The vitamin D deficiency pandemic: Approaches for diagnosis, treatment and prevention

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

Novel Insights into Somatic Comorbidities in Children and Adolescents Across Psychiatric Diagnoses: An Explorative Study

Many children with psychiatric disorders display somatic symptoms, although these are frequently overlooked. As somatic morbidity early in life negatively influences long-term outcomes, it is relevant to assess comorbidity. However, studies of simultaneous psychiatric and somatic assessment in children are lacking. The aim of this study was to assess the prevalence of somatic comorbidities in a clinical sample of children and adolescents with psychiatric disorders in a naturalistic design. Data were assessed from 276 children with various psychiatric disorders (neurodevelopmental disorders, affective disorders, eating disorders and psychosis) aged 6-18 years. These data were collected as part of routine clinical assessment, including physical examination and retrospectively analyzed. For a subsample (n = 97), blood testing on vitamin D3, lipid spectrum, glucose and prolactin was available. Results of this cross-sectional study revealed that food intake problems (43%) and insomnia (66%) were common. On physical examination, 20% of the children were overweight, 12% displayed obesity and 38% had minor physical anomalies. Blood testing (n = 97) highlighted vitamin D3 deficiency (< 50 nmol/L) in 73% of the children. None of the predefined variables (gender, age, medication and socioeconomic factors) contributed significantly to the prevalence of somatic comorbidities. The main somatic comorbidities in this broad child- and adolescent psychiatric population consisted of (1) problems associated with food intake, including obesity and vitamin D3 deficiency and (2) sleeping problems, mainly insomnia. Child and adolescent psychiatrists need to be aware of potential somatic comorbidities and may promote a healthy lifestyle.

Optimizing serum 25(OH)D levels to mitigate the risk of age-related ocular diseases: insights from a large-scale prospective cohort study

BACKGROUND

Investigations into the association between serum 25-hydroxyvitamin D (25(OH)D) levels and the risk of age-related ocular diseases have yielded inconsistent results. Thus, we aimed to provide robust longitudinal evidence, identify optimal serum thresholds, and explore the underlying mechanisms.

METHODS

We analyzed data of 322,953 participants from the UK Biobank. The serum 25(OH)D levels were assessed using chemiluminescent immunoassay. Outcomes were incidences of cataract, primary open-angle glaucoma (POAG), age-related macular degeneration (AMD), and diabetic retinopathy (DR). Hazard ratios and 95% confidence intervals were estimated using Cox proportional hazards models. Nonlinear relationships were explored using restricted cubic splines, and mediation analyses were performed to delineate potential mechanistic pathways.

RESULTS

Our findings revealed U-shaped associations for cataract and AMD, and L-shaped associations for DR (all P < 0.05), with an optimal threshold of approximately 50 nmol/L, while no association with POAG was observed. Below this threshold, each 10 nmol/L increase in serum 25(OH)D concentration was linked to a 3.5%, 4.2%, and 6.0% reduction in the risk of cataract, AMD, and DR, respectively (HR 0.965 [95% CI 0.951-0.980]; HR 0.958 [95% CI 0.921-0.997]; HR 0.940 [95% CI 0.894-0.989], respectively), while above 50 nmol/L, no significant protective effects were observed. Mediation analyses revealed that the low-grade inflammation score and triglyceride-glucose index may mediate the effects of serum 25(OH)D on cataract and DR.

CONCLUSIONS

This study identified 50 nmol/L as the optimal serum 25(OH)D threshold for reducing risks of cataract, AMD and DR, with no benefits beyond this level. The protective effects may be mediated through modulation of inflammation and glucolipid metabolism pathways. The threshold effects highlight the importance of targeted vitamin D supplementation under careful monitoring of serum levels to optimize ocular health outcomes.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Co-administration of vitamin D and N-acetylcysteine to modulate immunosenescence in older adults with vitamin D deficiency: a randomized clinical trial

Background

Immunosenescence is an important factor in the impaired immune response in older adults and plays a significant role in the development of biological aging. Targeting immunosenescence could present a novel pharmacological approach to mitigating aging and age-related diseases. We aimed to investigate the effect of N-acetylcysteine (NAC) and vitamin D (Vit-D) on the senescence of peripheral blood mononuclear cells (PBMCs).

Method

This randomized clinical trial was conducted on older adults with Vit-D deficiency. Eligible participants were randomly assigned to one of four groups to receive either (A) 1000 IU of Vit-D daily (D1) (B), 1000 IU of Vit-D plus 600 mg of NAC daily (D1N) (C), 5000 IU of Vit-D daily (D5), or (D) 5000 IU of Vit-D plus 600 mg of NAC daily (D5N) for 8 weeks. Senescence-associated beta-galactosidase (SA-β-gal) staining, expression of senescence-related genes, and serum inflammatory factors were measured at baseline and after 8 weeks.

Results

After the intervention, supplementation with D5N and D5 significantly downregulated p16, interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) expression and decreased SA-β-gal activity compared to the D1 group. Additionally, co-administration of NAC with 1000 IU of Vit-D significantly downregulated p16 transcripts in PBMCs compared to Vit-D 1000 IU alone. No significant differences were observed between the groups in serum IL-6, C-reactive protein (CRP), or the neutrophil-to-lymphocyte ratio (NLR) after the intervention.

Conclusions

The loading dose of Vit-D significantly attenuates senescence in PBMCs of older adults. However, co-administration of NAC with both the standard and loading doses of Vit-D further enhances these beneficial effects.

Clinical trial registration

https://irct.behdasht.gov.ir, identifier IRCT20230508058120N1.

Risk factors and nomogram model for recurrence of benign paroxysmal positional vertigo in postmenopausal women: a multicenter cross-sectional study

Objective

To explore the risk factors for recurrent benign paroxysmal positional vertigo (BPPV) in postmenopausal women within 1 year of canalith repositioning procedure (CRP), and develops a risk model based on serum 25-hydroxyvitamin D (25(OH)D), estradiol, and calcium levels to provide early identification of high-risk groups and guide prevention and treatment strategies.

Methods

Data from postmenopausal women with BPPV, diagnosed and successfully treated with CRP at five hospitals in Sichuan Province between January 2019 and January 2024, were retrospectively analyzed. Participants were divided into BPPV validation and training sets in a 3:7 ratio. Clinical data were categorized into recurrence and non-recurrence subgroups based on whether BPPV recurred after treatment. LASSO regression identified factors influencing recurrence within 1 year after CRP, and multivariate logistic regression (MLR) analysis was used to develop a risk nomogram prediction model (NPM).

Results

A total of 490 patients were enrolled, with 147 in the validation set and 343 in the training sets. Among them, 151 patients (30.82%) experienced recurrenced, including 58 (30.61%) in the validation set and 106 (30.90%) in the training sets. LASSO and MLR analyses identified migraine (OR = 2.208, 95% CI = 1.278-3.817), serum calcium (OR = 0.601, 95% CI = 0.447-0.81), 25(OH)D (OR = 0.785, 95% CI = 0.713-0.864), and serum estradiol (OR = 0.820, 95% CI = 0.752-0.894) as significant factors influencing recurrence within 1 year after CRP treatment in postmenopausal women with BPPV.

Conclusion

The recurrence rate of BPPV within 1 year after CRP treatment in postmenopausal women is high. Migraine, 25(OH)D, calcium, and estradiol are associated with recurrence. The risk prediction model, developed using these factors, demonstrates good discrimination and calibration. It effectively predicts the recurrence risk within 1 year after successful CRP treatment, offering practical clinical value.

Type 1 Diabetes Mellitus and Vitamin D

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

An investigation of thyroid and parathormone hormones and related biochemical factors in individuals with and without symptoms indicative of temporomandibular disorder admitted to the internal medicine department

OBJECTIVE

To investigate the effect of parathormone and thyroid hormones, along with their associated biochemical factors in individuals with and without symptoms indicative of temporomandibular disorder (TMDs) admitted to the internal medicine department.

METHODS

The study involved 416 participants with symptoms indicative of TMDs and 415 controls. Serum concentrations of anti-thyroid peroxidase antibody (Anti-TPO Ab), free triiodothyronine, free thyroxine, thyroid-stimulating hormone, parathyroid hormone, calcium, sodium, potassium, magnesium, phosphorus, vitamin D, vitamin B12, folate, creatine kinase, haemoglobin, ferritin, C-reactive protein and sedimentation rate were analysed.

RESULTS

The serum level of anti-TPO Ab was found to be elevated in participants with symptoms indicative of TMDs in comparison to controls (p < .001). However, no significant differences were observed in the other parameters assessed between the two groups (p > .05).

CONCLUSION

Serum concentrations of parathormone and thyroid hormones associated biochemical factors are not affected in participants with symptoms indicative of TMDs except Anti-TPO Ab.

Inverse association of triglyceride-glucose and triglyceride/HDL-c indexes with serum 25(OH) vitamin D levels in US adults

The triglyceride-glucose index (TyG) and the triglyceride to high-density lipoprotein ratio (TG/HDL-c) are novel indicators for assessing insulin resistance (IR) in epidemiological studies. This study aimed to evaluate the association between 25-hydroxy-vitamin D [25(OH)D] levels and these two indicators in the adult population of the United States. 14,380 participants aged 20 years and older were included from the National Health and Nutrition Examination Survey (NHANES). Multivariable linear regression models were used to analyze the association between 25(OH)D and TyG, as well as TG/HDL-c. Smooth fitting curves were employed to identify potential non-linear relationships between 25(OH)D, TyG, and TG/HDL-c. The findings revealed a negative association between 25(OH)D and TyG, with the effect being more pronounced in males and individuals with diabetes (p < 0.01). Similarly, 25(OH)D was negatively associated with TG/HDL-c, with a stronger impact observed in males compared to females. The study population was divided into four quartiles based on 25(OH)D concentration, and TyG and TG/HDL-c levels in Q3 and Q4 were lower than those in Q1. Furthermore, a non-linear relationship was observed between 25(OH)D and TyG, with an inflection point at 19.352 ng/mL. A non-linear relationship was also found between TG/HDL-c and 25(OH)D, with an inflection point at 37.211 ng/mL. 25(OH)D is an independent factor significantly associated with TyG and TG/HDL-c indexes. This negative association may be related to the role of 25(OH)D in insulin resistance.

Micronutrient Deficiencies in Pediatric IBD: How Often, Why, and What to Do?

Inflammatory bowel disease (IBDs), including Crohn's disease (CD), and ulcerative colitis (UC) are complex diseases with a multifactorial etiology, associated with genetic, dietetic, and other environmental risk factors. Children with IBD are at increased risk for nutritional inadequacies, resulting from decreased oral intake, restrictive dietary patterns, malabsorption, enhanced nutrient loss, surgery, and medications. Follow-up of IBD children should routinely include evaluation of specific nutritional deficits and dietetic and/or supplementation strategies should be implemented in case deficiencies are detected. This narrative review focuses on the prevalence, risk factors, detection strategy, and management of micronutrient deficiencies in pediatric IBD.

Foods fortified with vitamin D. Mith or reality?

Introduction

Prevalence of Vitamin D Deficiency Among Young Elite Soccer Players Living Above 55 Degrees North Latitude and Evaluation of the Effectiveness of Self-Used Preventive Methods

The widespread prevalence of vitamin D deficiency among young elite soccer players living above 40° north latitude is a significant issue. Considering the adverse effects of vitamin D deficiency, it is crucial to investigate its prevalence and the effectiveness of self-used preventive strategies among high-risk groups. This study involved 209 young athletes (aged 7-18 years, mean age: 12.79 ± 3.04 years, weight: 50.11 ± 17.75 kg, height: 1.60 ± 0.19 m, and BMI: 18.69 ± 2.75) from a leading soccer academy, residing above 55° north latitude. Blood samples were collected in winter to analyze the total 25-hydroxyvitamin D (25(OH)D) levels using liquid chromatography-mass spectrometry. High prevalence of insufficiency (38.3%) and deficiency (26.8%) of 25(OH)D was identified. There were no significant differences in the severity of deficiency among different age groups (6-9 years, 10-14 years, and 15-18 years) or during growth spurts. The analysis of self-used preventive methods showed no significant differences between the compared groups (p=0.149). Vitamin D deficiency and insufficiency are widespread among young elite soccer players living above 55° north latitude and training indoors. The effectiveness of self-used preventive methods is considered low.

The impact of vitamin D on atopic disorders: assessing evidence for a causal relationship

Since the beginning of COVID-19 pandemic, there has been a noticeable increase in the consumption of vitamin D. Evidence accentuates the generation of a pro-tolerogenic T helper 2 cell state with vitamin D, suppressing T helper 1 inflammatory response. T helper 2 cell polarization is characteristic of atopy. However, although the literature on vitamin D and atopy has yielded controversial results, multiple studies have described an inverse relationship between vitamin D levels and the severity of atopy, as well as an improvement of the pathology with vitamin D supplementation. A different approach is offered in the analysis of the immunological mechanisms by which vitamin D acts in the human body, supporting its use as a promoter of homeostasis. In this sense, vitamin D promotes a balanced state through the action of regulatory T cells, controlling cytokines, both pro- and anti-inflammatory, and by reducing B cell prolif eration and differentiation, thus preventing the possible development of atopy.

Vitamin D probiotics fortification improve vitamin D and total antioxidant capacity levels among pregnant women: a single-blinded randomized controlled trial

Vitamin D deficiency remains a significant public health concern especially in Ghana. In pregnant women, it has been associated with various adverse maternal and neonatal outcomes. However, there is inadequate standard measures to reduce vitamin D deficiency and improve total antioxidant capacity (TAC). For the first time, this study investigated the effectiveness of vitamin D fortified probiotic yogurt intake on serum vitamin D and total antioxidant capacity levels in pregnant women in Ghana. This single blinded randomized controlled trial study included 126 (63 fortified and 63 non-fortified group) pregnant women within their first trimester attending antenatal care at selected hospitals in the Ashanti Region, Ghana. Participants were followed up for 6 months. Sociodemographic and clinical data were collected. Venous blood samples were also collected at baseline and end line for serum 25(OH)D and TAC quantification using ELISA (Thermo scientific). Statistical analyses were done in SPSS version 26.0 and R Language version 4.4.4. The baseline Vitamin D deficiency was 88.1% and weak TAC was 73.0%, however not statistically influenced by sunlight exposure (p > 0.05). Besides, race of participants (p = 0.003) was significantly associated with Vitamin D deficiency. Moreover, Vitamin D deficiency (86.5% vs. 13.5%; p = 0.985) and weak TAC (84.8% vs. 15.2%; p = 0.351) were more predominant among pregnant women with inadequate dietary pattern, however not statistically significant. At end line, fortified study group had significantly higher levels of Vitamin D (p < 0.01) and TAC (p < 0.0001) compared to non-fortified group with higher Vitamin D deficiency (93.0%; p = 0.022) and weak TAC (55.8%: p < 0.0001). The prevalence of Vitamin D deficiency and low total antioxidant capacity (TAC) among pregnant women is notably high, especially among Ghanaian populations. Targeted interventions, such as Vitamin D fortification during pregnancy, are essential to enhance Vitamin D and TAC levels, potentially reducing adverse maternal and neonatal outcomes.Trial registration: The Pan African Clinical Trial Registry (PACTR), Random Controlled Trial PACTR202408762065192 on 21st August 2024. Retrospectively registered.

Association between the CALLY index, vitamin D, and asthma: insights from NHANES

Purpose

The CALLY index integrates C-reactive protein (CRP), albumin and lymphocyte counts to accurately reflect the inflammatory, nutritional and immune status of the body. Multiple studies have indicated that the CALLY index plays a key role in a variety of diseases, especially asthma, and is closely associated with inflammatory response, airway remodeling and immune imbalance in asthma. Research has shown that vitamin D is associated with asthma susceptibility, severity, and control, and its levels may influence inflammatory and immune markers associated with the CALLY index, which may play a role in the association between the CALLY index and asthma.

Patients

Using data from the National Health and Nutrition Examination Survey (NHANES) from 2001 to 2010, the association between CALLY index and asthma and the role of vitamin D in American adults were analyzed in depth. Through multiple logistic regression, subgroup analysis, and other statistical means, the potential pathophysiological links between the three are revealed, providing theoretical support for the prevention and treatment of related diseases.

Results

A total of 17,946 individuals were included in this study, of which 2,317 were diagnosed with asthma. Fully adjusted multivariate logistic regression analysis revealed that the CALLY index was significantly negatively associated with asthma, with an odds ratio (OR) of 0.996 [95% confidence interval (CI) 0.993-0.999]. Specifically, each unit increase in the CALLY index was associated with a 0.996-fold reduction in asthma risk. In addition, mediation effect analysis showed that vitamin D partially mediated the association between the CALLY index and asthma, with a mediation ratio of 3.36%.

Conclusion

This study reveals an association between the CALLY index and reduced risk of asthma in the US population and suggests that vitamin D plays an incomplete mediating role. This finding provides a new theoretical basis for the diagnosis, treatment, and prevention of asthma and is expected to be a potential biomarker.

Vitamin D and Chronic Rhinosinusitis with Nasal Polyps: A Narrative Review and Perspectives

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a subtype of chronic rhinosinusitis (CRS) characterized by bilateral nasal polyps, primarily affecting adults. It is often associated with hyposmia and asthma and driven by persistent Th2 inflammation, particularly in Caucasian patients. The disease is recurrent and significantly impacts quality of life, yet its pathophysiology remains poorly understood. Management includes intranasal steroids, short courses of systemic corticosteroids, surgery for refractory cases, and biologics. However, despite these treatment options, disease control remains challenging. Low vitamin D levels have been associated with worse clinical outcomes, while supplementation studies show promise in improving symptoms in deficient patients. Emerging research suggests that vitamin D modulates immunity, fibroblast activity, and epithelial integrity, potentially contributing to CRSwNP pathogenesis, though the exact mechanisms remain unclear. This review synthesizes current research on vitamin D's role in systemic and local inflammation in CRSwNP. By highlighting its potential therapeutic implications, this work aims to guide future research and inform clinical practice. Additionally, it may serve as a foundation for understanding the broader impact of vitamin D deficiency in sinonasal diseases and other atopic conditions.

Brazilian older adults' vitamin D insufficiency and deficiency: a systematic review and meta-analysis

This systematic review and meta-analysis aimed to identify the prevalence of vitamin D insufficiency and deficiency in older Brazilian adults. Design: Systematic review and meta-analysis. The search explored the MEDLINE, EMBASE, and LILACS platforms. Clinical and observational studies published before November 9, 2022, were included. The review was registered in PROSPERO No. 74,732 and evaluated using the adapted Loney scale. The search strategy identified 1,169 articles, of which 26 met the inclusion criteria, totaling 9,606 older adults. The vitamin D deficiency prevalence was 34.2% (95%CI: 25.0-44.6), and the insufficiency prevalence was 35.2% (95%CI: 31.0-39.5). The highest prevalence found was in the southern region (86.3% deficiency) and the southeast (51.4% insufficiency). Cross-sectional studies have shown a similar prevalence of vitamin D deficiency and insufficiency to the overall prevalence (34.2% and 33.7%). A statistically significant difference was found in the studies' risk of bias assessment (insufficiency subgroup). The results show a high prevalence of vitamin D insufficiency and deficiency in older Brazilian adults, pronounced even in places with higher incidences of sunlight.

Effectiveness and Potential Toxicity of Bread Fortification With Vitamin D in General Population: A Predictive Modeling Study

BACKGROUND

Vitamin D fortification of bakery's wheat flour, which excludes flours used for confectionaries and bulky breads, can be a suitable strategy to improve vitamin D status of the general population.

OBJECTIVES

This study aimed to generate a predictive model to anticipate the effectiveness and potential risk of vitamin D-fortified bread in different fortification doses in general population.

METHODS

To gather baseline data before implementation of flour fortification, a cross-sectional descriptive study was conducted on a representative sample comprising 1051 subjects aged 7-65 y from 2 cities Birjand and Yazd. Demographic, anthropometric, and laboratory assessments were performed for all subjects. The amount of bread consumption was estimated using a 24-h recall questionnaire. A simulation model was used to examine the impact of various fortification doses of vitamin D in bread on the proportion of both adults and children achieving sufficient circulating 25-hydroxycalciferol [25(OH)D] concentrations (>50 nmol/L) and potential harm thresholds (>375 nmol/L). The baseline serum 25(OH)D concentration data were used as a reference for comparison at each fortification dose. Circulating 25(OH)D between 27.5 and 50 nmol/L and below 27.5 nmol/L was considered as insufficiency and deficiency, respectively.

RESULTS

Substantial proportions of both children and adults fell into the insufficient (37.5% and 37.4%, respectively) and deficient (34.7% and 31.8%, respectively) categories. Our model showed that the fortification dose of 250 IU/100g bread could be an effective strategy for significantly improving vitamin D status in the general population. Higher doses, such as 500 IU/100g, results in >70% of the population achieving sufficient 25(OH)D concentrations. However, starting at 400 IU/100 g bread, a very small percentage (0.1%) of the population could reach potentially harmful concentrations.

CONCLUSIONS

By adding 250-350 IU vitamin D per 100 g bread, over half of the general population can reach to sufficient vitamin D status with no potential risk of toxicity.

Genetic variants in vitamin D metabolism-related genes are associated with vitamin D status and adiposity markers

Single nucleotide variants (SNVs) in vitamin D (VD) metabolism genes have been shown to be associated with serum 25(OH)D concentrations. Although these associations have been reported in other populations, they are less studied in Mexico, a country with high vitamin D deficiency (VDD) despite ample sun exposure. Therefore, we investigate the association between VD-metabolism related SNVs, serum 25(OH)D concentrations, and their impact on VDD and adiposity indicators. We hypothesized that SNVs are associated with serum 25(OH)D concentrations in the Mexican population. We included 1977 individuals (597 males and 1380 females) from the Health Worker Cohort Study. Nine genetic variants: rs10741657 (CYP2R1), rs6013897 (CYP24A1), rs10877012 (CYP27B1), rs10783219 and rs4516035 (VDR), rs4588 and rs7041 (GC), rs4944957 and rs3794060 (NADSYN1), in VD metabolism-related genes were genotyped. Linear and logistic regression models were used to assess the association of interest. In our study, 7 genetic variants were associated with serum 25(OH)D concentrations and VDD. A genetic risk score was created using variants rs6013897 (CYP24A1), rs4516035 (VDR), and rs4588 (GC), which were associated with lower serum 25(OH)D concentrations, higher VDD prevalence, and increased odds of VDD. A second GRS using all 9 variants showed weaker associations. Gene-gene interactions between rs3794060-rs4944957 (NADSYN1), and rs10877012(CYP27B1)-rs7041(GC), were associated with serum 25(OH)D concentrations and VDD, respectively. Additionally, SNV interactions with body mass index, waist circumference, and body fat distribution were identified. These findings suggest that SNVs influence serum 25(OH)D concentrations and adiposity indicators, with potential clinical implications for obesity management.

Causal relationship between serum 25-hydroxyvitamin D and coronary heart disease: A bi-directional two-sample Mendelian randomization study

BACKGROUND AND AIM

Coronary heart disease (CHD) is the leading cause of severe cardiovascular events, such as acute myocardial infarction. This study investigates the interaction between serum 25-hydroxyvitamin D (25(OH)D) levels and CHD. However, most current studies are observational, which may introduce bias into the results.

METHODS AND RESULTS

We conducted a two-way, two-sample Mendelian randomization study. The CHD sample was drawn from the 2021 population in the FinnGen database (cases: 21,012; controls: 197,780), while the serum 25(OH)D sample was obtained from the 2020 European population in the GWAS Catalog database (417,580 cases). Based on the inverse variance weighted (IVW) results, we found that the risk of CHD decreased with increasing serum 25(OH)D concentrations (P < 0.05), and that higher CHD risk was associated with lower serum 25(OH)D concentrations (P = 0.04).

CONCLUSIONS

Our study found that increased serum 25(OH)D concentration may serve as a protective factor against CHD. Additionally, we found that CHD can be a risk factor that affects serum 25(OH)D concentrations in humans.

Nutrient Intakes in Vegans, Lacto-Ovo-Vegetarians, Orthodox Fasters, and Omnivores in Russia: A Cross-Sectional Study

In Eastern Europe, the number of vegetarians is growing, and the number of people adhering to Christian Lents is traditionally high. However, data on the nutritional value of plant-based diets in this part of the world are limited. The aim of this study was to compare the nutritional intakes of three groups with different plant-based patterns with that of omnivores in Russia, Moscow region. The nutrient intakes of 46 vegans, 49 lacto-ovo-vegetarians, 42 people who adhered to Orthodox Great Lent, and 48 omnivores were assessed. The food frequency questionnaire method was used for data collection and analysis. The differences in absolute and calorie adjusted nutrient intakes between the groups were analysed. Additionally, a pairwise comparison of the general plant-based group (combined of the vegan, lacto-ovo-vegetarian, and Great Lent samples) and the omnivorous groups was conducted. Vegan diet was the most favourable in micronutrient composition. The intake of many micronutrients increased when switching to a more plant-based diet from a more animal-based one. The opposite association was observed only for selenium and vitamins D and B12. Fasting people consumed more iodine and n-3 polyunsaturated fatty acids; however, after the calorie content was standardized, the omnivores caught up with them. The omnivores had the largest list of dietary inadequacies: they significantly more often than all other groups had inadequate intake of cholesterol (excessive), fibre, potassium, magnesium, iron, and vitamins B1, B6, B9, and E (insufficient). Inadequate intake of polyunsaturated fatty acids, calcium, iodine, chromium, molybdenum, and zinc; or vitamins B2, PP, H, B12, and D was observed rather often in all the studied groups. Although, the vegan diet was richer in most micronutrients, plant products often contain substances that reduce the bioavailability of various nutrients, which can partially affect their status in the body, and, thus, may increase the need in them in vegetarians and fasters.

Contributions of Dietary Patterns and Factors to Regulation of Rheumatoid Disease

Rheumatoid arthritis (RA) is a systemic autoimmune disease that commonly causes pain in joints and the progressive destruction of cartilage and bone, which significantly reduces the quality of life and increases the social burden. However, there is still no cure for RA, so it is highly important to explore additional adjuvant treatment methods. Studies have indicated that malnutrition, changes in intestinal microbiota, and changes in immune status caused by dietary imbalance are directly related to the onset of RA, indicating that dietary intervention may offer a simple, economical, and practical avenue to relieve RA. Therefore, in this review, we discuss the pathogenesis of RA and summarize the influence of different dietary patterns on RA. In particular, we pointed out that high-fat, high-sugar, and high-salt diets contribute to RA progression, whereas the Mediterranean diet (MD) is beneficial for preventing RA. Furthermore, the ingredients of food, such as dietary fiber, probiotics, and vitamins, help reduce the level of inflammation and relieve joint pain, which may play critical roles in the treatment of RA. Therefore, dietary intervention provides a potential effective approach for adjuvant therapy of RA.

Effectiveness of Extracellular Vesicle Application in Skin Aging Treatment and Regeneration: Do We Have Enough Evidence from Clinical Trials?

In recent years, there has been a dynamic development in therapies utilizing extracellular vesicles (EVs) including exosomes. Therefore, we have conducted an analysis of the scientific literature to verify the current state of knowledge about these therapies. A total of 12 clinical studies were analyzed, covering the use of EVs in treating skin aging, acne scars, alopecia, and wound healing. The results indicate that EVs and exosomes hold potential in regenerative skin therapies, offering innovative and non-invasive therapeutic approaches. At the same time, significant challenges related to the standardization of their production and the lack of large-scale randomized studies were identified. Thus, we also evaluated the investigated clinical trials in regard to the MISEV (Minimal Information for Studies of Extracellular Vesicles) criteria. This review provides a comprehensive overview of the contemporary applications of EVs in skin therapy and regenerative medicine, highlighting directions for further research.

Vitamin D in Reproductive Health Disorders: A Narrative Review Focusing on Infertility, Endometriosis, and Polycystic Ovarian Syndrome

Vitamin D (VD) is a fat-soluble steroid hormone with essential physiological functions beyond calcium and bone metabolism. In recent years, its role in women's reproductive health has gained attention, influencing ovarian function, follicular development, endometrial receptivity, and steroid hormone regulation. VD deficiency has been linked to reproductive disorders such as polycystic ovarian syndrome (PCOS), endometriosis, and infertility. Studies indicate that up to 40-50% of healthy pregnant women have insufficient VD levels, which may contribute to adverse pregnancy outcomes and reduced fertility. With growing evidence connecting VD to reproductive health, this review examines its molecular and endocrine mechanisms in fertility, endometriosis, and PCOS. It explores VD's therapeutic potential and its implications for improving clinical approaches and future research in reproductive medicine. Maintaining adequate VD levels is crucial for ovarian function, immune modulation in reproductive tissues, and overall fertility. Its deficiency is associated with insulin resistance, hormonal imbalances, and inflammatory processes, which contribute to reproductive pathophysiology. Establishing reference values for VD in reproductive medicine is essential for optimizing fertility treatments and improving clinical outcomes. This review synthesizes current research on VD's role in reproductive health and highlights the need for further investigation into its therapeutic applications.

1α,25-Dihydroxyvitamin D3 accelerates skin wound re-epithelialization by promoting epidermal stem cell proliferation and differentiation through PI3K activation: an in vitro and in vivo study

1α,25-Dihydroxyvitamin D3 (VD3), the active form of vitamin D, plays a crucial role in wound healing. In this study, we aimed to investigate the effect of VD3 on the proliferation and differentiation of epidermal stem cells (EpSCs) and monitor its impact on re-epithelialization. We established a murine full-thickness skin defect model and applied four doses of VD3 (0, 5, 50, and 250 ng/mouse/day) to the wounds topically for three days. Immunostaining and flow cytometry confirmed the effect of VD3 on the proliferation and differentiation of EpSCs in wounds. This effect of VD3 (0, 1, 10, and 50 nM) on EpSCs and its possible mechanism were further confirmed in vitro by CCK8, westen blot, immunostaining, and flow cytometry. We found that on day five post-wounding, the means±SD length of the neo-epidermis was 195.88±11.57, 231.84±16.45, 385.80±17.50, and 268.00±8.22 μm in the control, 5, 50, and 250 ng groups, respectively, with a significant difference from the control (all P<0.05). Immunostaining and flow cytometry showed that VD3 improved the proliferation and differentiation of K15+ EpSC (vs control, all P<0.05), K14+ epidermal progenitor cells (vs control, all P<0.05), and K10+ epidermal terminal cells (vs control, all P<0.05) in vivo and in vitro. The PI3K signaling pathway appeared to underlie this response because significant inhibition of the response was found when inhibitors were used to inhibit PI3K. Our study demonstrated that VD3 is a potent promoter of cutaneous wound healing by stimulating EpSC proliferation and differentiation through PI3K activation.

Comparison of vitamin D status in healthy Bangladeshi urban and rural individuals and their association with serum calcium and alkaline phosphatase: A pilot study

Vitamin D insufficiency is a worldwide problem that is likely underestimated since physical symptoms may only be apparent in individuals with severe deficiencies. Previously, people in South Asian countries were thought to be vitamin D sufficient because of plentiful sunshine, but vitamin D insufficiency has also been reported in these countries. In a South Asian country like Bangladesh, people living in the rural and urban parts of the country can have considerable differences in their sun exposure, types of clothing worn, and levels of air pollution. This pilot study aimed to explore the vitamin D status (measured by serum 25[OH]D) of healthy urban and rural Bangladeshi people and to examine the association of serum 25(OH)D concentration with calcium and alkaline phosphatase concentrations. A total of 101 apparently healthy adult individuals, aged 20-58 years, were enrolled from both urban and rural areas. The participants were selected from students, staff and patient attendants from the outpatient department (OPD) of Bangabandhu Sheikh Mujib Medical University and Mirsarai Upazila Health Complex, Chittagong. The overall rate of vitamin D insufficiency was 39.6% and of vitamin D deficiency was 51.5%. However, it was observed that the proportion of vitamin D-deficient participants in urban areas (70.6%) was more than double that of participants living in rural areas (32%) and that serum 25(OH)D concentrations were higher in rural compared to urban participants with similar sunlight exposure times. However, participants aged 50 years or more showed similar concentrations of serum vitamin D levels irrespective of their habitat. This pilot study highlights the need for further larger-scale studies in Bangladesh to determine the reasons for the high rates of vitamin D inadequacy overall and the differences between rural and urban populations.

Prevalence and factors associated with vitamin D deficiency in children and adolescents with type 1 diabetes mellitus: Baseline data from a clinical trial in Rio de Janeiro

OBJECTIVES

The therapeutic potential of vitamin D has been studied regarding adjuvant interventions. Some studies have evaluated the factors associated with vitamin D deficiency (VDD) in healthy populations, but they are scarce in children and adolescents with type 1 diabetes mellitus (T1DM). The objective of this study was to describe the prevalence of and factors associated with VDD in children and adolescents with T1DM.

METHODS

This was a cross-sectional analysis of the baseline data from a controlled clinical trial. Participants were between 7 and 16 y old, diagnosed with T1DM for at least 1 y, and classified as having VDD when 25-hydroxyvitamin D (25[OH]D) was less than 30 ng/mL. The following data were collected: sociodemographic, clinical, laboratory, lifestyle, anthropometric, and Fok-I polymorphism (rs2228570). A multivariable logistic regression model was developed to adjust the effect of potential confounders. The odds ratio (OR) with 95% confidence interval (CI) was used. The significance level used was 5%.

RESULTS

A total of 143 children and adolescents were enrolled; 51% were female and the mean age was 11.5 ± 2.2 y old. The prevalence of VDD was 79% and the mean 25(OH)D of participants with VDD was 19.2 ± 6.1 ng/mL. The factors associated with VDD were low level of physical activity (OR, 2.9, 95% CI, 1.1-7.6, P = 0.031), poor glycemic control (OR, 5.0, 95% CI, 1.9-13.2, P = 0.001), and excess weight (OR, 3.6, 95% CI, 1.1-11.1, P = 0.029).

CONCLUSIONS

A high prevalence of VDD was observed as well as some associated lifestyle and clinical variables. Recommendations for children and adolescents with T1DM include monitoring their 25(OH)D and encouraging healthy eating practices and routine physical exercise.

Exploring factors associated with vitamin D nutritional status in Japanese baseball players

BACKGROUND

Vitamin D is a nutrient necessary for conditioning athletes. This cross-sectional study aimed to determine the nutritional status of vitamin D in farm-league professional baseball players to examine vitamin D requirements.

METHODS

This study included 35 players enrolled in farm team A of the Nippon Professional Baseball Organization in the spring of 2022. The survey items included anthropometric measurements, serum 25-hydroxyvitamin D [25(OH)D] levels as an indicator of vitamin D nutritional status, a simple questionnaire for predicting vitamin D deficiency in Japanese adults, mean daily sun exposure duration, and body surface area (BSA).

RESULTS

The serum 25(OH)D level was 29.8±1.8 ng/mL, and 17 (49%) participants were vitamin D deficient (<30 ng/mL). The serum 25(OH)D levels showed positive correlations with body height (r=0.459, P<0.01), fat-free mass (r=0.347, P<0.05), muscle mass (r=0.341, P<0.05), and BSA (r=0.434, P<0.01). Furthermore, the consumption frequency of fish with high vitamin D levels in regular diets, BSA, and body fat mass were identified as predictors of the serum nutritional status of vitamin D.

CONCLUSIONS

Athletes engaged in outdoor sports, such as the study participants, had inadequate vitamin D levels. In addition, the frequency of consumption of fish with high vitamin D levels in regular diets, BSA, and body fat mass were identified as predictors of the serum nutritional status of vitamin D. Further studies of the relationship between vitamin D supplementation and performance are needed.

Redefining vitamin D status: Establishing population-based indirect reference intervals through big data analysis

OBJECTIVES

To establish accurate population-based reference intervals (RIs) for serum 25-hydroxyvitamin D [25(OH)D] using the refineR indirect method and real-world data (RWD), accounting for demographic, methodological, and seasonal factors.

METHODS

A retrospective analysis of 130,030 serum 25(OH)D samples collected from 2018 to 2022 at a tertiary hospital in Barcelona was performed. Samples were measured using VDSP-certified Liaison and Atellica immunoassays. The refineR algorithm was employed to establish RIs, utilizing Box-Cox transformations to adjust for data distribution. Demographic variables (sex and age), assay differences, medical department and seasonal variations were analysed. RIs were verified using a subset of healthy individuals.

RESULTS

The median serum 25(OH)D level was 25 ng/mL (62.5 nmol/L). Vitamin D deficiency (≤20 ng/mL, ≤50 nmol/L) was observed in 34.2% of samples, and severe deficiency (≤12 ng/mL, ≤30 nmol/L) in 12.6%. The default Box-Cox transformation estimated RIs of 11.5-64.5 ng/mL (28.7-161.2 nmol/L), while the modified Box-Cox transformation yielded RIs of 14.2-65.9 ng/mL (35.5-164.7 nmol/L). Women exhibited wider RIs (14.5-68.6 ng/mL, 36.2-171.5 nmol/L) compared to men (11.6-57.3 ng/mL, 29-143.2 nmol/L). Method-specific RIs were 10.2-58.6 ng/mL (25.5-146.5 nmol/L) for the Liaison assay and 9.9-59.3 ng/mL (24.7-133.2 nmol/L) for the Atellica assay. The lowest RIs were observed in outpatients (4.3-46.4 ng/mL, 10.7-116 nmol/L) and endocrinology patients (5.5-43.9 ng/mL, 13.7-109.7 nmol/L). Seasonal variation significantly impacted RIs, with higher levels during summer months.

CONCLUSIONS

The refineR algorithm effectively established population-based RIs for serum 25(OH)D in Barcelona, revealing significant demographic and seasonal variations. Redefining 25-hydroxyvitamin D thresholds based on population-specific data may reduce unnecessary screening and supplementation, minimizing associated risks. This study highlights the need for population-, seasonal-, and method-specific RIs to improve vitamin D assessment and management.

Vitamin D and Type 2 Diabetes Mellitus: Molecular Mechanisms and Clinical Implications-A Narrative Review

Vitamin D has been widely studied for its implications on type 2 diabetes mellitus, a chronic condition characterized by insulin resistance, inflammation, and metabolic dysfunction. This review explores the molecular mechanisms underpinning vitamin D's effects on glucose metabolism, inflammation, and adipogenesis, while assessing its potential clinical applications in type 2 diabetes. In its 1,25-dihydroxyvitamin D3 form, vitamin D modulates various metabolic processes, affecting proinflammatory cytokines and activating the AMPK pathway, inhibiting mTOR signaling, and promoting adipocyte differentiation. These effects enhance insulin sensitivity and reduce chronic inflammation, key contributors to metabolic dysfunction. In this context, the progression of prediabetes has been linked to vitamin D, which limits pathological progression and increases the likelihood of restoring a normal metabolic state, crucial in diabetes progression. Moreover, vitamin D has been reported to reduce the likelihood of developing diabetes by 15%, particularly in doses higher than the traditional recommendations for bone health. Despite promising evidence, discrepancies in study designs, serum vitamin D measurements, and population-specific factors highlight the need for standardized methodologies and personalized approaches. In conclusion, vitamin D has complementary therapeutic potential in treating type 2 diabetes, revealing gaps in research, such as optimal dosing and long-term effects across populations. Future studies should integrate molecular insights into clinical practice to optimize vitamin D's impact on metabolic health.

Serum Vitamin D levels in males with premature androgenetic alopecia: a prospective case-control study

INTRODUCTION

Androgenetic alopecia (AGA), the predominant form of hair loss, affects a significant global population. While emerging research suggests a potential correlation between serum vitamin D levels and AGA severity, the current body of evidence remains inconclusive, necessitating further investigation to elucidate this relationship and its clinical implications.

Nutrition for Optimal Lactation

BACKGROUND

Breastfeeding is the ideal method of feeding for all newborns and is associated with multiple positive health outcomes. Human milk provides all essential nutrients and bioactive molecules needed for optimal infant health and development. Maternal nutrition during lactation plays an important role in supporting breastfeeding and in preventing nutrition and metabolic imbalances. The aim of this narrative review was to describe the most prevalent nutrition issues in lactating women and provide a summary of current diet recommendations as well as controversies on supplementation, in order to facilitate the information for clinicians and health professionals.

SUMMARY

Breastfeeding is a nutritionally demanding stage and adequate nutrition is key to avoid alterations in maternal nutritional status, to produce an adequate quantity of milk with good quality, and to avoid nutrition programming of diseases. Anemia and vitamin D, A, iodine, and iron deficiencies are common, while obesity and metabolic diseases keep rising. Inadequate maternal intake of many nutrients is also frequent in this stage.

Immune Modulatory Effects of Vitamin D on Herpesvirus Infections

In addition to its classical role in calcium and phosphate metabolism regulation, vitamin D also has an important impact on immunity modulation. Vitamin D regulates the immune response, shifting from a proinflammatory state to a more tolerogenic one by increasing the release of anti-inflammatory cytokines while downregulating proinflammatory cytokines. Thus, low levels of vitamin D have been associated with an increased risk of developing autoimmune diseases like multiple sclerosis and type 1 diabetes. Furthermore, this prohormone also enhances the release of well-known antimicrobial peptides, like cathelicidin LL-37 and β-defensins; therefore, it has been proposed that vitamin D serum levels might be related to the risk of well-known pathogen infections, including herpesviruses. These are a group of widely spread viral pathogens that can cause severe encephalitis or tumors like Kaposi's sarcoma and Burkitt lymphoma. However, there is no consensus on the minimum levels of vitamin D or the recommended daily dose, making it difficult to establish a possible association between these two factors. This narrative non-systematic review will analyze the mechanisms by which vitamin D regulates the immune system and recent studies about whether there is an association between vitamin D serum levels and herpesvirus infections.

Association of 25-hydroxyvitamin D with Parkinson's disease based on the results from the NHANES 2007 to 2018 and Mendelian randomization analysis

An abundance of observational researches had suggested that vitamin D insufficient was related to Parkinson's disease (PD) risk. However, their relationships were debatable and the causality remains uncertain. We intended to evaluate the association between 25-hydroxyvitamin D [25(OH)D] and Parkinson's disease (PD) risk using NHANES data (2007-2018) and Mendelian randomization (MR) analyses with the genome-wide association study (GWAS) summary data. Demographic characteristics and multivariable-adjusted logistic regression were conducted to assess the relationship between the serum 25(OH)D levels and risk of PD prevalence by utilizing NHANES database. Besides, a two-sample MR analysis was applied to evaluate the causal association between serum 25(OH)D levels and PD risk. The main analysis was conducted by citing the inverse-variance-weighted (IVW) approach, while additional MR approaches and multiple sensitivity analysis were cited to evaluate the robustness and pleiotropy for the discoveries. In total, 30,796 adults from NHANES 2007-2018 were selected for the present research. As a result, 1.1% participants with PD (mean age: 61.9 ± 15.5 years), while 68.5% reported vitamin D insufficient. Compared with participants without PD, those with PD had a greater level of 25(OH)D (P < 0.01). However, after adjusted for demographic characteristics and comorbid factors, this association was not observed. Furthermore, no potential causal relationships between the serum level of 25(OH)D and PD risk were found via MR analysis (IVW-MR: OR = 1.082; 95% CI, 0.902 to 1.297; P = 0.395). After eliminating variants with horizontal pleiotropy risk, pleiotropy-robust MR analysis presented similar results. In conclusion, this research suggested that serum 25(OH)D levels was not correlated with PD risk. Additionally, the MR analyses revealed no significant causal association between serum 25(OH)D levels and PD risk at the genetic level. Awareness of these findings may improve personalized prevention and treatment of PD.

Enhancing the Design of Nutrient Clinical Trials for Disease Prevention-A Focus on Vitamin D: A Systematic Review

OBJECTIVES

This systematic review (SR) highlights principles for nutrient clinical trials and explore the diverse physiological functions of vitamin D beyond its traditional role in the musculoskeletal system related to clinical study designs.

BACKGROUND

Thousands of published research articles have investigated the benefits of vitamin D (a nutrient example taken in this SR) beyond the musculoskeletal system, including the immune, pulmonary, and cardiovascular systems; pregnancy; autoimmune disorders; and cancer. They illustrated vitamin D's molecular mechanisms, interactions, and genomic and nongenomic actions.

METHODS

This SR was designed to identify shortcomings in clinical study designs, statistical methods, and data interpretation that led to inconsistent findings in vitamin D-related publications. SR also highlights examples and insights into avoiding study design errors in future clinical studies, including randomized controlled clinical trials (RCTs). The SR adheres to the latest PRISMA statement, guidelines, and the PICOS process.

RESULTS

Inappropriate or flawed study designs were frequent in clinical trials. Major failures discussed here include too short clinical study duration, inadequate or infrequent doses, insufficient statistical power, failure to measure baseline and achieved levels, and recruiting vitamin D-sufficient participants. These design errors have led to misleading interpretations. Thus, conclusions from such studies should not be generalized or used in guidelines, recommendations, or policymaking.

CONCLUSION

Adequately powered epidemiological studies and RCTs with sufficient vitamin D and duration in individuals with vitamin D deficiency reported favorable clinical outcomes, enriching the literature, enabling to understand its physiology and mechanisms. Proper study designs with rigorous methodologies and cautious interpretation of outcomes are crucial in advancing the nutrient field. The principles discussed apply not only to vitamin D, but also other micro-nutrients and nutraceutical research. Adhering to them enhances the credibility and reliability of clinical trials, SRs, and meta-analysis outcomes. The study emphasizes the importance of focused, hypothesis-driven, well-designed, statistically powered RCTs to explore the diverse benefits of nutrients, conducted in index nutrient deficient participants, and avoidance of study design errors. Findings from such studies should be incorporated into clinical practice, policymaking, and public health guidelines, improving the health of the nation and reducing healthcare costs.

Discovering Vitamin-D-Deficiency-Associated Factors in Korean Adults Using KNHANES Data Based on an Integrated Analysis of Machine Learning and Statistical Techniques

Background/Objectives: Vitamin D deficiency (VDD) is a global health concern associated with metabolic disease and immune dysfunction. Despite known risk factors like limited sun exposure, diet, and lifestyle, few studies have explored these factors comprehensively on a large scale. This cross-sectional study aimed to identify VDD-associated factors in South Korea via an integrative approach of machine learning and statistical analyses using Korea National Health and Nutrition Examination Survey (KNHANES) IX-1 data. Methods: Using the KNHANES dataset, six machine learning algorithms were applied to evaluate VDD (serum 25[OH]D3 < 20 ng/mL)-associated factors through feature importance scores. Thereafter, multivariate linear and logistic regression models were applied to the dataset-stratified by sex and age. Results: Among 583 variables, 17 VDD-associated factors were identified using the CatBoost model, which achieved the highest F1 score. When these factors were assessed through statistical analysis, dietary supplement use emerged as a consistent factor associated with VDD across all subgroups (younger men, younger women, older men, and older women). In younger adults, HDL cholesterol, blood and urinary creatinine, water intake, urban residence, and breakfast frequency were significantly associated with VDD. Additionally, blood urea nitrogen and fasting plasma glucose in men and urinary sodium in women showed sex-specific associations with serum 25(OH)D levels. Conclusions: This study identified key VDD-associated factors in the South Korean population, which varied by age or sex. These findings highlight the multifaceted nature of VDD, influenced by dietary, lifestyle, and biochemical factors and underscore the need for strategies integrating machine learning and statistical analysis.

Can the use of vitamin D-fortified sunscreen cream be the solution to the vitamin D deficiency pandemic?

Current approaches to vitamin D supplementation are generally limited to its oral intake. In this experimental study, the effects of applying vitamin D-fortified sunscreen creams to the skin on the absorption, and therefore levels of serum vitamin D metabolites were investigated. Forty 8-week-old male Wistar Albino rats were used in the study. Eight rats (Group B) were sacrificed to determine the baseline values of biochemical parameters. The remaining 32 rats were randomly divided into 4 equal groups as follows: Group S, only the back skin of the rats were shaved; Group SD, only vitamin D3 diluted with sunflower oil was applied to the shaved area; Group SC, only sunscreen cream was applied to the shaved area; and Group SDC, sunscreen cream fortified with vitamin D3 was applied to the shaved area. Serum 25(OH)D3 and 24,25(OH)2D3 levels were determined at the end of 8 weeks. Mean (± SD) serum 25(OH)D3 levels of groups B, S, SD, SC, and SDC were determined as 17.7 ± 5.7, 13.5 ± 3.1, 54.1 ± 13.0, 19.6 ± 2.7, 67.2 ± 16.5 ng/mL, respectively. There were statistically significant differences in serum 25(OH)D3 values between groups S and SD (p < 0.001) and between groups SC and SDC (p = 0.002). A positive correlation was found between serum 25(OH)D3 and 24,25(OH)2D3 parameters (r = 0.772; p < 0.001). With this study, it was concluded that vitamin D-fortified sunscreen cream increases serum vitamin D levels by exerting transdermal activity. Further studies are required to confirm this observations.

Association Between Vitamin D and COVID-19-Related Outcomes: An Umbrella Review of Meta-Analyses

CONTEXT

COVID-19 remains globally pandemic, and although several meta-analyses have explored the association between vitamin D and COVID-19 relative to clinical outcomes, a unified view has not yet emerged.

OBJECTIVE

To summarize the evidence for associations between vitamin D levels and COVID-19-related clinical outcomes and to assess the strength and validity of these associations.

DATA SOURCES

PubMed, Embase, Web of Science, Scopus, and the Cochrane Database of Systematic Reviews databases were searched from January 1, 2020, to June 15, 2024.

DATA EXTRACTION

Two reviewers independently extracted data and assessed study quality.

DATA ANALYSIS

Low vitamin D levels increased the risk of infection by 1.26- to 2.18-fold, the risk of severe illness by 1.50- to 5.57-fold, the risk of intensive care unit (ICU) admission by more than 2-fold, and the risk of death by 1.22- to 4.15-fold. In addition, patients with vitamin D deficiency had an average increase in length of hospital stay of 0.54 days compared with patients with high vitamin D levels. Overall, vitamin D supplementation may reduce severity (eg, ICU admissions, need for mechanical ventilation) and shorter length of hospital stay but has a nonsignificant effect on infection and mortality rates. In addition, there were significant differences in vitamin D levels between individuals testing positive for COVID-19 and those testing negative (mean difference [MD] = -3.22 ng mL-1; 95% CI, -5.18 to -1.25), those with severe cases and those with mild cases (MD = -4.60 ng mL-1; 95% CI, -5.49 to -3.71), and nonsurvivors and survivors of COVID-19 infection (MD = -6.59 ng mL-1; 95% CI: -8.94 to -4.24).

CONCLUSIONS

Low vitamin D levels are associated with higher infection rates, more severe disease, and higher mortality rates among individuals with COVID-19, whereas vitamin D supplementation may reduce patients' disease severity. The beneficial effects on infection rates and mortality remain to be further explored, however, in higher-quality, randomized controlled studies. Nonetheless, caution is warranted because the methodological quality of most meta-analyses and the level of evidence for most outcomes are very low.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration No. CRD42022385036.

Association of serum vitamin D level and live birth rate in women undergoing frozen embryo transfer-a retrospective cohort study

PURPOSE

To assess the association of serum vitamin D level and the live birth rate in women undergoing frozen embryo transfer (FET).

METHODS

This is a retrospective cohort study involving 1489 infertile women who had frozen embryo transfer at two tertiary reproductive medicine centres from 2019 to 2021. Only the first frozen embryo transfer was included for women who had repeated transfers during the period. Archived serum samples taken at LH surge or before the start of progestogens for FET were analysed for 25(OH)D levels using mass spectrometry. The main outcome measure was the live birth rate. Vitamin D deficiency was defined as serum 25(OH)D < 50 nmol/l (< 20 ng/ml) based on the Endocrine Society Clinical Practice guidelines.

RESULTS

The median age was 36 (25th-75th percentile 34-38) years. 37.7% (561/1489) women had cleavage stage embryo transfer and 62.3% (928/1489) women had blastocyst transfer. When analysing the results based on the threshold in the Endocrine Society guideline of 50 nmol/l (20 ng/ml) for vitamin D deficiency, there were no statistically significant differences in the live birth rate in the vitamin D deficient and non-deficient groups [151/489 (30.9%) vs 341/998 (34.2%), OR 0.861, 95% CI 0.683-1.086 P = 0.205]. There were no statistically significant differences in the pregnancy rates, ongoing pregnancy rates, and miscarriage rates between the two groups.

CONCLUSION

Serum vitamin D is not associated with birth rate in women undergoing FET.

Bridging Gaps in Migraine Management: A Comprehensive Review of Conventional Treatments, Natural Supplements, Complementary Therapies, and Lifestyle Modifications

Background: Migraine, a complex neurological condition, poses significant challenges for both sufferers and healthcare providers. While prescription medications play a vital role in managing migraine attacks, the quest for natural, non-pharmacological alternatives has garnered increasing interest. This review explores the efficacy and safety of natural supplements as treatments for migraine relief, comparing them with conventional prescription medications. Methods: The review delves into herbal supplements, clinical studies on natural remedies, aromatherapy, dietary influences, and lifestyle modifications in the context of migraine management in several databases. Results: The findings shed light on the potential of natural supplements as complementary or alternative approaches to traditional migraine therapies, offering insights into a holistic and personalized treatment paradigm for migraine sufferers. Conclusions: Natural supplements have gained attention as potential treatments for migraine relief, often perceived as safer alternatives to conventional medications.

Causal associations between osteoporosis and HBV infection across Asian and European populations: evidence from Mendelian randomization and colocalization analysis

Introduction

Clinical studies have demonstrated a potential association between chronic hepatitis caused by hepatitis B virus (HBV) infection and osteoporosis. However, the causal relationship between HBV infection and osteoporosis remains to be determined.

Methods

We investigated whether HBV infection is causally associated with osteoporosis using Mendelian randomization (MR) in East Asian and European populations, respectively. The data we utilized were obtained from the genome-wide association studies (GWAS) database. Various MR methods, including inverse variance weighted (IVW), MR Egger, weighted median, simple median and simple mode were employed to estimate the association between HBV infection and osteoporosis. Heterogeneity analysis and sensitivity tests were performed to ensure the robustness of the results. Bayesian co-localization (coloc) analysis was also applied to calculate the posterior probability of causal variants and to identify common genetic variants between HBV infection and osteoporosis.

Results

MR analysis indicated that HBV infection increased the risk of osteoporosis onset in two East Asian cohort (IVW, OR = 1.058, 95% CI = 1.021 to 1.097, P = 0.002 and OR = 1.067, 95% CI = 1.029 to 1.106, P < 0.001). However, a clear effect of genetic susceptibility to HBV on the enhanced risk of osteoporosis was not observed in two European cohort (IVW, OR = 1.000, 95% CI = 0.999 to 1.001, P = 0.171 and OR = 1.003, 95% CI = 0.981 to 1.025, P = 0.780). Additional MR methods and sensitivity analyses further validated the reliability and robustness of our results. Bayesian co-localization analysis revealed co-localization of HBV infection and osteoporosis on STAT4 at rs11889341based on East Asian GWAS data.

Conclusions

Our study identified a causal relationship between HBV infection and osteoporosis in East Asian and European populations. These results provided strong evidence that HBV infection augmented the risk of developing osteoporosis in East Asian populations and provided novel therapeutic targets.

Does Systematic Use of Small Doses of Vitamin D Have Anti-Inflammatory Effects and Effectively Correct Deficiency Among Healthy Adults?

BACKGROUND

Calcitriol, beyond its well-established role in calcium and phosphate homeostasis, contributes to immunological processes. No known vitamin D dosage regimen effectively corrects the deficiency while accounting for immunoregulatory effects. Therefore, the purpose of this assessment was to determine whether regular administration of low doses of vitamin D might correct deficiency and have immunoregulatory effects.

METHODS

A total of 35 healthy volunteers were asked to supplement with vitamin D daily at a dosage of 500 or 1000 IU, depending on the degree of deficiency, for 12 months. At the beginning of the study and after the end of the supplementation period, concentrations of 25(OH)D; PTH; total calcium; inorganic phosphorus; and the inflammatory cytokines IL-17, IL-10, TGF-β, and IFN-γ were determined in all participants.

RESULTS

Correction of vitamin D deficiency was achieved with accompanying decreases in PTH and pro-inflammatory cytokine concentrations, while the concentration of anti-inflammatory cytokines remained stable.

CONCLUSIONS

Therefore, regular vitamin D supplementation, even in small doses, effectively corrected the deficiency and had immunomodulatory effects.

Vitamin D Deficiency and Associated Factors in Children: A Multicenter Study of 21,811 Samples in Southern China

Objective

To investigate the prevalence of vitamin D deficiency (VDD) in children/adolescents in extreme southern China.

Methods

This multicenter, cross-sectional study included 21,811 children aged 0-18 years from 18 districts in Hainan Province, using a multistage stratified random sampling method from January 2021 to March 2022.

Results

Serum 25(OH)D levels decreased with age (p trend <0.001). VDD prevalence increased significantly from 3.7% (95% CI: 3.2, 4.3) in children aged 0-3 years to 43.5% (95% CI: 42.1, 45.0) in those aged 13-18 years. Girls and urban residents showed higher deficiency rates. Adolescents (13-18 years) had the highest prevalence of VDD (43.5%), while toddlers (0-3 years) had the lowest (3.7%). Factors influencing vitamin D status included gender, urban residency, and breastfeeding duration. Seasonal variations showed higher deficiency rates in autumn, particularly among preschoolers. Regional differences were noted, with the highest deficiency in semiarid and subhumid zones for various age groups.

Conclusion

A significant increase in VDD with age, particularly among adolescents, urban girls, and during autumn, emphasizing the need for targeted strategies.

Vitamin D Supplementation Reduces Hyperlipidemia and Improves Bone Mass in Pediatric Obesity

The objective of this study was to provide guidelines to clinicians for the evaluation, treatment, and prevention of vitamin D deficiency with an emphasis on the care of patients who are at risk for obesity and diabetes. Our aim was to determine the relationship between vitamin D3 and metabolic syndrome, and investigate the effect of vitamin D3 supplementation on hyperlipidemia, glucose metabolism, and bone mass in pediatric patients with obesity. We conducted a study between January 2018 and January 2020, with a total of 723 children invited to participate. Of these, 283 were in the vitamin D supplement group (SG) and 440 were in the placebo group (PG). We evaluated blood pressure, fasting glucose, high-density lipoprotein, total cholesterol, low-density lipoprotein, and bone mineral density (BMD) in all subjects. We observed that cholesterol, triglyceride, and glucose levels were strongly associated with 25(OH)D3 levels at baseline. After vitamin D3 supplementation, we observed a significant increase in body mass index (BMI) (P = 0.02) and serum 25(OH)D3 (P < 0.01) levels in the vitamin D3 group compared to the placebo group. Additionally, serum lipids such as total cholesterol (P <0.01), HDL-c (P < 0.01), total cholesterol/HDL-c (P < 0.01), LDL-c/HDL-c (P < 0.01), and triglycerides/HDL-c (P < 0.01) were significantly decreased in the vitamin D group compared to the placebo group. Serum vitamin D3 was inversely associated with cholesterol, triglycerides, and fasting glucose. Our results suggest that vitamin D3 supplementation enhances the beneficial effect of hyperlipidemia, glucose metabolism, and bone mass in pediatric patients with obesity.

Survey on vitamin D supplementation in children in France: Evaluation of real-life practices following the new 2022 French recommendations

BACKGROUND AND OBJECTIVE

In 2022, recommendations for vitamin D supplementation in children were updated in France. The objective of this study was to assess real-life practices of vitamin D supplementation in children following these recommendations.

METHODS

A thirty-three-question questionnaire was distributed to members of the scientific societies of paediatrics and general medicine via an online platform.

RESULTS

There were 966 respondents, of whom 87 % were paediatricians and 13 % were general practitioners. About half of the physicians (47 %) were in private practice, 49 % worked in a hospital centre and 6 % worked in a maternal and child health centre. As recommended and regardless of the professional practice, vitamin D supplementation was almost systematically prescribed in all age groups (over 90 % of respondents), in daily doses up to 2 years of age (97 % of all respondents) and then every 3 months in older children (year-round in 38 % and winter/spring only in 40 %). Contrary to the new recommendations, loading doses of 200,000 units of vitamin D were prescribed by 5 % of respondents and non-pharmaceutical forms of vitamin D (e.g. unlicensed food supplements) were prescribed by 10 % of respondents. Although risk factors such as low sun exposure and dark skin were well known by respondents (75 % and 74 % respectively), obesity and veganism were only reported by half the respondents (40 % and 53 % respectively). Two-thirds (61 %) of respondents reported assessing calcium intakes when following children; however, only 10 % of them use specific questionnaires or calcium equivalence tables. Finally, the calcium content of foods and its bioavailability appeared to be poorly understood by health professionals.

CONCLUSION

This survey shows that the practice of paediatricians and general practitioners are in accordance with the new recommendations for vitamin D supplementation in very young children. The identification by this survey of knowledge gaps will allow targeted information campaigns.

Prevention and Treatment of Vitamin D Deficiency in India: An Expert Group Consensus

Vitamin D deficiency is highly prevalent in India, yet no standardized guidelines exist for classifying vitamin D status or its prevention and treatment. Even more, there is no consensus specific to vitamin D supplementation for the Indian population, and there are inconsistencies in the cut-off values for deficiency, severe deficiency, and insufficiency across various guidelines, which this evidence-based consensus seeks to resolve, thus guiding healthcare professionals in identifying, preventing, and managing vitamin D deficiency. An expert group of 41 endocrinologists from across India developed the consensus using the DELPHI method, achieving over 90% agreement on all recommendations. The consensus defines vitamin D deficiency, severe deficiency, and insufficiency, recommending supplementation strategies to maintain physiological 25(OH) D levels of 40-60 ng/mL (100-150 nmol/L). Tailored treatment regimens for neonates, infants, children, adolescents, adults, the elderly, pregnant and lactating women, and individuals with co-morbid conditions are provided to ensure optimal health for all age groups in India.

Vitamin D Deficiency as a Risk Factor for Diabetic Retinopathy: A Systematic Review and Meta-Analysis

Diabetic retinopathy (DR), a significant microvascular complication of diabetes mellitus (DM), remains a major cause of vision loss worldwide. Vitamin D, recognized for its role in bone health, has also been implicated in various non-skeletal conditions, including DR. This systematic review analyzed data from 20 studies involving 22,408 participants to explore the relationship between vitamin D levels and DR. Studies were included based on strict eligibility criteria, ensuring they could distinctly classify participants into DR and non-DR groups and provide quantitative measurements of vitamin D levels. Of these, nine studies were included in the meta-analysis. The pooled analysis revealed a significant association between lower vitamin D levels and increased odds of DR, with a combined odds ratio (OR) of 1.15 (95% CI: 1.10-1.20) under the fixed-effects model and 1.17 (95% CI: 1.08-1.27) under the random-effects model. Mean serum vitamin D levels were lower in individuals with DR (18.11 ± 5.35 ng/mL) compared to those without DR (19.71 ± 7.44 ng/mL), with a progressive decline observed across DR severity stages. Subgroup analyses showed significantly lower levels of vitamin D in proliferative DR compared to non-proliferative stages. Heterogeneity (I2 = 89%) was noted, most probably due to geographic differences, varying methodologies for vitamin D measurement, and DR classification approaches. Secondary analyses indicated that vitamin D deficiency prevalence ranged from 27% to 95% in DR populations, highlighting its potential role in disease progression. This review highlights the need for longitudinal studies to better understand the causal relationship. The findings also call attention to a critical gap in the literature regarding the therapeutic role of vitamin D supplementation in preventing and managing DR. Addressing vitamin D deficiency as a modifiable risk factor in DM care may offer new avenues for reducing the burden of DR.

The Interplay Between Vitamin D Deficiency, Iron Status, and Anemia Risk in Moroccan Women of Reproductive Age: A Cross-Sectional Analysis

Background: Vitamin D and iron deficiencies are prevalent among Moroccan women of reproductive age (WRA). Research suggests that Vitamin D deficiency (VDD) may impair iron bioavailability, potentially leading to iron deficiency (ID) and anemia. Objectives: This study investigates associations between vitamin D status, iron levels, and anemia risk in WRA, aged 18-49, from Meknes, Morocco. Methods: A cross-sectional study was conducted among 463 participants, measuring serum 25(OH)D, blood count parameters, iron, ferritin, C-reactive protein, and creatinine. Lifestyle factors, including dietary intake, sun exposure, and physical activity, were assessed through validated questionnaires, and anthropometric data were collected. Linear and logistic regression models analyzed associations, while ROC analysis evaluated VDD's predictive accuracy for ID and anemia. Results: VDD (25(OH)D < 20 ng/mL) was significantly associated with reduced hemoglobin, hematocrit, red blood cells, and ferritin (all p < 0.01), indicating vitamin D's role in erythropoiesis and iron storage. Multivariate logistic regression showed that VDD increased the risk of anemia (OR: 7.17, 95% CI: 3.19-19.28, p < 0.001), ID (OR: 2.20, 95% CI: 1.32-3.77, p = 0.007), and IDA (OR: 4.10, 95% CI: 1.73-12.08, p = 0.004). Dietary iron intake was inadequate, showing minimal protective effects against anemia and ID (β(SE): -0.08(0.03), p = 0.030 and β(SE): -0.05(0.02), p = 0.037). Conclusions: VDD is a significant risk factor for impaired iron status and anemia in Moroccan WRA, highlighting the need for targeted nutritional interventions and further research.

A Plant-Based Food Guide Adapted for Low-Fat Diets: The VegPlate Low-Fat (VP_LF)

Strong evidence supports the paramount importance of the composition of the diet for health. Not only diet should provide nutritional adequacy, but some foods and dietary components can also support the management of common chronic diseases, with mechanisms independent of nutritional adequacy. Among the various intervention diets, low-fat vegan diets have been shown to be effective for cardiometabolic health, mainly influencing insulin resistance, adiposity, and blood lipids. This type of diet relies on reducing or eliminating all added fats and choosing low-fat foods, mainly unprocessed whole-plant foods. We hereby propose a tool for planning low-fat vegan diets, the VegPlate Low-Fat (VP_LF), which has been obtained from a specific adaptation of the VegPlate method, which was already presented in previous publications for adults and some life stages and situations. The reduction in fats in the diet, which ranges between 10% and 15% of total energy, and the varied inclusion of foods from plant groups make it easier to provide adequate amounts of all nutrients with a normal- or lower-calorie intake, in comparison with diets that do not limit fat intakes. We expect that this new proposal will help nutrition professionals embrace low-fat diets as a first-line intervention for individuals affected by different health conditions who can benefit from these diets.

Resonance frequency analysis of dental implants in patients with vitamin D deficiency

OBJECTIVES

Vitamin D deficiency may influence dental implant osseointegration unfavourably. The aim of this study was to compare dental implant stabilities of patients with different levels of vitamin D and investigate the effects of vitamin D supplementation.

MATERIALS AND METHODS

One hundred and twenty-nine patients who underwent dental implantation were grouped regarding vitamin D levels and supplement use: Group A; vitamin D deficiency and supplement usage, Group B; insufficiency with supplement usage, Group C; insufficiency without supplements and Group D; vitamin D sufficiency. Resonance frequency analysis (RFA) measurements were performed at baseline and 3 months. Patients with vitamin D deficiency (Group A) and insufficiency (Group B) were prescribed supplements by specialists. Pearson correlation analysis was used to examine an association between vitamin D levels and implant stability.

RESULTS

Primary stability of Group D (76.34 ± 6.55) was significantly higher than Groups A, B and C at baseline (p < 0.05). At 3 months, Group C scored significantly lower than the other groups (p < 0.05). The results revealed a correlation between serum levels of vitamin D and RFA measurements at 3 months (p < 0.05).

CONCLUSION

It was observed that high vitamin D levels influenced implant stabilities positively, as evidenced by higher Implant Stability Quotient values. Low levels of vitamin D may be associated with a decrease in implant stability.

STATEMENT OF CLINICAL RELEVANCE

Vitamin D, concerning its impact on bone metabolism, is currently of particular interest in implant dentistry. The lower stability scores in patients with vitamin D deficiency reinforce the recommendation of Vitamin D supplementation when treating those patients with dental implants.