Vitamin D deficiency

Correlation of Serum Calcium and Vitamin D Levels in Patients with and without Periodontitis before and after Nonsurgical Periodontal Therapy

AIM

To evaluate and correlate levels of serum calcium and 25-hydroxycholecalciferol (vitamin D) in subjects with periodontitis and in subjects with healthy periodontium before and following nonsurgical periodontal therapy (NSPT).

MATERIALS AND METHODS

A total of 52 patients were enrolled in the study with 26 patients in each group. The control group included patients without periodontitis, whereas the study group included patients with periodontitis. On the first visit, ~ 3-5 mL of venous blood was collected from all the participants for the assessment of calcium and Vitamin D levels in the blood. The various parameters evaluated included probing depth, clinical attachment level (CAL), gingival index (Loe and Silness 1963). Plaque index (Silness and Loe 1964), and IOPA (site having greatest pocket depth). Participants of both the groups received NSPT which involved extensive scaling and root planing. On the second visit (after 3 months), the same clinical parameters except IOPA were recorded in all the participants. On the third visit (after 6 months from the first visit), the blood sample was again collected for the evaluation of serum calcium and Vitamin D, and all the parameters of baseline were recorded.

RESULT

The result of the study showed that Vitamin D levels at baseline were less in test subjects (12.73 ± 2.25) as compared to controls (17.81 ± 4.03), which improved at 6 months for the test group (24.53 ± 1.98) but not the control group (17.8 ± 4.14) following NSPT. All the clinical parameters improved for both groups. There was no statistically significant difference in the calcium levels of both groups at baseline or 6 months.

CONCLUSION

Vitamin D levels were found to be lower in periodontitis patients than healthy controls, vitamin D levels improved in the test subjects along with the clinical parameters following NSPT highlighting the beneficial role of Vitamin D in maintaining periodontal health. No changes were seen in calcium levels in either of the groups at any point in time.

CLINICAL SIGNIFICANCE

Vitamin D can reduce the incidence and severity of periodontal disease by its various anti-inflammatory and immunomodulatory effects in addition to its traditional role in bone metabolism. Thus, maintaining adequate levels of systemic vitamin D could be critical to periodontal health. This study justifies this notion and further suggests the adjunctive role of vitamin D supplementation to improve therapeutic outcomes. How to cite this article: Wadhwa S, Saurav K, Arora SA, et al. Correlation of Serum Calcium and Vitamin D Levels in Patients with and without Periodontitis before and after Nonsurgical Periodontal Therapy. J Contemp Dent Pract 2024;25(11):1034-1038.

Supplementation of high doses of vitamin D during the gestational period do not cause reproductive, teratogenic and genotoxic damage in mice

Vitamin D deficiency during pregnancy may have adverse effects on embryo-fetal and postnatal development. Indeed, vitamin D supplementation has been indicated for pregnant women. However, there are no studies that indicate the safe dose of this supplementation during the gestational period. Therefore, the present study assessed the effects of high doses of vitamin D and vitamin D combined with calcium on reproductive performance, embryo-fetal development, and DNA integrity in Swiss mice. A total of 140 pregnant female mice treated with vitamin D and vitamin D combined with calcium were analyzed in two experiments. In one experiment, mice received intramuscular supplementation at doses of 600,000, 6,000,000, or 60,000,000 IU of vitamin D. These same doses were also associated with the dose of 8.56 mg/kg of calcium. In the other experiment, mice received a single oral dose of 6,000, 60,000, or 600,000 IU of vitamin D. These same doses were also associated with the dose of 8.56 mg/kg of calcium. The treatments were always carried out in the 10th gestational day. The results show that neither intramuscularly nor orally administered vitamin D and vitamin D combined with calcium affected reproductive performance, embryo-fetal development, or DNA integrity at the different doses tested. These pioneering results confirm the safety of using this type of high doses of supplementation, including during pregnancy.

Effects of preconceptional vitamin D levels on in vitro fertilization outcomes in infertile patients with polycystic ovary syndrome: A retrospective cohort study

BACKGROUND

Vitamin D plays various roles in different stages of reproduction, and abnormalities in its levels are associated with diseases such as polycystic ovary syndrome (PCOS). This study aimed to determine the relationship between initial vitamin D levels and in vitro fertilization (IVF) outcomes in PCOS patients.

METHODS

This retrospective cohort study included 1174 PCOS patients who consulted the Acıbadem Maslak Hospital IVF Clinic between January 2015 and March 2021. We investigated the effect of preconceptional vitamin D levels on IVF outcomes using data analysis with SigmaPlot 14.5.

RESULTS

We found a significant positive correlation between preconceptional vitamin D levels and positive clinical pregnancy rates (p < 0.001) as well as increased endometrial thickness (EMT) on human chorionic gonadotropin (hCG) day (p < 0.001, r = 0.262). The optimal vitamin D cut-off value for predicting positive hCG test results was identified as 13.24 ng/mL, as determined by receiver operating characteristic curve analysis (sensitivity = 0.839, specificity = 0.677). No association was observed with other IVF outcome parameters, miscarriage rates, or clinical pregnancy rates based on EMT.

CONCLUSIONS

The study suggests that PCOS patients with vitamin D levels above 13.24 ng/mL are more likely to achieve positive hCG results after IVF. These findings highlight the potential importance of vitamin D supplementation in improving pregnancy outcomes for PCOS patients. Additionally, increased EMT on hCG day may explain the higher clinical pregnancy rates associated with elevated vitamin D levels.

The effect of active vitamin D supplementation on body weight and composition: A meta-analysis of individual participant data

BACKGROUND & AIMS

Obesity is associated with vitamin D (VitD) deficiency. However, previous studies showed mixed effects of VitD (25-hydroxyVitD/calcidiol) supplementation on body weight. The biological actions of VitD require the hydroxylation of inactive VitD into active VitD (1.25-dihydroxyVitD/calcitriol). This step is highly regulated; therefore, supplementing with inactive VitD might not be sufficient to overcome the potential adverse health effects of VitD deficiency. The objective of this study was to conduct a systematic review and individual participant data (IPD) meta-analysis of data acquired from randomised placebo-controlled calcitriol trials (RCTs) to determine the effects of calcitriol on body weight and weight-related parameters.

METHODS

Studies were identified from MEDLINE, EMBASE, and CENTRAL databases up to January 27, 2024, and excluded those involving dialysis or cancer patients. We obtained IPD from eligible trials and assessed bias using the Cochrane Collaboration risk-of-bias tool and methodological quality using the Heyland Methodological Quality Score. The study was prospectively registered with PROSPERO (CRD42017076202).

RESULTS

Although none of the studies reported information regarding our primary objective, we obtained IPD for 411 patients, with 206 randomised to receive calcitriol and 205 to placebo. This dataset enabled us to conduct an IPD meta-analysis with 17,084 person-months of follow-up (median: 11 months). Meta-analysis showed that calcitriol does not alter body weight, BMI, waist circumference, fat mass or lean body mass compared to placebo. Adjusting for age and sex did not alter the outcomes.

CONCLUSIONS

In conclusion, this systematic review and IPD meta-analysis indicate that calcitriol does not affect body weight in normal-weight postmenopausal women and lean patients with type 1 diabetes nor in people suffering from obesity, type 2 diabetes and chronic kidney disease. Whether calcitriol lowers body weight in VitD-sufficient people with obesity remains to be elucidated.

High Parathyroid Hormone Rather than Low Vitamin D Is Associated with Reduced Event-Free Survival in Childhood Cancer

BACKGROUND

Vitamin D deficiency is linked to poor cancer outcomes but the impact of its consequence, elevated parathyroid hormone (PTH), remains understudied. PTH receptor activation influences cancer progression in vitro, yet the effect of elevated PTH on pediatric cancer survival is unexamined.

METHODS

This retrospective study examines associations between PTH, 25-OH vitamin D (25OHD), and event-free survival (EFS) and overall survival (OS) in patients with pediatric cancer. Laboratory data from 4,349 patients (0-18 years) at a tertiary pediatric cancer unit were analyzed for the highest PTH and lowest 25OHD levels at diagnosis and the following 5 years. Data on relapse, secondary malignancies, and mortality were stratified by PTH levels above/below the cohort median (47 pg/mL) and 25OHD levels ≤30 nmol/L. EFS and OS were analyzed and hazard ratios (HR) were calculated for the entire cohort and six cancer subgroups.

RESULTS

PTH and 25OHD values were available for 1,286 patients (731 male). Higher PTH associated with inferior EFS in primary malignant brain tumors [HR, 1.80 (1.19-2.72)], embryonal malignancies [HR, 2.20 (1.1-4.43)], and lymphatic malignancies [HR 1.98 (1.05-3.72)]. Vitamin D deficiency associated with inferior EFS in embryonal malignancies [HR 2.41 (1.24-4.68)]. In a multivariate Cox model, only higher PTH remained significant for inferior EFS.

CONCLUSIONS

Elevated PTH may indicate adverse outcomes in certain pediatric cancers.

IMPACT

This study identifies elevated parathyroid hormone as a potential marker for poor outcomes in patients with pediatric cancer, emphasizing the need for adequate vitamin D and calcium management.

The senolytic agent ABT263 ameliorates osteoporosis caused by active vitamin D insufficiency through selective clearance of senescent skeletal cells

Background/Objective

Active vitamin D insufficiency accelerates the development of osteoporosis, with senescent bone cells and the senescence-associated secretory phenotype (SASP) playing crucial roles. This study aimed to investigate whether the senolytic agent ABT263 could correct osteoporosis caused by active vitamin D insufficiency by selectively clearing senescent cells.

Methods

Bone marrow mesenchymal stem cells (BM-MSCs) from young and aged mice were treated with ABT263 in vitro, and 1,25(OH)2D-insufficient (Cyp27b1+/-) mice were administered ABT263 in vivo. Cellular, molecular, imaging, and histopathological analyses were performed to compare treated cells and mice with control groups.

Results

ABT263 induced apoptosis in senescent BM-MSCs by downregulating Bcl2 and upregulating Bax expression. It also induced apoptosis in senescent BM-MSCs from 1,25(OH)2D-insufficient mice. ABT263 administration corrected bone loss caused by 1,25(OH)2D insufficiency by increasing bone density, bone volume, trabecular number, trabecular thickness, and collagen synthesis. It also enhanced osteoblastic bone formation and reduced osteoclastic bone resorption in vivo. ABT263 treatment corrected the impaired osteogenic action of BM-MSCs by promoting their proliferation and osteogenic differentiation. Furthermore, it corrected oxidative stress and DNA damage caused by 1,25(OH)2D insufficiency by increasing SOD-2 and decreasing γ-H2A.X expression. Finally, ABT263 corrected bone cell senescence and SASP caused by 1,25(OH)2D insufficiency by reducing the expression of senescence and SASP-related genes and proteins.

Conclusion

ABT263 can correct osteoporosis caused by active vitamin D insufficiency by selectively clearing senescent skeletal cells, reducing oxidative stress, DNA damage, and SASP, and promoting bone formation while inhibiting bone resorption. These findings provide new insights into the potential therapeutic application of senolytic agents in the treatment of osteoporosis associated with active vitamin D insufficiency.

The translational potential of this article

This study highlights the therapeutic potential of ABT263, a senolytic compound, in treating osteoporosis caused by active vitamin D insufficiency. By selectively eliminating senescent bone cells and their associated SASP, ABT263 intervention demonstrates the ability to restore bone homeostasis, prevent further bone loss, and promote bone formation. These findings contribute to the growing body of research supporting the use of senolytic therapies for the prevention and treatment of age-related bone disorders. The translational potential of this study lies in the development of novel therapeutic strategies targeting cellular senescence to combat osteoporosis, particularly in cases where vitamin D insufficiency is a contributing factor. Further clinical studies are warranted to validate the efficacy and safety of ABT263 and other senolytic agents in the treatment of osteoporosis in humans.

Micronutrients and Androgenetic Alopecia: A Systematic Review

SCOPE

Hair loss is a common problem that can negatively impact individuals' psychological well-being. Androgenetic alopecia (AGA) is one of the most prevalent types of nonscarring hair loss. This review summarizes the existing evidence on the relationship between AGA and various micronutrients, including vitamin B, vitamin D, vitamin A, vitamin C, iron, selenium, zinc, manganese, and copper.

METHODS

A literature search was conducted to identify relevant articles published between 1993 and 2023. The search identified 49 relevant articles.

RESULTS

The findings suggest that deficiencies or imbalances in these micronutrients may contribute to the pathogenesis of AGA and represent modifiable risk factors for hair loss prevention and treatment. Vitamin B, vitamin D, iron, and zinc appear to play critical roles in hair growth and maintenance. Deficiencies in these micronutrients have been associated with increased risk of AGA, while supplementation with these nutrients has shown potential benefits in improving hair growth and preventing hair loss. However, the current evidence is not entirely consistent, with some studies reporting no significant associations.

CONCLUSION

Deficiencies or imbalances in specific vitamins and minerals, especially vitamin B, vitamin D, Fe, Se, and Zn are involved in the pathogenesis of AGA and may represent modifiable risk factors for the treatment and prevention of this condition.

Association of serum 25-hydroxyvitamin D with cardiovascular mortality and kidney outcome in patients with early stages of CKD

PURPOSE

While serum 25-hydroxyvitamin D (25[OH]D) deficiency is prevalent in chronic kidney disease (CKD), the effects of 25(OH)D deficiency on cardiovascular mortality and kidney outcomes in patients with early-stage CKD remain incompletely understood.

METHODS

This multicenter retrospective cohort study included adult patients with stages 1-3 CKD from 19 medical centers across China between January 2000 and May 2021. The primary outcome was cardiovascular mortality. The secondary study outcome included CKD progression (defined as a sustained > 40% eGFR decrease from baseline or progress to end-stage kidney disease), and annual percentage change of eGFR.

RESULTS

Of 9229 adults with stages 1-3 CKD, 27.0% and 38.9% had severe (< 10 ng/mL) and moderate (10 to < 20 ng/mL) serum 25(OH)D deficiency, respectively. Compared with patients having 25(OH)D ≥ 20 ng/mL, a significantly higher risk of cardiovascular mortality (hazard ratio [HR] 1.90, 95% CI 1.37-2.63), CKD progression (HR 2.20, 95% CI 1.68-2.88), and a steeper annual decline in eGFR (estimate - 7.87%; 95% CI - 10.24% to - 5.51% per year) was found in those with serum 25(OH)D < 10 ng/mL. Similar results were obtained in subgroups and by sensitivity analyses.

CONCLUSIONS

25(OH)D deficiency is associated with increased risks of cardiovascular mortality and CKD progression in patients with early-stage CKD. Studies are needed to determine whether early intervention for 25(OH)D deficiency could improve the prognosis of patients with early-stage CKD.

Short interbirth interval and adverse pregnancy outcomes: a Bayesian network approach

Background

Interbirth interval (IBI), the time between consecutive births, has been tied to perinatal outcomes.

Objective

To analyze adverse perinatal events following short IBI in a large South American sample.

Study design

Observational, retrospective, hospital-based study including malformed and nonmalformed live- and stillbirths. Outcomes were preterm birth (PTB), low birth weight (LBW), and specific birth defects. Logistic regressions were used to evaluate the risk of selected variables for short IBI and for adverse outcomes after short IBI, adjusting by confounders. Bayesian networks exhibited relationships among short IBI, outcomes, and variables.

Results

Short IBI rate was 2%-3%. Maternal age and a previous abortion were the main confounders. A significant high risk for short IBI was found in mothers ≤19 years while mothers ≥30 were at low risk, mediated by a previous abortion. The risk of short IBI, adjusted by confounders, was significant for LBW but not for PTB. An unadjusted risk of short IBI was observed for gastroschisis, which disappeared after adjusting for confounders. Maternal age ≤19 and previous abortion were directly related with gastroschisis; the relationship between gastroschisis and short IBI occurred through any of these two variables. A direct relationship between gastroschisis and maternal age ≥30 was observed.

Conclusions

Only young mothers were directly related with short IBI. In older mothers, a short IBI mainly occurred after a previous abortion. Short IBI was a risk factor only for LBW. The PTB and gastroschisis relationship with short IBI was indirect, mediated by young maternal age and/or a previous abortion.

Prevalence of Vitamin D Deficiency and Its Association With Anthropometric and Hematological Parameters Among Infants at a Tertiary Care Center in Meerut, India: A Cross-Sectional Study

INTRODUCTION

Vitamin D is crucial in calcium homeostasis and bone metabolism, and its deficiency is widespread even in sun-rich regions like India. The present study sought to elucidate the prevalence of vitamin D deficiency in infants and its potential association with various anthropometric and hematological parameters.

METHODS

The study was conducted in a tertiary care hospital in northern India (in 2013-14) and involved 77 nine-month-old infants. Data collection included demographic information, anthropometric measurements, and laboratory parameters like levels of serum vitamin D, intact parathyroid hormone (iPTH), calcium, phosphorus, alkaline phosphatase (ALP), hemoglobin (Hb), packed cell volume (PCV), total RBC count, and mean corpuscular volume (MCV). Vitamin D status was classified based on serum 25-hydroxyvitamin D [25(OH) D] levels.

RESULTS

The prevalence of vitamin D deficiency was 42.9% (33 out of 77 infants). Infants with vitamin D deficiency had significantly lower mean body weight (8.26 ± 0.89 kg) as compared to vitamin D non-deficient infants (8.72 ± 0.99 kg) (p = 0.04). Hematological analysis revealed significantly lower Hb levels (9.59 ± 1.68 g/dL) in the vitamin D deficient group compared to the vitamin D non-deficient group (10.35 ± 1.44 g/dL) (p = 0.04). Other significant differences included lower PCV (p = 0.03) and MCV (p = 0.002) in the vitamin D-deficient group.

CONCLUSION

This study highlights the high prevalence of vitamin D deficiency (42.9%) among infants and its significant association (p-value less than 0.05) with reduced body weight and hematological indices like Hb, PCV, and MCV. These findings underscore the need for routine screening, nutritional interventions, and vitamin D supplementation to address vitamin D deficiency among infants. Further research involving diverse populations is required to validate these results, further guiding optimum public health strategies.

Role of Bile Acid Receptors in the Development and Function of Diabetic Nephropathy

Diabetic nephropathy (DN) is a prevalent microvascular complication that occurs often in individuals with diabetes. It significantly raises the mortality rate of affected patients. Therefore, there is an urgent need to identify therapeutic targets for controlling and preventing the occurrence and development of DN. Bile acids (BAs) are now recognized as intricate metabolic integrators and signaling molecules. The activation of BAs has great promise as a therapeutic approach for preventing DN, renal damage caused by obesity, and nephrosclerosis. The nuclear receptors (NRs), farnesoid X receptor (FXR), pregnane X receptor (PXR), vitamin D receptor (VDR); and the G protein-coupled BA receptor, Takeda G-protein-coupled receptor 5 (TGR5) have important functions in controlling lipid, glucose, and energy metabolism, inflammation, as well as drug metabolism and detoxification. Over the past 10 years, there has been advancement in comprehending the biology and processes of BA receptors in the kidney, as well as in the creation of targeted BA receptor agonists. In this review, we discuss the role of BA receptors, FXR, PXR, VDR, and TGR5 in DN and their role in renal physiology, as well as the development and application of agonists that activate BA receptors for the treatment of kidney diseases.

Effect of Vitamin D Supplementation on Inflammatory Markers in Obese Patients with Acute and Chronic Orthopedic Conditions

Numerous studies have shown that vitamin D may play an important role in modulating the inflammatory process. This study aimed to evaluate the effect of vitamin D supplementation on inflammatory markers in patients with orthopedic disorders and obesity. Thirty-three obese subjects were included in the study and were divided into two groups based on their medical condition: acute orthopedic diseases and chronic orthopedic diseases. Inclusion criteria for the research included age 18-75 years, BMI > 30 kg/m2, vitamin D deficiency, and no previous vitamin D supplementation. Samples were collected before and after 3 months of 4000 IU/day vitamin D supplementation. The study used enzyme-linked immunosorbent assay (ELISA) and measured serum levels of markers such as chitinase-3-like protein 1 (YKL-40), interleukin 6 (IL-6), interleukin 17 (IL-17), tumor necrosis factor (TNF-α), and adiponectin. After 3 months of vitamin D supplementation, a statistically significant increase in vitamin D and IL-17 levels was observed in the group with acute orthopedic diseases. Similarly, after supplementation, a statistically significant increase in vitamin D, IL-6 and TNF-α levels was observed in the group with chronic orthopedic diseases. Moreover, after vitamin D supplementation, statistically significantly higher adiponectin levels were observed in the chronic orthopedic group than in the acute orthopedic group. Despite high-dose vitamin D supplementation, inflammatory markers increased in acute and chronic orthopedic conditions. Based on our study, vitamin D does not reduce inflammation in patients with orthopedic conditions and obesity.

Bone Mineral Density, Bone Biomarkers, and Joints in Acute, Post, and Long COVID-19: A Systematic Review

SARS-CoV-2 is highly transmissible and affects the respiratory system. People with COVID-19 are at higher risk of physical and mental health conditions, which could impact bone health. The aim of this review was to explore the effects of COVID-19 on BMD, BTMs, and joints. An electronic search of the PubMed, Web of Science, Scopus, and Ovid Medline databases considered studies published between 1 January 2020 and 1 November 2023. The search was limited to English, original studies in adult humans. The title and abstract of the identified papers were screened, followed by a full-text review using inclusion and exclusion criteria. The data extracted included the study and participant characteristics, BTMs, BMD, and joint abnormalities. The Newcastle-Ottawa scale quality assessment tool was used to assess the risk of bias. Five studies involving 305 out of 495 infected individuals observed a reduced BMD after COVID-19, with the most significant reduction occurring a year later. Both bone resorption and bone formation markers decreased, while regulatory markers showed higher levels in infected patients. COVID-19 may harm bone health by increasing bone regulatory markers and reducing bone formation and absorption, leading to a lower BMD. Elderly, frail, and osteopenic or osteoporotic individuals are at higher risk and should be regularly monitored for bone loss if they have long COVID.

Elevated vitamin D levels in diurnally-active female fruit bats

Animal species have evolved to enhance their survival by focusing their temporal activity on specific parts of the diurnal-nocturnal cycle. Various factors, including inter-specific competition and anti-predator behavior, as well as anthropogenic effects like light pollution, have prompted some species to expand or shift their temporal niches. Our study focuses on the temporal niche shift of the Egyptian fruit bat (Rousettus aegyptiacus) to diurnal activity in Israel. Through an extensive citizen-science study, we assessed the distribution of these bats' diurnal activity across Israel. We also documented the sex and age of bats from a colony known for its diurnal activity and collected blood samples from them for metabolic analysis. Our findings indicate that the shift toward daytime activity predominantly takes place in urban settings and is mostly exhibited by females. We found a significant physiological effect of this temporal shift, namely: diurnal bats' vitamin D levels were significantly higher, and their parathyroid hormone (PTH) levels were significantly lower than those of nocturnal bats. We suggest that the reproductive metabolic demands of female bats might be a key factor driving this shift to diurnal activity. We hypothesize that the increase in vitamin D, derived from sunlight hours, might play a crucial role in regulating calcium homeostasis, thus contributing to the bats' physiological needs during the reproduction season.

Blood Pressure Decreases in Overweight Elderly Individuals on Vitamin D: A Randomized Trial

Context

Evidence for a beneficial role of vitamin D on blood pressure (BP) outcomes is inconclusive.

Objective

This work aimed to investigate the effect of 2 doses of cholecalciferol (vitamin D3) supplementation coadministered with calcium on systolic blood pressure (SBP) and diastolic blood pressure (DBP).

Methods

Exploratory analyses were conducted from a 1-year, multicenter, double-blind, randomized controlled trial (RCT). Total of 221 ambulatory older overweight individuals received calcium dose and oral vitamin D3, at the equivalent of 600 IU/day or 3750 IU/day.

Results

SBP and DBP decreased significantly in the overall group, and in the high-dose group at 6 and 12 months. Similar trends were observed in the low-dose group, but did not achieve statistical significance. In participants with a body mass index (BMI) greater than 30, SBP decreased significantly in both treatment groups whereas DBP significantly decreased in the high-dose group only. In the subgroups of hypertensive participants (N = 143), there was a decrease in SBP and DBP at 6 and 12 months, with both vitamin D doses and independently of BMI levels. Using multivariate linear mixed models with random effects in the overall group of participants, SBP at 6 and 12 months was significantly predicted by BMI (β = .29; P = .05) and by baseline SBP (β = .16; P < .001), but not by vitamin D treatment dose.

Conclusion

Vitamin D and calcium decrease SBP and DBP in overweight older individuals, but more is not necessarily better. This effect is seen in individuals with BMI greater than 30, in hypertensive patients, and seems to be largely independent of dose.

Vitamin D Supplementation: Shedding Light on the Role of the Sunshine Vitamin in the Prevention and Management of Type 2 Diabetes and Its Complications

As the incidence of type 2 diabetes mellitus (T2DM) continues to increase globally, researchers are keen to investigate various interventions to mitigate its impact. Among these, vitamin D supplementation has attracted significant attention due to its influence on insulin secretion from the pancreas and insulin receptors in body cells. A substantial body of evidence indicates that vitamin D supplementation can reduce low-grade inflammation, a critical factor in developing insulin resistance. In addition, vitamin D aids in sustaining low resting concentrations of reactive oxygen species and free radicals, normalizes Ca2+ signaling, diminishes the expression of cytokines that are pro-inflammatory, and enhances the production of cytokines that are anti-inflammatory. This review discusses the effects of vitamin D on the glycemic control of individuals with T2DM and evaluates the impact of vitamin D supplementation on glycemic markers in this population. The investigation employs a comprehensive analysis of the existing literature with a special focus on recent studies published in the past decade. Based on the findings in the literature, it can be concluded that vitamin D supplementation alongside anti-diabetic medications may enhance glycemic control and potentially reduce the risk of diabetic complications. The evidence supports the notion that vitamin D supplementation can be a valuable addition to pharmacological agents for the management of T2DM, potentially enhancing glycemic control and overall health outcomes in affected individuals.

Post-Transplant Vitamin D Deficiency in Lung Transplant Recipients: Impact on Outcomes and Prognosis

Despite the recognized clinical significance of vitamin D deficiency in other solid organ transplant recipients, its specific relevance in lung transplantation remains to be fully understood. In this study, we performed a retrospective observational study on the impact of vitamin D deficiency on clinical outcomes and prognosis in 125 lung transplant recipients (LTRs) from October 2014 to March 2020 at a university hospital in Seoul, South Korea. Among 125 LTRs, 51 patients (40.8%) were vitamin D deficient. LTRs in the vitamin D-deficient group exhibited a higher incidence of post-transplant pneumonia and overall mortality than those with normal vitamin D levels during the follow-up period. This trend persisted when subjects were stratified into vitamin D tertiles. Furthermore, post-transplant vitamin D levels and C-reactive protein (CRP) significantly impacted pneumonia incidence and survival outcomes. Prognosis also varied based on cumulative vitamin D supplementation after transplantation, with patients receiving higher cumulative supplementation demonstrating improved prognosis. Our findings underscore the importance of assessing and maintaining optimal vitamin D levels post-transplantation, suggesting a potential avenue for improving outcomes in lung transplant recipients, especially in mitigating infection risk and enhancing long-term survival. Further research into optimal vitamin D levels and supplementation strategies in this population is warranted.

Correlation between hyperlipidemia and serum vitamin D levels in an adult Chinese cohort

Vitamin D deficiency has emerged as a significant concern in public health due to its potential association with various metabolic disorders. This study aimed to investigate the relationship between serum vitamin D levels and the susceptibility to hyperlipidemia among adults. Using a multi-stage sampling approach, we recruited a cohort of 2072 eligible individuals aged over 18 years. Serum 25-hydroxyvitamin D [25(OH)D] levels were measured alongside glucolipid metabolic markers, and comprehensive demographic and physical data were collected. The cohort exhibited a hyperlipidemia prevalence of 42.18%, with 19.88% demonstrating vitamin D deficiency. Notably, 23.68% of individuals with vitamin D deficiency also presented hyperlipidemia. Statistical analysis revealed a significantly higher prevalence of hyperlipidemia among those with vitamin D deficiency compared to those with sufficient levels (23.68% vs. 17.11%, P < 0.05). After adjusting for various factors including age, geographical region, exercise status, BMI, fasting glucose level, and blood pressure, lower serum 25(OH)D concentrations were found to significantly increase the risk of hyperlipidemia (Odds Ratio [OR] = 1.41; 95% CI: 1.057, 1.885; P < 0.05). Further stratification of the hyperlipidemic cohort revealed that vitamin D deficiency was associated with 1.459- and 1.578-times higher risks for total cholesterol and triglyceride abnormalities, respectively, compared to those with sufficient vitamin D levels. Moreover, each 10 ng/mL decrease in serum vitamin D level corresponded to an increased risk of total cholesterol (OR = 0.82; 95% CI: 0.728, 0.974; P < 0.05) and triglyceride abnormalities (OR = 0.79; 95% CI: 0.678, 0.927; P < 0.05). However, there were no significant differences observed between vitamin D-sufficient and-deficient groups regarding Low-Density Lipoprotein (LDL) and High-Density Lipoprotein (HDL) abnormalities. These findings underscore the potential role of serum vitamin D deficiency as an independent risk factor contributing to the elevated prevalence of hyperlipidemia in the adult population.

SARS-CoV-2 infection causes a decline in renal megalin expression and affects vitamin D metabolism in the kidney of K18-hACE2 mice

Patients with coronavirus disease 2019 (COVID-19) often experience acute kidney injury, linked to disease severity or mortality, along with renal tubular dysfunction and megalin loss in proximal tubules. Megalin plays a crucial role in kidney vitamin D metabolism. However, the impact of megalin loss on vitamin D metabolism during COVID-19 is unclear. This study investigated whether severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection reduces megalin expression in proximal tubules and its subsequent effect on vitamin D metabolism in mice expressing human angiotensin converting enzyme 2 (K18-hACE2 mice). Histological and immunohistochemical staining analyses revealed glomerular and capillary congestion, and elevated renal neutrophil gelatinase-associated lipocalin levels, indicative of acute kidney injury in K18-hACE2 mice. In SARS-CoV-2-infected mice, immunohistochemical staining revealed suppressed megalin protein levels. Decreased vitamin D receptor (VDR) localization in the nucleus and increased mRNA expression of VDR, CYP27B1, and CYP24A1 were observed by quantitative PCR in SARS-CoV-2-infected mice. Serum vitamin D levels remained similar in infected and vehicle-treated mice, but an increase in tumor necrosis factor-alpha and a decrease in IL-4 mRNA expression were observed in the kidneys of the SARS-CoV-2 group. These findings suggest that megalin loss in SARS-CoV-2 infection may impact the local role of vitamin D in kidney immunomodulation, even when blood vitamin D levels remain unchanged.

Vitamin D Supplementation Selectively Affects Peripheral Lymphocyte Subsets in Infertile Women

Background

This study aimed to explore the effect of vitamin D supplementation on lymphocyte subsets in infertile women.

Methods

The study involved a total of 247 patients who suffered recurrent embryo implantation failure (RIF) or recurrent spontaneous abortion (RSA) between January and December 2019 in the Reproductive Medicine Center of Children's Hospital of Shanxi and Women Health Center of Shanxi. The differences in the vitamin D and lymphocyte subsets of the two diseases, the correlation between the 25-hydroxy vitamin D and lymphocyte subsets, the changes in the lymphocyte subsets after vitamin D supplementation and the impact on pregnancy outcome were analysed.

Results

The prevalence of vitamin D deficiency was 77.33% (191/247). After vitamin D supplementation, there were no significant differences in helper T cells (Th), cytotoxic T cells (Tc), Th/Tc and natural killer cells (NK) (p > 0.05), but there were significant differences in leukocyte differentiation antigens 3+ (CD3+), natural killer T cells (NKT), B lymphocytes and vitamin D (p < 0.05). Before vitamin D supplementation, the difference in the composition ratio of different vitamin D levels between the RIF and RSA groups was not statistically significant. At different vitamin D levels, there were no significant differences in CD3+, Th, Tc, Th/Tc, NK or B lymphocyte (p > 0.05), but there was a significant difference in NKT (p < 0.05).

Conclusion

Vitamin D supplementation can reduce the level of NKT in infertile women, which may be of benefit to the pregnancy outcome of couples who experience RIF.

Assessing the relative importance of vitamin D deficiency in cardiovascular health

Previous research has suggested a potential link between vitamin D (VD) deficiency and adverse cardiovascular health outcomes, although the findings have been inconsistent. This study investigates the association between VD deficiency and cardiovascular disease (CVD) within the context of established CVD risk factors. We utilized a Random Forest model to predict both CVD and VD deficiency risks, using a dataset of 1,078 observations from a rural Chinese population. Feature importance was evaluated using SHapley Additive exPlanations (SHAP) to discern the impact of various risk factors on the model's output. The results showed that the model for CVD prediction achieved a high accuracy of 87%, demonstrating robust performance across precision, recall, and F1 score metrics. Conversely, the VD deficiency prediction model exhibited suboptimal performance, with an accuracy of 52% and lower precision, recall, and F1 scores. Feature importance analysis indicated that traditional risk factors such as systolic blood pressure, diastolic blood pressure, age, body mass index, and waist-to-hip ratio significantly influenced CVD risk, collectively contributing to 70% of the model's predictive power. Although VD deficiency was associated with an increased risk of CVD, its importance in predicting CVD risk was notably low. Similarly, for VD deficiency prediction, CVD risk factors such as systolic blood pressure, glucose levels, diastolic blood pressure, and body mass index emerged as influential features. However, the overall predictive performance of the VD deficiency prediction model was weak (52%), indicating the absence of VD deficiency-related risk factors. Ablation experiments confirmed the relatively lower importance of VD deficiency in predicting CVD risk. Furthermore, the SHAP partial dependence plot revealed a nonlinear relationship between VD levels and CVD risk. In conclusion, while VD deficiency appears directly or indirectly associated with increased CVD risk, its relative importance within predictive models is considerably lower when compared to other risk factors. These findings suggest that VD deficiency may not warrant primary focus in CVD risk assessment and prevention strategies, however, further research is needed to explore the causal relationship between VD deficiency and CVD risk.

Effect of serum 25-hydroxyvitamin D level on quadriceps strength: a systematic review and meta-analysis

BACKGROUND

Vitamin D deficiency has been linked to poor muscle function, cartilage degeneration, and the development of knee osteoarthritis. However, the impact of serum 25-hydroxyvitamin D [25(OH)D] level on quadriceps muscle strength remains inconclusive, largely due to variations in study designs, differences in study populations, and the influence of confounding factors such as co-supplementation with other vitamins. The existing literature presents mixed findings, highlighting the need for a comprehensive evaluation of the available evidence.

PURPOSE

This systematic review and meta-analysis aim to summarise.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

Searches were conducted using Medline (Ovid), Embase (Ovid), CINAHL (EBSCOhost), and SPORTDiscus (EBSCOhost), which aimed to summarise recent (published after 2000 and before March 1st, 2024) studies reporting the effects of serum 25(OH)D levels on quadriceps strength. Appraisal tool for Cross-Sectional Studies (AXIS) for cross-sectional studies and Quality in Prognosis Studies (QUIPS) for longitudinal studies. Results from the AXIS and QUIPS tools were used for GRADE quality assessment. The review was carried out using PRIMSA guidelines and registered in PROSPERO (ID: CRD42022313240).

RESULTS

Four hundred studies were screened and 28 studies with 5752 participants were included. 28 published studies (24 cross-sectional and 4 longitudinal) were identified. Key results supported the significant positive correlation between serum 25(OH)D levels and isokinetic quadriceps strength at 180°/s in elderly and athletic populations with a correlation coefficient of 0.245 (95%CI: 0.078-0.398, p = 0.004). However, no significant correlation was found with isometric quadriceps strength or isokinetic strength at 60°/s (r = 0.190, p = 0.085). There was only a weak negative correlation with MVC.

CONCLUSION

This review found a statistically significant positive correlation between serum 25(OH)D levels and isokinetic quadriceps strength. This has important clinical implications, especially in the elderly cohort, with higher 25(OH)D levels being associated with a reduced incidence of falls and fragility fractures.

Vitamin D status in patients with chronic obstructive pulmonary disease at Chris Hani Baragwanath Hospital, Johannesburg, South Africa

Background

There has been a growing interest in nutritional/lifestyle factors, including vitamin D, that may affect chronic obstructive pulmonary disease (COPD). Most data are from Caucasian populations and temperate climates, with minimal African data.

Objectives

The primary objective was to determine the prevalence of vitamin D deficiency (25-hydroxyvitamin D (25(OH)D) ≤20 ng/mL) and insufficiency (25(OH)D 21 - 29 ng/mL) among patients with COPD. Secondary objectives were to investigate the association between vitamin D and demographic/lifestyle factors, lung function parameters, markers of COPD severity and corticosteroid use.

Methods

A prospective, cross-sectional study of 76 patients with COPD was conducted at a tertiary hospital in Johannesburg, South Africa. Patients were interviewed regarding demographic/lifestyle factors, COPD severity markers and corticosteroid therapy. The most recent spirometry result was recorded. Blood samples were taken for measurement of calcium, alkaline phosphatase and vitamin D levels. Patients were stratified according to vitamin D status (deficiency and non-deficiency (25(OH)D >20 ng/mL, i.e. combined insufficiency and adequate levels)), and statistical analysis was performed to assess for associations.

Results

The sample included 72% males and 63% black African patients. The prevalences of vitamin D deficiency and insufficiency were 48% (95% confidence interval (CI) 42 - 54) and 35% (95% CI 30 - 41), respectively. A Modified Medical Research Council (mMRC) dyspnoea score ≥2 was associated with a relative risk of 1.34 (95% CI 1.05 - 1.7) for vitamin D deficiency in univariate analysis. In multivariate regression analysis, only sunlight exposure (<1 hour/day) was an independent predictor of vitamin D deficiency (odds ratio 2.4; 95% CI 1.3 - 4.5).

Conclusion

There was a high prevalence of suboptimal vitamin D levels in this COPD sample population. A higher mMRC score was associated with an increased risk of vitamin D deficiency, while low sunlight exposure was the only independent predictor of vitamin D deficiency.

Study synopsis

What the study adds. This is the first study to provide prevalence data regarding vitamin D status in COPD patients in sub-Saharan Africa. The study highlights a relationship between vitamin D status and both symptom severity and sunlight exposure.Implications of the findings. Owing to the high prevalence of suboptimal vitamin D status among COPD patients, it may be useful to screen patients for vitamin D deficiency, especially those with a more severe phenotype. There may be scope for further studies to evaluate whether vitamin D supplementation corrects the deficiency and provides any clinical outcome benefit.

Efficacy of vitamin D supplementation on depressive symptoms in older patients: a meta-analysis of randomized controlled trials

Background

The relationship between vitamin D and depression has garnered significant attention in recent years. However, the efficacy of vitamin D in ameliorating depression among specific subgroups of older patients remains controversial. This study aimed to assess the impact of vitamin D supplementation on depressive symptoms and the prevalence of depression in older adults. Additionally, the study sought to examine potential moderating factors, including differences among population subgroups and various supplementation strategies.

Methods

A systematic literature search was conducted in the databases PubMed, EMBASE, Web of Science, and the Cochrane Library up to March 2024. The RevMan 5.3 software was utilized to calculate the standardized mean difference (SMD) and to evaluate the quality of evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. The objective was to determine the efficacy of vitamin D supplementation in alleviating depressive symptoms or treating depression in older adults.

Results

This meta-analysis encompassed eleven studies, comprising a total of 21,561 participants. The findings did not indicate a statistically significant therapeutic benefit of vitamin D supplementation for depression in older patients [SMD: -0.10; 95% CI: (-1.19, 0.00); p = 0.05]. Subgroup analyses revealed that the efficacy of vitamin D intervention in geriatric depression correlated with several factors, including baseline serum 25(OH)D levels, the dosage of the intervention, gender, and the initial presence of depressive symptoms or a diagnosis of depression.

Conclusion

The current evidence is insufficient to conclusively establish the significant efficacy of vitamin D supplementation in alleviating depressive symptoms among older patients. Consequently, additional randomized controlled trials are warranted to further validate the relationship between vitamin D supplementation and depression in the older adults.

Vitamin D Levels in the United States: Temporal Trends (2011-2018) and Contemporary Associations with Sociodemographic Characteristics (2017-2018)

Background: The most recent vitamin D data from the National Health and Nutrition Examination Survey (NHANES) have not been examined. We used data from NHANES to describe trends in 25-hydroxyvitamin D [25(OH)D] from 2011 to 2018 and for the most recent cycle (2017-2018) to identify groups with lower levels of 25(OH)D and factors predictive of 25(OH)D. Methods: The 31,628 participants were weighted to represent the entire U.S. population. For each 2-year NHANES survey cycle (2011 to 2018), we calculated the weighted median (25th and 75th percentiles) of 25(OH)D and the proportion of the population within the following categories (nmol/L): <30, 30-<50, 50-<75, 75-<125, and ≥125. For 2017-2018, we stratified by demographic and behavioral factors. Multivariate linear regression identified variables predictive of 25(OH)D. Results: The median 25(OH)D (nmol/L) increased slightly from 2013-2014 [66.5 (25th and 75th percentiles: 51.3, 83.0)] to 2017-2018 [68.7 (52.3, 87.8)], and the prevalence of 25(OH)D <50 nmol/L decreased slightly (23.4% vs. 21.3%). In 2017-2018, characteristics associated with lower 25(OH)D were age (12-39 years), male gender, non-Hispanic Black, higher BMI, lower income and education, winter season, not taking vitamin D supplements, or "never" using sunscreen. When stratified by age, race/ethnicity, and gender simultaneously, median 25(OH)D was lowest among non-Hispanic Black females aged 12-19 (38.5 nmol/L) or 20-39 (38.9 nmol/L). Predictors of 25(OH)D level differed by race/ethnicity, e.g., increasing BMI was associated with larger decrements in 25(OH)D among Mexican Americans. Conclusions: This analysis is the first to examine vitamin D levels stratified by multiple characteristics simultaneously. This strategy identified populations at higher risk for health sequelae due to low levels of vitamin D. For example, high levels of deficiency were found in non-Hispanic Black females of reproductive age.

Implications of vitamin D levels or status for mortality in rheumatoid arthritis: analysis of 2001-2018 data from the National Health and Nutrition Examination Survey

Background

Inadequate levels of vitamin D (VitD) have been linked to increased rates of various health conditions and mortality. However, little is known about the relationship between mortality outcomes and 25-hydroxyvitamin D [25(OH)D] levels in individuals with rheumatoid arthritis (RA). This study aimed to examine this association using data from the National Health and Nutrition Examination Survey.

Methods

A cohort of 2,290 individuals aged 20 to 85 years with RA was analyzed. Lower 25(OH)D levels were inversely associated with all-cause mortality, with a hazard ratio (HR) of 0.91 (0.87 to 0.96) per 10 nmol/L increase. Comparatively, the HR for the VitD insufficiency group was 0.64 (0.50 to 0.83), and for the VitD sufficiency group, it was 0.60 (0.44 to 0.80), both compared to the VitD deficiency group. Cause-specific analysis showed that higher 25(OH)D levels were associated with reduced mortality from heart disease (HR: 0.88, 0.82 to 0.95) and malignant neoplasms (HR: 0.86, 0.79 to 0.94). No significant correlation was found between 25(OH)D levels and cause-specific mortalities for other conditions.

Results

Stratified by gender, the HR for males was 0.92 (0.85 to 0.99) and for females was 0.91 (0.86 to 0.98) per 10 nmol/L increase in 25(OH)D levels. Among individuals aged 20-59 years, no significant correlation was observed, while for those aged 60 years and older, the HR was 0.86 (0.82 to 0.90) per 10 nmol/L increase. Nonlinear analysis identified a sharp increase in HR below 59.95 nmol/L, while HR remained below 1 for 25(OH)D levels above 59.95 nmol/L.

Conclusion

This study reveals a strong negative correlation between 25(OH)D levels and overall mortality in individuals with RA. Notably, this association is particularly significant for mortality related to heart disease and malignant neoplasms. Targeted VitD supplementation should be emphasized, especially in individuals aged 60 years and older with RA. The proposed minimum threshold for adequate 25(OH)D levels in the RA population is 60 nmol/L.

Associations between pre-infection serum vitamin D concentrations and Omicron COVID-19 incidence, severity and reoccurrence in elderly individuals

OBJECTIVE

Previous studies suggest a link between vitamin D status and COVID-19 susceptibility in hospitalised patients. This study aimed to investigate whether vitamin D concentrations in elderly individuals were associated with their susceptibility to Omicron COVID-19 incidence, the severity of the disease and the likelihood of reoccurrence during the era of the post-'zero-COVID-19' policies in China.

DESIGN

In this retrospective study, participants were categorised into three groups based on their 25(OH)D concentrations: deficiency (< 20 ng/ml), insufficiency (20 to < 30 ng/ml) and sufficiency (≥ 30 ng/ml). The demographic and clinical characteristics, comorbidities and the incidence rate, reoccurrence rate and severity of Omicron COVID-19 were retrospectively recorded and analysed by using hospital information system data and an online questionnaire survey.

SETTING

China.

PARTICIPANTS

222 participants aged 60 years or older from a health management centre.

RESULTS

Our findings revealed significant differences in the incidence (P = 0·03) and recurrent rate (P = 0·02) of Omicron COVID-19 among the three groups. Participants with lower 25(OH)D concentrations (< 20 ng/ml) exhibited higher rates of initial incidence and reoccurrence and a greater percentage of severe and critical cases. Conversely, individuals with 25(OH)D concentrations ≥ 30 ng/ml had a higher percentage of mild cases (P = 0·003). Binary and ordinal logistic regression models indicated that vitamin D supplementation was not a significant risk factor for COVID-19 outcomes.

CONCLUSIONS

In the elderly population, pre-infection vitamin D deficiency was associated with increased susceptibility to incidence, severity of illness and reoccurrence rates of Omicron COVID-19.

Vitamin D Deficiency as a Contributing Factor to Chronic Rhinitis in Middle-Aged and Older Adults: An Epidemiological Study

BACKGROUND

Recent studies suggest a critical role for vitamin D in respiratory diseases, including asthma and allergic rhinitis. However, the relationship between vitamin D deficiency and chronic rhinitis, particularly in middle- and older-aged populations, remains underexplored. This study aimed to investigate the association between vitamin D deficiency and chronic rhinitis in middle- and older-aged adults while controlling for lifestyle and physical status factors.

METHODS

Data from 12,654 participants aged 40 years and older were analyzed from the fifth Korean National Health and Nutrition Examination Survey (2010-2012). The prevalence of chronic rhinitis and its association with serum vitamin D levels were assessed using multiple logistic regression models, adjusting for demographic, lifestyle, and physical characteristics.

RESULTS

The prevalence of chronic rhinitis was 21.1%. Participants with chronic rhinitis had a higher prevalence of vitamin D deficiency (69.9% vs. 65.2%) and lower mean vitamin D levels (17.73 ng/mL vs. 18.19 ng/mL) compared to those without chronic rhinitis. After adjusting for confounding factors, vitamin D deficiency remained significantly associated with an increased likelihood of chronic rhinitis (OR = 1.21, 95% CI, 1.082-1.348, p = 0.001).

CONCLUSIONS

This study identifies a significant association between vitamin D deficiency and chronic rhinitis in middle- and older-aged adults, suggesting that maintaining adequate vitamin D levels may be important in managing chronic rhinitis.

Vitamin D deficiency in non-scarring and scarring alopecias: a systematic review and meta-analysis

Background

Numerous studies have linked vitamin D deficiency (VDD) to the pathogenesis of various alopecia disorders.

Objective

This study aimed to investigate whether patients with alopecia are more likely to have VDD or lower vitamin D levels than controls, and the prevalence of VDD among patients with certain alopecia disorders.

Methods

Electronic searches were conducted using PubMed, Embase, Scopus, and Cochrane Library databases from the dates of their inception until September 2024. Studies that reported data allowing for the calculation of odds ratios, mean differences, or correlation coefficients related to vitamin D levels and alopecia were included, while studies without a confirmed diagnosis of alopecia or those involving patients taking vitamin D supplements were excluded.

Results

It was found that 51.94% of patients with alopecia areata (AA), 50.38% of patients with female pattern hair loss (FPHL), 47.38% of patients with male androgenic alopecia (MAGA), 53.51% of patients with telogen effluvium (TE), and 38.85% of patients with primary scarring alopecia had VDD. Compared to controls, AA patients had a pooled odds ratio (OR) of VDD of 2.84 (95% confidence interval: 1.89-4.26, I2 = 84.29%, p < 0.01) and a pooled unstandardized mean difference (UMD) of vitamin D levels of -8.20 (-10.28 - -6.12, I2 = 74.25%, p < 0.01) ng/mL. For FPHL patients, a pooled OR of VDD of 5.24 (1.50-18.33, I2 = 81.65%, p < 0.01) and a pooled UMD of vitamin D levels of -15.67 (-24.55 - -6.79, I2 = 91.60%, p < 0.01) ng/mL were found. However, for MAGA, a pooled VDD OR of 4.42 (0.53-36.61, I2 = 88.40%, p < 0.01), and a pooled UMD of vitamin D levels of -2.19 ng/mL (-4.07 - -0.31 ng/mL, I2 = 7.64%, p = 0.37) were found. For TE patients, pooled UMD of vitamin D levels of -5.71 (-10.10 - -1.32) ng/mL were found.

Conclusion

People with alopecia frequently have VDD; however, only in patients with AA or FPHL was the association of VDD and decreased vitamin D levels statistically significant compared to control. The findings indicate screening for vitamin D could benefit patients with AA or FPHL, potentially addressing vitamin D deficiency. Further study on vitamin D supplementation as a treatment for alopecia is recommended.

Vitamin D Supplementation Does Not Enhance Gains in Muscle Strength and Lean Body Mass or Influence Cardiorespiratory Fitness in Vitamin D-Insufficient Middle-Aged Men Engaged in Resistance Training

BACKGROUND

This study checked whether vitamin D (Vit-D) supplementation improves the efficacy of resistance training (RT) in terms of increasing muscle strength and lean body mass (LBM), and influencing cardiorespiratory fitness (VO2max) in Vit-D-deficient middle-aged healthy men.

METHODS

Participants (n = 28) were quasi-randomly assigned to one of two groups, which, in a double-blind manner, supplemented their diet daily with either Vit-D (8000 IU; VD) or placebo (PLC) during participation in a 12-week supervised RT program.

RESULTS

During the intervention, serum Vit-D concentrations increased 2.6-fold (p < 0.001) in the VD group, while no changes occurred in the PLC group. Muscle strength gains (p < 0.001) as measured in seven exercises performed on RT equipment and increases (p < 0.001) in LBM were similar in the two groups. Total fat mass, percent total fat, and percent android fat decreased (p < 0.05) to a similar extent in both groups, but there was no change in VO2max in either group.

CONCLUSIONS

In conclusion, in healthy Vit-D-insufficient middle-aged men engaged in resistance training, Vit-D supplementation increases serum 25(OH)D levels but does not enhance gains in muscle strength and LBM, or decreases in fat mass and fat percentage, and does not affect cardiorespiratory fitness.

Outcomes of High-Dose Versus Low-Dose Vitamin D on Prognosis of Sepsis Requiring Mechanical Ventilation: A Randomized Controlled Trial

Background: Critically ill patients with sepsis have a high incidence of vitamin D deficiency. Vitamin D promotes the synthesis of human cathelicidin antimicrobial peptide, a precursor of LL-37, which is a part of the innate immune system. This study investigated the effectiveness and safety of the early administration of high-dose enteral vitamin D3 in comparison with low-dose vitamin D3 in patients with sepsis requiring mechanical ventilation (MV). Methods: Eighty adult patients with sepsis requiring MV with known vitamin D deficiency were randomly assigned to receive either an enteral 50 000 IU (Group I) or 5000 IU (Group II) vitamin D supplementation. Clinical and laboratory parameters were evaluated at baseline and on days 4 and 7 between the study groups. The change in serum procalcitonin (PCT) levels on day 7 was the primary outcome, while the change in serum LL-37 levels on day 7, changes in sequential organ failure assessment (SOFA) score, and clinical pulmonary infection score on day 7, MV duration, and hospital length of stay (LOS) were the secondary outcomes. Results: The (day 7-day 0) change in serum PCT and LL-37 levels and SOFA score were significantly different in Group I (P = .010, P < .001, and P < .001, respectively). The SOFA score was significantly different on days 4 and 7 in Group I (P < .001 and P < .001, respectively). The incidence of early ventilator-associated pneumonia was significantly different between both treatment groups (P = .025). The hospital LOS was shorter in Group I (P < .001). No 25-hydroxyvitamin-D toxicity was observed in either group. Conclusions: Early enteral administration of high-dose vitamin D3 in critically ill patients with sepsis requiring MV along with standard treatment for sepsis decreased serum procalcitonin levels, increased serum LL-37 levels, and ameliorated illness severity scores.

Systemic Factors Affecting Pain Management in Dentistry

There are several factors that affect a patient's experience of pain. These include both local and systemic factors. The systemic factors that affect patients' dental and orofacial pain experience include, but not limited to, hormonal, nutritional, systemic infections, neurodegenerative, and autoimmune, among others. Comprehensive medical history is essential to delineate any possible systemic factors affecting pain experience. A thorough review of systems should form the foundation, since multiple factors can affect the prognosis of pain management. This would facilitate early recognition and trigger prompt referrals to the appropriate medical professionals. This helps to reduce the health care burden.

The association between dynamic changes in vitamin D and frailty alterations: A prospective analysis of UK Biobank participants

BACKGROUND

Frailty is a common geriatric syndrome associated with reduced reserves and increased vulnerability to stressors among older adults. Vitamin D deficiency has been implicated in frailty, as it is essential for maintaining musculoskeletal functions. The relationship between dynamic changes in vitamin D levels and frailty over time has not been extensively studied.

METHODS

This study utilized data from the UK Biobank. Baseline and longitudinal changes in vitamin D levels were measured. Frailty status was assessed using both the frailty phenotype and frailty index approaches and classified as robust, pre-frail, or frail. Changes in frailty status were assessed by frailty phenotype at baseline (2006-2010) and the follow-up (2012-2013). Mixed effect model was performed to examine the association between vitamin D levels and frailty status. Using multistate transition models, we assessed the impact of increasing vitamin D levels on the probabilities of transitioning between robust, pre-frail, and frail states.

RESULTS

Based on the frailty phenotype, 287 926 individuals (64.8%) were identified as having various degrees of frailty (median age 58.00 [51.00, 64.00] years, 55.9% females). Using the frailty index approach, 250 566 individuals (56%) were found to have different levels of frailty (median age 59.00 [51.00, 64.00] years, 55.3% females). Baseline vitamin D levels were found to be significantly associated with frailty status (frailty phenotype: ORfrail 0.78, 95% CI [0.76, 0.79], P < 0.001; frailty index: ORfrail 0.80, 95% CI [0.78, 0.81], P < 0.001). Dynamic changes in vitamin D levels were also found to be associated with changes in frailty over time. Furthermore, increasing vitamin D levels were associated with a transition from frailty to a healthier status. A higher degree of vitamin D (estimated at 1 nmol/L) was associated with a lower risk of transitioning from robust to prefrail (HR 0.997, 95% CI [0.995, 0.999]) and from prefrail to frail (HR 0.992, 95% CI [0.988, 0.995]).

CONCLUSIONS

This study highlights the importance of vitamin D in the context of frailty. Low vitamin D levels are associated with increased frailty risk, while increasing vitamin D levels may contribute to improving frailty status. Recognizing the relationship between vitamin D levels and frailty can inform personalized management and early interventions for frail individuals. Further research is needed to explore the potential effects of vitamin D interventions on frailty and deepen our understanding of the biological connections between vitamin D and frailty.

The pharmacokinetic differences between 10- and 15-μg daily vitamin D doses

AIMS

The reference nutrient intake for vitamin D in people aged ≥4 years is 10 μg/day (400 IU/day) in the UK, but the recommended daily allowance is 15 μg/day (600 IU/day) for people aged 1-70 years in the USA. Here, we aim to compare the 25-hydroxyvitamin D (25(OH)D) serum concentration profiles between the 2 doses.

METHODS

With world-wide trial data of adults aged ≥18 years, 45-93 kg, we constructed a minimal physiologically based pharmacokinetics model of serum concentrations of vitamin D and 25(OH)D using nonlinear mixed effects modelling. We used this model to forecast the mean, 2.5th and 97.5th percentiles for serum 25(OH)D concentrations in British adults aged ≥16 years.

RESULTS

Our final model used bodyweight to adjust volume of each compartment and maximum clearance of 25(OH)D. No other covariate was identified. The model accurately predicted independent data from trials of a broad range of dosing regimens. We simulated British adults and showed that circulating 25(OH)D concentrations in 95% of people taking 10 μg/day for a year is predicted to reach 50 nmol/L in 32 weeks, while 97.5% of those on 15 μg/day were predicted to attain this threshold within 28 weeks.

CONCLUSION

Both doses are efficacious in >95% of the British population. The daily dose of 15 μg can help 97.5% of the British adults achieve 50 nmol/L serum 25(OH)D and reach the 25 nmol/L threshold in 4 weeks.

Vitamin D is involved in the regulation of Cl- uptake in zebrafish (Danio rerio)

Cl- is a major anion in the bodily fluids of vertebrates, and maintaining its homeostasis is essential for normal physiological functions. Fishes inhabiting freshwater (FW) passively lose body fluid ions, including Cl-, to the external environment because of the electrochemical gradient of ions across the body surface. Therefore, FW fishes have to actively absorb Cl- from the surroundings to maintain ion homeostasis in their bodily fluids. Hormonal control is vital for modulating ion uptake in fish. Vitamin D is involved in the regulation of Ca2+ uptake and acid secretion in fish. In the present study, we found that the levels of bioactive vitamin D, 1α,25-dihydroxyvitamin D3 (1α,25(OH)2D3), significantly increased in zebrafish embryos and adults after exposure to water containing low levels of Cl-. Moreover, the administration of 1α,25(OH)2D3 treatment (20 μg/L) in zebrafish embryos, and intraperitoneal (i.p.) injection of 1α,25(OH)2D3 (5 μg/kg body mass) in zebrafish adults, resulting the increased Cl- content in bodily fluid in zebrafish. Na+-Cl- cotransporter 2b (NCC2b) and Cl- channel 2c (CLC2c) are specifically expressed during Cl- uptake by ionocytes in zebrafish. Our results indicated that the mRNA and protein expression of NCC2b and CLC2c considerably increased in the zebrafish with exogenous 1α,25(OH)2D3 treatment. Additionally, exogenous 1α,25(OH)2D3 administration increased the number of NCC2b- and CLC2c-expressing cells in yolk skins of zebrafish embryos and the gill filaments of zebrafish adults. Transcript signals of vitamin D receptors (VDRs) were identified in NCC2b-expressing cells. Knockdown of VDRa and VDRb significantly reduced the expression of NCC2b and CLC2c and the number of NCC2b- and CLC2c-expressing cells. These results indicate that vitamin D can affect Cl- uptake in zebrafish and extend our knowledge of the role of vitamin D in fish physiology.

Association Between Body Mass Index (BMI), Vitamin D, and Testosterone Levels

Introduction Obesity is measured scientifically by calculating body mass index (BMI). Body mass index in men is linked to various hormonal imbalances. This study aims to observe the relationships between BMI, vitamin D, and testosterone levels in patients attending the outpatient clinic at Hayatabad Medical Complex, Peshawar, Pakistan. Methods This observational cross-sectional study involved 272 patients, presenting to the medical outpatient department from January 1st, 2023, to December 31st, 2023. Body mass index, serum vitamin D, and testosterone levels were measured for each participant. Body mass index was categorized into normal, overweight, and obese. Statistical analysis was calculated, including descriptive statistics, logistic regression, and correlation analysis to evaluate associations between these variables. Results The mean BMI of the participants was 25.82 ± 7.88 kg/m². A significant inverse correlation was observed between BMI and vitamin D levels (r = -0.79, p < 0.001) and between BMI and testosterone levels (r = -0.87, p < 0.001). A positive correlation was found between vitamin D and testosterone levels (r = 0.87, p < 0.001). Logistic regression analysis revealed that higher BMI in the range of overweight or above was associated with a 2.5-fold increase in the likelihood of vitamin D deficiency (odds ratio (OR) = 2.50, 95% CI = 1.8-3.5, p < 0.001) and a 3.1-fold increase in the likelihood of low testosterone levels (OR = 3.10, 95% CI = 2.2-4.3, p < 0.001). Conclusion In this study, higher BMI is significantly associated with lower vitamin D and testosterone levels. These findings suggest that addressing obesity could help mitigate hormonal imbalances, such as vitamin D deficiency and low testosterone, which are linked to metabolic health risks. It can also be hypothesized that obesity can be a risk factor for vitamin D and testosterone deficiency.

A systematic review on the impact of nutrition and possible supplementation on the deficiency of vitamin complexes, iron, omega-3-fatty acids, and lycopene in relation to increased morbidity in women after menopause

A balanced and healthy diet during the menopausal transition and after menopause is crucial for women to reduce the risk for morbidities and chronic diseases due to deficiency of essential nutrients.

PURPOSE

The objective of this study was to conduct a systematic review of studies that analyzed the impact of vitamin and nutrient deficiencies in postmenopausal women in relation to increased morbidities and chronic conditions.

METHODS

Observational studies were searched in the databases PubMed, UpToDate, and Google Scholar.

RESULTS

We searched 122 studies, of which 90 were included in our analysis. The meta-analysis of the data could not be performed because of the heterogeneity of the statistical methods in the included studies. In our study, we focused on the aspects of vitamin B6, vitamin B12, vitamin D, iron, omega-3-fatty acids, and lycopene, belonging to the family of carotenoids. Postmenopausal women with deficiencies of these nutrients are more vulnerable to comorbidities such as cardiovascular and cerebrovascular events, metabolic diseases, osteoporosis, obesity, cancer and neurodegenerative diseases such as Parkinson's disease, Alzheimer's disease, depression, cognitive decline, dementia, and stroke. We concluded that women after menopause tend to have a greater probability of suffering from deficiencies in various vitamins and nutrients, and consequently have an increased risk of developing morbidities and chronic diseases.

CONCLUSION

In conclusion, maintaining optimum serum levels of nutrients and vitamins, either through a balanced and healthy diet consuming fresh fruits, vegetables, and fats or by taking appropriate supplementation, is essential in maintaining optimal health-related quality of life and reducing the risk for women during the menopausal transition and after menopause. Nevertheless, more recent studies need to be assessed to formulate adequate recommendations to achieve positive clinical outcomes.

Sodium-glucose cotransporter 2 inhibitors and renin-angiotensin-aldosterone system, possible cellular interactions and benefits

Sodium glucose cotransporter 2 inhibitors (SGLT2is) are a newly developed class of anti-diabetics which exert potent hypoglycemic effects in the diabetic milieu. However, the evidence suggests that they also have extra-glycemic effects. The renin-angiotensin-aldosterone system (RAAS) is a hormonal system widely distributed in the body that is important for water and electrolyte homeostasis as well as renal and cardiovascular function. Therefore, modulating RAAS activity is a main goal in patients, notably diabetic patients, which are at higher risk of complications involving these organ systems. Some studies have suggested that SGLT2is have modulatory effects on RAAS activity in addition to their hypoglycemic effects and, thus, these drugs can be considered as promising therapeutic agents for renal and cardiovascular disorders. However, the exact molecular interactions between SGLT2 inhibition and RAAS activity are not clearly understood. Therefore, in the current study we surveyed the literature for possible molecular mechanisms by which SGLT2is modulate RAAS activity.

Biological Effects of CYP11A1-Derived Vitamin D and Lumisterol Metabolites in the Skin

Novel pathways of vitamin D3, lumisterol 3 (L3), and tachysterol 3 (T3) activation have been discovered, initiated by CYP11A1 and/or CYP27A1 in the case of L3 and T3. The resulting hydroxymetabolites enhance protection of skin against DNA damage and oxidative stress; stimulate keratinocyte differentiation; exert anti-inflammatory, antifibrogenic, and anticancer activities; and inhibit cell proliferation in a structure-dependent manner. They act on nuclear receptors, including vitamin D receptor, aryl hydrocarbon receptor, LXRα/β, RAR-related orphan receptor α/γ, and peroxisome proliferator-activated receptor-γ, with selectivity defined by their core structure and distribution of hydroxyl groups. They can activate NRF2 and p53 and inhibit NF-κB, IL-17, Shh, and Wnt/β-catenin signaling. Thus, they protect skin integrity and physiology.

Associations between serum 25-hydroxyvitamin D and prognosis of chronic kidney disease: a prospective cohort study

BACKGROUND AND OBJECTIVES

25-hydroxyvitamin D [25(OH)D] deficiency is prevalent in patients with chronic kidney disease (CKD), the associations between serum 25(OH)D levels and mortality in patients with CKD remain unclear, and this study aimed to explore these associations further.

METHODS

4989 participants with CKD were enrolled in the study, and the Cox regression model was used to assess the effects of serum 25(OH)D concentrations on mortality risk. A restricted cubic spline model was used to explore the dose-response relationships, and threshold effect analysis was performed based on inflection points identified by a two-piecewise linear regression model. In addition, subgroup and sensitivity analyses were employed.

RESULTS

1255 participants died during a mean follow-up period of 70 months. Compared with the 25(OH)D-deficient group, the fully adjusted hazard ratios and 95% confidence intervals for the 25(OH)D-adequate group were 0.631 (0.545, 0.730) for all-cause mortality, 0.569 (0.435, 0.743) for cardiovascular mortality, 0.637 (0.461, 0.878) for hypertension mortality, and cancer mortality was 0.596 (0.426, 0.834). The inflection points of serum 25(OH)D concentration affecting all-cause and cardiovascular mortality were 89 nmol/L, and 107 nmol/L, respectively. Subgroup analyses and interaction tests suggested that the effects varied across populations. The results of sensitivity analyses indicated a reliable correlation.

CONCLUSION

We found an association between serum 25(OH)D concentrations and the prognosis of patients with CKD as a reliable predictor of early intervention and intensive care.

Evolutionary formation of melatonin and vitamin D in early life forms: insects take centre stage

Melatonin, a product of tryptophan metabolism via serotonin, is a molecule with an indole backbone that is widely produced by bacteria, unicellular eukaryotic organisms, plants, fungi and all animal taxa. Aside from its role in the regulation of circadian rhythms, it has diverse biological actions including regulation of cytoprotective responses and other functions crucial for survival across different species. The latter properties are also shared by its metabolites including kynuric products generated by reactive oxygen species or phototransfomation induced by ultraviolet radiation. Vitamins D and related photoproducts originate from phototransformation of ∆5,7 sterols, of which 7-dehydrocholesterol and ergosterol are examples. Their ∆5,7 bonds in the B ring absorb solar ultraviolet radiation [290-315 nm, ultraviolet B (UVB) radiation] resulting in B ring opening to produce previtamin D, also referred to as a secosteroid. Once formed, previtamin D can either undergo thermal-induced isomerization to vitamin D or absorb UVB radiation to be transformed into photoproducts including lumisterol and tachysterol. Vitamin D, as well as the previtamin D photoproducts lumisterol and tachysterol, are hydroxylated by cyochrome P450 (CYP) enzymes to produce biologically active hydroxyderivatives. The best known of these is 1,25-dihydroxyvitamin D (1,25(OH)2D) for which the major function in vertebrates is regulation of calcium and phosphorus metabolism. Herein we review data on melatonin production and metabolism and discuss their functions in insects. We discuss production of previtamin D and vitamin D, and their photoproducts in fungi, plants and insects, as well as mechanisms for their enzymatic activation and suggest possible biological functions for them in these groups of organisms. For the detection of these secosteroids and their precursors and photoderivatives, as well as melatonin metabolites, we focus on honey produced by bees and on body extracts of Drosophila melanogaster. Common biological functions for melatonin derivatives and secosteroids such as cytoprotective and photoprotective actions in insects are discussed. We provide hypotheses for the photoproduction of other secosteroids and of kynuric metabolites of melatonin, based on the known photobiology of ∆5,7 sterols and of the indole ring, respectively. We also offer possible mechanisms of actions for these unique molecules and summarise differences and similarities of melatoninergic and secosteroidogenic pathways in diverse organisms including insects.

Acute kidney injury is associated with soluble vascular cell adhesion molecule 1 levels and short-term mortality in patients with ischemic stroke

BACKGROUND

The mechanisms that modulate the onset of acute kidney inlury (AKI) after ischemic stroke (IS) and valuable biomarkers to predict the occurrence and prognosis of AKI among patients with IS are missing.

OBJECTIVE

To evaluate the frequency of AKI and the prognostic validity of clinical and laboratory biomarkers in predicting AKI and short-term mortality after the IS.

METHODS

Ninety-five patients with IS were enrolled. Baseline IS severity was assessed using the National Institutes of Health Stroke Scale (NIHSS) and disability was determined after three-month follow-up using the modified Rankin Scale. Patients with IS were also categorized as survivors and non-survivors after the follow-up. Baseline data and laboratory biomarkers were obtained up to 24 h of the admission.

RESULTS

Fifteen (15.7 %) patients with IS presented AKI. The proportion of patients with vitamin D deficiency and the mortality were higher among those with AKI than those without AKI (p=0.011 and p-0.009, respectively). Patients with AKI showed higher disability and higher increased soluble vascular cellular adhesion molecule-1 (sVCAM-1) than those without AKI (p=0.029 and p=0.023, respectively). Logistic regression analysis showed that only sVCAM-1 was associated with the occurrence of AKI after IS [odds ratio (OR): 2.715, 95 % confidence intereval (CI): 1.12-6.67, p=0.027]. When both AKI and NIHSS were evaluated as explanatory variables, this panel showed an OR of 5.782 (95 % CI: 1.09-30.43, p<0.001) and correctly classified 83.6 % of cases.

CONCLUSION

In conclusion, sVCAM-1 levels showed a potential useful for prediction of AKI after IS.

Vitamin D Supplementation for Children with Epilepsy on Antiseizure Medications: A Randomized Controlled Trial

BACKGROUND

Antiseizure medications (ASMs) are crucial for managing epilepsy in children. However, a well-documented side effect of ASMs is their impact on bone health, often due to interference with vitamin D metabolism. This can lead to vitamin D deficiency in children with epilepsy. This study aimed to determine if a daily dose of 400 IU or 1000 IU would maintain adequate vitamin D levels in children with epilepsy.

METHODS

A phase IV randomized controlled trial enrolled children aged 2-16 years with epilepsy and receiving antiseizure medications. Children were divided into two groups: the monotherapy group, which was defined as children on one antiseizure medication (ASM), and the polytherapy group, which was defined as children receiving two or more ASMs. Eligible children with levels above 75 nmol/L were randomized to receive a maintenance dose of either 400 IU/day or 1000 IU/day of cholecalciferol. Baseline and 6-month assessments included demographic data, anthropometric measurements, seizure type, medications, seizure control, and 25(OH)D level.

RESULTS

Out of 163 children, 90 were on monotherapy and 25 on polytherapy. After 6 months of vitamin D maintenance, the proportion of children with 25(OH)D concentration below 75 nmol/L was 75.0% in the 400 IU group and 54.8% in the 1000 IU group. In the monotherapy group, baseline seizure-free children increased from 69% to 83.6% after treating vitamin D deficiency.

CONCLUSION

Daily vitamin D supplementation with 1000 IU may be beneficial for children with epilepsy, particularly those receiving monotherapy, to maintain sufficiency and potentially improve seizure control.

Vitamin D for the management of chronic obstructive pulmonary disease

BACKGROUND

COPD is a common, preventable and treatable airway disease, and is currently the third leading cause of death worldwide. About one billion people worldwide are estimated to have vitamin D deficiency or insufficiency. Vitamin D deficiency is common among people with COPD, and has been reported to be associated with reduced lung function and increased risk of acute exacerbations of COPD. Several clinical trials of vitamin D to prevent acute exacerbations of chronic obstructive pulmonary disease (AECOPD) and improve COPD control have been conducted, but an up-to-date meta-analysis of all double-blind, randomised, placebo-controlled trials of this intervention is lacking.

OBJECTIVES

To assess the effects of vitamin D for the management of acute exacerbations and symptoms for people with COPD.

SEARCH METHODS

We searched the Cochrane Airways Trials Register and reference lists of articles. We also searched trial registries directly, and contacted the authors of studies in order to identify additional trials. The date of the last search was 24 August 2022.

SELECTION CRITERIA

We included double-blind, randomised, placebo-controlled trials of vitamin D or its hydroxylated metabolites, for adults with a clinical diagnosis of chronic obstructive pulmonary disease based on the presence of characteristic symptoms and irreversible airflow obstruction. We did not impose restrictions regarding disease severity or baseline vitamin D status, in order to maximise generalisability.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. The primary outcome was the rate of moderate or severe exacerbations (requiring systemic corticosteroids, antibiotics or both). We also performed subgroup analyses to determine whether the effect of vitamin D on the rate of moderate or severe exacerbations was modified by baseline vitamin D status, COPD severity or regular inhaled corticosteroid use. The main secondary outcomes of interest were the proportion of participants experiencing one or more exacerbations (moderate or severe), the change in forced expiratory volume in one second (FEV1, % predicted) and the proportion of participants with one or more serious adverse events of any cause, mortality (all-cause) and quality of life. We used GRADE to assess the certainty of evidence for each outcome.

MAIN RESULTS

We included 10 double-blind, randomised, placebo-controlled trials in this review, involving a total of 1372 adults. Five studies contributed to the primary outcome analysis of the rate of moderate or severe exacerbations requiring systemic corticosteroids, antibiotics or both. The duration of studies ranged from six weeks to 40 months, and all investigated the effects of administering cholecalciferol (vitamin D3). One study included two intervention arms, one where vitamin D3 was given and one where calcitriol (1,25-dihydroxyvitamin D) was given. The majority of participants had mild to moderate COPD, and profound vitamin D deficiency (25-hydroxyvitamin D (25(OH)D) < 25 nmol/L) at baseline was rare (123 participants contributing data to subgroup analysis). Administration of vitamin D or its hydroxylated metabolites results in little to no change in the overall rate of exacerbations requiring systemic corticosteroids, antibiotics or both (rate ratio (RR) 0.98, 95% CI 0.86 to 1.11; 5 studies, 980 participants; high-certainty evidence). Vitamin D supplementation did not influence any meta-analysed secondary outcomes. These were all based on moderate- or high-certainty evidence aside from adverse events and quality of life, which were based on low-certainty evidence. We observed little to no change in the proportion of participants experiencing one or more moderate or severe exacerbations (odds ratio (OR) 0.94, 95% CI 0.72 to 1.24; 5 studies, 980 participants; high-certainty evidence). Additionally, vitamin D probably results in little to no difference in the inter-arm mean change in FEV1 (% predicted) (mean difference 2.82 higher in intervention arm, 95% CI -2.42 to 8.06; 7 studies, 1063 participants; moderate-certainty evidence). There was also probably no effect of vitamin D on the incidence of serious adverse events due to any cause; although we identified an anticipated absolute effect of 36 additional adverse events per 1000 people, the confidence interval included the null hypothesis of no effect (OR 1.19, 95% CI 0.82 to 1.71; 5 studies, 663 participants; moderate-certainty evidence). Vitamin D may have little to no effect on mortality (OR 1.13, 95% CI 0.57 to 2.21; 6 studies, 1019 participants; low-certainty evidence). It also may have little to no effect on quality of life as measured by validated instruments (narrative findings; 5 studies, 663 participants; low-certainty evidence). We assessed one study as being at high risk of bias in at least one domain; this did not contribute data to the meta-analysis of the primary outcome reported above. Sensitivity analysis that excluded this study from the meta-analysed outcome to which it contributed, the inter-arm mean change in FEV1, did not change the findings.

AUTHORS' CONCLUSIONS

We found that administration of vitamin D results in little to no effect on the rate of moderate or severe exacerbations requiring systemic corticosteroids, antibiotics or both or the proportion of participants experiencing one or more exacerbations (moderate or severe) (both high-certainty evidence). Further, vitamin D probably has no effect on the inter-arm difference in change in lung volumes and the proportion of participants with one or more serious adverse event of any cause (both moderate-certainty evidence), and may make little to no difference to mortality or quality of life (both low-certainty evidence). We recommend further research on the balance of benefits and harms of vitamin D supplements in COPD for those with very low or very high starting vitamin D levels, because we assessed the available evidence as low-certainty for these groups.

Update in exploring the connection and clinical implications between vitamin D and knee osteoarthritis

Knee osteoarthritis is a prevalent joint disorder characterized by cartilage degeneration, pain, and impaired physical function. Vitamin D might be implicated in the management of knee osteoarthritis through its effects on bone health, cartilage preservation, inflammation modulation, and muscle function. This literature review aims to synthesize the current state of literature to provide information about the correlation between vitamin D and knee osteoarthritis. Methods: We conducted a comprehensive literature search in databases such as PubMed, Web of Science, Scopus, and Google Scholar to identify studies published in the last ten years investigating the association between vitamin D and knee osteoarthritis. Vitamin D deficiency has been linked to cartilage degeneration and more severe symptomatology of knee osteoarthritis. The evidence supports an association between vitamin D levels and knee osteoarthritis, but with some studies showing mixed results, there is a need for further research.

Role of vitamin D in COVID-19 and other viral infections

Vitamin D is a steroid hormone that is naturally produced in the body or obtained through dietary sources, primarily under the influence of UVB radiation. This essential nutrient has a vital role in numerous physiological processes, encompassing immune function, cell growth, differentiation, insulin regulation, and cardiovascular well-being, along with its pivotal role in sustaining the delicate equilibrium of calcium and phosphate concentrations in the body. Moreover, vitamin D reinforces mucosal defense and bolsters the immune system through immunomodulation, making it a critical component of overall health. Numerous studies have unveiled the profound connection between vitamin D and the predisposition to respiratory tract infections, including well-known viruses such as influenza and the novel severe acute respiratory syndrome coronavirus 2. Vitamin D deficiency has been consistently linked to increased severity of coronavirus disease 2019 (COVID-19) and a heightened risk of mortality among afflicted individuals. Retrospective observational studies have further substantiated these findings, indicating that levels of vitamin D are linked with both the occurrence and severity of COVID-19 cases. Vitamin D has its influence on viral infections through a multitude of mechanisms, such as promoting the release of antimicrobial peptides and fine-tuning the responses of the immune system. Additionally, vitamin D is intertwined with the intricate network of the renin-angiotensin system, suggesting a potential impact on the development of complications related to COVID-19. While further clinical trials and extensive research are warranted, the existing body of evidence strongly hints at the possible use of vitamin D as a valuable tool in the prophylaxis and management of COVID-19 and other viral infectious diseases.

Associations between vitamin D status and biomarkers linked with inflammation in patients with asthma: a systematic review and meta-analysis of interventional and observational studies

BACKGROUND

Numerous studies indicate an association between vitamin D status and inflammatory biomarkers in patients with asthma, but findings are inconsistent. This review aims to summarize the relationship between serum vitamin D status, assessed by 25-hydroxyvitamin D (25(OH)D) level, and inflammatory biomarkers in children and adults with asthma.

METHODS

A literature search of interventional and observational studies on 25(OH)D up to November 2022 was conducted across six electronic databases. Outcomes of interest included a range of inflammatory biomarkers classified in four categories: T helper 2 (Th2) pro-inflammatory, non-Th2 pro-inflammatory, anti-inflammatory, and non-specific biomarkers. Study characteristics were extracted and risk of bias was evaluated using the American Academy of Nutrition and Dietetics tool. Meta-analysis was conducted on studies with a low risk of bias, while narrative reporting was used to present the direction of associations (positive, no association, or negative) for each biomarker, overall and within the low-risk studies.

RESULTS

We included 71 studies (3 interventional, 68 observational) involving asthma patients. These studies investigated the association between serum 25(OH)D and Th2 pro-inflammatory biomarkers (N = 58), non-Th2 pro-inflammatory biomarkers (N = 18), anti-inflammatory biomarkers (N = 16), and non-specific biomarkers (N = 10). Thirteen (18.3%) studies, 50 (70.4%), and 8 (11.3%) were at high, moderate, and low risk of bias, respectively. In all studies, irrespective of risk of bias, the most frequently reported finding was no significant association, followed by a negative association between 25(OH)D and pro-inflammatory biomarkers and a positive association with anti-inflammatory biomarkers. In low-risk studies, one biomarker could be meta-analysed. The pooled estimate for 25(OH)D and serum IgE showed a negative association (β (95% CI)= - 0.33 (-0.65 to - 0.01); I2 = 88%; N = 4 studies). A negative association between 25(OH)D and blood eosinophils was also observed in the largest of three studies, as well as with cathelicidin (LL-37) in the only study reporting it. For other biomarkers, most low-risk studies revealed no significant association with 25(OH)D.

CONCLUSION

Serum 25(OH)D is negatively associated with serum IgE and possibly with blood eosinophils and LL-37, supporting an in vivo immunomodulatory effect of 25(OH)D. Future research should employ rigorous methodologies and standardized reporting for meta-analysis aggregation to further elucidate these associations.

Vitamin D, periodontitis and tooth loss in older Irish adults

The aim of this study is to investigate whether 25-hydroxyvitamin D (25(OH)D) is associated with periodontitis and tooth loss in older adults. A total of 2346 adults underwent a detailed dental examination as part of the health assessment of a national population study - The Irish Longitudinal Study of Ageing. 25(OH)D analysis was performed on frozen non-fasting total plasma using LC-MS. The analysis included both multiple logistic regression and multinominal logistic regression to investigate associations between 25(OH)D concentration, periodontitis and tooth loss, adjusting for a range of potential confounders. Results of the analysis found the mean age of participants was 65·3 years (sd 8·2) and 55·3 % of the group were female. Based on the quintile of 25(OH)D concentration, participants in the lowest v. highest quintile had an OR of 1·57 (95 % CI 1·16, 2·13; P < 0·01) of having periodontitis in the fully adjusted model. For tooth loss, participants in the lowest v. highest quintile of 25(OH)D had a RRR of 1·55 (95 % CI 1·12, 2·13; P < 0·01) to have 1-19 teeth and a RRR of 1·96 (95 % CI 1·20, 3·21; P < 0·01) to be edentulous, relative to those with ≥ 20 teeth in the fully adjusted models. These findings demonstrate that in this cross-sectional study of older men and women from Ireland, 25(OH)D concentration was associated with both periodontitis and tooth loss, independent of other risk factors.

Disparities in the Cardiometabolic Impact of Adiposity among African American and Hispanic Adolescents

As adiposity increases in youth, so does the prevalence of cardiometabolic risk factors (CMRFs). The etiology of adiposity-based chronic disease and CMRFs includes ethnoracial disparities that are rarely considered in current treatment approaches. Precision interventions require further characterization of these disparities among high-risk youth. The objective of this study was to characterize differences in CMRF among African American (AA) and Hispanic (H) adolescents with varying levels of adiposity. A cross-sectional analysis of 2284 adolescents aged 12-17 was conducted using 3-year clinical data from Lifedoc Health. CMRF prevalence were compared using χ2, with logistic regression models (LRM) applied to explore the relationships between exposures (age, sex, ethnoracial group, adiposity) and CMRF outcomes. Prevalence of CMRF rose with increasing adiposity, which was the strongest determinant of risk overall. However, individual risk profiles differed between the two groups, with H having higher prevalence of metabolic syndrome (MetS), higher triglycerides and liver enzymes, and low high-density lipoprotein cholesterol (HDL-c). Meanwhile, AA had higher prevalence of elevated blood pressure (BP) in the overweight category, prediabetes in overweight to severe obesity, and type 2 diabetes in obesity. LRM showed 3.0-fold greater chance of impaired glucose metabolism in AA than H, who were 1.7, 5.9, and 8.3 times more likely to have low HDL-c, high liver enzymes, and high triglycerides, respectively. Overweight/obesity prevalence was very high among AA and H adolescents. Excess adiposity was associated with an increased prevalence of CMRF, with individual risk factors differing between groups as adiposity increased. Research within routine clinical settings is required to better characterize these discrepancies and ameliorate their adverse impact on health in the transition to adulthood.

Evaluating the Role of Vitamin D in Alleviating Chronic Pruritus: A Meta-Analysis

Chronic pruritus is a distressing condition that significantly impacts patients' quality of life. Recent research has increasingly focused on the potential role of vitamin D, given its immunomodulatory properties, in managing this condition. This meta-analysis seeks to systematically assess the effectiveness of vitamin D supplementation in alleviating chronic pruritus across diverse clinical contexts. We conducted an extensive search through multiple databases, covering literature up to July 2024, to identify relevant randomized controlled trials (RCTs) that evaluated the effect of vitamin D on chronic pruritus. Eligible studies were those that provided data on changes in pruritus severity, as measured by standardized tools, before and after vitamin D treatment. The data were synthesized using a random-effects model to address variability among the studies. This meta-analysis is registered with PROSPERO (registration number: CRD42024579353). The findings indicate that vitamin D supplementation is associated with a significant reduction in pruritus severity, the skin lesion area, and levels of inflammatory cytokines, including tumor necrosis factor (TNF), interleukin-6 (IL-6), and high-sensitivity C-reactive protein (hs-CRP), compared to controls. These results suggest that vitamin D could be a promising therapeutic option for chronic pruritus, though further rigorous studies are required to validate these findings and to elucidate the mechanisms involved.