Vitamin D physiology

Value of inflammatory markers for monitoring disease severity and progression in granuloma induced by cosmetic oil injections

OBJECTIVE

Cosmetic oil injections can cause foreign body granulomas, leading to inflammation-driven extrarenal production of activated vitamin D (1,25(OH)2D3) and severe hypercalcemia. This study investigates longitudinal changes in inflammatory markers: interleukin 2 receptor (IL-2R), peptidyl dipeptidase (ACE), and ferritin in patients with oil-induced granuloma.

MATERIALS AND METHODS

109 male patients were stratified according to baseline calcium status. 28 % had hypercalcemia, and 72 % normocalcemia. Normocalcemic patients were subdivided based on serum parathyroid hormone (PTH) concentrations into suppressed (< 2.0 pmol/L, n = 30) or normal (≥ 2.0 pmol/L, n = 49) concentrations. Blood samples were collected over 48 months and longitudinal changes in inflammatory markers and calcium homeostasis were examined using Pearson correlation and mixed model analyses.

RESULTS

IL-2R, ACE, and ferritin were positively correlated with serum concentration of ionized calcium, while IL-2R was associated with serum 1,25(OH)2D3. In patients with hypercalcemia, IL-2R decreased at 6 (p = 0.041), 24 (p = 0.048), and 36 months (p = 0.035). ACE increased at 48 months (p = 0.008). In patients with normocalcemia and suppressed PTH, IL-2R increased at 24 months (p = 0.021), while serum ferritin increased in patients with normocalcemia and normal PTH at 6 (p = 0.040), 12 (p = 0.008), 24 (p = 0.028), and 48 months (p = 0.005).

CONCLUSIONS

Positive correlations were observed at baseline between ionized calcium concentrations and IL-2R, ionized calcium and ferritin, and 1,25(OH)₂D₃ and IL-2R. Hypercalcemia and suppressed PTH was associated with elevated IL-2R and ferritin concentrations at baseline. Over time, IL-2R and ferritin concentrations decreased in patients with hypercalcemia, some treated with immunomodulatory drugs. IL-2R and ferritin concentrations increased in untreated patients with normocalcemia.

High reliance on fortified foods when optimizing diets of adolescents in Sweden for adequate vitamin D intake and climate sustainability

The global food system contributes roughly one-third of global greenhouse gas emissions (GHGEs) making shifts towards more sustainable food consumption an imperative. Such diets also need to factor in nutrient requirements and cultural acceptability. Our aim was to simulate dietary changes for adolescents in Sweden to achieve the recommended intake (RI) for vitamin D while factoring in additional nutrients, cultural acceptability and keeping the diet within planetary boundaries for climate change. A baseline diet was estimated from Sweden's national dietary survey Riksmaten Adolescents 2016-17 (n = 3099, ages 11-18 years), which provided food intake via two 24-hour recalls. Intake data were linked to the Swedish Food Agency's food composition database and GHGE estimates from the Research Institutes of Sweden's (RISE) Food Climate Database. Linear programming was used to optimize the baseline diet to meet the RI for vitamin D (10 µg/day), reduce GHGEs to ≤ 1.7 kg CO2-equivalents/person/day, and minimize dietary changes from baseline to factor in cultural acceptability. A second optimization included 25 additional nutrients requirements. Both optimized diets met their respective requirements reducing GHGEs by 54 % but relied heavily on milk and yoghurt (fortified by law), which provided > 60 % of vitamin D intake. Both diets also required major shifts toward plant-based foods and the second optimization demanded a five-fold greater change in diet from baseline compared to first optimization. Results suggest that adolescents in Sweden can achieve RIs for vitamin D and other nutrients while greatly reducing diet-related GHGEs, though cultural acceptability may be a challenge.

Hypoparathyroidism: diagnosis, management and emerging therapies

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

Predictors of Vitamin D Status in Religious and Intermittent Fasting: A Comparative Study in Orthodox Nuns and Women from the General Population

Background: Vitamin D plays a key role in bone metabolism and immune regulation. Populations with restricted sun exposure or limited dietary intake are particularly vulnerable to vitamin D deficiency. Orthodox Christian nuns represent a unique group in this regard, due to traditional clothing, limited outdoor activity, and prolonged religious fasting. However, few studies have compared them with lay individuals following similar dietary practices. Objective: This study aimed to investigate predictors of serum 25-hydroxyvitamin D [25(OH)D] concentrations in two female populations: Orthodox Christian nuns and women from the general population practicing intermittent (religious or non-religious) fasting. We also aimed to develop predictive models of vitamin D status for each group based on lifestyle and biochemical parameters. Methods: A total of 85 women (40 Orthodox nuns and 45 laywomen), aged 30-50 years, were enrolled. Serum 25(OH)D, parathyroid hormone (PTH), calcium levels, and anthropometric indices, including body mass index (BMI), total body fat, and visceral fat, were measured. Dietary calcium and vitamin D intake, as well as sun exposure, were assessed using validated questionnaires. Separate stepwise multiple regression models were constructed for each group to identify independent predictors of 25(OH)D concentrations. An additional combined model, including all participants, was also explored. Results: PTH was the most significant predictor, negatively correlating with 25(OH)D concentrations in both groups (p = 0.038), highlighting its regulatory role in vitamin D metabolism. When analyzed separately, the model for Orthodox nuns showed stronger explanatory power (adjusted R2 = 0.718; p = 0.013) compared with the control group (adjusted R2 = 0.362; p = 0.038), with PTH emerging as a key predictor in both. Conclusions: Distinct predictors of vitamin D status were identified in each group, reflecting the complex interplay between lifestyle and physiological factors. These findings suggest that targeted interventions, such as addressing PTH regulation in fasting populations or enhancing sun exposure in the general population, may be more effective in preventing vitamin D deficiency depending on the context.

Exercise without Weight Loss Prevents Seasonal Decline in Vitamin D Metabolites: The VitaDEx Randomized Controlled Trial

Many adults become vitamin D deficient or insufficient during winter at northerly latitudes when cutaneous vitamin D synthesis does not occur. Vitamin D accumulates in adipose tissue and people with overweight or obesity are more likely to have low systemic vitamin D. This randomized controlled trial demonstrates that regular exercise completely maintains serum concentrations of the active vitamin D metabolite 1,25(OH)2D3 over winter and may ameliorate the decline in 25(OH)D status in overweight men and women, even without weight loss. The binding of 1,25(OH)2D3 to the vitamin D receptor mediates the crucial role for vitamin D in the healthy function of multiple organ systems and vitamin D supplementation does not impact circulating 1,25(OH)2D3. Thus, the VitaDEx study provides causal evidence that exercise plays an important role in vitamin D metabolism that is distinct from the effects of oral supplementation.

Vitamin D and Acute Kidney Injury: A Reciprocal Relationship

Vitamin D is a sterol prohormone with no intrinsic biological activity. Calcitriol, the active form of vitamin D, is synthesized in the kidneys. It has well-known pleiotropic and cytoprotective properties. In addition to regulating parathyroid hormone secretion and enhancing gut calcium absorption, it exhibits antioxidant, anti-inflammatory, antiproliferative, and antineoplastic effects. However, the role of vitamin D in AKI is unclear, unlike in CKD. Thus, this review aimed to understand how dysregulated vitamin D homeostasis occurs in AKI, as well as to explore how vitamin D deficiency and excess influence AKI. A comprehensive literature search was conducted between January 2000 and June 2024 to uncover relevant works detailing vitamin D homeostasis in health as well as investigating the impact of vitamin D deficiency and excess in humans, animals, and in vitro cell models of AKI. According to the findings of this review, vitamin D appears to have a reciprocal relationship with AKI. Acute renal injury, among other factors, can cause hypo- or hypervitaminosis D. Conversely, AKI can also be caused by vitamin D deficiency and toxicity. Even though hypovitaminosis D is associated with AKI, it is uncertain how it impacts AKI outcomes in distinct clinical scenarios. Newer therapeutic options might emerge as a result of understanding these challenges. Vitamin D supplementation may ameliorate renal injury but needs further validation. Furthermore, hypervitaminosis D has also been implicated in AKI by causing hypercalcemia and hyperphosphatemia. It is crucial to avoid prolonged, uncontrolled, and unsupervised supraphysiological vitamin D administration, especially intramuscular injection.

Association of serum 25-hydroxyvitamin D with sleep disorders in individuals with prediabetes and diabetes: a prospective cohort study

Background

Sleep disorders are common globally and are linked to various adverse health outcomes, including cardiovascular disease, type 2 diabetes, and mental health conditions. Emerging evidence suggests a potential role of serum 25-hydroxyvitamin D (25(OH)D) in regulating sleep. Individuals with prediabetes and diabetes are at an increased risk of both vitamin D deficiency and sleep disorders, yet the relationship between these factors remains insufficiently studied. Utilizing data from the UK Biobank, this study aims to investigate the association between serum 25(OH)D concentrations and the risk of sleep disorders in individuals with prediabetes and diabetes.

Methods

We conducted a cross-sectional study of 81,533 participants (mean age 59.6 [SD 7.1] years, comprising 41,275 males [50.6%] and 40,278 females [49.4%]) from the UK Biobank, followed by a prospective study of 80,546 participants (mean age 59.6 [SD 7.1] years, comprising 40,513 males [50.3%] and 40,033 females [49.7%]) within the same cohort, focusing on individuals with prediabetes and diabetes. Baseline serum 25(OH)D concentrations were categorized into four groups: severe deficiency (<25.0 nmol/L), moderate deficiency (25.0-50.0 nmol/L), insufficiency (50.0-75.0 nmol/L), and sufficiency (≥75.0 nmol/L). Multivariable logistic regression and Cox proportional hazards models were used, adjusting for demographic, lifestyle, and health-related confounders.

Results

Over an average follow-up of 12.8 years, we documented 2,704 cases of sleep disorders and found that higher serum 25(OH)D concentrations were significantly associated with reduced sleep disorder risk. In fully adjusted models, sufficient serum 25(OH)D concentrations reduced sleep disorder risk by 48% in prediabetes (HR = 0.52; 95% CI: 0.41-0.65) and 52% in diabetes (HR = 0.48; 95% CI: 0.34-0.67). Subgroup analysis found that adequate vitamin D concentrations were associated with improved sleep health especially in people ≤60 years of age, women, BMI≥30kg/m², and those who had never smoked.

Conclusion

This study provides strong evidence that higher serum 25(OH)D concentrations are associated with a reduced risk of sleep disorders in individuals with prediabetes and diabetes. These findings suggest that maintaining adequate vitamin D concentrations may offer a potential strategy to improve sleep health in this population.

Utility of the Fragility Score (FS) Determined Through Radiofrequency Ecographic Multi-Spectrometry (REMS) in the Follow-Up of Patients with Axial Spondyloarthritis (AxSpA)

Objectives: Bone mineral density (BMD) variation under vitamin D supplementation, determined using dual-energy X-ray absorptiometry (DXA), is the gold standard and the main tool used in most studies in this domain. However, the scientific literature is lacking with regard to the usefulness of REMS in BMD follow-up, especially the importance of the fragility score (FS). The main objective of this study was to determine whether FS follow-up is relevant in a group of patients with axial spondyloarthritis and whether REMS could have clinical applicability. Methods: Patients with a certain diagnosis of axial spondyloarthritis (AxSpA) were recruited from two medical healthcare centers and were scanned using Radiofrequency Echographic Multi-Spectrometry in order to obtain their fragility score (FS), an objective measurement of bone quality. The main group was randomized into a vitamin D supplementation branch and a non-supplementation branch and followed up every 6 months for 18 months in total. Comparisons between the branches were made using MiniTab v.20 statistical software. Results: Lower FS values were obtained in patients who initially had high scores, suggesting a positive impact of vitamin D on bone quality (p = 0.008). Muscle strength was evaluated through a visual analogue scale (VAS), with improvements being seen in the supplementation branch (p < 0.005). Furthermore, although some patients had experienced falls in previous years, during the study period, no new events were recorded in either group. Conclusions: The FS is a reliable tool for evaluating bone architecture and is useful in everyday practice for the management of patients taking vitamin D supplements.

Vitamin D Status Determines Cardiometabolic Effects of Testosterone Replacement Therapy in Men with Late-Onset Hypogonadism

Background/Objectives: Low testosterone levels and low vitamin D status are associated with increased cardiometabolic risk. The purpose of this study was to investigate whether vitamin D status determines the cardiometabolic effects of testosterone replacement therapy. Methods: The study population consisted of three groups of men with late-onset hypogonadism: vitamin D-naive individuals with 25-hydroxyvitamin D levels between 20 and 30 ng/mL (group I), males with 25-hydroxyvitamin D levels between 30 and 60 ng/mL receiving vitamin D supplementation because of previous low vitamin D status (group II), and vitamin D-naïve subjects with 25-hydroxyvitamin D levels between 30 and 60 ng/mL (group III). Circulating levels of total testosterone, 25-hydroxyvitamin D, glucose, insulin, lipids, uric acid, high-sensitivity C-reactive protein (hsCRP), homocysteine, fibrinogen, and urinary albumin-to-creatinine ratio (UACR) were assessed before and six months after intramuscular testosterone administration (250 mg every three weeks). Results: Group I differed from the remaining groups in baseline values of 25-hydroxyvitamin D, hsCRP, homocysteine, fibrinogen, UACR, and the Framingham Risk Score. In all three groups, testosterone injections increased plasma testosterone levels and had a neutral effect on 25-hydroxyvitamin D concentration. In groups II and III, the drug improved insulin sensitivity and reduced LDL cholesterol, uric acid, hsCRP, homocysteine, fibrinogen, and UACR. In group I, the impact of testosterone was limited to a small decrease in HDL cholesterol and hsCRP. Only in groups II and III did testosterone reduce the Framingham Risk Score. There were no differences in the strength of testosterone action between both groups. In groups II and III, the replacement-induced changes in insulin sensitivity, LDL cholesterol, uric acid, hsCRP, homocysteine, fibrinogen, UACR, and the Framingham Risk Score positively correlated with 25-hydroxyvitamin D concentration. Conclusions: The study results suggest that the cardiometabolic effects of exogenous testosterone in men with testosterone deficiency may be determined by vitamin D status.

Evaluation of the role of thyroid hormones, vitamin B12, vitamin D3, folic acid and ferritin serum levels in pterygium development

To evaluate the relationship between pterygium and serum thyroid hormone, vitamin B12, vitamin D3, folic acid, and ferritin levels between pterygium patients and control and to assess its correlation with clinical findings. 18-65-year-old 100 pterygium patients and age and sex matched 60 healthy control subjects were included. The peripheric blood sampling results were investigated. Free triiodothyronine (FT3), free thyroxine (FT4), thyroid stimulating hormone (TSH), vitamin B12, vitamin D3, folic acid, and ferritin levels of pterygium and control groups were compared. FT3 level was higher in the patient group compared to the control group, while vitamin B12, vitamin D3, folic acid and ferritin levels were significantly lower in the patient group compared to the control group (p < 0.05) No significant difference was found between the patient and control groups in terms of age, gender and body mass index (BMI) (p = 0.295, p = 0.625, p = 0.547, respectively). This study reports that pterygium patients have lower serum vitamin B12, folic acid, ferritin and vitamin D3 levels than healthy individuals.

Running Low: A Seasonal Analysis of Micronutrient Deficiencies on External-Load Measures in Elite Female Rugby League Players

Iron and vitamin D are essential for physiological mechanisms underpinning physical capacities characterizing team-sport performance. Yet, the impact of iron deficiency on physical capacities beyond endurance is not clear.

PURPOSE

The purpose of this study was to assess variations in seasonal micronutrient concentrations and how iron deficiency impacts external-load measures in elite female rugby league players.

METHODS

Iron and vitamin D status were measured in 28 players (age 24 [4] y, body mass 76 [11] kg) across 3 time points of the 17-week National Rugby League Women's season. Physical demands were evaluated using external-load measures (eg, total distance, PlayerLoad) for training and competition. Linear mixed-effects models were employed to assess the effect of change in serum ferritin concentration on external-load measures. Effect sizes with 95% CIs were calculated to interpret the magnitude of difference in change in indices and performance outcomes between iron-deficient and iron-sufficient players.

RESULTS

Iron-deficiency prevalence ranged from 26% to 57% across the season, and <22% of players were vitamin D deficient at each time point. Weak to strong positive associations (R2 = .3-.6) were observed between all external-load measures and moderating variables (serum ferritin, week, position, and athlete). However, these associations were largely attributable to the contribution of week and position. Differences in load measures between iron-deficient and iron-sufficient players were mostly trivial to small.

CONCLUSIONS

Iron status of elite female rugby league players had little effect on most workload measures within this cohort. However, longitudinal monitoring is warranted to identify how external-load measures are affected individually in response to fluctuations in serum ferritin.

The epidemiology, pathology and pathogenesis of MS: Therapeutic implications

Multiple sclerosis (MS) is a chronic, and potentially disabling, inflammatory disease of the central nervous system (CNS). MS is generally characterized by recurrent, and self-limited, episodes of neurological dysfunction, which occur unpredictably and often result in multifocal tissue injury within the CNS. Currently, women are affected two to three times as often as men although this may not have been the case during earlier Time-Periods. The pathogenesis of MS is known to involve both critical genetic and environmental mechanisms. Nevertheless, in addition to these two mechanisms, disease-pathogenesis also involves a "truly" random event. Indeed, it is this random mechanism, which is responsible for the currently-observed (and increasing) excess of women among patients with MS. This review summarizes the current state of knowledge regarding the pathogenesis of MS (includong its epidemiology, pathology, and genetics) and considers the therapeutic implications that these pathogenetic mechanisms have both for our currently available therapies as well as for the possible therapeutic approaches to the management of this potentially disabling condition in the future.

Association between serum vitamin D level and cardiovascular disease in Chinese patients with type 2 diabetes mellitus: a cross-sectional study

The relationship between 25-hydroxyvitamin D (25(OH)D) status and cardiovascular disease (CVD) in the diabetes population still needs to be clarified. This study aimed to explore the association of 25(OH)D with CVD and cardiometabolic risk factors in Chinese population with type 2 diabetes mellitus (T2DM). This cross-sectional study was performed with 1378 hospitalized patients with T2DM. Participants were classified into three groups according to the serum 25(OH)D levels: vitamin D adequate, vitamin D insufficiency and vitamin D deficient. Multivariate logistic regression analysis, stratified analysis and interaction analysis were performed to determine the relationship between serum 25(OH)D levels and CVD outcome. After adjusting for confounders, serum 25(OH)D levels were significantly negatively associated with cardiovascular disease in type 2 diabetic patients [OR: 0.97 (0.94, 0.99), p = 0.0131]. Taking the vitamin D-sufficient group (≥ 20 ng/mL) as a reference, the vitamin D-deficiency group (< 12 ng/mL) was associated with a significantly higher risk of cardiovascular disease, with a 1.25-fold increased risk after adjusting for all potential confounders [OR: 2.25 (1.33, 3.79), p = 0.0023]. Stratification analysis showed that the association between vitamin D deficiency and increased risk of cardiovascular disease was particularly significant in women [OR: 4.32 (1.54, 12.12), p = 0.0055], older adults [OR: 4.14 (1.10, 15.56), p = 0.0355], normal-weight [OR: 4.09 (1.51, 11.10), p = 0.0056] and obese subjects [OR: 3.66 (1.03, 13.05), p = 0.0453]. Vitamin D deficiency was significantly associated with an increased risk of overweight/obesity [OR: 1.57 (1.10, 2.24), p = 0.0134], hypertension [OR: 1.81 (1.30, 2.51), p = 0.0004], hypertriglyceridemia [OR: 1.56 (1.12, 2.16), p = 0.0078] and reduced HDL-C [OR: 1.67 (1.19, 2.35), p = 0.0033]. Serum 25(OH)D levels were significantly negatively associated with CVD in T2DM patients and vitamin D deficiency was significantly associated with an increased risk of overweight/obesity, hypertension and dyslipidemia.

Influence of cholecalciferol supplementation on changes in total 25OHD, free 25OHD, and free 25OHD % in relation to calcium, bone, and glucose homeostasis in young, infertile men

BACKGROUND AND OBJECTIVE

While all types of vitamin D metabolites are bound to vitamin D binding protein and albumin leaving only a small fraction in its free active form, only serum concentrations of total 25-hydroxy vitamin D (25OHD) are used to determine vitamin D status in clinical practice. This study aimed to describe the association of total 25-hydroxy vitamin D (25OHD), calculated free 25OHD, and free 25OHD% (free 25OHD × 100 %/total 25OHD) with mineral, bone, and metabolic variables and assess the impact of cholecalciferol supplementation.

RESEARCH DESIGN AND METHODS

Secondary data from a single-center, double-blinded, randomized, placebo-controlled clinical trial (NCT01304927) in 307 infertile men. The treatment group (n = 151) initially received 300,000 IU cholecalciferol as a bolus followed by 1400 IU daily for 150 days and was compared to a placebo group (n = 156).

RESULTS

At baseline men with free 25OHD% > 0.03 % had lower serum triglycerides (mmol/L) (0.8 vs. 1.0; p = 0.002), lower LDL (mmol/L) (2.7 vs. 3.1; p = 0.003), lower fasting blood glucose (mmol/L) (4.9 vs. 5.2; p = 0.012), and lower PTH (pmol/L) (3.8 vs. 4.6; p = 0.015) compared to men with free 25OHD% < 0.02 %. When the study population was stratified according to total 25OHD or free 25OHD, the metabolic markers and bone variables did not show any differences. Cholecalciferol supplementation increased total 25OHD after 150 days compared to placebo and the difference was highest in men with lowest vitamin D status. Cholecalciferol supplementation did not change free 25OHD%.

CONCLUSION

The free 25OHD% is better associated with metabolic health markers such as serum triglycerides, LDL, and fasting blood glucose, but not bone or calciotrophic markers except parathyroid hormone. The free 25OHD% is not affected by cholecalciferol supplementation.

A trend of osteocalcin in diabetes mellitus research: bibliometric and visualization analysis

Background

Osteocalcin has attracted attention for its potential role in diabetes management. However, there has been no bibliometric assessment of scientific progress in this field.

Methods

We analysed 1680 articles retrieved from the Web of Science Core Collection (WoSCC) between 1 January 1986 and 10 May 2024 using various online tools.

Result

These papers accumulated 42,714 citations,with an average of 25.43 citations per paper. Publication output increased sharply from 1991 onwards. The United States and China are at the forefront of this research area.

Discussion

The keywords were grouped into four clusters: 'Differential and functional osteocalcin genes', 'Differential expression of osteocalcin genes in relation to diabetes mellitus', 'Role of osteocalcin in the assessment of osteoporosis and diabetes mellitus', and 'Indirect involvement of osteocalcin in metabolic processes'. Analysis using the VoS viewer suggests a shift in research focus towards the correlation between osteocalcin levels and diabetic complications, the clinical efficacy of therapeutic agents or vitamins in the treatment of osteoporosis in diabetic patients, and the mechanisms by which osteocalcin modulates insulin action. The proposed focus areas are "osteocalcin genes", "insulin regulation and osteoporosis ", "different populations", "diabetes-related complications" and "type 2 diabetes mellitus","effect of osteocalcin expression on insulin sensitivity as well as secretion","osteocalcin expression in different populations of diabetic patients and treatment-related studies".

Vitamin D3 requirements and relative bioavailability for starter male White Pekin ducks fed either cholecalciferol or 25-hydroxycholecalciferol

The objectives were to investigate effects of various concentrations of dietary vitamin D3 (VD3) or 25-hydroxycholecalciferol (25-OH-D3) on growth performance, VD3 status, calcium (Ca) metabolism, and tibia mineralization of starter male White Pekin ducks, and dietary requirements and relative bioavailability of these two compounds. One-day-old male White Pekin ducks (n = 624) were assigned to 13 dietary treatments, including 6 added VD3 concentrations (100, 200, 400, 800, 1200, and 2000 IU/kg), and 2 vitamin D3 sources (VD3 and 25-OH-D3), plus a negative control (no vitamin D3 supplementation) for 21 days. Each group had 6 replicate pens of 8 birds per pen. At 21 days of age, growth performance, carcass traits, plasma 25-OH-D3 and Ca content, and tibia mineralization were examined. There was a high incidence of leg disease and mortality in ducks fed the control diet; however, those negative effects were avoided by adequate VD3 or 25-OH-D3 supplementation. Ducks in the negative control group had the lowest body weight, average daily weight gain (ADG), average daily feed intake (ADFI), breast muscle percentage, plasma 25-OH-D3, plasma Ca, and tibia indices (weight, diameter, ash, density, tibia mineral, strength) (P < 0.05), with all these end points enhanced linearly or quadratically as dietary VD3 or 25-OH-D3 increased (P < 0.05). Furthermore, at 100 or 200 IU/kg, ducks fed 25-OH-D3 had greater body weight, ADG, ADFI, plasma Ca, plasma 25-OH-D3, tibia weight, tibia diameter, tibia ash than those fed VD3 (P < 0.05), indicating 25-OH-D3 was more effective in stimulating growth, Ca absorption, and tibia mineralization. For growth performance, breast muscle percentage, plasma Ca, and tibial indices of starter male Pekin ducks, the VD3 requirements were 281 to 633 IU/kg, whereas 25-OH-D3 requirements were 119 to 395 IU/kg. Based on slope ratio comparisons from multiple linear regressions of plasma 25-OH-D3, bioavailability of 25-OH-D3 was 186% relative to cholecalciferol.

Immunotherapy in the management of inflammatory bone loss in osteoporosis

Osteoporosis, a progressive skeletal disorder characterized by decreased bone mass and increased fracture risk, has traditionally been treated with pharmacological agents targeting bone remodeling. However, emerging research highlights the critical role of immune system in regulating bone metabolism, introducing the concept of Osteoimmunology. Chronic low-grade inflammation is now recognized as a significant contributor to osteoporosis, particularly in postmenopausal women and the elderly. Immune cells, such as T cells and B cells, and their secreted cytokines directly influence bone resorption and formation, tipping the balance toward net bone loss in inflammatory environments. Immunotherapy, a treatment modality traditionally associated with cancer and autoimmune diseases, is now gaining attention in the management of osteoporosis. By targeting immune dysregulation and reducing inflammatory bone loss, immunotherapies offer a novel approach to treating osteoporosis that goes beyond merely inhibiting bone resorption or promoting bone formation. This therapeutic strategy includes monoclonal antibodies targeting inflammatory cytokines, cell-based therapies to enhance the function of regulatory T and B cells, and interventions aimed at modulating immune pathways linked to bone health. This chapter reviews the emerging role of immunotherapy in addressing inflammatory bone loss in osteoporosis. Present chapter also explores the underlying immune mechanisms contributing to bone degradation, current immunotherapeutic strategies under investigation, and the potential of these approaches to revolutionize the management of osteoporosis.

Nutrigenomics and neurological disorders: exploring diet-brain interactions for cognitive health

This review article investigates the intricate relationship between nutrigenomics and neurological disorders, highlighting how genetic variations affect an individual's response to nutrients. The study delves into the role of diet-related oxidative stress and the gut-brain axis in the progression and management of brain disorders such as Parkinson's disease, Alzheimer's disease, epilepsy, stroke, migraines, and depression. The review encompasses various clinical trials and introduces new trends and techniques, including omics and artificial intelligence, in identifying and managing neurological disorders. The main findings emphasize that personalized diet recommendations, tailored to an individual's genetic makeup, can significantly improve cognitive health and manage neurological conditions. The study concludes that further research in the field of nutrigenomics is essential to advancing personalized nutrition strategies for better neurological functioning, ultimately linking diet, genes, and brain health.

The relationships of serum vitamin D concentration with linear speed and change of direction performance in soccer players

The aim of the study was to establish whether the level of 25 hydroxyvitamin D (25(OH)D) in serum has an influence on speed (m/s) and change of direction (COD, s) performance. Twenty male soccer players from the top league participated in the study. All subjects were evaluated for the serum concentration of 25(OH)D at the beginning of the preseason. The linear sprint test was performed at 5 m and 30 m, and COD (time and deficit) at the beginning (BPP) and after (APP) 6 weeks of the preparatory period. The results revealed that 20% of soccer players had a significant deficiency of 25(OH)D (<20 ng/mL) and 30% had insufficient 25(OH)D levels (between 20 and 30 ng/mL). Positive correlations were found between the training effect for the ∆COD (BPP-APP) (p = 0.003) and ∆deficit (BPP-APP) (p = 0.039). Significant differences were noticed for the ∆COD (m = 0.60 [s]) and ∆deficit (m = 0.56[s]) in the soccer players whose 25(OH)D concentration was <=30 ng/mL, and for the ∆COD (p = 0.002) and ∆deficit (p = 0.017) in the soccer players whose 25(OH)D concentration was >30 ng/mL. The training effect was significantly higher for the soccer players whose 25(OH)D concentration was above 30 ng/mL. Soccer players with higher 25(OH)D levels achieved superior results in the COD test and demonstrated better deficit outcomes, affirming the positive influence of 25(OH)D on muscle metabolism.

SLIM-Based High-Resolution Ion Mobility Reveals New Structural Insights into Isomeric Vitamin D Metabolites and their Isotopologues

Testing for vitamin D deficiency remains a high-volume clinical assay, much of which is done using mass spectrometry-based methods to alleviate challenges in selectivity associated with immunoassays. Ion mobility-mass spectrometry (IM-MS) has been proposed as a rapid alternative to traditional LC-MS/MS methods, but understanding the structural ensemble that contributes to the ion mobility behavior of this molecular class is critical. Herein we demonstrate the first application of high-resolution Structures for Lossless Ion Manipulations (SLIM) IM separations of several groups of isomeric vitamin D metabolites. Despite previous IM studies of these molecules, the high resolving power of SLIM (Rp ∼ 200) has revealed additional conformations for several of the compounds. The highly similar collision cross sections (CCS), some differing by as little as 0.7%, precluded adequate characterization with low-resolution IM techniques where, in some cases, wider than expected peak widths and/or subtle shoulders may have hinted at their presence. Importantly, these newly resolved peaks often provided a unique mobility that could be used to separate isomers and provides potential for their use in quantification. Lastly, the contribution of isotopic labeling to arrival time distribution for commonly used 13C- and deuterium-labeled internal standards was explored. Minor shifts of ∼0.2-0.3% were observed, and in some instances these shifts were specific to the conformer being measured (i.e., "closed" vs "open"). Accounting for these shifts is important during raw data extraction to ensure reproducible peak area integration, which will be a critical consideration in future quantitative applications.

Is Serum Vitamin D Associated with Depression or Anxiety in Ante- and Postnatal Adult Women? A Systematic Review with Meta-Analysis

BACKGROUND/OBJECTIVES

To collect evidence from studies that explored the associations between serum vitamin D (25[OH]D) concentrations/status and the presence of depressive/anxiety symptoms in the ante- and/or postnatal periods (PROSPERO-CRD42023390895).

METHODS

Studies that assessed serum 25[OH]D concentrations in adult women during the ante/postnatal periods and those that used valid instruments to identify the experience/severity of depressive/anxiety symptoms were included. Independent researchers performed the identification/selection of studies, data extraction, risk of bias (RoB) assessment, and bibliometric analysis steps.

RESULTS

Of the total of 6769 eligible records, 15 cohort studies [high (n = 3), moderate (n = 7), and low (n = 5) RoB], nine cross-sectional studies [moderate (n = 3) and low (n = 6) RoB], and one case-control study [moderate RoB] were included (n = 25). Depression (n = 24) and anxiety (n = 4) symptoms were assessed. A significant difference in antenatal serum 25[OH]D concentrations between the groups of women with and without depression was identified (mean difference: -4.63 ng/mL; 95% confidence interval [95% CI]: -8.88; -0.38). Postnatal serum 25[OH]D concentrations were found to be, on average, -2.36 ng/mL (95% CI: -4.59; -0.14) lower in women with postnatal depression than in those without. Maternal antenatal anxiety was associated with significantly lower concentrations/deficiency of 25[OH]D in only one included study.

CONCLUSIONS

Based on very low/low-quality evidence, it was observed that reduced serum 25[OH]D concentrations in the ante- and postnatal period are associated with the presence of ante- and postnatal depressive symptoms, respectively. Low/deficient antenatal serum 25[OH]D concentrations may not be related to the presence of anxiety symptoms before childbirth. Well-designed longitudinal studies are needed to explore the estimated pooled effect of these associations.

Vitamin D3 application and factors of its activity in the adrenal cortex of andropausal rats: A functionally-histological study

INTRODUCTION AND AIM

Vitamin D supplementation in aging subjects manifests a positive effect on various health-related parameters. We performed a functionally-histological analysis of the adrenal cortex regarding the factors of vitamin D activity and corticosterone output after vitamin D3 application in a rat model of the andropause.

MATERIAL AND METHODS

Middle-aged Wistar rats were divided into sham operated (SO; n=8), orchidectomized (Orx; n=8) and vitamin D3-treated orchidectomized (Orx+vit. D; n=8) groups. Vitamin D3 (5 μg/kg b.m.) was administered subcutaneously for three weeks, while the SO and Orx groups received the vehicle alone. Set objectives were achieved using histochemistry/immunohistochemistry, stereology, ultrastructural and biochemical analyses.

RESULTS

Orchidectomy (Orx) decreased the adrenal cortex-related volume densities of vascular (p<0,0001), vitamin D receptor (VDR; p<0,0166), cytochrome P450 oxidase 2R1 (CYP 2R1; p<0,0001) and cytochrome P450 oxidase 24 (CYP 24; p<0,0001) depots, but increased the volume density of cytochrome P450 27B1 (CYP 27B1; p<0,0001) depots. In Orx+vit. D rats, increase of the adrenal cortex-related volume densities of collagen (p<0,0001), VDR (p<0,0001) and CYP 2R1 (p<0,0001) depots as well as the lipid-droplet diameter (p<0,0001) in adrenocortical outer zona fasciculata cells was observed, while a decrease of volume densities of the vascular (p<0,0001), CYP 27B1 (p<0,0001) and CYP 24 (p<0,0001) depots was registered, all versus Orx group. Plasma level of ACTH was decreased (p=0,0155) and serum concentrations of 25-hydroxyvitamin D3 and corticosterone were increased (p<0,0001 and p=0,0187, respectively), all after the same treatment.

CONCLUSIONS

Increased corticosterone output after vitamin D3 application to andropausal rats appears not to be related to increased availability of 25-hydroxyvitamin D3 and decreased degradation of 1,25-dihydroxyvitamin D3 in adrenal tissue, but rather involves the central regulatory mechanisms.

Sex-dependent association of serum vitamin D with muscle strength in older adults: NHANES 2001-2002

BACKGROUND

Although several studies have suggested a potential positive association between serum vitamin D levels and muscle strength in older adults, it remains unclear whether this relationship is sex-dependent.

AIM

To evaluate the association between serum 25 hydroxyvitamin D [25(OH)D] levels and muscle strength in older adults and to assess whether this association is dependent on sex.

METHODS

This cross-sectional study utilized data from the National Health and Nutrition Examination Survey (NHANES) conducted between 2001 and 2002. A total of 1173 individuals aged 50-85 years (630 men and 543 women) were included in the analysis. The peak isokinetic force of the knee extensor was assessed using a kinetic communicator isokinetic dynamometer. Serum 25(OH)D levels were measured using the standardized liquid chromatography-tandem mass spectrometry method. Linear regression analyses were conducted to estimate coefficients and 95% confidence intervals for muscle strength across tertiles of serum vitamin D levels, adjusting for potential confounders.

RESULTS

Tertiles of serum vitamin D were positively associated with muscle strength in older men (p-trend = 0.007), whereas no association was observed in older women (p-trend = 0.140) or in the total sample (men and women together; p-trend = 0.139).

CONCLUSION

Serum vitamin D levels were positively associated with muscle strength specifically in older men, whereas no association was observed in older women. These results suggest that the relationship between vitamin D and strength may be sex-dependent.

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.

A comparative study of hormonal contraceptive use and vitamin D levels at Gondar Town 2023

Vitamin D deficiency is an emerging public health problem globally, with devastating health consequences. Some studies suggest that exogenous sex hormones, found in hormonal contraceptives, may enhance vitamin D levels. However, the reasons for this association are not fully understood, as women using hormonal contraception may have different lifestyle habits affecting their vitamin D status. Therefore, this study seeks to explore the relationship between hormonal contraceptive use and vitamin D levels. A Facility based comparative cross-sectional study was conducted in Gondar town from February to April 2023, involving a total of 162 women using three types of hormonal contraceptives (Norplant, DMPA, and COC) and 162 age and BMI-matched non-users as controls in a 1:1 ratio. Participants were selected using systematic random sampling. A semi-structured questionnaire was used to collected data regarding the socio-demographic, economic, obstetric, lifestyle, and clinical information. 5 milliliters of blood samples were collected from each participant for Laboratory analysis of serum vitamin D, calcium, and alkaline phosphates using a Beckman Coulter chemistry analyzer. Independent t-tests, ANOVA with post hoc Bonferroni test was used to compare statistics between the two groups, and logistic regression models to identify factors associated with Vitamin D deficiency. The mean serum Vitamin D levels of Norplant, DMPA, and COC users were 24.08 (± 5.17), 24.83 (± 5.52), and 31.90 (± 6.94) respectively; whereas control group has mean Vitamin D level of 22.00 (± 7.97). On the current study the prevalence of Vitamin D deficiency (< 20 ng/ml) among hormonal contraceptive users was found to be 21.6% (35/162), whereas 48.14% (78/162) of non-user controls had vitamin D deficiency. The odds of having Vitamin D deficiency was higher among participants who attained higher education, who never eat fish and have never been used vitamin D Supplements. However, the use of combined oral contraceptives (COC) shown to reduce the odd of having vitamin D deficiency by 90%. Similarly, individuals with normal and hypercalcemia state shown to have lower odd of having Vitamin D deficiency. Users of combined oral contraceptives (COC) had significantly higher mean serum Vitamin D levels compared to users of Norplant and DMPA, as well as non-users. The prevalence of Vitamin D deficiency was lower among COC users compared to non-users, highlighting a potential protective effect of COC use against Vitamin D deficiency.

1,25-dihydroxyvitamin-D3 distinctly impacts the paracrine and cell-to-cell contact interactions between hPDL-MSCs and CD4+ T lymphocytes

INTRODUCTION

Human periodontal ligament-derived mesenchymal stromal cells (hPDL-MSCs) possess a strong ability to modulate the immune response, executed via cytokine-boosted paracrine and direct cell-to-cell contact mechanisms. This reciprocal interaction between immune cells and hPDL-MSCs is influenced by 1,25-dihydroxyvitamin-D3 (1,25(OH)2D3). In this study, the participation of different immunomodulatory mechanisms on the hPDL-MSCs-based effects of 1,25(OH)2D3 on CD4+ T lymphocytes will be elucidated using different co-culture models with various cytokine milieus.

MATERIAL AND METHODS

hPDL-MSCs and CD4+ T lymphocytes were co-cultured indirectly and directly with inserts (paracrine interaction only) or directly without inserts (paracrine and direct cell-to-cell contact interaction). They were stimulated with TNF-α or IL-1β in the absence/presence of 1,25(OH)2D3. After five days of co-cultivation, the CD4+ T lymphocyte proliferation, viability, and cytokine secretion were analyzed. Additionally, the gene expression of soluble and membrane-bound immunomediators was determined in hPDL-MSCs.

RESULTS

In the indirect and direct co-culture model with inserts, 1,25(OH)2D3 decreased CD4+ T lymphocyte proliferation and viability. The direct co-culture model without inserts caused the opposite effect. 1,25(OH)2D3 mainly decreased the CD4+ T lymphocyte-associated secretion of cytokines via hPDL-MSCs. The degree of these inhibitions varied between the different co-culture setups. 1,25(OH)2D3 predominantly decreased the expression of the soluble and membrane-bound immunomediators in hPDL-MSCs to a different extent, depending on the co-culture models. The degree of all these effects depended on the absence and presence of exogenous TNF-α and IL-1β.

CONCLUSION

These data assume that 1,25(OH)2D3 differently affects CD4+ T lymphocytes via the paracrine and direct cell-to-cell contact mechanisms of hPDL-MSCs, showing anti- or pro-inflammatory effects depending on the co-culture model type. The local cytokine microenvironment seems to be involved in fine-tuning these effects. Future studies should consider this double-edged observation by executing different co-culture models in parallel.

Seasonal variation of total and bioavailable 25-hydroxyvitamin D [25(OH)D] in the healthy adult Slovenian population

Objective: The aim of our study was to compare the total 25(OH)D fraction, the bioavailable vitamin fraction, and the free vitamin D fraction in spring and fall in a group of healthy individuals. Methods: In our study, we collected blood samples from healthy participants at the end of both summer and winter, and measured serum levels of albumin, DBP, and 25(OH)D. Utilizing these data, we calculated the percentage of free and bioavailable vitamin D. Our cohort comprised 87 participants, with a male-to-female ratio of 14:73, aged 35.95 ± 12.55 years, ranging from 19 to 70 years. We employed the chemiluminescence method to determine the vitamin 25(OH)D levels, the ELISA method was utilized to determine DBP levels, the albumin BCP Assay was performed using the ADVIA biochemical analyzer (Siemens) and an online calculator was used to determine the free and bioavailable 25(OH)D levels. Results: Our findings indicate significantly lower 25(OH)D levels in winter (44.13 ± 17.82 nmol/L) compared to summer (74.97 ± 22.75 nmol/L; p < 0.001). For vitamin D binding protein there was no significant difference from summer (236.2 ± 164.39 mg/L) to winter (239.86 ± 141.9 mg/L; p = 0.77), albumin levels were significantly higher in summer (49.37 ± 4.15 g/L vs. 47.97 ± 3.91 g/L, p = 0.01), but the magnitude of the change may not be large enough to be solely responsible for the stability of vitamin D levels throughout the year. In the winter season a significantly lower calculated bioavailable 25(OH)D vitamin (7.45 ± 5.66 nmol/L against 13.11 ± 8.27 nmol/L; p < 0.001) was observed, and the free fraction also showed a significant decrease (17.3 ± 12.9 pmol/L versus 29.7 ± 19.1 pmol/L; p < 0.0001). We observed a moderately positive correlation between 25(OH)D and bioavailable percentage in winter (r = 0.680; p < 0.001), in contrast with a lower positive association in summer (r = 0.343; p < 0.001). Conclusion: Our data suggest a positive correlation between total and bioavailable 25(OH)D levels. In addition to the statistically significant variation in 25(OH)D between the two observation periods, there was an additional variation in the free vitamin D percentage. The summertime synthesis of vitamin D in the skin could contribute directly to the free fraction of vitamin D. Standardizing the measurement of free 25(OH)D and clinical studies is necessary to establish reference values before these methods can be implemented in clinical practice.

Blood 25-hydroxyvitamin D3 concentration of Japanese Black cattle at two farms with different rearing environments, Kagoshima prefecture, Japan

Forty-two Japanese Black cattle on two farms in Kagoshima prefecture, Japan were used in this study. The rearing style of farm A was in a dark barn with a large roof to block sunlight (n=21). The rearing style of farm B was grazing, and exposed to direct sunlight (n=21). Blood sampling was performed twice on the same cattle in August 2022 (summer) and February 2023 (winter). As the results, the serum 25(OH)D3 concentrations were significantly lower in cattle of farm A than in cattle of farm B (P<0.01), and were significantly lower in winter season than in summer season (P<0.01). These results showed that there were differences in blood 25(OH)D3 concentrations between the farms or seasons.

The relationship between serum vitamin D, testosterone, and oxidative stress levels in women with sexual dysfunction: A case-controlled study

OBJECTIVE

Female sexual dysfunction (FSD) is highly prevalent and can result from hypovitaminosis D. Besides the role of vitamin D in normal bone development, studies showed it could reduce oxidative stress and lipid peroxidation. This prospective study aims to evaluate the relationship between serum vitamin D, testosterone, and oxidative stress levels in women with FSD.

MATERIALS AND METHODS

In this cross-sectional study, a total of 40 women with FSD (age range: 18-45 years) were randomly assigned into two groups of intervention and control. In the intervention group, patients received vitamin D 300,000 IU intramuscularly (IM) and then 50,000 IU orally once a week for four weeks. We measured the serum vitamin D, testosterone, and oxidative stress levels, as well as the Female Sexual Function Index (FSFI) at baseline and monthly for three months.

RESULTS

Serum testosterone levels significantly increased in the intervention group at the end of the third month (P = 0.014). Also, FSFI scores significantly improved (P < 0.01) in the intervention group compared to the control group. While there was positive a correlation between serum vitamin D levels with glutathione, total antioxidant capacity (TAC), testosterone, and FSFI score, there was a negative correlation between serum vitamin D levels with malondialdehyde (MDA), protein carbonyl, and nitric oxide.

CONCLUSION

We witnessed that women with FSD had low serum vitamin D levels. So, modifying serum vitamin D levels must be considered as a treatment option. Moreover, vitamin D supplementation improved testosterone, serum oxidative stress, and sexual function.

Calcium homeostasis and endometriosis: A Mendelian randomization study

Background

Previous observational studies have investigated the correlation between calcium homeostasis modulator levels and endometriosis risk. Yet, the genetic association between body calcium homeostasis and endometriosis risk remains to be elucidated.

Methods

Four tiers of Mendelian randomization (MR) analysis were conducted, as follows: (1) single univariate MR and (2) multivariate MR to evaluate the correlation between calcium homeostasis regulators and endometriosis; (3) inverse MR to probe the influence of endometriosis on body calcium homeostasis; (4) two-sample MR to scrutinize the connection between calcium levels and endometriosis categories.

Results

The two-sample MR analysis unveiled a robust positive correlation between genetically inferred calcium levels and endometriosis risk (IVW: OR = 1.15, 95 % CI: 1.02-1.29, p = 0.018). The MVMR analysis corroborated that the positive correlation of calcium levels with endometriosis persisted after adjusting for 25(OH)D and PTH. The inverse MR analysis disclosed a significant association between endometriosis and 25(OH)D (β = 0.01, 95 % CI: 0.00-0.02, p = 0.007) and calcium (β = 0.02, 95 % CI: 0.00-0.04, p = 0.035). The two-sample MR analysis further demonstrated that calcium levels were positively linked solely to endometriosis of uterus (i.e. adenomyosis, IVW: OR = 1.23, 95 % CI: 1.01-1.49, p = 0.038), with no evidence of a influence on other endometriosis categories.

Conclusions

This study, employing various types of MR, offers some genetic evidence for the relationship between calcium homeostasis and endometriosis, augmenting the current comprehension of the complex association between the two and suggesting that calcium levels are a risk factor for endometriosis. These findings provide a unique genetic perspective that may spur further investigation and may inform future strategies for managing patients with endometriosis.

Hypervitaminosis D is correlated with adverse dental implant outcomes: A retrospective case-control study

OBJECTIVES

To investigate vitamin-D levels effect on the survival/success and on marginal bone levels of dental implants.

METHODS

Patients with peri-implant disease and healthy control patients with functionally loaded dental implants were included in this retrospective case-control study. Forty patients with 201 implants were in the diseased-cohort, while thirty-three patients with 90 implants were in the control-cohort. Patient blood 25(OH)D levels were assessed through quantitative blood test. The correlation between abnormal 25(OH)D levels and disease status of each patient was assessed using Fisher's exact tests. The correlation of each implant's outcomes with vitamin-D status was assessed using Kaplan-Meier survival analysis and Mann-Whitney U tests.

RESULTS

Patients with blood 25(OH)D levels >70 ng/mL (hypervitaminosis-D) had a 21.1-fold increase in the risk of implant failure or severe peri-implant bone loss regarding patients with intermediate (>30, ≤70 ng/mL) levels. Kaplan-Meier survival analysis revealed that implants in the hypervitaminosis-D cohort had a survival probability of 73.7 % (95 % CI:56.5-84.5 %) at 19-years after surgery, compared to 95 % for implants in patients with intermediate 25(OH)D levels (95 % CI:88.3-97.9 %). Additionally, implants in the hypervitaminosis-D cohort lost bone faster than implants in the intermediate cohort. These results were specific to the patient cohort with elevated blood 25(OH)D levels and not observed in patients taking vitamin-D supplementation. The impact of hypervitaminosis-D was enriched for implants in the maxilla, and not as apparent for implants in the mandible.

CONCLUSIONS

Blood 25(OH)D levels >70 ng/mL were correlated with adverse implant outcomes, including implant failure and peri-implant bone loss, especially in the maxilla.

CLINICAL RELEVANCE

These results suggest that hypervitaminosis D may be a previously unidentified risk factor for dental implant complications and should be further investigated to elucidate the underlying mechanism.

The Association of Vitamin D Levels and Dental Caries in Older Adults: A Cross-Sectional Study

INTRODUCTION

Most research examining vitamin D and dental caries focuses on children and younger adults. This study investigated the association between vitamin D levels and dental caries in older adults using data from the United States National Health and Nutrition Examination Survey from 2011 to 2016.

METHODS

Data were analyzed from 2723 participants aged 65 years and older who completed both dental examinations and serum 25(OH)D tests. Dental caries assessments included the decayed, missing, and filled teeth (DMFT) index and the presence of untreated dental caries. Vitamin D levels were measured as serum 25(OH)D concentrations and categorized as severely deficient (<25 nmol/L), deficient (25-49.9 nmol/L), insufficient (50-74.9 nmol/L), and normal (≥75 nmol/L). Logistic regression and Poisson regression models were used to assess the association between vitamin D levels and dental caries, adjusting for demographic factors.

RESULTS

The mean DMFT score was 17.73 ± 8.34, with 35.1% of participants having untreated dental caries. Vitamin D deficiency was associated with a 1.44 times higher likelihood of untreated caries (95% CI: 1.15, 1.81), which weakened after adjustment for demographic factors (adjusted OR: 1.23, 95% CI: 0.97, 1.55). Severe vitamin D deficiency correlated with a 1.13 times higher DMFT score (95% CI: 1.06, 1.20), with the association remaining similar after adjustment (adjusted RR: 1.12, 95% CI: 1.05, 1.20). Significant differences in vitamin D levels were observed across gender, race/ethnicity, and country of birth.

CONCLUSIONS

This study suggests the potential importance of adequate vitamin D levels for maintaining dental health among older adults. Vitamin D deficiency is associated with a higher risk of poorer DMFT scores. Public health strategies that include vitamin D screening and supplementation, particularly for high-risk groups, may improve oral health outcomes in the older adult population. Further research is needed to elucidate the mechanisms by which vitamin D influences dental health and the potential for vitamin D supplementation to reduce the burden of dental caries in older adults.

Prevalence and Risk Factors of Vitamin D, Calcium and Phosphate Deficiency among Apparently Healthy Children Aged 6-24 Months in a Semi-urban Community in Southwest, Nigeria

BACKGROUND

Adequate levels of calcium, phosphate and Vitamin D are essential for bone physiology and growth, as well as preventing some common childhood illnesses. This study aimed to determine the prevalence of the deficiencies of these nutrients and factors affecting their serum levels in Nigerian children.

METHODS

This was a cross-sectional study that involved 220 apparently healthy children aged 6-24 months in Ikenne Local Government Area of Ogun State, Nigeria. Serum calcium and phosphate were assayed using the calorimetric method, while Vitamin D (25-OH Vitamin D) was assayed with ELISA.

RESULTS

The mean (±standard deviation [SD]) serum Vitamin D level was 55.07 ± 16.53 ng/ml, while the mean (±SD) serum calcium and phosphate were 2.27 ± 0.13 mmol/l and 1.28 ± 0.18 mmol/l, respectively. Eleven (5%) of the children had hypovitaminosis D, 23 (10.5%) had hypocalcaemia and 12 (5.5%) had hypophosphataemia. Factors found to be significantly associated with hypovitaminosis D included low consumption of milk and the use of a hijab veil, while malnutrition (both undernutrition and overnutrition) was significantly associated with hypocalcaemia.

CONCLUSION

The prevalence levels of hypovitaminosis D and hypophosphataemia were low, while hypocalcaemia was more common. Low milk consumption and use of a hijab veil were risk factors for hypovitaminosis D, while malnutrition was a risk factor for hypocalcaemia. Malnourished children, especially overnourished ones, should be routinely screened for hypocalcaemia because of its high prevalence among them.

Assessment of Vitamin D Status in Primary Hyperparathyroidism Patients: A Retrospective Study

BACKGROUND

Primary hyperparathyroidism (PHPT), a condition that manifests in various clinical forms, is a significant health concern. Normocalcemic primary hyperparathyroidism (NPHPT) is characterized by normal calcemia despite elevated parathyroid hormone (PTH) levels. Vitamin D deficiency can contribute to the clinical spectrum and complexity of NPHPT. Low vitamin D levels can elevate PTH, making it difficult to distinguish between NPHPT and secondary hyperparathyroidism. Additionally, it might mask hypercalcemia, leading to an underestimation of the disease severity. Our study aims to shed light on these complexities by investigating normocalcemic and hypercalcemic PHPT patient's clinical, hormonal, and biochemical patterns, including their vitamin D status.    Materials: In this retrospective study, we enrolled 60 PHPT patients with autonomous parathyroid function confirmed using a combination of ultrasonography, radionuclide scan, and parathyroid function index calculation. We evaluated the albumin-corrected calcemia, calciuria, PTH, 25(OH)D level, serum phosphate, bone mineral density, and major clinical symptoms (fracture, nephrolithiasis). A comparative analysis and a correlation study were performed between normo- and hypercalcemic and vitamin D-deficient and vitamin D-non-deficient groups.

RESULTS

 The median age was 62 years, 51.66% (31/60) being normocalcemic and 46.66% (29/60) presenting a deficient 25(OH)D level. In the group with 25(OH)D below 20 ng/mL, we observed a reduced level of albumin-corrected calcemia, without a significant increase of PTH compared to the adequate 25(OH)D level group. The frequency of the NPHPT and the risk of fracture were significantly higher in the deficient 25(OH)D group (20/60, 33.33% and 8/60, 13.33%) than in the adequate one (11/60, 18.33% and 1/60, 1.66%) with OR=4.7 (p<0.004) and OR=9.7 (p<0.027), respectively. We also found a positive correlation between PTH and adenoma size, the parathyroid function index and adenoma size, as well as PTH and phosphate levels. However, the correlation between 25(OH)D and phosphate levels was negative and moderate (rho=-0.504, p<0.001), adding a new layer of complexity to our understanding of these relationships.

CONCLUSION

Our study provided significant insight into the link between vitamin D status and normocalcemic PHPT. We found that vitamin D-deficient patients with normocalcemic PHPT have an increased fracture risk, which requires meticulous monitoring and possible supplementation with vitamin D. This should be done carefully to avoid exacerbating hypercalcemia or hypercalciuria. Further research is needed to refine these management strategies and deepen our understanding of the complex relationships between the analyzed parameters.

Low levels of Vitamin D during pregnancy associated with gestational diabetes mellitus and low birth weight: results from the MAASTHI birth cohort

Introduction

India has a high prevalence of Vitamin D insufficiency among women of childbearing age. In this study, we aimed to evaluate the potential relationship between Vitamin D deficiency and gestational diabetes mellitus (GDM) and low birth weight (LBW) of newborns in the "Maternal antecedents of adiposity and studying the transgenerational role of hyperglycaemia and insulin" (MAASTHI) birth cohort.

Methods

A prospective cohort study involving 230 participants was conducted in public hospitals located in urban Bengaluru, India. Healthy pregnant women who visited these hospitals for antenatal care (ANC) and who were between 14 and 36 weeks of gestational age were recruited after obtaining their informed consent. An oral glucose tolerance test (OGTT) was administered between 24 and 36 weeks of pregnancy and blood samples were preserved at -80°C for Vitamin D analysis. Follow-up at birth included recording the child's birth weight.

Results

We found that 178 (77.4%) of the study participants were vitamin D deficient, 44 (19.1%) were diagnosed with GDM, and 64 (27.8%) gave birth to LBW babies. Women in the lowest quartile of serum Vitamin D levels had three times higher odds of developing GDM than women in the higher quartiles [OR = 3.22 (95% CI: 1.03, 10.07), p = 0.04] after adjusting for age, parity, socioeconomic status, season, and adiposity. For every one-unit increase in Vitamin D levels, Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) decreased by nearly 18%. Furthermore, causal mediation analysis showed that a decrease in one unit of Vitamin D is associated with a decrease of 0.015 units of fasting blood sugar (FBS) and 0.019 units of postprandial blood sugar (PPBS) as it flows through the mediator variable insulin resistance. Vitamin D-deficient women were twice at risk of giving birth to LBW babies (OR 2.04, 95% CI 0.99, 4.19, p = 0.05).

Discussions

Low levels of Vitamin D during pregnancy are associated with a greater risk of pregnant women developing GDM and giving birth to LBW babies in urban Bengaluru.

Does vitamin D supplementation benefit patients with type 1 diabetes mellitus who are vitamin D deficient? A study was performed at the Sudan Childhood Diabetes Center from 2019 to 2022

Objectives

Type 1 diabetes mellitus is a chronic autoimmune disease caused by insufficient production of insulin. Many studies have linked type 1 diabetes mellitus to vitamin D3 deficiency. We investigated the prevalence of vitamin D deficiency in Sudanese children and adolescents with type 1 diabetes mellitus and assessed the impact of vitamin D deficiency treatment on their glycemic control.

Methods

In 2019-2022, we conducted a quasi-experimental study on 115 children with type 1 diabetes mellitus (1-19 years old) at the Sudan Childhood Diabetes Center. Vitamin D supplements were given orally to deficient patients for 3 months. The concentrations of hemoglobin A1c, fasting blood glucose, insulin dosage, and vitamin D (25-hydroxyvitamin D (25(OH)D)) were measured before and after vitamin D3 administration. One-way ANOVA and paired sample t-tests were used to evaluate the effect of supplementation.

Results

Only 27% of type 1 diabetes mellitus children were deficient in vitamin D, whereas 31.1% were inadequate and 40.9% were sufficient. The administration of vitamin D supplements slightly improved hemoglobin A1c levels in 67.7% of the patients, but the difference was not significant (mean 10.8 ± 2.1% before, 10.1 ± 2.5% after, p0.05 = 0.199). However, there was a significant decrease in the fasting blood glucose level (mean: 174.978.5-136.759.1 ng/ml; p0.05 = 0.049). Vitamin D levels were significantly increased after treatment (mean = 49.6 ng/mL; t-test = -11.6, 95% CI 40.8-(-28.6); p0.05 = 0.000). After vitamin D3 supplementation, 25.8% of individuals changed their insulin dosage; however, there was no significant variation in insulin needs.

Conclusions

The prevalence of vitamin D deficiency in children and adolescents with type 1 diabetes mellitus in Sudan is relatively high; incorporating vitamin D supplements in their treatment plan may improve their glycemic control.

Vitamin D and reproductive disorders: a comprehensive review with a focus on endometriosis

Vitamin D is a fat-soluble steroid hormone that was initially known only for regulating calcium and phosphorus levels and maintaining bone health. However, it was later discovered that many organs express vitamin D metabolizing enzymes and have a ligand for vitamin D, which regulates the expression of an extensive assortment of genes. As a result, vitamin D is indispensable for the proper function of organs, and its deficiency is believed to be a critical factor in symptoms and disorders such as cardiovascular diseases, autoimmune diseases, and cancers. The significance of vitamin D in reproductive tissues was recognized later, and studies have revealed its crucial role in male and female fertility, as well as proper reproductive function during pregnancy. Vitamin D deficiency has been identified as a risk factor for infertility, gonadal cancers, pregnancy complications, polycystic ovary syndrome, and endometriosis. However, data investigating the association between vitamin D levels and reproductive disorders, including endometriosis, have encountered inconsistencies. Therefore, the present study aims to review existing research on the effect of vitamin D on proper reproductive function, and the role of deficiency in reproductive diseases and specifically focuses on endometriosis.

Calcium and vitamin D homoeostasis in male fertility

Calcium and vitamin D have well-established roles in maintaining calcium balance and bone health. Decades of research in human subjects and animals have revealed that calcium and vitamin D also have effects on many other organs including male reproductive organs. The presence of calcium-sensing receptor, vitamin D receptor, vitamin D activating and inactivating enzymes and calcium channels in the testes, male reproductive tract and human spermatozoa suggests that vitamin D and calcium may modify male reproductive function. Functional animal models have shown that vitamin D deficiency in male rodents leads to a decrease in successful mating and fewer pregnancies, often caused by impaired sperm motility and poor sperm morphology. Human studies have to a lesser extent validated these findings; however, newer studies suggest a positive effect of vitamin D supplementation on semen quality in cases with vitamin D deficiency, which highlights the need for initiatives to prevent vitamin D deficiency. Calcium channels in male reproductive organs and spermatozoa contribute to the regulation of sperm motility and capacitation, both essential for successful fertilisation, which supports a need to avoid calcium deficiency. Studies have demonstrated that vitamin D, as a regulator of calcium homoeostasis, influences calcium influx in the testis and spermatozoa. Emerging evidence suggests a potential link between vitamin D deficiency and male infertility, although further investigation is needed to establish a definitive causal relationship. Understanding the interplay between vitamin D, calcium and male reproductive health may open new avenues for improving fertility outcomes in men.

Vitamin D Deficiency Is Associated with Advanced Liver Fibrosis and Impaired Fasting Glucose in Alcohol Use Disorder

BACKGROUND

Vitamin D deficiency is a risk factor for liver disease, insulin resistance, and beta cell dysfunction. Individuals with alcohol use disorder (AUD) have many comorbidities, with a heavy burden of liver disease and metabolic complications, including type 2 diabetes mellitus (T2DM).

OBJECTIVE

We aimed to analyze the prevalence and associations of vitamin D deficiency in patients admitted for in-hospital treatment of AUD.

METHODS

A cross-sectional study was conducted in patients consecutively admitted for the treatment of AUD between January 2017 and October 2023. Sociodemographic data, substance use characteristics, and blood parameters were available at admission. Vitamin D status was assessed through the serum concentrations of 25-hydroxyvitamin D [25(OH)D] levels using a direct competitive chemiluminescent immunoassay method. Deficiency of vitamin D was defined as a concentration less than 20 ng/mL; impaired fasting glucose (IFG) was defined by fasting blood glucose >100 mg/dL (5.6 mmol/L), and advanced liver fibrosis by an FIB-4 index >3.25.

RESULTS

Two hundred and forty-three patients were included (75% male) with a mean age of 49 ± 10 years, mean BMI of 26.4 ± 7.3, mean alcohol consumption of 163 ± 81 g/day, and a mean duration of AUD of 18.1 ± 11.2 years. Mean 25(OH)D, fasting blood glucose, AST, ALT, and platelets were 14.4 ± 10.2 ng/mL, 103.4 ± 40.9 mg/dL, 55.1 ± 75.8 U/L, 44.8 ± 76.6 U/L, and 206.3 ± 84.8 × 109/L, respectively. The prevalence of vitamin D deficiency was 80.6%, and 41.1% of patients had levels less than 10 ng/mL. IFG was present in 32.3% of patients, and 20.5% had FIB-4 values >3.25. In the multivariable analysis, IFG (OR, 2.51; 95% CI: 1.02-6.17, p = 0.04) and advanced liver fibrosis (OR, 4.27; 95% CI: 1.21-15.0, p = 0.02) were the only factors associated with vitamin D deficiency.

CONCLUSIONS

Vitamin D deficiency was very prevalent in this series of patients with AUD and was associated with impaired fasting glucose and advanced liver fibrosis.

VDRA downregulate β-catenin/Smad3 and DNA damage and repair associated with improved prognosis in ccRCC patients

The clear cell renal cell carcinoma (ccRCC) spotlighted the poorest survival, while chromophobe renal cell carcinoma (chRCC) was associated with the best survival. Earlier studies corroborated vitamin D receptor (VDR) was a promising molecular for improving the prognosis of RCC. In contrast to VDRA, the one of VDR isoforms, VDRB1 (VDR isoform B1) has an N-terminal extension of 50 amino acids and is less ligand-dependent. However, the functional differences between VDRA and VDRB1, and their roles in the prognosis of ccRCC and chRCC, have not been investigated. In the present study, we uncovered that the transcripts related to vitamin D pathway and cellular calcium signaling were effectively decreased in the context of ccRCC, yet failed to exert a comparable effect within chRCC. Specially, minimally levels of VDRA wherein kidneys of patients suffering from ccRCC predict shorter survival time. In addition, the protein expressions for β-catenin/Smad3 pathway and DNA damage and repair pathways were obviously impeded in VDRA-overexpressed ccRCC cells, yet this inhibitory effect was conspicuously absent in enable VDRB1 cells. Our results provide a new idea to improve the prognosis of ccRCC via VDRA upregulation.

The multi-faceted nature of age-associated osteoporosis

Age-associated osteoporosis (AAOP) poses a significant health burden, characterized by increased fracture risk due to declining bone mass and strength. Effective prevention and early treatment strategies are crucial to mitigate the disease burden and the associated healthcare costs. Current therapeutic approaches effectively target the individual contributing factors to AAOP. Nonetheless, the management of AAOP is complicated by the multitude of variables that affect its development. Main intrinsic and extrinsic factors contributing to AAOP risk are reviewed here, including mechanical unloading, nutrient deficiency, hormonal disbalance, disrupted metabolism, cognitive decline, inflammation and circadian disruption. Furthermore, it is discussed how these can be targeted for prevention and treatment. Although valuable as individual targets for intervention, the interconnectedness of these risk factors result in a unique etiology for every patient. Acknowledgement of the multifaceted nature of AAOP will enable the development of more effective and sustainable management strategies, based on a holistic, patient-centered approach.

Environmental factors and their impact on chronic pain development and maintenance

It is more than recognized and accepted that the environment affects the physiological responses of all living things, from bacteria to superior vertebrates, constituting an important factor in the evolution of all species. Environmental influences range from natural processes such as sunlight, seasons of the year, and rest to complex processes like stress and other mood disorders, infections, and air pollution, being all of them influenced by how each creature deals with them. In this chapter, it will be discussed how some of the environmental elements affect directly or indirectly neuropathic pain, a type of chronic pain caused by a lesion or disease of the somatosensory nervous system. For that, it was considered the edge of knowledge in translational research, thus including data from human and experimental animals as well as the applicability of such findings.

Effects of dietary imbalances of micro- and macronutrients on the ocular microbiome and its implications in dry eye disease

Dry eye disease (DED) is a complex and multifactorial ocular surface disease affecting a large proportion of the population. There is emerging evidence of the impact of the microbiomes of the ocular surface and gut on the symptoms of DED, with many parallels being drawn to inflammatory diseases of other organ systems. A key factor involved in the promotion of healthy microbiomes, and which has been associated with ocular surface disease, is micro- and macronutrient deficiency. A comprehensive review of how these deficiencies can contribute to DED is absent from the literature. This review reports the composition of healthy ocular and gut microbiomes, and how nutrient deficiencies may impact these floral populations, with linkage to the subsequent impact on ocular health. The review highlights that vitamin B1 and iron are linked to reduced levels of butyrate, a fatty acid implicated in inflammatory conditions such as ulcerative colitis which itself is a condition known to be associated with ocular surface diseases. Vitamin B12 has been shown to have a role in maintaining gut microbial eubiosis and has been linked to the severity of dry eye symptoms. Similar beneficial effects of gut microbial eubiosis were noted with vitamin A and omega-3 polyunsaturated fatty acids. Selenium and calcium have complex interactions with the gut microbiome and have both been implicated in the development of thyroid orbitopathy. Further, diabetes mellitus is associated with ocular surface diseases and changes in the ocular microbiome. A better understanding of how changes in both the gut and eye microbiome impact DED could allow for an improved understanding of DED pathophysiology and the development of new, effective treatment strategies.

Exploring the Significance of Vitamin D Levels as a Biomarker in Ear Diseases: A Narrative Review

This narrative review examines the role of vitamin D as a biomarker in ear disorders, including benign paroxysmal positional vertigo (BPPV), otitis media, bell's palsy, Meniere's disease, and hearing loss. PubMed, The Cochrane Library, and Google Scholar were utilized to conduct a comprehensive literature search, and findings were combined from studies from 2014 to 2024. As highlighted in this review, there is a consistent association between vitamin D deficiency and an increased risk and recurrence of disease especially in BPPV and otitis media. Its importance as a prognostic biomarker is emphasized in Bell's palsy, where higher levels of deficiencies in vitamin D are associated with higher grades of severity on the House Brackmann grading system. Vitamin D deficiency can also lead to sensorineural hearing loss due to its receptors present in the inner ear or its effect on calcium metabolism. Serum levels of vitamin D have also been shown to influence treatment outcome of sensorineural hearing loss. The role of vitamin D in Meniere's disease is unclear as no cause has been identified for the increase in endolymphatic fluid. The findings of this review emphasize the importance of serum vitamin D as a biomarker in ear disorders and advocate for more studies to be conducted to assess the importance of optimal dosing of vitamin D for the progression and outcome of these diseases.

Prenatal vitamin D supplementation to prevent childhood asthma: 15-year results from the Vitamin D Antenatal Asthma Reduction Trial (VDAART)

This article provides an overview of the findings obtained from the Vitamin D Antenatal Asthma Reduction Trial (VDAART) spanning a period of 15 years. The review covers various aspects, including the trial's rationale, study design, and initial intent-to-treat analyses, as well as an explanation of why those analyses did not achieve statistical significance. Additionally, the article delves into the post hoc results obtained from stratified intent-to-treat analyses based on maternal vitamin D baseline levels and genotype-stratified analyses. These results demonstrate a statistically significant reduction in asthma among offspring aged 3 and 6 years when comparing vitamin D supplementation (4400 IU/d) to the standard prenatal multivitamin with vitamin D (400 IU/d). Furthermore, these post hoc analyses found that vitamin D supplementation led to a decrease in total serum IgE levels and improved lung function in children compared to those whose mothers received a placebo alongside the standard prenatal multivitamin with vitamin D. Last, the article concludes with recommendations regarding the optimal dosing of vitamin D for pregnant women to prevent childhood asthma as well as suggestions for future trials in this field.

Vitamin D deficiency and non-infectious uveitis: A systematic review and Meta-analysis

BACKGROUND

Vitamin D plays a critical role in immunomodulation, and its deficiency is implicated in the pathogenesis of several autoimmune diseases. Nevertheless, its relationship with non-infectious uveitis (NIU), an inflammatory ocular disorder, remains inconclusive.

METHODS

A systematic search was conducted in three databases from database inception until May 8, 2023, to investigate the potential relationship between vitamin D deficiency and NIU. We included observational studies reporting the measurement of vitamin D levels in patients with NIU and healthy controls without restriction of language or date of publication. Three pairs of authors independently screened the title and abstracts for potential eligibility and then in full text. A third author resolved disagreements. Three pairs of independent reviewers abstracted the data from the fully reviewed records and evaluated the risk of bias. We followed The MOOSE and PRISMA guidelines. Random effects meta-analyses were used for primary analysis. Studies not included in the meta-analysis were summarized descriptively. This review was registered in PROSPERO: CRD42022308105.

FINDINGS

Of 933 records screened, 11 studies were included, and five were meta-analyzed, encompassing 354 cases and 5728 controls (mean participant age ranging from 7.1 to 58.9 years). Patients with vitamin D deficiency exhibited an Odds Ratio of 2.04 (95% CI = 1.55-2.68, P < 0.00001) for developing NIU compared to controls. Overall, potential sources of bias were low across most studies.

INTERPRETATION

Our findings suggest that vitamin D may play an essential role in the pathophysiology of NIU. While the included studies demonstrated generally low potential bias, additional rigorous prospective studies are necessary to confirm these findings and further elucidate the underlying mechanisms involved. Vitamin D supplementation could represent a possible therapeutic strategy for preventing or managing NIU if substantiated. Clinicians should consider screening for and addressing vitamin D deficiency in patients with or at risk for NIU.

Vitamin D receptor induces oxidative stress to promote esophageal squamous cell carcinoma proliferation via the p53 signaling pathway

Background

Esophageal squamous cell carcinoma (ESCC) is a common pathological esophageal cancer with poor prognosis. Vitamin D deficiency reportedly occurs in ESCC patients, and this is related to single nucleotide polymorphism of vitamin D receptor (VDR).

Objective

We investigated the effect of VDR on ESCC proliferation, invasion, and metastasis and its potential mechanism.

Methods

ESCC and normal tissues were collected from 20 ESCC patients. The ESCC tissue microarray contained 116 pairs of ESCC and normal tissues and 73 single ESCC tissues. VDR expression and its clinicopathological role were determined by real-time quantitative polymerase chain reaction, Western blot, and immunohistochemistry staining. sh-VDR and VDR overexpression were used to validate the effect of VDR on ESCC cell phenotype, and tandem mass tag-based quantitative proteomics and bioinformatics methods identified differential VDR-related proteins. The downstream pathway and regulatory effect were analyzed using ingenuity pathway analysis (IPA). Differentially expressed proteins were verified through parallel reaction monitoring and Western blot. In vivo imaging visualized subcutaneous tumor growth following tail vein injection of VDR-deficient ESCC cells.

Results

High VDR expression was observed in ESCC tissues and cells. Gender, T stage, and TNM stage were related to VDR expression, which was the independent prognostic factor related to ESCC. VDR downregulation repressed ESCC cell proliferation, invasion, and migration in vitro and subcutaneous tumor growth and lung metastases in vivo. The cell phenotype changes were reversed upon VDR upregulation, and differential proteins were mainly enriched in the p53 signaling pathway. TP53 cooperated with ABCG2, APOE, FTH1, GCLM, GPX1, HMOX1, JUN, PRDX5, and SOD2 and may activate apoptosis and inhibit oxidative stress, cell metastasis, and proliferation. TP53 was upregulated after VDR knockdown, and TP53 downregulation reversed VDR knockdown-induced cell phenotype changes.

Conclusions

VDR may inhibit p53 signaling pathway activation and induce ESCC proliferation, invasion, and metastasis by activating oxidative stress.

What is known about the effects of vitamin D in neuropsychiatric lupus?

Systemic lupus erythematosus (SLE) is an autoimmune disease that can affect several organs and systems. The central and/or peripheral nervous system can suffer from complications known as neuropsychiatric lupus (NPSLE). Studies have associated the manifestations of SLE or NPSLE with vitamin D deficiency. It has been shown that hypovitaminosis D can lead to cognition deficits and cerebral hypoperfusion in patients with NPSLE. In this review article, we will address the main features related to vitamin D supplementation or serum vitamin D levels with neuropsychiatric manifestations, either in patients or in animal models of NPSLE.

Dementia, osteoporosis and fragility fractures: Intricate epidemiological relationships, plausible biological connections, and twisted clinical practices

Dementia, osteoporosis, and fragility fractures are chronic diseases, often co-existing in older adults. These conditions pose severe morbidity, long-term disability, and mortality, with relevant socioeconomic implications. While in the research arena, the discussion remains on whether dementia is the cause or the consequence of fragility fractures, healthcare professionals need a better understanding of the interplay between such conditions from epidemiological and physiological standpoints. With this review, we summarized the available literature surrounding the relationship between cognitive impairment, dementia, and both low bone mineral density (BMD) and fragility fractures. Given the strength of the bi-directional associations and their impact on the quality of life, we shed light on the biological connections between brain and bone systems, presenting the main mediators, including gut microbioma, and pathological pathways leading to the dysregulation of bone and brain metabolism. Ultimately, we synthesized the evidence about the impact of available pharmacological treatments for the prevention of fragility fractures on cognitive functions and individuals' outcomes when dementia coexists. Vice versa, the effects of symptomatic treatments for dementia on the risk of falls and fragility fractures are explored. Combining evidence alongside clinical practice, we discuss challenges and opportunities related to the management of older adults affected by cognitive impairment or dementia and at high risk for fragility fracture prevention, which leads to not only an improvement in patient health-related outcomes and survival but also a reduction in healthcare cost and socio-economic burden.

Predicting comorbidities of pregnancy: A comparison between total and free 25(OH)D and their associations with parathyroid hormone

Pregnancy is a unique time when amplified sex steroid concentrations promote an escalation in vitamin D binding protein (DBP) synthesis, associated with increased total vitamin D and metabolites, including 25-hydroxyvitamin D (25(OH)D). Free 25(OH)D concentration increases disproportionately to total 25(OH)D during pregnancy, likely an adaptation to supply the woman and fetus with readily available 25(OH)D. Highlighting the importance of the calcium metabolic stress during pregnancy, the interactional relationship between serum 25(OH)D and PTH has been evaluated. Maternal total 25(OH)D and total 25(OH)D/iPTH are measures of vitamin D status and biomarkers for potential pregnancy complications. It has been proposed that free 25(OH)D and free 25(OH)D/iPTH could be better indicators of vitamin D status and predictors of pregnancy complications such as gestational diabetes (GDM), hypertensive disorders of pregnancy, and preterm delivery. This study aims to determine if free 25(OH)D and its association with PTH are more accurate predictors of comorbidities of pregnancy than total 25(OH)D and its association with PTH. In this post hoc analysis of the Kellogg Pregnancy Study, a double-blind randomized placebo-controlled trial, participants included 297 women with singleton pregnancies: 191 participants were randomized into a group receiving a daily prenatal (400 IU vitamin D3) while 196 received a prenatal plus extra supplementation (4400 IU vitamin D3). Blood and urine samples were collected monthly. 297 participants' serum total 25(OH)D concentrations were measured using radioimmunoassay at baseline (visit 1) and 5-7 months' gestation (visit 6-7). 93 participants' serum free 25(OH)D and PTH concentrations were measured using ELISA and immunoradiometric assay, respectively, at visit 1 and 6-7; 66 participants had paired samples and were included in this analysis. Data were analyzed using SAS 9.4, Cary, N.C. or SPSS v28, IBM Corporation, Armonk, N.Y. Results were considered significant with a p < 0.05. A significant relationship exists between the ratio of total 25(OH)D/iPTH and free 25(OH)D/iPTH grouped by total 25(OH)D ≥ 30 ng/mL and < 30 ng/mL as an indicator of maternal vitamin D status. There was a statistically significant relationship between lower mean free 25(OH)D/iPTH and the development of GDM at visit 1 (p = 0.0003) and at visit 6-7 (p = 0.001) while total 25(OH)D/iPTH and GDM were significantly related only at visit 1 (p = 0.029). In this exploratory cohort, neither free 25(OH)D/iPTH nor total 25(OH)D/iPTH were significantly associated with increased incidence of preterm delivery, hypertensive disorders, or combined comorbidities of pregnancy. An univariate logistic regression evaluating the outcome of gestational diabetes while independently controlling for independent factors showed the ratio of free 25(OH)D/iPTH was more closely associated with gestational diabetes than the ratio of total 25(OH)D/iPTH, although neither were significant. This proof-of-concept analysis suggests that the ratio of free 25(OH)D/iPTH is associated with the development of gestational diabetes throughout pregnancy while total 25(OH)D/iPTH is only associated with the outcome early in pregnancy. Further investigation is warranted to explore this relationship between calcium metabolic stress during pregnancy with a larger cohort to improve validity,reproducibility, and relevance to other pregnancy comorbidities.