Prevalence, trend, and predictor analyses of vitamin D deficiency in the US population, 2001-2018

Cross-Sectional Associations between Clinical Biochemistry and Nutritional Biomarkers and Sarcopenic Indices of Skeletal Muscle in the Baltimore Longitudinal Study of Aging

BACKGROUND

Investigating relationships between nutritional and clinical biochemistry biomarkers and skeletal muscle mass, strength and function (sarcopenic indices) may 1) highlight micronutrients of interest for potential preventive or treatment strategies for sarcopenia, or 2) highlight biomarkers that may be useful for identifying individuals at risk of sarcopenia.

OBJECTIVES

Investigate associations between nutritional biomarkers (vitamin D, vitamin B12, folate, magnesium, potassium, calcium, and iron), clinical biomarkers (hemoglobin, ferritin, albumin, creatinine, and hemoglobin A1c: HbA1c), and sarcopenic indices (appendicular lean mass: ALM); height-adjusted ALM: ALMht; fat-free mass as a percentage of total body weight; extended short physical performance battery score: extSPPB; height-adjusted hand grip strength: HGSht; height-adjusted knee extension concentric strength, and; height-adjusted knee extension isometric strength) in males and females.

METHODS

Using multivariable linear regression analysis, we investigated cross-sectional associations between biomarkers and sarcopenic indices in data collected from 1761 participants (age 22-103 y) from the Baltimore Longitudinal Study of Aging.

RESULTS

Hemoglobin was positively associated with ALM (β = 0.20, P = 0.021), HGSht (β = 0.25, P = 0.001), and extSPPB (β = 0.13, P = 0.024) in males, and with extSPPB in females (β = 0.15, P = 0.019). In males, serum iron was positively associated with ALMht (β = 0.0021, P = 0.038) and extSPPB (β = 0.0043, P = 0.045). In females, ferritin was positively associated with knee-extension strength measurements. Serum creatinine was positively associated with lean mass measures in males and females and with muscle strength and function measures in males with normal renal function (estimated glomerular filtration rate ≥60 mL/min/1.73 m2). In males, high HbA1c was associated with lower ALMht (β = -0.21, P = 0.023), extSPPB (β = -0.40, P = 0.027), and HGSht (β = -0.56, P = 0.031). In males and females, magnesium was positively associated with extSPPB, and potassium was positively associated with measures of knee-extension strength.

CONCLUSIONS

The associations found between measures of iron status and creatinine and sarcopenic indices, in males in particular, indicate potential importance for muscle health. Future longitudinal and intervention studies are warranted to confirm these findings.

Commutability assessment of new standard reference materials (SRMs) for determining serum total 25-hydroxyvitamin D using ligand binding and liquid chromatography-tandem mass spectrometry (LC-MS/MS) assays

Commutability is where the measurement response for a reference material (RM) is the same as for an individual patient sample with the same concentration of analyte measured using two or more measurement systems. Assessment of commutability is essential when the RM is used in a calibration hierarchy or to ensure that clinical measurements are comparable across different measurement procedures and at different times. The commutability of three new Standard Reference Materials® (SRMs) for determining serum total 25-hydroxyvitamin D [25(OH)D], defined as the sum of 25-hydroxyvitamin D2 [25(OH)D2] and 25-hydroxyvitamin D3 [25(OH)D3], was assessed through an interlaboratory study. The following SRMs were assessed: (1) SRM 2969 Vitamin D Metabolites in Frozen Human Serum (Total 25-Hydroxyvitamin D Low Level), (2) SRM 2970 Vitamin D Metabolites in Frozen Human Serum (25-Hydroxyvitamin D2 High Level), and (3) SRM 1949 Frozen Human Prenatal Serum. These SRMs represent three clinically relevant situations including (1) low levels of total 25(OH)D, (2) high level of 25(OH)D2, and (3) 25(OH)D levels in nonpregnant women and women during each of the three trimesters of pregnancy with changing concentrations of vitamin D-binding protein (VDBP). Twelve laboratories using 17 different ligand binding assays and eight laboratories using nine commercial and custom liquid chromatography-tandem mass spectrometry (LC-MS/MS) assays provided results in this study. Commutability of the SRMs with patient samples was assessed using the Clinical and Laboratory Standards Institute (CLSI) approach based on 95% prediction intervals or a pre-set commutability criterion and the recently introduced International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) approach based on differences in bias for the clinical and reference material samples using a commutability criterion of 8.8%. All three SRMs were deemed as commutable with all LC-MS/MS assays using both CLSI and IFCC approaches. SRM 2969 and SRM 2970 were deemed noncommutable for three and seven different ligand binding assays, respectively, when using the IFCC approach. Except for two assays, one or more of the three pregnancy levels of SRM 1949 were deemed noncommutable or inconclusive using different ligand binding assays and the commutability criterion of 8.8%. Overall, a noncommutable assessment for ligand binding assays is determined for these SRMs primarily due to a lack of assay selectivity related to 25(OH)D2 or an increasing VDBP in pregnancy trimester materials rather than the quality of the SRMs. With results from 17 different ligand binding and nine LC-MS/MS assays, this study provides valuable knowledge for clinical laboratories to inform SRM selection when assessing 25(OH)D status in patient populations, particularly in subpopulations with low levels of 25(OH)D, high levels of 25(OH)D2, women only, or women who are pregnant.

Exploring the Complexities of Seafood: From Benefits to Contaminants

Seafood plays a vital role in human diets worldwide, serving as an important source of high-quality protein, omega-3 fatty acids, and essential vitamins and minerals that promote health and prevent various chronic conditions. The health benefits of seafood consumption are well documented, including a reduced risk of cardiovascular diseases, improved cognitive function, and anti-inflammatory effects. However, the safety of seafood is compromised by multiple hazards that can pose significant health risks. Pathogenic microorganisms, including bacteria, viruses, and parasites, in addition to microbial metabolites, are prominent causes of the foodborne diseases linked to seafood consumption, necessitating reliable detection and monitoring systems. Molecular biology and digital techniques have emerged as essential tools for the rapid and accurate identification of these foodborne pathogens, enhancing seafood safety protocols. Additionally, the presence of chemical contaminants such as heavy metals (e.g., mercury and lead), microplastics, and per- and polyfluoroalkyl substances (PFASs) in seafood is of increasing concern due to their potential to accumulate in the food chain and adversely affect human health. The biogenic amines formed during the microbial degradation of the proteins and allergens present in certain seafood species also contribute to food safety challenges. This review aims to address the nutritional value and health-promoting effects of seafood while exploring the multifaceted risks associated with microbial contamination, chemical pollutants, and naturally occurring substances. Emphasis is placed on enhanced surveillance, seafood traceability, sustainable aquaculture practices, and regulatory harmonization as effective strategies for controlling the risks associated with seafood consumption and thereby contributing to a safer seafood supply chain.

Vitamin D Deficiency and Cardiovascular Disease Risk Factors Among American Indian Adolescents: The Strong Heart Family Study

Introduction

We aimed to describe the prevalence of vitamin D deficiency among American Indian adolescents and determine its association with cardiovascular disease (CVD) risk factors.

Methods

Our study population consisted of 307 adolescents (aged ≤20 years) participating in the Strong Heart Family Study with serum 25-hydroxyvitamin D (25[OH]D) measured on samples collected during baseline examinations (2001-2003). We defined baseline prevalence of vitamin D deficiency as 25(OH)D ≤20 ng/mL. We evaluated outcomes related to obesity (BMI, waist circumference, wait-to-hip ratio, and body fat percentage), diabetes, cholesterol, and metabolic syndrome. We used generalized estimating equations to determine whether the prevalence of the outcomes differed according to vitamin D deficiency status, while controlling for covariates. To determine incidence, we conducted a follow-up examination a median 5.8 years after baseline (2006-2009) and a second follow-up a median of 13.3 years after baseline (2014-2018). We calculated incidence rates (IR) per 100 person-years for the total group and stratified by vitamin D deficiency status at baseline. Finally we used shared frailty cox proportional hazards models to determine if the risk of the outcomes differed according to vitamin D deficiency status, while controlling for covariates.

Results

The prevalence of vitamin D deficiency was 50.8% at baseline, and it was associated with the prevalence of obesity, low HDL-C, and metabolic syndrome, while controlling for covariates. By the first follow-up, the IRs per 100 person-years were the following: obesity (5.03), diabetes (1.07), any dyslipidemia (10.80), and metabolic syndrome (3.31). By the second follow-up, the IR of diabetes was significantly higher among those with (vs without) baseline vitamin D deficiency (1.32 vs 0.68 per 100 person-years; P = .02), although the association was not significant after adjusting for covariates.

Conclusion

Vitamin D deficiency in adolescence may be associated with the CVD risk factors obesity, low HDL-C, and metabolic syndrome and may also contribute to the development of diabetes later in life.

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.

Associations of a metal mixture and vitamin D with sleep duration among adolescents and young adults from the 2011-2018 NHANES cycles

INTRODUCTION

Heavy metal exposure has been associated with poor sleep, but little is known about the cumulative associations of multiple metals with sleep duration, particularly among adolescents. This study examined the association of blood lead (Pb), cadmium (Cd), and mercury (Hg) concentrations with sleep duration and possible effect modification by vitamin D.

METHODS

The study sample consisted of 16-25-year-olds (n = 2637) from the 2011-2018 National Health and Nutrition Examination Survey. The association of each blood metal and serum vitamin D level with self-reported sleep duration was examined through linear regression models. Interaction terms and stratified models tested the effect modification of metal association with sleep by vitamin D level or status. Cumulative and interactive associations among the metals and serum vitamin D were also estimated using Bayesian Kernel Machine Regression (BKMR).

RESULTS

In linear regressions, there was little evidence of an association between individual metals, vitamin D level, and sleep duration. Both linear regressions and BMKR models showed little indication of interactions among metals and vitamin D levels. BKMR results suggested an overall joint association, with longer sleep duration at higher percentile of the metal-vitamin D mixture (75th percentile vs 50th: β=0.07 hours; 95 % CrI: 0.01, 0.13).

CONCLUSION

In the context of low-level metal exposure, individual metals were unrelated to sleep duration. We found some evidence that higher levels of the mixture of blood Pb, Cd, Hg, and serum vitamin D level may be associated with slightly longer sleep duration, underscoring the importance of considering multiple environmental exposures. Additional analyses, especially in higher risk groups (e.g., higher exposures; higher prevalence or severity of vitamin D deficiency) are warranted.

Association Between Shift Work and Vitamin D Levels in Brazilian Female Workers

Objectives: Vitamin D plays a crucial role in maintaining bone and muscle health and is associated with various health conditions. Risk factors for reduced vitamin D levels include occupation. The aim of this study was to explore the association between shift work and vitamin D levels among female workers. Methods: This cross-sectional study was conducted among 304 women from an industrial group located in southern Brazil. Vitamin D deficiency was defined as serum 25(OH)D levels < 20 ng/mL, and deficiency/insufficiency was defined as serum levels < 30 ng/mL. Work shift data were collected through interviews using the start and end times of work shifts, classified as "day shift" (6:00 AM ≤ hh:hh < 10:00 PM) and "night shift" (10:00 PM ≤ hh:hh < 6:00 AM), respectively. The association between vitamin D deficiency and shift work was expressed as prevalence ratio (PR), using Poisson regression adjusted for confounding variables. Results: The prevalence of vitamin D deficiency was 36.5% (95% CI: 31.1-41.9), while the prevalence of insufficiency was 75.7% (95% CI: 70.8-80.5). After adjustment, a significant association was found, with 65% and 17% higher probabilities of having vitamin D deficiency (PR = 1.65; 95% CI: 1.23-2.22; p = 0.001) and vitamin D deficiency/insufficiency (PR = 1.17; 95% CI: 1.02-1.35; p = 0.030) among nightshift workers compared with dayshift workers. Conclusions: The findings of this study indicate a high prevalence of hypovitaminosis D among Brazilian female fixed-shift workers as well as a higher probability of vitamin D deficiency and deficiency/insufficiency among nightshift workers compared with dayshift workers.

Exploring the relationship between serum 25-hydroxyvitamin D levels and intestinal fungal communities and their metabolites in postmenopausal Chinese women

BACKGROUND

Research gaps persist in understanding the interactions between serum 25 (OH)D levels, intestinal fungi, and their metabolites in postmenopausal women.

METHODS

This study, approved by the Ethics Committee of Zhongshan Hospital, Xiamen University, recruited postmenopausal women from Xiamen. Clinical assessments included Body Mass Index (BMI) calculations and blood tests for various bone-related markers using Roche's electrochemiluminescence system. Bone density was measured via dual-energy X-ray absorptiometry. Fecal DNA was extracted for Internal Transcribed Spacer (ITS) sequencing with a two-stage PCR process and analyzed using high-throughput Illumina sequencing. Metabolites were extracted from fecal samples and analyzed by ultra-high-performance liquid chromatography combined with mass spectrometry. Statistical analyses and data visualization were performed using R, focusing on fungal community structure and correlations with metabolites.

RESULTS

The study analyzed 81 postmenopausal women, categorized into vitamin D deficient (VDD), insufficient (VDI), and sufficient (VDS) groups based on serum 25 (OH)D levels. Other health markers, including age and BMI, were consistent across groups. Notably, Linear discriminant analysis identified distinct fungal communities across VDD, VDI, and VDS groups. In the VDD group, notable fungi included Hanseniaspora occidentalis and Pichia. The VDI group showed enrichment of Candida, while the VDS group had higher abundances Such as Phanerochaete, and Nectriaceae. Alpha diversity metrics, such as the Chao1 index, differed significantly among the groups (p < 0.05). Correlation analysis (Spearman) revealed that fungi like Trichosporon and Penicillium positively associated with 25 (OH)D3, whereas fungi such as Cystofilobasidium were negatively correlated with bone mineral density (BMD). Metabolites like Glutaric acid positively correlated with 25 (OH)D3, while L-Citrulline and Deoxycholic acid were negatively correlated. Additionally, Argininosuccinic acid correlated positively with BMD, whereas Acamprosate and p-Hydroxyphenylacetic acid were negatively associated.

CONCLUSION

In postmenopausal women, fungal community composition varies significantly with vitamin D status, potentially correlating with serum 25 (OH)D levels and BMD, indicating that specific fungal species may be relevant for therapeutic strategies with osteoporosis and offering insights into the broader bone health effects of vitamin D.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

The Increasing Prevalence of Autism Spectrum Disorder in the U.S. and Its Implications for Pediatric Micronutrient Status: A Narrative Review of Case Reports and Series

INTRODUCTION

Micronutrient deficiencies are considered uncommon in the United States. However, children with autism spectrum disorder (ASD) are at higher risk due to food selectivity and restrictive eating patterns. The prevalence of ASD in the U.S. has quadrupled over the past two decades, amplifying the need to address nutritional gaps in this population.

OBJECTIVE

This narrative review examines the prevalence and clinical impact of underreported micronutrient deficiencies beyond vitamin C in children with ASD using case reports and series.

METHODS

Case reports and case series reporting micronutrient deficiencies in children with ASD published from 2014 to 2025 were identified through PubMed and ScienceDirect using search terms "autism and deficiency" and "autism and vitamin A, K, magnesium, iron deficiency". Eligible cases included children aged 2-18 years with ASD and laboratory-confirmed micronutrient deficiencies.

RESULTS

A total of 44 cases from 27 articles were analyzed. Frequently reported deficiencies were vitamin D (25.0%), vitamin A (24.8%), B-vitamins (18.0%), calcium (10.8%), and iron (9.6%). Less common deficiencies included iodine, zinc, vitamin E, etc. Diseases such as xerophthalmia, rickets, pellagra, and goiter were reported. Co-occurring deficiencies were present in 70% of cases, and all cases reported food selectivity, with deficiencies occurring despite normal growth parameters in some children.

CONCLUSIONS

Based on cases reviewed, children with ASD are at high risk for micronutrient deficiencies, despite meeting normal growth parameters. Further research is needed to develop a standardized nutrition assessment, but combining anthropometric, biochemical, and dietary assessments can aid in early intervention and prevent complications.

High prevalence of low vitamin D status in the Czech Republic: a retrospective study of 119,925 participants

OBJECTIVES

Given the high worldwide prevalence of vitamin D deficiency and its role in numerous diseases affecting mortality and morbidity, this study seeks to determine the prevalence of low 25-hydroxyvitamin D levels in the Czech Republic, where population-level data are currently lacking.

STUDY DESIGN

This retrospective study utilized a large dataset to analyze 25-hydroxyvitamin D levels over an extended period.

METHODS

We analyzed data from 119,925 individuals aged 0-100 years categorizing them as sufficient (75-250 nmol/L), insufficient (50-75 nmol/L), or deficient (<50 nmol/L). We also examined levels of CRP, homocysteine, and their correlations with 25-hydroxyvitamin D levels across age groups. Age, sex, sampling month, sunlight exposure (monthly and annual), and influenza virus positivity were assessed for their relationship with the 25-hydroxyvitamin D levels.

RESULTS

The study found a high prevalence of 25-hydroxyvitamin D inadequacy, with sufficient levels observed in 65.6% of infants (0-12 months). The lowest prevalence of sufficiency was in the 6-15 years (19.2%) and 16-30 years (22.1%) groups. The highest deficiency prevalence was in the 91-100 years group (51.8%). 25-hydroxyvitamin D levels in all age groups and both sexes correlated with all selected parameters. Lower sun exposure, higher flu virus positivity, male gender, and elevated homocysteine and CRP levels were negatively correlated with 25-hydroxyvitamin D levels.

CONCLUSIONS

The prevalence of 25-hydroxyvitamin D inadequacy in the Czech Republic is high. It is advisable to consider testing, monitoring, and providing medical recommendations for vitamin D supplementation as part of health prevention strategies in the general population.

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.

Illuminating the Connection: Cutaneous Vitamin D3 Synthesis and Its Role in Skin Cancer Prevention

Sunlight exposure plays an important role in human health, impacting processes such as mood, blood pressure regulation, and vitamin D3 production. Solar ultraviolet B radiation initiates vitamin D3 synthesis in the skin, which is subsequently metabolized into its biologically active form. UVB exposure plays a key role in enabling vitamin D3 synthesis, but it can also contribute to skin carcinogenesis, creating a complex interplay between its beneficial and harmful effects. Vitamin D deficiency, affecting over half the global population, is linked to a range of chronic diseases, including cancers, cardiovascular conditions, and autoimmune disorders. Simultaneously, excessive solar UVB exposure increases the risk of non-melanoma and melanoma skin cancers through mechanisms involving DNA damage and oxidative stress. This review examines the dual role of UVB radiation in health and disease, focusing on the mechanisms of cutaneous vitamin D3 synthesis, the epidemiology of skin cancer, and the protective roles of vitamin D3's photoproducts and its active metabolite, 1,25-dihydroxyvitamin D3. Understanding these interconnections is critical for developing strategies that balance adequate sun-induced vitamin D3 production with skin cancer prevention.

A narrative review focusing on randomized clinical trials of vitamin D supplementation for COVID-19 disease

Current evidence is inconsistent on whether vitamin D supplementation can prevent COVID-19 infection or improve its clinical outcomes. To better understand and look into the issue, we went through the background knowledge of COVID-19 and vitamin D, searched in Pubmed [by using key words in the title containing "randomized clinical trial", "COVID-19", and "vitamin D (25-hydroxyvitamin D, or cholecalciferol, or calcidiol, or calcifediol) supplementation"] for publications of studies on vitamin D/supplementation in COVID-19 patients, especially those about the randomized clinical trials (RCTs). After reviewing these papers, we did a short background review of vitamin D and the pathophysiology of COVID-19, summarized the key features of the 25 RCTs in text and tabulated in a table of some of the features, commented, compared and discussed the differences between RCTs (for example, change the serum 25-hydroxyvitamin D concentration from nmol/L to ng/mL, making the comparison easier). The take-home question of the review is that serum 25-hydroxyvitamin D concentration is an important indicator of the supplementation effect of vitamin D correction but may not be reliable in predicting the supplementation effect on the clinical outcomes of COVID-19.

Kidney development at a glance: metabolic regulation of renal progenitor cells

The aberrant regulation of renal progenitor cells during kidney development leads to congenital kidney anomalies and dysplasia. Recently, significant progress has been made in understanding the metabolic needs of renal progenitor cells during mammalian kidney development, with evidence indicating that multiple metabolic pathways play essential roles in determining the cell fates of distinct renal progenitor populations. This review summarizes recent findings and explores the prospects of integrating this novel information into current diagnostic and treatment strategies for renal diseases. Reciprocal interactions between various embryonic kidney progenitor populations establish the foundation for normal kidney organogenesis, with the three principal kidney structures-the nephrons, the collecting duct network, and the stroma-being generated by nephron progenitor cells, ureteric bud/collecting duct progenitor cells, and interstitial progenitor cells. While energy metabolism is well recognized for its importance in organism development, physiological function regulation, and responses to environmental stimuli, research has primarily focused on nephron progenitor metabolism, highlighting its role in maintaining self-renewal. In contrast, studies on the metabolic requirements of ureteric bud/collecting duct and stromal progenitors remain limited. Given the importance of interactions between progenitor populations during kidney development, further research into the metabolic regulation of self-renewal and differentiation in ureteric bud and stromal progenitor cells will be critical.

Prevalence of Vitamin D Deficiency Among Healthy Young Adults at Kuwait University

OBJECTIVE

 This study aims to investigate the prevalence of vitamin D deficiency among healthy young medical and dental students at Kuwait University.

METHODS

This cross-sectional study included a total of 201 medical and dental students (male = 99; female = 102) at Kuwait University. Blood samples were collected to assess 25-hydroxyvitamin D (25(OH)D) by electrochemiluminescence (ECL) immunoassay, and a questionnaire was distributed to address related qualitative data. P-values less than 0.05 were considered significant.

RESULTS

Vitamin D deficiency (<50 nmol/L) was reported in 171 (85.1%) of the participants. A total of 17 (8.5%) participants exhibited insufficient vitamin D (50.1-75 nmol/L), and only 13 (6.5%) students had optimal vitamin D (>75 nmol/L). According to gender, vitamin D deficiency was more common in male students (89, 89.9%) compared to females (82, 80.4%). Vitamin D levels for students in the clinical academic years (sixth and fifth years) were significantly higher (P < 0.001) compared to the non-clinical years (fourth, third, and second years).

CONCLUSION

 The prevalence of vitamin D deficiency was very high among medical and dental students of Kuwait University. The students with high academic years suffered more from vitamin D deficiency.

Heterogeneity in experiences of vitamin D deficiency in an early to mid-19th century population from Montreal, Quebec

OBJECTIVE

To use the prevalence of prenatal/infancy interglobular dentine (IGD) as a proxy for suboptimal vitamin D status and explore its link to mortality, biological sex, cultural behaviours and environmental factors during the end of the pre-industrial/ beginning of the industrial period.

MATERIALS

50 skeletons from the St. Antoine cemetery (1799-1854), Montreal, Quebec with a well-preserved first mandibular molar.

METHODS

Thin sections were prepared for histological examination of IGD in crown dentine.

RESULTS

IGD prevalence was 74 % (37/50) and not significantly correlated statistically to sex and age-at-death. Most IGD occurred at birth and up to 3 years-old, six individuals were affected in utero, 54 % of the sample (27/50) presented longstanding IGD and six individuals displayed multiple IGD episodes.

CONCLUSIONS

Prenatal IGD episodes revealed suboptimal maternal vitamin D levels, which, alongside a high frequency of IGD episodes around birth/from birth until a certain age, suggest cultural influences. Multiple and longstanding IGD episodes might also reflect suboptimal seasonal vitamin D attainment.

SIGNIFICANCE

This study provides in-depth data on IGD within a relatively large archaeological North American sample, proving relevant to epidemiological studies on suboptimal vitamin status in 19th century Montreal.

LIMITATIONS

The total number of IGD episodes is underestimated due to methodological biases; first-generation migrants in this study could not be identified and excluded from the sample.

SUGGESTIONS FOR FURTHER RESEARCH

Use of a larger sample with a wider age-at-death range; further research on infants and children to investigate links between growth and lesion formation and visibility.

Vitamin D levels do not correlate with severity of idiopathic peripheral neuropathy

BACKGROUND AND AIMS

Peripheral neuropathy (PN) is a common neurological condition in elderly adults. Vitamin D deficiency has been associated with diabetic and chemotherapy-induced neuropathy, but its role in idiopathic PN, in which no underlying cause of neuropathy can be identified, has not been investigated.

METHODS

Two hundred thirty patients with idiopathic PN enrolled in the Peripheral Neuropathy Research Registry (PNRR) at Johns Hopkins University School of Medicine had vitamin D testing information on record. Linear and logistic regressions were used to investigate the relationship between absolute vitamin D level or vitamin D insufficiency (<20 ng/mL) and both the severity of neuropathy as measured by the reduced total neuropathy score (TNSr) and severity of neuropathic pain.

RESULTS

Sixteen (7%) patients were vitamin D insufficient (<20 ng/mL). Controlling for factors known to correlate with severity of neuropathy, there was no correlation between absolute vitamin D levels and TNSr (correlation coefficient 0.01, 95% CI -0.03 to 0.07, p = .59) and no association between vitamin D insufficiency and TNSr (correlation coefficient 0.3, 95% CI -2.8 to 3.4, p = .86). Vitamin D insufficiency was not associated with the presence of neuropathic pain (OR 4.1, 95% CI 0.6-26.0, p = .13), and there was no correlation between vitamin D levels and pain score (correlation coefficient 0.01, 95% CI -0.02 to 0.03, p = .59).

INTERPRETATION

In a single-center cohort of patients with idiopathic PN, there was no correlation between vitamin D levels and the severity of neuropathy or neuropathic pain.

Vitamin D supplementation can improve the 28-day mortality rate in patients with sepsis-associated acute kidney injury

PURPOSE

Vitamin D levels are generally lower in septic patients and are associated with poor prognosis. Observational studies suggest improved renal recovery in acute kidney injury (AKI) patients with increased vitamin D levels. Still, large RCTs did not show significant clinical benefits, possibly due to the limited number of sepsis or AKI patients included. This study aimed to examine the impact of vitamin D supplementation on 28-day all-cause mortality in patients with sepsis-associated acute kidney injury (S-AKI).

METHODS

A retrospective cohort study was conducted using data from the MIMIC-IV (v2.0) database, which included 18,713 ICU patients with S-AKI. Propensity score matching (PSM) was used to adjust for confounding factors, and multivariate Cox regression was employed to calculate hazard ratios (HRs) and 95% confidence intervals (CIs). Patient survival and clinical characteristics will be assessed utilizing Kaplan-Meier curves, with comparisons conducted using the log-rank test.

RESULTS

Kaplan-Meier survival analysis revealed significant differences in survival between the groups. Multivariate Cox regression indicated a reduced risk of 28-day mortality associated with vitamin D supplementation (HR: 0.73, 95% CI: 0.67-0.80, p < 0.001). The results after PSM were consistent with those of the original cohort. Similar results were observed for in-hospital mortality and 90-day mortality. The Restricted Cubic Spline curve (RCS) indicated an increasing trend in the therapeutic effect of vitamin D with increasing SOFA score.

CONCLUSIONS

Vitamin D supplementation is associated with decreased all-cause mortality in patients with S-AKI, and those with more severe conditions may benefit even more.

Revisiting Vitamin D Guidelines: A Critical Appraisal of the Literature

BACKGROUND/OBJECTIVE

The goal of this review is to compare the 2024 and 2011 Endocrine Society's Clinical Practice Guidelines on vitamin D2 or vitamin D3 (vitamin D). The 2024 Guideline made recommendations for the general healthy population for skeletal and extra skeletal health benefits of vitamin D. This contrasts with the 2011 Guidelines which provided clinicians with guidance on how to evaluate and treat patients with vitamin D deficiency and prevent recurrence.

DISCUSSION

The 2024 Guideline focused on randomized controlled trials and ignored association studies and other studies that have supported the skeletal and extra skeletal health benefits of vitamin D. The 2024 Guideline recommended empiric vitamin D in children and adolescents aged 1 to 18 years to reduce risk of upper respiratory tract infections, pregnant women to improve pregnancy-related outcomes, prediabetic patients to reduce risk of diabetes, and to improve mortality in those over 75 years.

CONCLUSION

These guidelines do not apply to individuals with abnormalities in calcium, phosphate, vitamin D, and bone metabolism which were provided in the 2011 Guidelines. For nonpregnant adults up to the age of 75, they recommend the Dietary Reference Intakes of 600 IUs (international units; 1 IU = 25 ng of vitamin D), and 800 IUs as recommended by The Institute of Medicine. Association studies have suggested that to obtain maximum extraskeletal benefits from vitamin D including reducing risk of upper respiratory tract infection for children and adults, autoimmune disorders, pre-eclampsia, low birth weight, neonatal dental caries, and deadly cancers circulating concentrations of 25-hydroxyvitamin D should be at least 30 ng/mL with a preferred range of 40-60 ng/mL as recommended by the 2011 Guidelines.

Assessing the relative importance of vitamin D deficiency in cardiovascular health

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

Vitamin D beyond the blood: Tissue distribution of vitamin D metabolites after supplementation

Vitamin D3's role in mineral homeostasis through its endocrine function, associated with the main circulating metabolite 25-hydroxyvitamin D3, is well characterized. However, the increasing recognition of vitamin D3's paracrine and autocrine functions-such as cell growth, immune function, and hormone regulation-necessitates examining vitamin D3 levels across different tissues post-supplementation. Hence, this review explores the biodistribution of vitamin D3 in blood and key tissues following oral supplementation in humans and animal models, highlighting the biologically active metabolite, 1,25-dihydroxyvitamin D3, and the primary clearance metabolite, 24,25-dihydroxyvitamin D3. While our findings indicate significant progress in understanding how circulating metabolite levels respond to supplementation, comprehensive insight into their tissue concentrations remains limited. The gap is particularly significant during pregnancy, a period of drastically increased vitamin D3 needs and metabolic alterations, where data remains sparse. Within the examined dosage ranges, both human and animal studies indicate that vitamin D3 and its metabolites are retained in tissues selectively. Notably, vitamin D3 concentrations in tissues show greater variability in response to administered doses. In contrast, its metabolites maintain a more consistent concentration range, albeit different among tissues, reflecting their tighter regulatory mechanisms following supplementation. These observations suggest that serum 25-hydroxyvitamin D3 levels may not adequately reflect vitamin D3 and its metabolite concentrations in different tissues. Therefore, future research should aim to generate robust human data on the tissue distribution of vitamin D3 and its principal metabolites post-supplementation. Relating this data to clinically appropriate exposure metrics will enhance our understanding of vitamin D3's cellular effects and guide refinement of clinical trial methodologies.

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

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

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

OBJECTIVE

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

DESIGN

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

SETTING

China.

PARTICIPANTS

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

RESULTS

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

CONCLUSIONS

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

Randomized control trial of moderate dose vitamin D alters microbiota stability and metabolite networks in healthy adults

Evidence indicates that both vitamin D and the gut microbiome are involved in the process of colon carcinogenesis. However, it is unclear what effects supplemental vitamin D3 has on the gut microbiome and its metabolites in healthy adults. We conducted a double-blind, randomized, placebo-controlled trial to identify the acute and long-term microbiota structural and metabolite changes that occur in response to a moderate dose (4,000 IU) of vitamin D3 for 12 weeks in healthy adults. Our results demonstrated a significant increase in serum 25-hydroxy-vitamin D (25(OH)D) in the treatment group compared to placebo (P < 0.0001). Vitamin D3 significantly increased compositional similarity (P < 0.0001) in the treatment group, and enriched members of the Bifidobacteriaceae family. We also identified a significant inverse relationship between the percent change in serum 25(OH)D and microbial stability in the treatment group (R = -0.52, P < 0.019). Furthermore, vitamin D3 supplementation resulted in notable metabolic shifts, in addition to resulting in a drastic rewiring of key gut microbial-metabolic associations. In conclusion, we show that a moderate dose of vitamin D3 among healthy adults has unique acute and persistent effects on the fecal microbiota, and suggest novel mechanisms by which vitamin D may affect the host-microbiota relationship.

IMPORTANCE

Preventative measures to reduce the rise in early-onset colorectal cancer are of critical need. Both vitamin D, dietary and serum levels, and the gut microbiome are implicated in the etiology of colorectal cancer. By understanding the intimate relationship between vitamin D, the gut microbiome, and its metabolites, we may be able to identify key mechanisms that can be targeted for intervention, including inflammation and metabolic dysfunction. Furthermore, the similarity of vitamin D to cholesterol, which is metabolized by the gut microbiome, gives precedence to its ability to produce metabolites that can be further studied and leveraged for controlling colorectal cancer incidence and mortality.

An error in concept and definition of recommended dietary allowance developed in 1941: Time to create new ones

The recommended dietary allowance (RDA) for vitamin C differs greatly (40-110 mg/d) across countries. In addition, vitamin D deficiency is, effectively, a pandemic, with a prevalence of approximately 25% to 80% across countries according to the findings in the recent scientific literature. However, these phenomena are attributable to a serious error in the concept and definition of RDA, which was developed in 1941. The current definition of RDA is the average daily dietary nutrient intake level that is deemed sufficient to meet the nutrient requirements of almost all (97-98%) healthy individuals. This is an extremely high intake level for a specific nutrient affecting only a few individuals (the upper 2.5%) of the generally healthy population. The RDA should be redefined by investigating at which intake level of a specific nutrient the incidence of a specific disease or mortality increases or decreases based on prospective cohort studies.

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

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

Vitamin D prophylaxis in persons with epilepsy?

Limited guidelines exist regarding osteoporosis prevention in the general population. Despite being a subject of controversy, the majority of research suggests that decreased vitamin D levels correlate with increased bone turnover, that is, an important risk factor for osteoporosis development. In most guidelines, daily vitamin D supplementation is recommended. In persons with epilepsy (PWE), the situation is more complex, as other factors can increase the chance of being vitamin D deficient. Currently, there are no internationally accepted guidelines regarding monitoring bone health in PWE. Our aim was to review the existing evidence in PWE on: (1) risk factors for vitamin D deficiency, (2) the identification of higher risk groups, and (3) the optimal ways to monitor bone health. Our narrative review shows that: (1) anti-seizure medication (ASM) use, especially enzyme-inducing ASM (EIASM) and valproic acid, is identified as an important risk factor for impaired bone health (e.g., increased risk for osteoporosis/fractures and/or vitamin D deficiency); (2) higher risk groups within the PWE population are present: intellectual or physical disability, institutionalized patients, puberty, early onset epilepsy and developmental epileptic encephalopathies, postmenopausal women, and use of multiple ASM/concomitant drugs (e.g. corticosteroids); and (3) a monitoring scheme can be suggested including laboratory tests, bone density measurements, managing of risk factors, and/or vitamin D supplementation. Overall, regular vitamin D measurement in PWE is a cost-effective and practical method for monitoring vitamin D deficiency, whereas in high-risk patients the combination of vitamin D measurement and bone densitometry is recommended. There is not enough evidence to advocate continuous vitamin D supplementation in all PWE. Children with epilepsy should receive the recommended daily intake of vitamin D for age and additional monitoring and supplementation if at higher risk of deficiency. There is a need for prospective trials exploring the potential benefit of vitamin D supplementation in PWE.

New insights into the vitamin D/PTH axis in endocrine-driven metabolic bone diseases

BACKGROUND

Endocrine regulation of bone metabolisms is the focus of the "Skeletal Endocrinology" series of meetings.

AIMS

To report on the outcome of the discussion on the role of vitamin D/PTH axis in endocrine osteopathies held during the 10th Skeletal Endocrinology Meeting which took place in Stresa (Italy) in March 2023.

OUTCOMES

Vitamin D/PTH axis has relevant influence on several outcomes in the general population and in patients affected by endocrinopathies such as hypoparathyroidism and secreting pituitary adenomas.

CONCLUSIONS

Assessing the status of the vitamin D/PTH axis and using vitamin D and PTH as therapeutic agents is mandatory in several endocrine-related bone metabolic conditions.

Vitamin D deficiency trends, risk factors, and occupational risk in active component service members of the U.S. Armed Forces, 2018-2022

Vitamin D contains 2 related fat-soluble substances, D3 and D2, that are essential for bone health and overall well-being. The burden of vitamin D deficiency within the active component of the armed forces is unknown. This study describes trends of vitamin D deficiency diagnoses in the active component of the U.S. Armed Forces. Risk factors for vitamin D, such as military occupation, were examined to see if preventive measures and targeted vitamin D screening would be beneficial, as the United States Preventive Task Force does not recommend universal screening for vitamin D, nor does TRICARE cover screening for asymptomatic individuals. The surveillance period covered January 1, 2018 through December 31, 2022. The data were derived from the Defense Medical Surveillance System (DMSS). Vitamin D deficiency was measured using ICD-9-CM and ICD-10-CM diagnoses recorded in inpatient and outpatient medical encounters. Incidence rate and average annual prevalence were calculated. A logistic regression was performed to obtain adjusted odds ratios. The rates of vitamin D deficiency diagnoses among active component service members (ACSMs) remained steady during the study period, with an incidence rate of 16.4 per 1,000 person-years and an average annual prevalence of 2.2%. Female service members, those of older age groups, and indoor workers demonstrated higher rates of vitamin D deficiency. Previously described demographic risk factors such as indoor work and history of obesity or malabsorption syndrome were also associated in this study with vitamin D deficiency in ACSMs, although older age groups in this study were not associated with vitamin D deficiency. Pilots and air crew had the lowest rates of vitamin D deficiency, while health care workers had the highest, when evaluating by occupation.

Can the AI tools ChatGPT and Bard generate energy, macro- and micro-nutrient sufficient meal plans for different dietary patterns?

Artificial intelligence chatbots based on large language models have recently emerged as an alternative to traditional online searches and are also entering the nutrition space. In this study, we wanted to investigate whether the artificial intelligence chatbots ChatGPT and Bard (now Gemini) can create meal plans that meet the dietary reference intake (DRI) for different dietary patterns. We further hypothesized that nutritional adequacy could be improved by modifying the prompts used. Meal plans were generated by 3 accounts for different dietary patterns (omnivorous, vegetarian, and vegan) using 2 distinct prompts resulting in 108 meal plans total. The nutrient content of the plans was subsequently analyzed and compared to the DRIs. On average, the meal plans contained less energy and carbohydrates but mostly exceeded the DRI for protein. Vitamin D and fluoride fell below the DRI for all plans, whereas only the vegan plans contained insufficient vitamin B12. ChatGPT suggested using vitamin B12 supplements in 5 of 18 instances, whereas Bard never recommended supplements. There were no significant differences between the prompts or the tools. Although the meal plans generated by ChatGPT and Bard met most DRIs, there were some exceptions, particularly for vegan diets. These tools maybe useful for individuals looking for general dietary inspiration, but they should not be relied on to create nutritionally adequate meal plans, especially for individuals with restrictive dietary needs.

Low Vitamin D Levels in Patients with Symptoms of Gastroparesis: Relationships with Nausea and Vomiting, Gastric Emptying and Gastric Myoelectrical Activity

Patients with gastroparesis (Gp) often have diets deficient in calories, electrolytes, and vitamins. Vitamin D levels have been reported to be low in some patients with Gp but has not been systematically studied.

AIMS

To determine vitamin D levels and relationships among symptoms, gastric emptying and gastric myoelectrical activity (GMA) in patients with symptoms of Gp.

METHODS

25-hydroxy-vitamin D was measured in patients at enrollment in the Gastroparesis Clinical Consortium Registry. Gastroparesis Cardinal Symptoms Index (GCSI), gastric emptying, and GMA before and after water load satiety test (WLST) were measured. GMA, expressed as percentage distribution of activity in normal and dysrhythmic ranges, was recorded using electrogastrography.

RESULTS

Overall, vitamin D levels were low (< 30 ng/ml) in 288 of 513 (56.1%) patients with symptoms of Gp (206 of 376 (54.8%) patients with delayed gastric emptying (Gp) and 82 of 137 (59.9%) patients with symptoms of Gp and normal gastric emptying). Low vitamin D levels were associated with increased nausea and vomiting (P < 0.0001), but not with fullness or bloating subscores. Low vitamin D levels in patients with Gp were associated with greater meal retention at four hours (36% retention) compared with Gp patients with normal vitamin D levels (31% retention; P = 0.05). Low vitamin D in patients with normal gastric emptying was associated with decreased normal 3 cpm GMA before (P = 0.001) and increased tachygastria after WLST (P = 0.01).

CONCLUSIONS

Low vitamin D levels are present in half the patients with symptoms of gastroparesis and are associated with nausea and vomiting and gastric neuromuscular dysfunction.

Navigating Complexities: Vitamin D, Skin Pigmentation, and Race

Vitamin D plays a critical role in many physiological functions, including calcium metabolism and musculoskeletal health. This commentary aims to explore the intricate relationships among skin complexion, race, and 25-hydroxyvitamin D (25[OH]D) levels, focusing on challenges the Endocrine Society encountered during clinical practice guideline development. Given that increased melanin content reduces 25(OH)D production in the skin in response to UV light, the guideline development panel addressed the potential role for 25(OH)D screening in individuals with dark skin complexion. The panel discovered that no randomized clinical trials have directly assessed vitamin D related patient-important outcomes based on participants' skin pigmentation, although race and ethnicity often served as presumed proxies for skin pigmentation in the literature. In their deliberations, guideline panel members and selected Endocrine Society leaders underscored the critical need to distinguish between skin pigmentation as a biological variable and race and ethnicity as socially determined constructs. This differentiation is vital to maximize scientific rigor and, thus, the validity of resulting recommendations. Lessons learned from the guideline development process emphasize the necessity of clarity when incorporating race and ethnicity into clinical guidelines. Such clarity is an essential step toward improving health outcomes and ensuring equitable healthcare practices.

Vitamin D for the Prevention of Disease: An Endocrine Society Clinical Practice Guideline

BACKGROUND

Numerous studies demonstrate associations between serum concentrations of 25-hydroxyvitamin D (25[OH]D) and a variety of common disorders, including musculoskeletal, metabolic, cardiovascular, malignant, autoimmune, and infectious diseases. Although a causal link between serum 25(OH)D concentrations and many disorders has not been clearly established, these associations have led to widespread supplementation with vitamin D and increased laboratory testing for 25(OH)D in the general population. The benefit-risk ratio of this increase in vitamin D use is not clear, and the optimal vitamin D intake and the role of testing for 25(OH)D for disease prevention remain uncertain.

OBJECTIVE

To develop clinical guidelines for the use of vitamin D (cholecalciferol [vitamin D3] or ergocalciferol [vitamin D2]) to lower the risk of disease in individuals without established indications for vitamin D treatment or 25(OH)D testing.

METHODS

A multidisciplinary panel of clinical experts, along with experts in guideline methodology and systematic literature review, identified and prioritized 14 clinically relevant questions related to the use of vitamin D and 25(OH)D testing to lower the risk of disease. The panel prioritized randomized placebo-controlled trials in general populations (without an established indication for vitamin D treatment or 25[OH]D testing), evaluating the effects of empiric vitamin D administration throughout the lifespan, as well as in select conditions (pregnancy and prediabetes). The panel defined "empiric supplementation" as vitamin D intake that (a) exceeds the Dietary Reference Intakes (DRI) and (b) is implemented without testing for 25(OH)D. Systematic reviews queried electronic databases for publications related to these 14 clinical questions. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology was used to assess the certainty of evidence and guide recommendations. The approach incorporated perspectives from a patient representative and considered patient values, costs and resources required, acceptability and feasibility, and impact on health equity of the proposed recommendations. The process to develop this clinical guideline did not use a risk assessment framework and was not designed to replace current DRI for vitamin D.

RESULTS

The panel suggests empiric vitamin D supplementation for children and adolescents aged 1 to 18 years to prevent nutritional rickets and because of its potential to lower the risk of respiratory tract infections; for those aged 75 years and older because of its potential to lower the risk of mortality; for those who are pregnant because of its potential to lower the risk of preeclampsia, intra-uterine mortality, preterm birth, small-for-gestational-age birth, and neonatal mortality; and for those with high-risk prediabetes because of its potential to reduce progression to diabetes. Because the vitamin D doses in the included clinical trials varied considerably and many trial participants were allowed to continue their own vitamin D-containing supplements, the optimal doses for empiric vitamin D supplementation remain unclear for the populations considered. For nonpregnant people older than 50 years for whom vitamin D is indicated, the panel suggests supplementation via daily administration of vitamin D, rather than intermittent use of high doses. The panel suggests against empiric vitamin D supplementation above the current DRI to lower the risk of disease in healthy adults younger than 75 years. No clinical trial evidence was found to support routine screening for 25(OH)D in the general population, nor in those with obesity or dark complexion, and there was no clear evidence defining the optimal target level of 25(OH)D required for disease prevention in the populations considered; thus, the panel suggests against routine 25(OH)D testing in all populations considered. The panel judged that, in most situations, empiric vitamin D supplementation is inexpensive, feasible, acceptable to both healthy individuals and health care professionals, and has no negative effect on health equity.

CONCLUSION

The panel suggests empiric vitamin D for those aged 1 to 18 years and adults over 75 years of age, those who are pregnant, and those with high-risk prediabetes. Due to the scarcity of natural food sources rich in vitamin D, empiric supplementation can be achieved through a combination of fortified foods and supplements that contain vitamin D. Based on the absence of supportive clinical trial evidence, the panel suggests against routine 25(OH)D testing in the absence of established indications. These recommendations are not meant to replace the current DRIs for vitamin D, nor do they apply to people with established indications for vitamin D treatment or 25(OH)D testing. Further research is needed to determine optimal 25(OH)D levels for specific health benefits.

Variants in Vitamin D-related Genes and Prostate Cancer Risk in Black Men

BACKGROUND

The relationship between vitamin D and prostate cancer has primarily been characterized among White men. However, Black men 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 six critical genes in the vitamin D pathway and prostate cancer risk in Black men.

METHODS

We assessed a total of 69 candidate variants in six genes ( 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. A statistical significance threshold of 0.000724 was used to account for the 69 variants tested.

RESULTS

None of the variants examined were significantly associated with prostate cancer risk among Black men after multiple comparison adjustment. Four variants tested P<0.05 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 non-significant 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.

[Relationship between serum 25-hydroxyvitamin D and handgrip strength in middle-aged and elderly people in five cities of Western China]

OBJECTIVE

To explore the association between serum 25-hydroxyvitamin D [25(OH)D] and handgrip strength in middle-aged and elderly people in 5 cities of Western China.

METHODS

Based on the data of a cross-sectional survey conducted in the 5 cities of Western China from February to July 2023, the relevant demographic characteristics of people were collected by questionnaire, handgrip strength was collected by physical examination, and serum 25(OH)D was detected by HPLC-MS/MS. The association between the serum 25(OH)D and handgrip strength was analyzed using Logistic regression and Chi-square test for between-group comparisons models.

RESULTS

The prevalence of 25(OH)D deficiency and insufficiency among the middle-aged and elderly people in the 5 cities of Western China was 52.9% and 34.5%, respectively. The people who were older, female, and sampled in winter had lower serum 25(OH)D levels (P < 0.05). The prevalence of loss of handgrip strength among the middle-aged and elderly people was 25.3%. The prevalence of handgrip strength loss was higher in the aged 65-80 participants with 25(OH)D deficiency (45. 0%) than in those with 25(OH)D insufficiency (32.6%) and 25(OH)D sufficiency (20.6%). The highest prevalence of loss of handgrip strength was found in the aged 75-80 participants with 25(OH)D deficiency (62. 1%), followed by the 25(OH)D insufficient group (11.1%, P < 0.05). The study found that middle-aged and elderly people with 25(OH)D deficiency had a 1.4-fold increased risk of handgrip strength loss compared with those with 25(OH)D sufficiency (OR=2.403, 95%CI: 1.202-4.804, P=0.013). No significant association was found between 25(OH)D insufficiency and handgrip strength status in the middle-aged and elderly people. For every 5 μg/L increase in total serum 25(OH)D, the risk of handgrip strength loss reduced by 13.1% (OR=0.869, 95%CI: 0.768-0.982, P=0.025). For every 5 μg/L increase in serum 25(OH)D2, the risk of handgrip strength loss reduced by 24.1% (OR=0.759, 95%CI: 0.582-0.990, P=0.042). No significant association was found between serum 25(OH)D3 levels and the risk of handgrip strength loss. The risk of handgrip strength loss in middle-aged and elderly people was reduced by 25.2% for each incremental increase in the total serum 25(OH)D levels (deficient, insufficient and sufficient) (OR=0.748, 95%CI: 0.598-0.936, P=0.011). The risk of handgrip loss was reduced by 40.0% for each incremental increase in serum 25(OH)D levels in the aged 65-80 and aged 65-69 participants, and by 80.0% for each incremental increase in 25(OH)D levels in the aged 75-80 parti-cipants.

CONCLUSION

Serum total 25(OH)D and 25(OH)D2 levels are associated with handgrip strength status in middle-aged and elderly people in the 5 cities of Western China.

Determining the vitamin D supplementation duration to reach an adequate or optimal vitamin D status and its effect on blood lipid profiles: a longitudinal study

BACKGROUND

Recently, Serum vitamin D (Vit. D) levels evaluation and the use of Vit. D supplements have increased substantially. There is no specific guideline for the duration of Vit. D supplementation, so yet Vit. D supplementation duration has remained a critical and controversial issue. This study aimed to determine the vit. D supplementation duration to reach an adequate or optimal Vit. D status and its effect on lipid profile.

METHODS

In this longitudinal study, 345 women with different status of Vit. D levels were enrolled and followed up for one year. Eligible participants received 50,000 IU Vit. D3 (cholecalciferol) once a month for 12 consecutive months. The serum Vit. D levels and lipid profiles were measured at baseline, 3rd, 6th, and 12th months after the intervention. Participants were categorized based on Vit. D level at baseline into deficiency (< 20 ng/mL), inadequate (20-30 ng/mL), and adequate (> 30 ng/mL) groups, and the data were compared at different times between the three groups.

RESULTS

Three deficiency (n = 73), inadequate (n = 138) and adequate (n = 134) groups of participants were followed. In all participants the average amount of Vit. D level changes were 8 ng/mL after one year of supplementation. The mean changes of serum Vit. D level in 6th and 12th months vs. 3th month was as below: In deficiency group: 4.08 ± 0.85 and 10.01 ± 1.02 ng/mL; (p < 0.001), in inadequate group: 3.07 ± 0.59 and 7.26 ± 0.78 ng/mL; (p = 0.001) and in adequate group: 2.02 ± 0.88 and 6.44 ± 1.005 ng/ml; (p = 0.001). Lipid profiles were improved in three groups. So, the mean changes of lipid profiles at the end of the study comparing with the baseline were: -5.86 ± 2.09, -7.22 ± 1.43 and - 6.17 ± 1.72 (mg/dl) for LDL (p < 0.05); -12.24 ± 3.08, -13.64 ± 3.21 and - 17.81 ± 2.94 (mg/dl) for cholesterol (p < 0.05) in deficiency, inadequate and adequate groups, respectively. For triglyceride, the mean changes were - 13.24 ± 5.78 and - 15.85 ± 7.49 (mg/dl) in deficiency and adequate groups, respectively (p < 0.05). Although the triglyceride decreased in the inadequate group at the end of the study but this difference was not significant (p = 0.67).

CONCLUSION

Taking of 50,000 IU Vit. D 3 monthly for 12 months resulted in reaching its level to adequate level in both deficiency and insufficient groups; however, in the adequate group its level did not reach above than 50 ng/mL. Therefore, 50,000 IU Vit. D3 supplementation monthly for one year can have beneficial effects on lipid profiles and there is no risk of toxicity in healthy women.

Assessment of serum vitamin D levels in children aged 0-17 years old in a Chinese population: a comprehensive study

Vitamin D deficiency and insufficiency pose global public health challenges, yet research on serum vitamin D levels in the 0-17-year-old age group in southeastern China remains limited. This study aimed to fill this gap by investigating serum 25(OH)D levels in children in the region aged 0-17 years, contributing crucial data for understanding vitamin D nutritional status. Liquid chromatography‒mass spectrometry/mass spectrometry (LC‒MS/MS) technology was used. Vitamin D testing was integrated into routine diagnostic procedures for 11,116 children in Wujiang District, Suzhou City. Among the 0-17-year age group, comprising 6348 boys and 4768 girls, the prevalence of serum 25(OH)D deficiency and insufficiency was 21.4% and 31.0%, respectively. The median serum 25(OH)D concentration was 29.72 ng/mL (21.84-39.84 ng/mL) in boys compared to 28.48 ng/mL (20.65-39.23 ng/mL) in girls. Seasonal variations were observed, with median serum 25(OH)D concentrations of 29.02 ng/mL (20.73-39.72 ng/mL) in spring, 28.79 ng/mL (21.53-39.37 ng/mL) in summer, 30.12 ng/mL (22.00-39.70 ng/mL) in autumn, and 28.58 ng/mL (19.97-39.46 ng/mL) in winter. Statistically significant differences were noted in the serum 25(OH)D levels during autumn and winter. In conclusion, the rate of adequate vitamin D levels in local children was 47.5%, revealing a relatively high prevalence of vitamin D deficiency (21.4%) and insufficiency (31.0%), especially during the post-preschool period. Advocating for vitamin D supplementation in children is crucial for ensuring adequate vitamin D support.

The Influence of Vitamin D Levels on Dental Caries: A Retrospective Study of the United States Population

(1) Background: This study examines vitamin D's impact on dental caries to inform prevention strategies, given its critical role in bone and calcium regulation, vital for dental health. (2) Methods: Data from 18,683 participants of the National Health and Nutrition Examination Survey (NHANES) 2011-2016 were analyzed. NHANES collects U.S. population data through interviews, physical exams, and tests, including vitamin D levels and dental health assessed using both the decayed, missing, and filled teeth (DMFT) index and the presence of untreated dental caries. Vitamin D levels were measured according to serum 25(OH)D concentrations, and the analyses adjusted for confounders such as body mass index (BMI) and socioeconomic status (SES) using Chi-square, Mann-Whitney U, Kruskal-Wallis tests, as well as logistic and Poisson regression. (3) Results: This study found a mean DMFT score of 7.36 and a 33.2% prevalence of untreated dental caries. A higher caries prevalence was correlated with a lower SES (p < 0.001), the male gender (p < 0.001), and a higher BMI (p < 0.001). Severe vitamin D deficiency (<25 nmol/L) doubled the risk of dental caries, with odds ratios of 2.261 and 1.953 after adjusting for demographic factors and BMI. (4) Conclusions: Our study confirms a significant relationship between low vitamin D levels and an increased risk of dental caries nationwide, even after accounting for sociodemographic factors, emphasizing the importance of maintaining sufficient vitamin D levels for preventing caries.

Epidemiology of Celiac Disease in Western Iran during 2019-2021

Celiac disease is a growing global public health concern. This epidemiological study is aimed at determining the prevalence of celiac disease in Kermanshah, Western Iran, from 2019 to 2021, as well as the frequency of gastrointestinal and nongastrointestinal manifestations associated with the disease. In this cross-sectional study, the medical records of all patients with a confirmed diagnosis of celiac disease between 2019 and 2021 were reviewed. The average population during the study period was 2,058,545. A researcher-developed checklist was used as the data collection tool, and descriptive statistics were employed for data analysis. During the study period, there were 113 patients diagnosed with celiac disease, with a mean age of 29.1 ± 16.6 years. The three-year prevalence of celiac disease was 5.49 (95% CI: 5.17-5.82) per 100,000 population. Among these patients, 70% (n = 78) was female. The most common gastrointestinal manifestations of the disease were abdominal pain (77.8%), constipation (59.3%), and diarrhea (54.9%). Iron-deficiency anemia (64.6%) and vitamin D3 deficiency (46.1%) were the most common nongastrointestinal manifestations. Growth retardation was observed in 39.0% of patients. This study demonstrated a higher prevalence of celiac disease in Kermanshah compared to global statistics. Given the association of celiac disease with other conditions such as diabetes, irritable bowel syndrome, growth retardation, and iron-deficiency anemia, healthcare providers should consider screening patients for celiac disease. Furthermore, community-based education is crucial in raising awareness about the significance of adhering to a proper diet and reducing wheat consumption.

Vitamin D Levels as a Potential Modifier of Eosinophilic Esophagitis Severity in Adults

BACKGROUND

Vitamin D deficiency is associated with atopic and immune-mediated diseases but has not been extensively assessed in eosinophilic esophagitis (EoE). We aimed to assess if vitamin D levels in newly diagnosed EoE patients were lower than in non-EoE controls and examine levels in relation to EoE clinical features.

METHODS

This secondary analysis of a prospective cohort study used data and biosamples from adults who underwent outpatient esophagogastroduodenoscopy. Before each procedure, blood was obtained and stored at -80oC. Serum 25-hydroxy-vitamin D3 (25(OH)D3) was measured by ELISA. Levels for cases and controls were compared at baseline. Within cases, 25(OH)D3 levels were compared for clinical, endoscopic, and histologic measures.

RESULTS

We analyzed 40 EoE and 40 non-EoE controls. Mean serum 25(OH)D3 level was slightly lower in EoE patients than controls (30.9 ± 15.3 ng/mL vs. 35.9 ± 15.4; p = 0.15). After controlling for age, sex, and race, adjusted levels were 10.8 ng/mL lower in EoE patients (95% CI: -19.0, -2.5), but 25(OH)D3 deficiency (< 20ng/mL) was similar in cases and controls (20% vs. 15%; p = 0.56). Levels of 25(OH)D3 were not associated with differences in clinical or endoscopic features of EoE, and EREFS and eosinophil counts did not significantly correlate with 25(OH)D3 levels (R of -0.28 [p = 0.08] and - 0.01 [p = 0.93], respectively). 25(OH)D3 levels were lower in EoE cases with lamina propria fibrosis (23.2 ± 9.6 vs. 45.0 ± 17.7; p = 0.03).

CONCLUSIONS

After adjusting for age, sex, and race, 25(OH)D3 levels were lower in EoE cases than controls, but deficiency was not common. 25(OH)D3 levels were generally similar across most EoE disease features.

Association between polycyclic aromatic hydrocarbons and periodontitis: Results from a large population-based study

AIM

To explore the association between polycyclic aromatic hydrocarbons (PAHs) (measured using urinary metabolites) and periodontitis using data from the National Health and Nutrition Examination Survey 2009-2014.

MATERIALS AND METHODS

Weighted binary logistic regression, Bayesian kernel machine regression (BKMR) and weighted quantile sum (WQS) regression were used to evaluate independent and joint associations between the six urinary monohydroxylated metabolites of PAHs (OH-PAHs) and periodontitis.

RESULTS

In all, 3413 participants were included in this study. All six urinary OH-PAHs were present at higher levels in the periodontitis group compared with the non-periodontitis group (p < .001). Fully adjusted multivariable logistic regressions showed positive associations between the six urinary OH-PAHs and periodontitis (p < .05). Higher concentrations of OH-PAHs were also positively associated with attachment loss, periodontal pocket depth (PPD) and the number of tooth loss. BKMR and WQS regression yielded similar positive associations between OH-PAH mixtures and periodontitis.

CONCLUSIONS

PAHs and their mixture are positively associated with periodontitis, which may provide novel insights into periodontitis prevention from an environmental exposure perspective.

Independent associations of serum calcium with or without albumin adjustment and serum phosphorus with nonalcoholic fatty liver disease: results from NHANES 1999-2018

Background

The associations of serum calcium and phosphorus with nonalcoholic fatty liver disease (NAFLD) remain unclear. In addition, there may be an effect of albumin correction on the association between serum calcium and NAFLD. We aimed to explore these relationships in the National Health and Nutrition Examination Survey (NHANES).

Methods

Eligible adult individuals from NHANES 1999-2018 were recruited for the study. We explored the associations of serum calcium, albumin-adjusted serum calcium, and serum phosphorus with NAFLD in multivariable-adjusted regression models. In addition, restricted cubic spline (RCS), stratified analysis, and multiple sensitivity analyses were used for further elaboration.

Results

The study sample consisted of 20,900 participants, with an observed NAFLD prevalence of 44.65%. Fully adjusted models indicated that serum calcium was inversely associated with NAFLD (odds ratio [OR] and 95% confidence interval [CI] = 0.70 (0.62, 0.78), p<0.0001), whereas albumin-adjusted serum calcium was positively associated with NAFLD (OR and 95% CI=1.59 (1.41, 1.79), p<0.0001). RCS modeling indicated that serum calcium without and with albumin adjustment was linearly(p nonlinear = 0.083) and nonlinearly (p nonlinear < 0.0001) associated with NAFLD, respectively, whereas serum phosphorus showed a U-shaped relationship with NAFLD(p nonlinear < 0.0001). Gender is a significant influence in all associations, and other variables may also have an effect. Sensitivity analyses indicated that these associations were independent of additional significant confounders.

Conclusion

Serum calcium and phosphorus were significantly associated with the development of NAFLD. These findings suggest the potential clinical significance of serum calcium/phosphorus and albumin levels in individuals at high risk for NAFLD. Our study supports the potential role of serum calcium/phosphorus homeostasis in the pathophysiology of NAFLD and could serve as NAFLD-related biomarkers.

Trends of serum 25(OH) vitamin D and association with cardiovascular disease and all-cause mortality: from NHANES survey cycles 2001-2018

Background

The focus of this survey is on survey data for adults aged 20 and above, covering nine survey cycles from 2001 to 2018. Additionally, the present study explored the correlation between vitamin D concentrations and both cardiovascular disease (CVD) and all-cause mortality.

Objective

The objectives of this study were to evaluate the trend of changes in the serum 25(OH)D concentration changes in US adults during the survey period, the prevalence of vitamin D deficiency, and the current status of vitamin D dietary intake and supplementation.

Methods

In-home health interviews were performed using meticulously designed questionnaires that gathered information on demographic details, socioeconomic conditions, dietary patterns, and overall health status. Health assessments were conducted in specially designed mobile centers.

Results

Survey data from 2001 to 2018 revealed a rise in serum 25(OH)D levels, from a weighted mean (95% CI) of 65.6 (63.8-67.4) nmol/L during 2001-2002 to 73.5 (70.4-76.5) nmol/L during 2017-2018, among US adults, while overall vitamin D deficiency rates remained stable (p = 0.152). Notably, in adults aged 20-39, 25(OH)D levels decreased (p = 0.002 for trend), and 25(OH)D deficiency increased (p = 0.003 for trend), especially among those with low incomes (deficiency >30%). Upon multivariable adjustment, an L-shaped relationship was found between serum 25(OH)D concentrations and both CVD and all-cause mortality (p < 0.001 for nonlinearity), as corroborated by sensitivity analyses.

Conclusion

From 2001 to 2018, US adults experienced a significant increase in their serum 25(OH) D concentration. However, subgroups of individuals, including young adults and individuals with lower socioeconomic status, exhibited a heightened risk of 25(OH)D deficiency. Furthermore, an L-shaped relationship was found between 25(OH)D concentration and both all-cause and CVD mortality among US adults.

Vitamin D Deficiency, Inflammation, and Diminished Endogenous Regenerative Capacity in Coronary Heart Disease

Background

Vitamin D deficiency (VDD) is associated with coronary heart disease (CHD) and poor outcomes, but supplementation does not improve prognosis. VDD has been implicated in and may promote greater risk through inflammation and impaired progenitor cell function.

Objectives

The authors examined VDD, high-sensitivity C-reactive protein (hsCRP), circulating progenitor cell (CPC) counts, and outcomes in patients with CHD. They hypothesized that the higher risk with VDD is mediated by inflammation and impaired regenerative capacity.

Methods

A total of 5,452 individuals with CHD in the Emory Cardiovascular Biobank had measurement of 25-hydroxyvitamin D, subsets of whom had hsCRP measurements and CPCs estimated as CD34-expressing mononuclear cell counts. Findings were validated in an independent cohort. 25-hydroxyvitamin D <20 ng/mL was considered VDD. Cox and Fine-Gray models determined associations between marker levels and: 1) all-cause mortality; 2) cardiovascular mortality; and 3) major adverse cardiovascular events, a composite of adverse CHD outcomes.

Results

VDD (43.6% of individuals) was associated with higher adjusted cardiovascular mortality (HR: 1.57, 95% CI: 1.09-2.28). There were significant interactions between VDD and hsCRP and CPC counts in predicting cardiovascular mortality. Individuals with both VDD and elevated hsCRP had the greatest risk (HR: 2.82, 95% CI: 2.16-3.67). Only individuals with both VDD and low CPC counts were at high risk (HR: 2.25, 95% CI: 1.46-3.46). These findings were reproduced in the validation cohort.

Conclusions

VDD predicts adverse outcomes in CHD. Those with VDD, inflammation and/or diminished regenerative capacity are at a significantly greater risk of cardiovascular mortality. Whether targeted supplementation in these high-risk groups improves risk warrants further study.

The Vitamin D Metabolite Ratio Is Associated With Volumetric Bone Density in Older Men

CONTEXT

Serum 25-hydroxyvitamin D (25(OH)D) is the current marker of vitamin D adequacy, but its relationship with bone health has been inconsistent. The ratio of 24,25-dihydroxyvitamin D3 to 25(OH)D3 (vitamin D metabolite ratio or VMR) is a marker of vitamin D that has been associated with longitudinal changes in bone mineral density (BMD) and fracture risk.

OBJECTIVE

High-resolution peripheral quantitative computed tomography (HR-pQCT) provides information on bone health beyond standard dual-energy x-ray absorptiometry, in that it measures volumetric BMD (vBMD) as well bone strength. The relationship of the VMR with vBMD and bone strength remains unknown.

METHODS

We evaluated the associations of the VMR and 25(OH)D3 with vBMD and bone strength in the distal radius and tibia, assessed by HR-pQCT in 545 older men participating in the Osteoporotic Fractures in Men (MrOS) Study. Primary outcomes were vBMD and estimated failure load (EFL, a marker of bone strength) at the distal radius and tibia.

RESULTS

The mean age was 84 ± 4 years, 88.3% were White, and 32% had an estimated glomerular filtration rate <60 mL/min/1.73 m2. In adjusted models, each twofold higher VMR was associated with a 9% (3%, 16%) higher total vBMD and a 13% (5%, 21%) higher EFL at the distal radius. Results were similar at the distal tibia. 25(OH)D3 concentrations were not associated with any of the studied outcomes.

CONCLUSION

Among older men, a higher VMR was associated with greater vBMD and bone strength while 25(OH)D3 was not. The VMR may serve as a valuable marker of skeletal health in older men.

Vitamin D status and its associations with bone mineral density, bone turnover markers, and parathyroid hormone in Chinese postmenopausal women with osteopenia and osteoporosis

Background

Vitamin D is a key factor in bone metabolism, yet vitamin D insufficiency and deficiency are prevalent among postmenopausal women, with potential repercussions on bone mineral density (BMD), bone turnover markers (BTMs), and parathyroid hormone (PTH). Nonetheless, the findings from existing studies exhibit inconsistency, and a notable gap exists in the availability of large-scale investigations.

Methods

In this real-world study, 8,532 postmenopausal women over 50 years old with a diagnosis of osteopenia (50.9%) and osteoporosis (49.1%) at the first visit were enrolled in this study. Serum 25(OH)D level, PTH, osteocalcin (OC) and Beta-CrossLaps of type 1 collagen containing cross-linked C-telopeptide (β-CTX), were measured. BMD at all sites, including the lumbar spine, femoral neck, and total hip were obtained by dual-energy X-ray absorptiometry (DXA). The associations of serum 25(OH)D level with BMDs and BTMs were investigated using spearman correlation analysis and analysis of general linear model adjusted by age and body mass index.

Results

The serum 25(OH)D level was 22.17 ± 9.75 ng/mL among all patients included in this study. For the osteopenia group, the serum 25(OH)D level was 22.40 ± 9.41 ng/mL, while for the osteoporosis group, it measured 21.93 ± 10.08 ng/mL. In the osteopenia group, the prevalence of vitamin D deficiency, insufficiency and sufficiency was 45.8, 34.6, and 19.6%, respectively, which was close to that of the osteoporosis group (47.4, 34.3, and 18.3%) (p = 0.202). Spearman correlation analysis unveiled negative associations between serum 25(OH)D concentrations and both BTMs and PTH within both the osteopenia and osteoporosis group. In the osteoporosis group, there were positive correlations between 25(OH)D levels and femoral neck BMD (r = 0.040, p = 0.010) and total hip BMD (r = 0.053, p = 0.001). Furthermore, we found that for the osteopenia group, greater vitamin D levels were associated with greater femoral neck BMD (p = 0.020) and total hip BMD (p = 0.008) and lower β-CTX (p < 0.001), OC (p < 0.001), and PTH (p < 0.001). The same trends were seen in osteoporosis patients (p < 0.05), and with greater lumbar spine BMD with higher levels of 25(OH)D (p = 0.009).

Conclusion

This study showed high prevalence of vitamin D deficiency and insufficiency in Chinese postmenopausal women with osteopenia and osteoporosis and the relationships between vitamin D and BMD, BTMs and PTH. The results contribute to a more comprehensive understanding of how vitamin D may impact bone health.