Vitamin D deficiency

Follicular fluid concentrations of the vitamin D metabolite 24,25(OH)2D3 are positively associated with live birth rate after assisted reproductive technology

OBJECTIVE

To investigate the relationship between concentrations of vitamin D metabolites in follicular fluid and outcome of assisted reproductive technology (ART) treatment.

DESIGN

Prospective cohort study including 116 women undergoing in vitro fertilization (IVF) or intra cytoplasmic sperm injection (ICSI) treatment.

RESULTS

All measured vitamin D metabolites 25OHD3, 1,25(OH)2D3 and 24,25(OH)2D3 are detectable in follicular fluid. Follicular fluid concentration of the 24,25(OH)2D3 metabolite was higher than corresponding serum values, while the opposite phenomenon was observed for the 1,25(OH)2D3 metabolite. Local conversion is plausible as the vitamin D activating enzymes (CYP2R1 and CYP27B1) as well as the vitamin D receptor (VDR) are highly expressed in the developing follicle. Women who achieved a live birth had 29 % higher 24,25(OH)2D3 and 15 % higher 25OHD3 concentrations in their follicular fluid (18 ± 7.9 versus 14 ± 6.2 nmol/L, p = 0.008 and 71 ± 22 versus 62 ± 18 nmol/L, p = 0.025, respectively) compared to women not achieving a live birth. Moreover, women with a low (≤ 15 %) follicular fluid 1,25(OH)2D3/24,25(OH)2D3 ratio had a higher live birth rate compared to women with a medium (16-84 %) or high (≥ 85 %) ratio (live birth rate: 53 % vs 29 % and 12 %, respectively, p = 0.032).

CONCLUSION

This study reveals that high levels of 24,25(OH)2D3 and low levels of the 1,25(OH)2D3/24,25(OH)2D3 ratio in follicular fluid are associated with increased live birth rates in women undergoing IVF/ICSI treatment. Conversion of vitamin D metabolites systemically or in the ovarian follicle may affect ART outcome. Further studies are warranted to support the findings from this pilot study and identify regulators of ovarian vitamin D metabolites.

Systematic review of optimizing brain-targeted vitamin D delivery: Novel approaches to enhance mental illness therapeutics

BACKGROUND

Vitamin D is increasingly recognized for its neuroprotective, anti-inflammatory, and immunomodulatory roles in mental health. However, its delivery to the central nervous system remains constrained by various factors.

OBJECTIVE

This systematic review evaluates strategies for optimizing brain-targeted vitamin D delivery, highlighting molecular, physiological, and technological approaches to enhance its efficacy in mental disorders.

METHODS

Following PRISMA guidelines, a comprehensive search across PubMed, Web of Science, Scopus, Embase, and PsycINFO was conducted. Relevant studies were assessed thematically, focusing on BBB transport mechanisms, nanocarriers, structural modifications, and transporter-mediated delivery.

RESULTS

Strategies including nanotechnology, biotin-based transporter targeting (e.g., SMVT/SLC5A6), DBP-Megalin/Cubilin-mediated transcytosis, and intranasal administration show promise in enhancing vitamin D brain uptake. Differences between serum and brain vitamin D concentrations, genomic and non-genomic VDR pathways, and psychiatric disorder-specific associations (e.g., depression, schizophrenia, ASD) were also examined.

CONCLUSIONS

Although limited by the scarcity of large-scale clinical data, emerging strategies demonstrate significant potential in enhancing brain-targeted vitamin D delivery. These findings lay a foundation for future translational research aimed at precision mental health interventions.

Selenium nano particles versus nano vitamin D3 in modulating anastrozole-induced osteoporosis on the mandibular alveolar bone of albino rats

AIM

Compare the efficiency of selenium nanoparticles (SeNPs) and Nano vitamin D3 in modulating alveolar bone osteoporosis induced by anastrozole in albino rats.

MATERIALS AND METHODS

28 female albino rats were randomly divided into 4 groups (7/group); Control group (GP I): rats were received distilled water orally. Anastrozole group (GP II): rats were orally given anastrozole (1 mg/kg/day) dissolved in distilled water. SeNP treated Anastrozole group (GP III): rats were orally given anastrozole with SeNP (0.5 mg/kg/day). Nano vitamin D3 treated Anastrozole group (GP IV): rats were orally given anastrozole with Nano vitamin D3 (40 IU/kg/day). After 4 weeks of drugs administration, mandibles were prepared and stained with hematoxylin & eosin, Masson trichrome and anti-osteocalcin antibody. New collagen area% in Masson trichrome and positive anti-osteocalcin osteoblasts count were measured and statistically analyzed.

RESULTS

Deleterious changes in the alveolar bone were detected in Gp II, while being markedly improved in treated groups. Moreover, GP II demonstrated large areas of old collagen, with positive anti-osteocalcin immunoreactivity in some osteoblasts and few osteocytes, meanwhile, control and treated groups showed more predominant newly formed collagen with positive immunoreactivity in nearly all osteoblasts, osteocytes, and some areas of bone matrix. Statistically, Gp III and Gp IV showed the significantly highest newly formed collagen mean area% and positive osteoblasts count, then Gp I, while Gp II represented the least recorded data.

CONCLUSIONS

SeNPs and Nano Vitamin D3 improve the structural and cellular quality of mandibular alveolar bone in anastrozole-induced osteoporosis of albino rats.

Transporters in vitamin uptake and cellular metabolism: impacts on health and disease

Vitamins are vital nutrients essential for metabolism, functioning as coenzymes, antioxidants, and regulators of gene expression. Their absorption and metabolism rely on specialized transport proteins that ensure bioavailability and cellular utilization. Water-soluble vitamins, including B-complex and vitamin C, are transported by solute carrier (SLC) family proteins and ATP-binding cassette (ABC) transporters for efficient uptake and cellular distribution. Fat-soluble vitamins (A, D, E, and K) rely on lipid-mediated pathways through proteins like scavenger receptor class B type I (SR-BI), CD36, and Niemann-Pick C1-like 1 (NPC1L1), integrating their absorption with lipid metabolism. Defective vitamin transporters are associated with diverse metabolic disorders, including neurological, hematological, and mitochondrial diseases. Advances in structural and functional studies of vitamin transporters highlight their tissue-specific roles and regulatory mechanisms, shedding light on their impact on health and disease. This review emphasizes the significance of vitamin transporters and their potential as therapeutic targets for deficiencies and related chronic conditions.

Bone Health in Women

Osteoporosis is a significant chronic condition worldwide, causing morbidity and mortality that may be prevented with mitigation of risk factors, screening, and treatment of low bone density to prevent fractures. Adequate intake of calcium and vitamin D as well as regular weight-bearing exercise are integral for optimal bone health. Decreased bone density on dual-energy x-ray absorptiometry screening or evidence of fragility fractures are qualifiers for treatment. Treatment options beyond the first-line treatment of oral bisphosphonates exist for those who do not tolerate these medications or for those who require intensified regimens due to very high risk of fracture.

Nonlinear Association Between Serum 25-Hydroxyvitamin D and Cardiac Autonomic Dysfunction in Diabetic Foot: A Threshold Effect on Heart Rate Variability

BACKGROUND

Previous studies have shown that vitamin D deficiency was associated with both cardiac autonomic dysfunction and the development of diabetic foot (DF). However, the impact of vitamin D levels on heart rate variability (HRV) in individuals with DF, a high-risk group, remains unclear. We explored the association between vitamin D status and HRV in individuals with DF.

METHODS

A total of 458 individuals with DF were assessed for vitamin D levels by 25-hydroxyvitamin D (25(OH)D) and evaluated for cardiovascular autonomic function using both time and frequency domains of the HRV measures. Multivariate regression analysis and restricted cubic spline regression were employed to examine the associations.

RESULTS

Vitamin D levels were positively associated with HRV indices in people with DF, including standard deviation of the normal sinus interval (SDNN), standard deviation of the 5-min average RR intervals (SDANN), low-frequency power (LF), high-frequency power (HF), and the LF/HF ratio (all p < 0.05). The associations between serum 25(OH)D and cardiac autonomic dysfunction were nonlinear. When 25(OH)D levels were < 50 nmol/L, the odds ratio (OR) for predicted cardiac autonomic dysfunction per SD increase in 25(OH)D was 0.56 (95% CI, 0.44-0.72). However, no significant effect was observed when 25(OH)D levels exceeded 50 nmol/L.

CONCLUSIONS

This study demonstrates that lower 25(OH)D levels are associated with reduced HRV in individuals with DF. Specifically, when 25(OH)D levels fall below 50 nmol/L, the risk of cardiac autonomic dysfunction in people with DF significantly increases.

Association between vitamin D receptor polymorphisms and diabetic retinopathy in Uygur Chinese with type 2 diabetes

PURPOSE

This study was to investigate the potential association between vitamin D receptor(VDR) gene polymorphisms and the risk of diabetic retinopathy(DR) in the Uygur population in China, focusing on four specific VDR gene single nucleotide polymorphisms(SNPs) as candidate SNPs.

METHODS

The study genotyped a total of 151 DR patients and 130 healthy controls from the Uygur population using the single-base terminal extension (SNaPshot) method for four VDR gene SNPs: rs1544410, rs7975232, rs2228570, and rs731236. Hardy-Weinberg equilibrium was assessed using the χ2 test. Genotype frequencies were determined by directly counting the genotypes and correlating them with population data. The χ2 test was utilized to compare allele and genotype frequencies between patients and controls.

RESULTS

Compared to the healthy control group, the study observed a significantly higher frequency of the "TT" genotype at rs1544410 in the DR group. Additionally, within the non-proliferative diabetic retinopathy (NPDR) group, a significantly higher frequency of the "AA" genotype at rs7975232 was noted. No significant differences were found in the comparison of all haplotypes between patients and controls.

CONCLUSIONS

The study concluded that the rs1544410 polymorphism is associated with DR, and the rs7975232 polymorphism is associated with susceptibility to NPDR in the Uygur population in China.

OSBPL11 is an African-specific locus associated with 25-hydroxyvitamin D concentrations and cardiometabolic health

Vitamin D deficiency is prevalent in Africa, but its genetic determinants are understudied. We report a genome-wide analysis of 25-hydroxyvitamin D (25(OH)D) concentrations in 3670 children from five countries across Africa with replication in four diaspora African ancestry populations (n=21,610). We identify a previously unreported locus at genome-wide significance in West African populations: OSBPL11 (Oxysterol Binding Protein Like 11, lead variant, rs2979356, p=8.01 × 10 -9 ). In vitro and molecular docking assays showed that OSBPL11 is a vitamin D binding protein likely involved in the intracellular binding of vitamin D metabolites. OSBPL11 knockdown mice have increased fat, reduced triglycerides and improved glucose tolerance, and rs2979356 was associated with cardiometabolic health in adults of African ancestry. We also identify previously reported loci determining vitamin D status. Our study advances understanding of vitamin D genetics in Africa and indicates a novel function for OSBPL11 in intracellular binding and transport of vitamin D metabolites.

Association between Vitamin D and mortality risk in gout patients

BACKGROUND

The correlation between gout patients' 25-hydroxyvitamin D [25(OH)D] levels and their risk of all-cause mortality (ACM) and cardiovascular mortality (CVM) remains inconclusive.

METHODS

Data from 7337 gout patients enrolled in the UK Biobank were analyzed, with death data acquired via connection to national death registries. At baseline, serum 25(OH)D levels were measured. We utilized Cox proportional hazards regression to evaluate the correlations between serum 25(OH)D levels and mortality, and mendelian randomization (MR) analyses to explore causality.

RESULTS

During 80 176 person-years of following up (median 11.4 years), 659 all-cause deaths were recorded, including 206 cardiovascular disease-related deaths. We found an L-shaped non-linear inverse connection (P non-linearity<0.05) between serum 25(OH)D levels and ACM and CVM with a cutoff value of 45 nmol/L. In contrast to gout patients with <45 nmol/L, those with 25(OH)D levels ≥45 nmol/L had a significantly decreased likelihood of ACM [Hazard Ratio (HR) 0.72; 95% confidence interval 0.61-0.86]. Nonlinear MR also confirmed the causal connection between sufficient 25(OH)D level threshold (≥50 nmol/L) and a reduced likelihood of ACM. Additionally, raising 25(OH)D over the deficiency thresholds (25 nmol/L) could also potentially mitigate CVM (P trend = 0.02).

CONCLUSIONS

Elevated serum 25(OH)D levels are associated with a reduced likelihood of death in gout patients.

Impact of vitamin D on glycemic control and microvascular complications in type 2 diabetes: A cross-sectional study

Vitamin D has been increasingly recognized for its potential role in modulating various health conditions, including diabetes and its complications. Despite growing evidence suggesting that adequate vitamin D levels may reduce the risk of developing type 2 diabetes and its associated microvascular complications, the precise nature of this relationship remains unclear. This study aims to elucidate the connection among vitamin D status, glycemic control, and microvascular complications in patients with type 2 diabetes, thereby highlighting the importance of vitamin D in diabetes management.This analytical cross-sectional study included 199 type 2 diabetic mellitus (T2DM) patients from the Jahrom city endocrinology clinic. Serum 25(OH)D levels were measured, and their microvascular complications (microalbuminuria, retinopathy, neuropathy, macroalbuminuria) and glycemic control (HbA1C) were measured and confirmed according to ADA guidelines and endocrinologist supervision. All analysis were done with SPSS software. The study enrolled 199 type 2 diabetic patients with a mean age of 56.79 ± 10.8 years, of which 63.3% were female and 57.3% had hypertension. The mean BMI was 28.91 kg/m², and 29.1% of participants had vitamin D deficiency. The prevalence of microvascular complications was 25.6% for retinopathy, 14.1% for neuropathy, and 40% for nephropathy. Vitamin D deficiency was notably higher among patients with retinopathy (37.25%), neuropathy (50%), and macroalbuminuria (56.25%). Patients with neuropathy and retinopathy had significantly lesser serum 25(OH)D concentrations compared to patients without these complications. There was a slight inverse correlation between vitamin D levels and both the urine albumin creatinine ratio (r = -0.175, p = 0.018) and HbA1C (r = -0.19, p = 0.007). Although the link between vitamin D levels and retinopathy was not statistically significant (η = 0.903, p = 0.68), the alteration in vitamin D levels was suggestively linked with neuropathy (η = 0.975, p < 0.001).Vitamin D deficiency is prevalent among type 2 diabetic patients and is related to a higher occurrence of microvascular complications and poorer glycemic control. These findings underscore the potential importance of managing vitamin D levels in reducing complications and improving diabetes outcomes. Future studies should investigate whether oral vitamin D supplements consumption can improve glycemic control and reduce microvascular complications in these patients.

Shared Genetic Architecture and Causal Relationship Between Serum 25-Hydroxyvitamin D and Bone Mineral Density

CONTEXT

Despite the well-established regulatory role of vitamin D in maintaining bone health, little is known about the shared genetics and causality of the association between serum 25-hydroxyvitamin D (25OHD) and bone mineral density (BMD).

OBJECTIVE

We aimed to investigate the shared genetic architecture and causal relationship between serum 25OHD and BMD, providing insights into their underlying biological mechanisms.

METHODS

Leveraging individual-level data from the UK Biobank (UKB) cohort and summary-level data from the genome-wide association studies (GWASs) conducted on European individuals for serum 25OHD (N = 417 580) and estimated heel BMD (eBMD, N = 426 824), we systematically elucidated the shared genetic architecture underlying serum 25OHD and eBMD through a comprehensive genome-wide cross-trait design.

RESULTS

Despite a lack of global genetic correlation (rg=-0.001; P = .95), a statistically significant local signal was discovered at 5p11-5q11.9. Two-sample mendelian randomization (MR) indicated no causal association in the overall population (β=.003, 95% CI, -0.04 to 0.03; P = .93), while positive causal effects were observed in males (β=.005, 95% CI, 0.00 to 0.01; P = .03) and older individuals (β=.009, 95% CI, 0.00∼0.02; P = .01) according to one-sample MR. A total of 49 pleiotropic single-nucleotide variations (SNVs), with 4 novel SNVs (rs1077151, rs79873740, rs12150353, and rs4760401), were identified, and a total of 95 gene-tissue pairs exhibited overlap, predominantly enriched in the nervous, digestive, exocrine/endocrine, and cardiovascular systems. Protein-protein interaction analysis identified RPS9 and RPL7A as hub genes.

CONCLUSION

This study illuminates the potential health benefits of enhancing serum 25OHD levels to mitigate the risk of osteoporosis among men and individuals older than 65 years. It also unveils a shared genetic basis between serum 25OHD and eBMD, offering valuable insights into the intricate biological pathways.

Serum vitamin D levels and long-term risk of elderly-onset inflammatory bowel disease: A large-scale prospective cohort study

BACKGROUND

Vitamin D is considered as a potential immunomodulator in inflammatory bowel disease development; however, emerging evidence remains inconsistent. We aimed to investigate prospective association between serum vitamin D level and long-term risk of elderly-onset inflammatory bowel disease in a large-scale cohort.

METHODS

Participants without inflammatory bowel disease at enrollment from the UK Biobank were included. Baseline blood samples were collected and serum 25-hydroxyvitamin D (25(OH)D) levels were measured. Participants were classified as vitamin D deficiency (<50 nmol/L), insufficiency (50-75 nmol/L) or sufficiency (≥75 nmol/L) based on predefined cutoffs. Primary outcome was incident elderly-onset inflammatory bowel disease, including ulcerative colitis and Crohn's disease. Hazard ratio (HR) and 95% confidence intervals (CIs) of related associations were determined using multivariable Cox regression.

RESULTS

Among 357,656 participants (mean age, 57.9±6.9 years), 196,499 (54.9%) and 121,035 (33.8%) had vitamin D deficiency and insufficiency, respectively. During median 13.3 years' follow-up, 1,622 elderly-onset inflammatory bowel disease cases were identified. Compared with vitamin D sufficiency, no associations with vitamin D deficiency (HR=0.91, 95%CI: 0.78-1.07) or insufficiency (HR=0.86, 95%CI: 0.73-1.01) were observed for elderly-onset inflammatory bowel disease. Similarly, no associations with per 10 nmol/L increase of serum 25(OH)D were detected for elderly-onset inflammatory bowel disease (HR=1.00, 95%CI: 0.98-1.03), ulcerative colitis (HR=1.00, 95%CI: 0.97-1.03) or Crohn's disease (HR=1.01, 95%CI: 0.97-1.05). Compared with the lowest quartile, no associations with higher quartiles of serum 25(OH)D were observed for inflammatory bowel disease (HRQ4VSQ1=1.03, 95%CI: 0.89-1.19), ulcerative colitis (HRQ4VSQ1=1.06, 95%CI: 0.90-1.26) or Crohn's disease (HRQ4VSQ1=0.93, 95%CI: 0.73-1.20). Further sensitivity and subgroup analyses demonstrated similar results.

CONCLUSION

Serum vitamin D level or deficiency status is not associated the development of elderly-onset inflammatory bowel disease, ulcerative colitis or Crohn's disease.

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

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

The Impact of LDL Cholesterol, HDL Cholesterol, Triglycerides, and Vitamin D on Short-Term Implant Survival Rate: A Prospective Observational Study

Background/Objectives: Dental implant success is influenced by a range of systemic and local factors. Emerging evidence suggests that metabolic markers such as lipid profiles and vitamin D levels may play a role in osseointegration and implant survival. The aim of this study was to evaluate the influence of low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, triglycerides, and vitamin D levels on the short-term survival rate of dental implants. Materials and Methods: A prospective observational study was conducted on patients receiving dental implants. Preoperative serum levels of LDL, HDL, triglycerides, and vitamin D were recorded. A total of 556 conical, platform-switching implants were placed in 166 patients, smokers and no smokers with mean age 48 years ± 4.7. Implant survival was evaluated from 14 to 21 days after placement, at 6- and at a 12-month follow-up. Spearman's rank correlation was performed to assess potential correlations between the abovementioned systemic factors and implant loss. Results: Out of 556 implants, 13 (2.34%) were lost from 14 to 21 days after placement, a further two (0.35%) were lost after 6 months after surgery and a further eight (1.44%) were lost 12 months after placement. No significant correlation was found between HDL levels, cholesterol levels, triglyceride levels and implant loss. Spearman's correlation analysis revealed a strong negative correlation between vitamin D levels and implant loss with no statistical significance. Conclusions: Within the limitations of this study, no statistically significant associations were found between lipid profile markers or vitamin D levels and early dental implant loss. Further large-scale and long-term studies are warranted to validate these findings and better understand the interplay between systemic biochemical markers and implant survival rate.

Recent Surge in Severe 25-hydroxyvitamin D Deficiency Among African American Children and Pregnant Women: Implications for Rickets

BACKGROUND

Nutritional rickets is disproportionately prevalent among African American children and is closely linked to vitamin D (VD) deficiency. This study aims to analyze the prevalence and trends of vitamin D deficiency in American children, as well as pregnant and lactating women, from 2001 to 2023, with a focus on African American children.

METHODS

We analyzed serum 25(OH)D levels from 2001 to 2023, as well as dietary and supplemental vitamin D intake from 2007 to 2020, among children aged 1-17 years and pregnant and lactating women. Data were from the US National Health and Nutrition Examination Survey.

RESULTS

In the 2021-2023 sample, African American children had the highest rate of severe 25(OH)D deficiency (< 25 nmol/L) at 13.8% among all racial groups. This represents a significant increase from 5% in 2001-2002. Additionally, 2% of African American toddlers aged 12-23 months had severely deficient 25(OH)D levels between 2003 and 2023. An increase in severe 25(OH)D deficiency was also observed in pregnant and lactating African American women during the 2021-2023 period. Furthermore, 83.3% of African American children and 61.4% of pregnant and lactating African American women had daily vitamin D intakes below 10 mcg (400 IU), the highest inadequacy rates among all racial groups from 2007 to 2020.

CONCLUSION

The recent rise in severe vitamin D deficiency among African American children, pregnant, and lactating women increases the risk of nutritional rickets and calls for prompt public health attention.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Updates in clinical trial-explored chemopreventive agents for cutaneous melanoma: mechanisms affecting melanocytes

Cutaneous melanoma is a highly aggressive skin cancer with rising incidence, driven by risk factors such as ultraviolet exposure, genetic predisposition, and immunosuppression. While surgical excision remains the primary treatment, interest in chemoprevention strategies is growing. Numerous natural and synthetic agents have shown preclinical promise, but evaluating their effectiveness is challenging due to their systemic effects on multiple cell types. This review provides a focused examination of the melanocyte-specific mechanisms of select agents that have been tested in clinical trials for melanoma chemoprevention. We discuss various molecular and cellular mechanisms driving the anti-melanoma properties of nonsteroidal anti-inflammatory drugs, statins, sulforaphane, vitamin D, and N-acetylcysteine. Despite promising preclinical and early clinical data, challenges remain regarding precise mechanisms, optimal dosing, long-term safety, and patient selection. Future research should focus on refining melanoma prevention strategies through well-designed clinical trials and personalized approaches integrating genetic and molecular risk factors.

The Importance of Vitamin D and Magnesium in Athletes

Vitamin D and magnesium are essential nutrients that play key roles in an athlete's performance, recovery, and overall health. Vitamin D is crucial for bone health (aiding calcium absorption and preventing stress fractures), muscle function (preventing weakness and injury), and reducing respiratory infections. Magnesium is fundamental in muscle function, adenosine triphosphate production for muscle contraction, electrolyte balance, bone strength, and cardiovascular health. The magnesium requirement of healthy adults is estimated at 300-400 mg/day, but there is evidence that athletes may have higher magnesium needs compared to sedentary persons. Magnesium and vitamin D are closely linked-vitamin D aids magnesium absorption, while magnesium is vital for vitamin D synthesis, transport, and activation. Given their importance in athletes, this article explores their functions, interactions, and the effects of deficiencies and supplementation in athletic populations.

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.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

LEVEL OF EVIDENCE

Level III.

Impact of Vitamin D3 Supplementation on Symptom Severity & IgE in Persistent Allergic Rhinitis

The potential for vitamin D₃ supplementation as adjunctive therapy in allergic rhinitis (AR) management remains a topic of considerable interest. Studies have investigated the relationship between serum vitamin D levels and AR severity, with conflicting results. To evaluate the impact of vitamin D₃ supplementation on symptom severity and IgE levels in patients with persistent allergic rhinitis (AR), and to assess the role of sustained supplementation in achieving long-term benefits. A randomized, double-blind, prospective interventional study was conducted at a teaching institute in India with 600 AR patients randomized into three groups: Group A (intranasal corticosteroids and placebo), Group B (intranasal corticosteroids and vitamin D₃ supplementation with maintenance doses), and Group C (intranasal corticosteroids and vitamin D₃ without maintenance doses). A control group of 200 healthy individuals was also included. Vitamin D₃, IgE levels, and Total Nasal Symptom Score (TNSS) were measured at baseline, 2 months, and 6 months. At baseline, 81.66% of AR patients had suboptimal vitamin D₃ levels compared to 65% in the control group. Group B showed the most significant improvement in vitamin D₃ levels, with 80% achieving normal levels by 6 months. TNSS and IgE levels also improved significantly in Group B, with sustained reductions compared to Groups A and C (p < 0.001). Group C showed a rebound in symptoms and IgE levels after discontinuation of supplementation. Sustained vitamin D₃ supplementation significantly improves symptom severity and IgE levels in patients with persistent AR. These findings suggest vitamin D₃ as a promising adjunct to standard AR treatment.

The Potential of an Artificially Ultraviolet B Irradiated Hay as a Source of Vitamin D

Roughage can be a significant source of vitamin D in herbivore diets. The vitamin D content of forages can vary considerably and depends, among others, on plant species, plant maturity and climate fluctuations. Ultraviolet B (UVB) exposure causes conversion of provitamin D to vitamin D and thus represents the most important influence. To characterise this effect, two batches of a young-cut roughage of high hygienic and nutritional quality were exposed to constant artificial UVB-irradiation up to 192 h and were sampled at regular intervals. In previous studies, both ergocalciferol (vitamin D2), cholecalciferol (vitamin D3) and/or their metabolites have been detected in plants. Therefore, the present roughage was analysed for both D2 and D3. Whereas cholecalciferol never exceeded the detection limit of 0.25 µg/100 g, ergocalciferol increased from 2.22 µg to 19.15 µg/100 g dry matter in a time-dependent manner. Additionally, the values indicate an interplay with other factors not investigated in this study, for example, leaf-stem-ratio in the different samples. The high amounts of ergocalciferol in the experimental roughage after UVB-exposure confirm the value of hay as a vitamin D source for managed herbivores. The quick rise with time cautions against neglecting UVB-irradiation's effect on feed, both in practical as well as in experimental settings.

Potential causal association between serum vitamin D levels and intervertebral disc degeneration: A mendelian randomization study

OBJECTIVES

Intervertebral disc degeneration (IDD) is a prevalent musculoskeletal disorder with substantial implications for disability and healthcare expenditures. The role of serum vitamin D (25-Hydroxyvitamin D, 25(OH)D) levels in the pathogenesis of various musculoskeletal conditions has been explored in prior observational studies, suggesting a potential association. While previous observational studies have suggested an association between the two conditions, it might confound the effect of 25(OH)D on IDD. This Mendelian randomization (MR) study seeks to elucidate the causal relationship between 25(OH)D and IDD.

METHODS

We performed a MR analysis using summary-level data from genome-wide association studies (GWAS) of 25(OH)D (sample size = 441,291 European) and IDD (sample size = 336,439 (cases = 41,669, controls = 294,770) European). Single nucleotide polymorphisms (SNPs) significantly associated with 25(OH)D (p < 5 × 10-8) were selected as instrumental variables. The associations between genetically predicted 25(OH)D and IDD were estimated using the inverse-variance weighted (IVW) method, with sensitivity analyses employing the weighted median, MR-Egger, and MR-PRESSO approaches to assess the robustness of the findings.

RESULTS

In the primary IVW analysis, genetically predicted 25(OH)D was unrelated associated with IDD (odds ratio (OR) = 0.9671, 95% confidence interval (CI): 0.8956-1.0444, p = 0.39). The results remained consistent across the sensitivity analyses, and no significant directional pleiotropy was detected (MR-Egger intercept: p = 0.64).

CONCLUSIONS

This study found no obvious evidence that 25(OH)D is causally associated with IDD risks. We call for larger sample size studies to further unravel the potential causal relationship and the exact mechanism.

Long-term laboratory follow-up is essential in pediatric patients with celiac

OBJECTIVES

Celiac disease (CeD) requires long-term follow. The role of laboratory testing other than celiac serology during follow up is unclear. We aimed to determine which laboratory tests are required during follow up based on the prevalence of abnormal tests and timing of abnormalities appearance.

METHODS

Retrospective chart-review of children diagnosed with CeD between 1999 and 2018 was conducted. Demographic, clinical and laboratory data were recorded from diagnosis and during follow-up.

RESULTS

The cohort included 500 children with CeD [59.8% females, median(IQR) age at diagnosis 5.7(3.7-8.9) years]. Mean follow-up time was 5.5 years (range 1.5-16.2). The most frequently abnormal laboratory tests at time of diagnosis were low ferritin (64.3%), vitamin D (33.6%), zinc (29.9%), hemoglobin (29.2%), and folate (14.7%). In 74 (14.8%) patients, anemia developed only during follow up, while in another 46 patients, anemia resolved after diagnosis and reappeared later (after a mean ± SD 2.8 ± 2.1 years from CeD diagnosis, for the entire group). Abnormal values that developed during follow up were low folate in 40 patients (3.9 ± 2.6 years), and abnormal liver enzymes in 18 patients (3.1 ± 2.7 years). Elevated TSH during follow-up was observed in 14/280 (5%) patients, after a mean ± SD of 2.2 ± 1.6 years from diagnosis. Patients diagnosed as teenagers (12-18 years) had shorter intervals to reappearance of anemia and folate deficiency.

CONCLUSIONS

Multiple laboratory abnormalities may occur in pediatric patients with CeD, both at diagnosis and during long-term follow-up. We suggest continued monitoring of hemoglobin, ferritin, folate, liver, and thyroid function in addition to celiac serology during follow-up of CeD.

Association of greenness exposure with serum vitamin D status and effects of ambient particulate matter among pregnant women in early pregnancy

Adequate vitamin D is essential for the health of both the mother and fetus, and it can be influenced by environmental factors. However, research on the associations between greenness exposure and vitamin D concentrations during pregnancy is limited. This retrospective birth cohort study, conducted from 2014 to 2018, assessed the greenness of residences using the satellite-derived normalised difference vegetation index (NDVI). Serum 25-hydroxyvitamin D [25(OH)D] concentrations were categorised as non-deficient (≥50 nmol/L) or deficient (<50 nmol/L). Multiple log-binomial regression models were used to estimate the association of NDVI with serum 25(OH)D concentrations and vitamin D deficiency (VDD). Subgroup and mediation analyses were conducted to estimate the association of ambient particulate matter (PM) on the association between NDVI and VDD. A total of 64,663 pregnant women with a mean maternal age of 30.6 (standard deviation: 3.86) years were included. 250-m NDVI was negatively associated with the risk of VDD (per 0.1-unit increase, relative risk [RR]: 0.98, 95 % CI: 0.97-0.99). With the highest quartile of NDVI exposure as the reference group, the upper-middle quartile (RR: 1.02, 95 % CI: 1.00-1.03), and lowest quartile (RR: 1.03, 95 % CI: 1.01-1.06) had an increased risk of VDD. At higher PM2.5 exposure concentrations, 250-m NDVI exposure was negatively associated with the risk of VDD (RR: 0.98, 95 %CI: 0.97-0.99, per 0.1-unit increase), but not at lower PM2.5 exposure concentrations. Among pregnant women with higher PM2.5, the mediation of PM2.5 exposure on the association between 250-m NDVI and VDD was 44.70 % (P = 0.0116). Among pregnant women with higher PM10 exposure, the mediation of PM10 exposure on the association between 250-m NDVI and VDD was 17.98 % (P = 0.002). These findings suggest that higher residential greenery significantly reduces the risk of VDD in pregnant women, particularly in those exposed to increased PM concentrations.

Unraveling the Relationship Between Vitamin D and Noncommunicable Diseases: A Systemic Review and Meta-Analysis

BACKGROUND

Subclinical vitamin D insufficiency is frequent in both developing and developed countries. Even after rickets was eliminated in the 1930s by fortifying milk, up to 1 billion people worldwide suffer from subclinical vitamin D deficiency (VDD). Numerous noncommunicable diseases (NCDs), including depression, autoimmune illnesses, diabetes, osteoporosis, and cardiovascular disease, are linked to this deficiency.

METHODOLOGY

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol was applied when conducting a systematic review. Relevant studies published between 2010 and 2023 were found by searching databases such as Web of Science, Scopus, and PubMed. To find correlations between deficiency of vitamin D and NCDs, data was extracted from the studies and analyzed using the Mixed Method Appraisal Tools (MMAT). In meta-analysis data combined from multiple observational Unraveling the Relationship Between Vitamin D and Noncommunicable Diseases-A Systemic Review and Meta-Analysis studies to evaluate the relationship between vitamin D insufficiency and health outcomes. Statistical techniques, such as calculating effect sizes and constructing confidence ranges, are employed to determine combined outcomes and investigate possible causal connections.

RESULTS

Fourteen studies-including cross-sectional studies, prospective cohorts, randomized controlled trials, and longitudinal studies-met the inclusion criteria. Significant correlations among deficiency of vitamin D and a number of NCDs, including anemia, diabetes, hypertension, rheumatoid arthritis (RA), mental health issues, and autoimmune hypothyroidism, were found in the review. The results highlight the prevalence of deficiency of vitamin D worldwide and its detrimental impact on health. In order to lower the risk of numerous NCDs, this review emphasizes the need for greater awareness and possible interventions to maintain appropriate vitamin D levels. A meta-analysis was conducted to investigate the potential causal connections between vitamin D insufficiency and different health disorders. It elucidates the connections between deficient levels of vitamin D and conditions such as mental health disorders, anemia, diabetes, hypertension, and autoimmune diseases. The study prioritizes the examination of temporal correlations, biological plausibility, and the removal of confounding factors to provide support for these associations. While the text acknowledges that experimental data, such as randomized controlled trials, would enhance the argument for causation, it mostly depends on observational studies.

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

Background

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

Methods

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

Results

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

Conclusion

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

Harnessing nutrients and natural products for sustainable drug development against aging

Developing treatments for age-related diseases requires cost-effective and efficient approaches. Nutrients and natural metabolites offer safer alternatives to synthetic drugs. Aging increases the need for solutions that protect health and repair cells. Recent studies show that nutrients and natural products reduce oxidative stress, regulate metabolism, and influence longevity-related genes. This review focuses on vitamins, minerals, antioxidants, and natural products that improve healthspan and combat aging. It also discusses challenges such as standardization, clinical validation, and regulatory approval. Finally, emerging trends, such as personalized nutrition and advanced delivery systems, highlight the potential of these metabolites for addressing aging.

From cultural dispositions to biological dimensions: a narrative review on the synergy between oral health and vitamin D through the lens of Indian habitus

Oral health is intricately related to systemic health, with new worldwide research demonstrating vitamin D's critical role in sustaining dental and periodontal health. Vitamin D regulates calcium and phosphate metabolism, which is required for the formation and maintenance of healthy teeth and bones. According to research, vitamin D deficiency may contribute to the etiology of periodontal disease by decreasing the host immune response, making it more susceptible to infections like gingivitis and periodontitis. Oral health in India is a tapestry of traditional practices, socioeconomic factors, lifestyle factors, and access to modern healthcare, all of which are intricately linked with the concept of habitus, which refers to deeply embedded habits, dispositions, and practices shaped by an individual's social space. Deep-rooted social and cultural influences have a substantial impact on oral hygiene practices, food patterns, and health-seeking behaviours. Oral diseases are considered as a worldwide health issue. Though standard Western medicine has had effectiveness in preventing and treating periodontal diseases and other oral disorders, the hunt for alternative solutions continues, and natural phytochemicals extracted from plants used in traditional medicine are regarded as viable alternatives to synthetic chemicals. India's traditional medical knowledge and practice, take a comprehensive approach to oral health, emphasizing the balance of physiological components and the use of natural treatments to maintain oral hygiene and treat oral disorders. However, the structural integrity of teeth and optimal oral health can be accomplished by combining Indian traditional medical practices with vitamin D supplementation, which has synergistic attributes for gum health, anti-inflammatory effects, and dental caries prevention. Nevertheless, the unique association of oral health, vitamin D deficiency and the habitus from Indian perspective is extremely underrepresented in academia. To the best of our knowledge, in the aforementioned context, the present narrative review is probably the maiden attempt to discern the crosstalk of oral health and Vitamin D from the perspectives of Indian habitus.

The role of macrophages in polycystic ovary syndrome: A review

Polycystic ovary syndrome (PCOS) is a common endocrine disorder among fertile women, which is influenced by genetics and environment. A recent study revealed that PCOS patients were in a chronic inflammatory state, and they had abnormally activated macrophages. This paper introduces the relationship between PCOS and macrophages. The forkhead box protein O1 (FOXO-1), migration inhibitory factor, sympathetic conservation disorder, and vitamin D are believed to influence macrophages in PCOS. There is evidence that PCOS-associated abnormalities are associated with macrophages, including insulin resistance, obesity, hyperandrogenism (HA), hyperhomocysteinemia (HHcy), cardiometabolic disorder and gut microbiota dysbiosis. This review summarizes the research status of macrophages in PCOS. Macrophages might be a potential PCOS treatment candidate.

Induction of Cell Death and Regulation of Autocrine Vitamin D Metabolism in Cervical Cancer by Physiological and GI20 Doses of 25-Hydroxycholecalciferol

Vitamin D and its metabolites exert anti-cancer properties in various cancers; however, their effects on cervical cancer remain largely unexplored. To investigate this gap, we exposed HeLa adenocarcinoma cervical cells to physiological and the growth inhibition 20% (GI20) concentration of 25-hydroxycholecalciferol, the precursor hormone of active 1,25-dihydroxycholecalciferol. We then assessed its impact on cell health, and the expression of the genes and proteins involved in the activation and catabolism of vitamin D at the cellular level by autocrine vitamin D metabolism via the vitamin D metabolizing system (VDMS). Cell health was evaluated by crystal violet and alamarBlue assays, while cell cycle progression and apoptotic cell death markers were assessed by flow cytometry. Gross morphology and ultrastructure were observed using brightfield microscopy and transmission electron microscopy. Gene and protein analyses of the autocrine VDMS were assessed using reverse transcription polymerase chain reaction and Western blot, respectively. Our findings reveal that 25(OH)D3 inhibits cell growth and induces apoptosis in HeLa cervical cells in a dose-dependent manner through the autocrine upregulation of CYP27B1 and VDR. These autocrine effects most likely promote the bioactivation of 25(OH)D3 and intracellular signaling of pro-apoptotic genomic pathways by liganded VDR. Furthermore, the upregulation of CYP24A1 at GI20 treatment likely increases the catabolism of 25(OH)D3 and 1,25(OH)2D3, and therefore may mitigate the anti-cancer action of the high-treatment dose. In summary, 25(OH)D3 holds immense potential as a complementary therapeutic treatment for cervical cancer.

Association of Serum 25-Hydroxyvitamin D With Stroke: Observational Mediation and Mendelian Randomization Study

CONTEXT

The causal association and biological mechanism linking serum 25-hydroxyvitamin D (25(OH)D) to stroke risk lacks epidemiological evidence.

OBJECTIVE

This study aimed to investigate the association between 25(OH)D concentration and stroke risk as well as the potential mediating factors.

DESIGN

The community-based prospective community-based cohort study, the Chin-Shan Community Cardiovascular Cohort, was conducted from 1990 to December 2011, with external validation using a 2-sample Mendelian randomization (MR) study.

PATIENTS

A total of 1778 participants with serum 25(OH)D data were enrolled.

METHODS

In the Chin-Shan Community Cardiovascular Cohort observational study, the outcome was ascertained as stroke, while in the 2-sample MR study, it was defined as ischemic stroke. Causal effects were estimated using restricted cubic spline analysis, COX proportional hazard ratios, mediation analysis, and 2-sample MR.

RESULTS

Over 12 years (21 598 person-years) of follow-up, 163 participants (9.17%) developed stroke. Higher 25(OH)D concentrations were associated with lower stroke risk (hazard ratio: 0.64; 95% confidence interval, 0.43-0.96) after full-model adjustments. Mediation analysis showed a significant association between 25(OH)D concentration and stroke risk mediated by hypertension in unadjusted models (mediation percentage 23.3%, P = .008) that became nonsignificant in full models (mediation percentage, 15.5%; P = .072). Two-sample MR confirmed a significant inverse association between genetically determined 25(OH)D and stroke risk (inverse variance weighted method odds ratio 0.92; 95% confidence interval: 0.85-0.99; P = .036). However, hypertension had an insignificant mediating role in the MR study.

CONCLUSION

Higher 25(OH)D levels are linked to reduced stroke risk, potentially mediated by hypertension. Prioritizing blood pressure management may improve stroke prevention in 25(OH)D-deficient patients.

Neuro-immuno-endocrinology of the skin: how environment regulates body homeostasis

The skin, including the hypodermis, is the largest organ of the body. The epidermis, the uppermost layer, is in direct contact with the environment and is exposed to environmental stressors, including solar radiation and biological, chemical and physical factors. These environmental factors trigger local responses within the skin that modulate homeostasis on both the cutaneous and systemic levels. Using mediators in common with brain pathways, immune and neuroendocrine systems within the skin regulate these responses to activate various signal transduction pathways and influence the systemic endocrine and immune systems in a context-dependent manner. This skin neuro-immuno-endocrine system is compartmentalized through the formation of epidermal, dermal, hypodermal and adnexal regulatory units. These units can act separately or in concert to preserve skin integrity, allow for adaptation to a changing environment and prevent the development of pathological processes. Through activation of peripheral nerve endings, the release of neurotransmitters, hormones, neuropeptides, and cytokines and/or chemokines into the circulation, or by priming circulating and resident immune cells, this system affects central coordinating centres and global homeostasis, thus adjusting the body's homeostasis and allostasis to optimally respond to the changing environment.

Sunscreen and 25-Hydroxyvitamin D Levels: Friends or Foes? A Systematic Review and Meta-Analysis

OBJECTIVE

To evaluate the impact of sunscreen use on 25-hydroxyvitamin D (25(OH)D) levels, addressing conflicting findings from observational and interventional studies.

METHODS

Potentially eligible studies were identified from the PubMed/MEDLINE, Scopus, and Web of Science databases from inception to November 2024, utilizing a search strategy incorporating terms related to "sunscreen" and "vitamin D." The studies eligible addressed the questions define based on the Population, Intervention, Comparator, Outcome framework: What are 25(OH)D levels in patients exposing to sun applying or not sunscreen? This review followed Preferred Reported Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The quality assessment and the risk of bias were analyzed using Quality Assessment of Diagnostic Accuracy Studies version 2.

RESULTS

We included 22 studies in the qualitative synthesis, and 7 in the quantitative one, encompassing a total of 9470 participants. In vitro studies consistently showed that sunscreen blocks UV-B radiation, crucial for vitamin D3 production, while population-based studies reported mixed findings. Some studies linked sunscreen use to lower 25(OH)D levels, particularly in individuals with limited sun exposure, while others observed no significant impact. Meta-analysis showed that the adoption of sunscreen is associated to a reduction of 25(OH)D serum concentration (standardized mean difference = -2 ng/mL, 95% confidence interval -3, -1) with a not important heterogeneity across studies (I-square = 37%, P = .15).

CONCLUSION

The existing evidence supports that sunscreen can impair vitamin D3 synthesis, and as a result decrease serum 25(OH)D levels, but further research is necessary to determine the broader health implications and guide public health recommendations.

The Effects of Vitamin D on Keratoconus Progression

PURPOSE

The aim of this study was to assess whether vitamin D (Vit D) supplementation affects local disease progression, as well as systemic inflammation, collagen degradation, and oxidative stress in adolescents affected by keratoconus (KC) and Vit D deficiency.

DESIGN

Prospective, interventional single-center study.

SUBJECTS

Forty patients (age range, 12.2-19.9) presenting with both KC and Vit D insufficiency (<30 ng/mL) were included in the study.

METHODS

Vit D was prescribed for 6 months as per standard of care. Follow-up visits were scheduled for 12 months. Each visit included the measurement of best spectacle-corrected visual acuity, maximal keratometry (Kmax), and thinnest corneal thickness. Blood samples were collected at month 0 and month 6 to measure Vit D levels and systemic biomarkers of inflammation, collagen degradation, and oxidative stress by ELISA or real-time polymerase chain reaction; full RNA sequencing was performed on 20 patients at month 0 and month 6.

MAIN OUTCOME MEASURES

The primary outcome of the study was the percentage of patients with a Kmax progression less than 1 diopter (D) throughout the entire study (ie, stable patients).

RESULTS

Overall, 65% of patients remained stable (75% of eyes) after 12 months. Specifically, best spectacle-corrected visual acuity, Kmax, and thinnest corneal thickness rates remained stable during the 12-month observational period. ELISA performed on blood plasma showed that Vit D upregulated the expression of Vit D binding protein. QPCR performed on peripheral leukocytes showed an increase in the expression of VDR and CD14 with no changes in the principal enzymes involved in Vit D activation/deactivation. ELISA and qPCR showed the modulation of collagen degradation and collagen crosslinking. Subgroup analysis with RNA sequencing showed differential response to Vit D treatment. Responder patients showed downregulation in inflammatory and platelet activation pathways, and upregulation of proteoglycan metabolism/biosynthesis enrichment.

CONCLUSIONS

Our findings support the hypothesis that Vit D supplementation can affect KC progression in adolescent patients with Vit D insufficiency possibly through the modulation of systemic inflammation, inhibition of collagen degradation, and promotion of proteoglycan synthesis. Our results strongly suggest that KC may be the ocular manifestation of a systemic disorder.

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.

Efficacy and safety of intermittent intravenous doxercalciferol in the treatment of secondary hyperparathyroidism in Chinese patients on maintenance hemodialysis: a phase II, open-label, prospective, multicenter study

Objective

This phase II, open-label, prospective, multicenter study evaluated the efficacy and safety of intermittent intravenous doxercalciferol in treating secondary hyperparathyroidism (SHPT) in Chinese maintenance hemodialysis (MHD) patients.

Methods

MHD patients aged 18 to 75 years with a serum intact parathyroid hormone (iPTH) level of 400 pg/mL or higher were enrolled and stratified into Mild, Moderate, and Severe groups based on baseline iPTH levels (400-599.99, 600-799.99, and ≥800 pg/mL, respectively). Patients received an initial dose of 4 μg of doxercalciferol three times weekly for 12 weeks, with subsequent dose adjustments to target iPTH levels of 150-300 pg/mL.

Results

Of the 45 patients enrolled, 44 completed the study, with 20 patients in the Mild Group, 12 in the Moderate Group, and 12 in the Severe Group. The baseline iPTH level for the 44 patients was 655.05 (469.68, 831.40) pg/mL, which decreased to 269.90 (176.45, 365.65) pg/mL after 12 weeks of treatment. The overall mean percentage change in iPTH levels from baseline to week 12 was -55.45% ± 20.08%, with 86.4% of patients (38 cases) achieving a ≥30% reduction compared to baseline. At week 12, 80.00% of patients (16 cases) in the Mild Group had iPTH levels within the target range of 150-300 pg/mL or less than 150 pg/mL, compared to 41.76% (5 cases) in the Moderate Group and 33.33% (4 cases) in the Severe Group. All three groups showed a decrease in serum alkaline phosphatase (ALP) levels, with the Severe Group experiencing a statistically significant reduction (P = 0.001). The most common adverse event was hypercalcemia, occurring in 33.3% of patients (15 cases), with only 8.9% (4 cases) experiencing severe hypercalcemia (serum calcium >2.8 mmol/L). Hypercalcemia was resolved after dose reduction or discontinuation of the medication.

Conclusion

Intermittent intravenous doxercalciferol effectively reduces iPTH levels in Chinese MHD patients, with a manageable safety profile. While hypercalcemia is a concern, the incidence of severe cases is not high. This study supports doxercalciferol as a potential treatment option for SHPT in Chinese MHD patients. Clinical Trial Registration: https://www.chictr.org.cn/showproj.html?proj=187332, identifier ChiCTR2300073196.

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

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

Vitamin D and Cognitive Impairment

BACKGROUND

Vitamin D deficiency is recognized as a significant public health concern, and it has been identified as one of the potentially modifiable risk factors for mild cognitive impairment (MCI). However, evidence regarding the relationship between vitamin D status and cognitive function remains conflicting.

OBJECTIVE

Therefore, this study aimed to examine the prevalence of vitamin D deficiency in the Thai elderly population and an association between vitamin D status and cognitive function, adiposity, and insulin sensitivity.

METHODS

This study enrolled participants aged 55-80 years with normal cognitive function (normal group) or MCI from the prospective cohort in the "Holistic approach of Alzheimer's disease in Thai people (HADThai study)". We used the baseline clinical data to determine the prevalence of vitamin D deficiency and its association between vitamin D status and cognitive function, adiposity, and insulin sensitivity.

RESULTS

A total of 718 subjects (71.9% women) with a mean age of 65.7 ± 5.8 years and a mean BMI of 23.9 ± 3.7 kg/m2 were enrolled. There were 470 (65.5%) participants with normal cognitive function and 248 (34.5%) with MCI. Vitamin D status did not differ significantly between individuals with normal cognitive function and those with MCI. The prevalence of vitamin D deficiency (<20 ng/mL) and vitamin D inadequacy (<30 ng/mL) in both normal cognitive function and MCI was around 6.5% and 40.0%, respectively. While serum 25(OH)D concentrations were inversely associated with body mass index (BMI), body fat, %body fat, and the homeostasis model assessment of insulin resistance (HOMA-IR), no relationship was found between vitamin D status and cognitive function.

CONCLUSIONS

Our study emphasized the high prevalence of vitamin D inadequacy among elderly individuals and an inverse association of vitamin D status and adiposity and insulin resistance. These findings emphasize the importance of addressing vitamin D deficiency in the elderly population to improve overall health outcomes. Nevertheless, our results do not support a direct role of vitamin D status in cognitive decline in this population. Further research, particularly studies with longer follow-up periods and the inclusion of patients with dementia with details of vitamin D supplementation, is needed to clarify the potential role of vitamin D in cognitive decline and neurodegenerative diseases.

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.

Natural environmental factors at birth on risk for rheumatoid arthritis: the impact of season, temperature, latitude, and sunlight exposure

BACKGROUND

Environmental factors contribute to approximately 41% of the risk of rheumatoid arthritis (RA). Previous studies have focused on anthropogenic environmental factors, while much less attention has been given to natural environmental factors. Our study explored the potential influence of natural environmental factors at birth on the risk of RA.

METHODS

This large retrospective study utilized data from the China Kadoorie Biobank. A restricted cubic spline (RCS) model was employed to explore nonlinear relationships between natural environmental factors and the risk of RA. Additionally, a multivariable Cox regression model, adjusted for confounding factors, was used to examine correlations between season of birth, geographic, climate, and the risk of RA.

RESULTS

A total of 512,715 participants were included in this study, of which 2889 (0.56%) were diagnosed with RA. The RCS analysis revealed that the monthly average temperature at birth (p < 0.001), the latitude (p = 0.027) of the birthplace, and the sunshine rate (p < 0.001) exhibited a nonlinear relationship with the risk of RA. Multivariable Cox regression analysis revealed that participants born in Spring and Summer (HR 1.13, 95% CI 1.05-1.23) had an increased risk of RA compared to those born in Autumn and Winter. Additionally, participants born at latitudes ≤ 24°N (HR 1.49, 95% CI 1.32-1.68), with sunshine rate ≤ 28% (HR 2.00, 95% CI 1.75-2.29) or ≥ 60% (HR 1.22, 95% CI 1.08-1.38) had an increased risk of RA. Being born in regions with a monthly average temperature ≥ 27 °C (HR 0.82, 95% CI 0.72-0.95) was associated with a decreased risk of RA.

CONCLUSION

Being born in Spring and Summer, as well as early-life exposure to low-latitude regions and extreme sunlight environments increases the risk of RA. Our study revealed significant associations between the risk of RA and natural environmental factors at birth, emphasizing the impact of the early-life environment on the onset of RA.

Cutaneous melanoma

Cutaneous melanoma is a common cancer in Australia and New Zealand, Europe, and North America, and its incidence is still increasing in many regions. Ultraviolet (UV) radiation exposure (for example, through excessive sunlight exposure) remains the primary risk factor for melanoma; however, public awareness campaigns have led to a marked reduction in mortality. In addition to genetic damage from UV radiation, specific genetic alterations have been linked to melanoma. The stage of the tumour at the time of diagnosis is of greater importance for melanoma prognosis than in almost any other cancer. Context-dependent genetic mutations that attenuate tumour-suppressive mechanisms or activate growth-promoting signalling pathways are crucial factors in the development of cutaneous melanoma. In addition to external factors such as UV radiation, the tumour microenvironment can contribute to melanoma progression, invasion and metastasis. Cutaneous melanoma treatment has improved considerably over the past decade with the discovery and development of immune checkpoint inhibitors and therapy targeting BRAF and MEK. Over the next decade, several priorities are likely to influence melanoma research and management, including the continued advance of precision medicine methods to identify the most suitable patients for the most effective treatment, with the aim of improving clinical outcomes.

The association of sun sensitivity, sun protective behaviors and depression in both genders: a study based on the U.S. population

Objective

The purpose of this study was to analyze the association between sun sensitivity, common sun protective behaviors (stay in shade, wear long sleeves, use sunscreen) and depression, respectively, in both genders, after adjusted for each other as confounders.

Materials and methods

Data from the National Health and Nutrition Examination Survey 2017-2018 cycle were aggregated. Sun sensitivity and sun protective behaviors were assessed through the dermatology questionnaire. Depression was assessed through the 9-item Patient Health Questionnaire, with a score > 4 as the cutoff point. Gender specific logistic regressions were carried out to analyze the association between sun sensitivity, sun protective behaviors and depression.

Results

A sample of 2,605 participants (mean age 39.99 ± 11.57 years) was analyzed, including 1,227 (47.1%) males and 1,378 (52.9%) females. No association between sun sensitivity and depression was observed. In the sample, stay in shade (OR = 1.27, 95% CI: 1.03-1.57) was positively associated with depression, use sunscreen (OR = 0.69, 95% CI: 0.53-0.90) was negatively associated with depression. Gender specific regressions showed no associations between sun protective behaviors and depression in males; both wear long sleeves (OR = 0.65, 95% CI: 0.42-0.99) and use sunscreen (OR = 0.71, 95% CI: 0.52-0.97) were negatively associated with depression in females.

Conclusion

No association between sun sensitivity and depression. Stay in shade was positively associated with depression, while use sunscreen was negatively associated. Gender differences were observed: no association between sun protective behaviors and depression in males; wear long sleeves and use sunscreen may be negatively associated with depression in females.

Vitamin D-related genetic variants and prostate cancer risk in Black men

BACKGROUND

The relationship between vitamin D and prostate cancer has primarily been characterized among White men. Black men, however, have higher prostate cancer incidence and mortality rates, chronically low circulating vitamin D levels, and ancestry-specific genetic variants in vitamin D-related genes. Here, we examine critical genes in the vitamin D pathway and prostate cancer risk in Black men.

METHODS

We assessed a total of 73 candidate variants in genes (namely GC, CYP27A1, CYP27B1, CYP24A1, VDR, and RXRA) including functional variants previously associated with prostate cancer and circulating 25(OHD) in White men. Associations with prostate cancer risk were examined using genome-wide association study data for approximately 10,000 prostate cancer cases and 10,000 controls among Black men and over 85,000 cases and 91,000 controls among White men for comparison. A statistical significance threshold of 0.000685 was used to account for the 73 variants tested.

RESULTS

None of the variants examined were significantly associated with prostate cancer risk among Black men after multiple comparison adjustment. Suggestive associations (P < 0.05) for four variants were found in Black men, including two in RXRA (rs41400444 OR=1.09, 95 % CI: 1.01-1.17, P = 0.024 and rs10881574 OR = 0.93, 0.87-1.00, P = 0.046) and two in VDR (rs2853563 OR = 1.07, 1.01-1.13, P = 0.017 and rs1156882 OR = 1.06, 1.00-1.12, P = 0.045). Two variants in VDR were also positively associated with risk in White men (rs11568820 OR = 1.04, 1.02-1.06, P = 0.00024 and rs4516035 OR = 1.03, 1.01-1.04, P = 0.00055).

CONCLUSION

We observed suggestive associations between genetic variants in RXRA and VDR and prostate cancer risk in Black men. Future research exploring the relationship of vitamin D with cancer risk in Black men will need larger sample sizes to identify ancestry-specific variants relevant to risk in this population.

Causal Links Between Gut Microbiota and Vitamin Deficiencies: Evidence from Mendelian Randomization Analysis

OBJECTIVE

Vitamin deficiencies, particularly in vitamins A, B12, and D, are prevalent across populations and contribute significantly to a range of health issues. While these deficiencies are well documented, the underlying etiology remains complex. Recent studies suggest a close link between the gut microbiota and the synthesis, absorption, and metabolism of these vitamins. However, the specific causal relationships between the gut microbiota composition and vitamin deficiencies remain poorly understood. Identifying key bacterial species and understanding their role in vitamin metabolism could provide critical insights for targeted interventions.

METHODS

We conducted a two-sample Mendelian randomization (MR) study to assess the causal relationship between the gut microbiota and vitamin deficiencies (A, B12, D). The genome-wide association study data for vitamin deficiencies were sourced from the FinnGen biobank, and the gut microbiota data were from the MiBioGen consortium. MR analyses included inverse variance-weighted (IVW), MR‒Egger, weighted median, and weighted mode approaches. Sensitivity analyses and reverse causality assessments were performed to ensure robustness and validate the findings.

RESULTS

After FDR adjustment, vitamin B12 deficiency was associated with the class Verrucomicrobiae, order Verrucomicrobiales, family Verrucomicrobiaceae, and genus Akkermansia. Vitamin A deficiency was associated with the phylum Firmicutes and the genera Fusicatenibacter and Ruminiclostridium 6. Additional associations for vitamin B12 deficiency included the Enterobacteriaceae and Rhodospirillaceae and the genera Coprococcus 2, Lactococcus, and Ruminococcaceae UCG002. Vitamin D deficiency was associated with the genera Allisonella, Eubacterium, and Tyzzerella 3. Lachnospiraceae and Lactococcus were common risk factors for both B12 and D deficiency. Sensitivity analyses confirmed the robustness of the findings against heterogeneity and horizontal pleiotropy, and reverse MR tests indicated no evidence of reverse causality.

CONCLUSIONS

Our findings reveal a possible causal relationship between specific gut microbiota characteristics and vitamin A, B12 and D deficiencies, providing a theoretical basis for addressing these nutritional deficiencies through the modulation of the gut microbiota in the future and laying the groundwork for related interventions.

Phosphate metabolism: its impact on disorders of mineral metabolism

Regulatory molecules typically work cooperatively to ensure the efficient functioning of hormonal systems. Examples include LH and FSH in reproductive biology, insulin and glucagon in glucose metabolism. Similarly, calcium and phosphorus are important regulators of skeletal homeostasis. In the circulation, these molecules are under the control of PTH, 1,25(OHD), and FGF23. In turn, these hormones depend upon a mutual and complex interplay among themselves. For example, alterations in calcium metabolism influence phosphorus homeostasis, as occurs in primary hyperparathyroidism (PHPT). Not as well recognized is the influence that abnormalities in phosphorus metabolism can have on calcium homeostasis. In this review, we call attention to the impact that abnormalities in phosphorus can have on calcium metabolism.

Strategies for preventing bone loss in populations with insufficient calcium and vitamin D intake

Calcium and vitamin D are essential nutrients for maintaining skeletal health, yet deficiencies in these nutrients are particularly widespread in regions such as Asia and Africa. Inadequate intake of these nutrients in these areas has been associated with diminished bone integrity and a rising incidence of osteoporosis. This review examines the underlying mechanisms of bone loss driven by calcium and vitamin D deficiencies, emphasizing their crucial roles in bone metabolism. It also presents strategies to improve nutrient intake, such as fortification of staple foods and supplementation, along with lifestyle modifications including increased physical activity, sun exposure, and dietary education, to prevent bone loss effectively. Special consideration is given to vulnerable populations, including older adults, individuals with limited sun exposure, and those with dietary restrictions, who are at higher risk of deficiency. The review further evaluates public health strategies, including government-initiated fortification and educational programs, as essential measures for tackling widespread nutrient deficiencies. Lastly, it explores future avenues for addressing calcium and vitamin D deficiencies, including the potential role of digital health tools, personalized nutrition, and innovative public health policies to alleviate the global burden of bone-related diseases.

Impact of Education and Gender on Knowledge, Attitudes, and Practices Toward Vitamin D Among the Lebanese Population With Emphasis on Young Adults

Background Vitamin D deficiency is a growing global health concern that affects populations, even in sun-rich regions such as Lebanon. Despite abundant sunlight, limited research has explored the knowledge, attitudes, and practices (KAP) related to vitamin D among young Lebanese adults. Study design This study employed an online quantitative cross-sectional design. Methods A self-administered online questionnaire distributed over six months (from August 2023 to January 2024) collected data on the participants' demographic characteristics, as well as their knowledge, attitudes, and practices related to vitamin D. Results Most participants (75.7%) had sufficient knowledge about vitamin D sources. The internet and physicians emerged as the dominant sources, cited by 175 participants, which represented 17.6% of the total responses related to vitamin D knowledge sources. Sunlight was perceived by the participants as the most crucial source. Additionally, 244 (33.7%) of the participants acknowledged the role of vitamin D in preventing osteoporosis, whereas 144 (20.4%) believed that it was aiding in calcium absorption. Significant levels of knowledge (defined as scores of ≥21 out of 40) and positive attitudes (defined as ≥4 correct answers out of six) were evident among more than 255 (75%) of the participants. However, over half expressed concerns about their vitamin D levels. Most were willing to take supplements (330, 92.7%) and undergo testing (326, 92.1%). Conclusion Although young Lebanese adults demonstrated good overall knowledge and positive attitudes toward vitamin D deficiency, implementing comprehensive awareness campaigns and health programs that emphasize behavior change is crucial for combating deficiency. These initiatives should focus on promoting tangible changes in practices, such as safe sun exposure, the consumption of vitamin D-rich foods, and adherence to testing and supplementation when necessary.

Vitamin D deficiency and oral health: a systematic review of literature

BACKGROUND

Vitamin D (VD) levels are gaining increasing interest in dentistry due to their association with several oral diseases.

OBJECTIVE

This study aimed to evaluate the relationship between vitamin D deficiency and various oral disorders.

MATERIALS AND METHODS

A broad search on the MEDLINE database via the PubMed interface and on the Spring Link platform was carried out using keywords related to the subject. An additional electronic search of gray literature was conducted via Google Scholar. Inclusion criteria were listed for the selection of articles and a reading grid was designed for the extraction of data relating to the research question. The quality of included studies was assessed using JBI's critical appraisal tools.

RESULTS

A total of 57 studies were identified. After reading the full text, 16 studies were included and selected for qualitative analysis. There is an association between vitamin D deficiency and different oral disorders. Indeed, ten publications assessed the association between vitamin deficiency and periodontal disease, three examined the relationship between vitamin D deficit and dental caries, and one examined the intriguing relationship between vitamin D deficiency and tooth mineralization and two articles interested in vitamin D deficiency and stomatitis.

CONCLUSION

The analysis of these selected articles shows that Vitamin D deficiency can lead to various oral health disorders during growth and adulthood. Indeed, it can be linked to tooth mineralization defects and increasing the risk of dental caries. Severe Vitamin D deficiency also increases the prevalence of periodontitis and gingival inflammation. It may also be linked to certain oral pathology entities, such as oral cancers and jaw osteonecrosis.

Associations of the serum 25-hydroxyvitamin D with mortality among patients in osteopenia or osteoporosis

PURPOSE

The correlation between serum 25-hydroxy vitamin D [(25(OH)D] and mortality in patients with osteopenia or osteoporosis remains unclear. Therefore, this study examined the relationship between serum 25(OH)D and mortality in patients with osteopenia or osteoporosis.

METHODS AND RESULTS

This prospective cohort study included patients with osteopenia or osteoporosis from the National Health and Nutrition Examination Survey from 2001 to 2018. Multivariate Cox regression models examined the correlation between serum 25(OH)D and all-cause mortality, cardiovascular mortality (CVD), and cancer mortality. The cohort included 9282 adult participants with a median follow-up period of 97.01 months, including 1394 all-cause deaths, 413 CVD-related deaths, and 322 cancer deaths. In fully adjusted models, higher serum 25(OH)D levels (≥75.0 nmol/L) were associated with a lower risk of all-cause mortality (hazard ratio 0.54, 95 % confidence interval 0.41 to 0.73) and cardiovascular death (0.47, 0.29 to 0.76), using participants with low 25(OH)D levels (<25 nmol/L) as the reference. In addition, we found an L-shaped non-linear dose-response relationship between serum 25(OH)D and all-cause and cardiovascular mortality, with inflection points of 38.8 nmol/L and 53.6 nmol/L, respectively.

CONCLUSION

Higher serum 25(OH)D concentrations are strongly associated with a diminished risk of all-cause and CVD mortality in patients with osteopenia or osteoporosis. This association has a threshold effect. More in-depth intervention studies are needed to clarify underlying mechanisms.