure of cellular receptors to microbial adhesion, and, more importantly, in the modulation of the inflammatory response. In recent years, the world has witnessed major outbreaks of an ancient infectious disease, dengue fever; the emergence of a pandemic caused by an unknown virus, SARS-CoV-2; and the resurgence of a common respiratory infection, influenza. Despite belonging to different viral families, the etiological agents of these infections present a common trait: their capacity to cause complications not only through their cytopathic effect on target tissues but also through the excessive inflammatory response produced by the human host against an infection. This review outlines the current understanding of the role that vitamin D plays in the prevention of the aforementioned diseases and in the development of their complications through its active participation as a major modulator of the immune response.