Vitamin D supplementation guidelines

A bibliometric analysis and visualization of literature on the relationship between vitamin D and obesity over the last two decades

OBJECTIVE

The purpose of this study was to employ bibliometric analysis to visualize hot spots and evolving trends in the studies on the relationship between vitamin D and obesity.

METHODS

From the Web of Science Core Collection database, articles on vitamin D and obesity from 2001 to 2021 were retrieved. For the bibliometric visualization analysis, CiteSpace was employed. Some of the figures were created using GraphPad software.

RESULTS

4454 pieces of articles and reviews were found, with an average citation of 30.68 times. There are many more published papers in the area of "nutrition dietetics" (1166, 26.179 %). The United States possesses the largest number of publications (1297, 29.12 %) and demonstrates definitive leadership in this field. The League of European Research Universities generates a higher percentage of publications (256, 5.748 %) than other institutions. Major studies are funded by the United States Department of Health and Human Services (531, 11.922 %) and the National Institutes of Health, USA (528, 11.855 %). The top five keywords with the highest co-occurrence frequency are "obesity" (1260), "vitamin d" (943), "insulin resistance" (651), "risk" (642), and "d deficiency" (636). The biggest keyword cluster was #0 "adolescent" among the 18 keyword clusters. The three latest keywords in the keyword burst were "mineral density"、"d insufficiency" and "25 hydroxyvitamin d concentration".

CONCLUSION

This bibliometric analysis shows an overview of the current status of the research on the association between vitamin D and obesity. The prevalence of vitamin D deficiency and the relationship between vitamin D and metabolic syndrome in obese individuals remains hot topics. We speculate that the effect of obesity on vitamin D levels and bone mineral density, and the influence of vitamin D insufficiency on various body systems in obese populations will be future trends.

Effect of vitamin D status and vitamin D supplementation on immune function and prevention of acute respiratory tract infections in dark-skinned individuals: a systematic review and meta-analysis

OBJECTIVE

This systematic review and meta-analysis examined the evidence for a potential relationship between vitamin D status and vitamin D supplementation on immune function biomarkers and prevention of acute respiratory tract infections (ARTI) in dark-skinned individuals.

DESIGN

Six databases were searched (inception to December 2021) for randomised controlled trials (RCT) and observational studies. A narrative synthesis and random-effects meta-analysis were used to synthesise the findings.

SETTING

Not applicable.

PARTICIPANTS

Ethnic groups other than white, with or without a white comparator.

RESULTS

After duplicates were removed, 2077 articles were identified for screening. A total of eighteen studies (n 36 707), including seven RCT and 11 observational studies, met the inclusion criteria, and three RCT (n 5778) provided sufficient data of high enough quality to be included in a meta-analysis. An inverse association between vitamin D status and at least one inflammatory biomarker in black adults was found in three studies, and vitamin D status was inversely associated with ARTI incidence in black and Indigenous groups in two studies. There was no significant effect of vitamin D supplementation on differences in ARTI incidence in ethnic minority groups (OR, 1·40; 95 % CI: 0·70, 2·79; P = 0·34), nor African American (OR, 1·77; 95 % CI: 0·51, 6·19; P = 0·37) or Asian/Pacific (OR, 1·08; 95 % CI: 0·77, 2·68; P = 0·66) subgroups.

CONCLUSIONS

There is a lack of conclusive evidence supporting an association between vitamin D status and immune function or ARTI incidence in dark-skinned individuals. Further RCT in diverse ethnic populations are urgently needed.

Vitamin D Status and Physical Functioning in Nursing Home Residents after Improved Adherence to the Vitamin D and Calcium Recommendation-A Quasiexperimental Study

Introduction

Dietary supplements with vitamin and calcium are recommended to nursing home residents in Denmark, but adherence to the recommendation is low. In a previous part of this study, we reported improved adherence by means of The Model for Improvement leading to increased awareness and change of workflows at two nursing homes. However, potential effects of this improved adherence are unknown.

Objective

The objective of this substudy was to investigate if the improved adherence to the recommendation affected vitamin D status, muscle strength, and physical functioning of the residents.

Methods

This was a 20-week quasiexperimental study involving 40 residents from two Danish nursing homes. Baseline and endpoint measurements took place in October 2021 and March 2022, respectively. Outcomes were number of residents taking vitamin D and calcium supplements; vitamin D status; handgrip strength; and physical functioning with timed-up-and-go test and 30-second chair stand test.

Results

Prevalence of vitamin D supplement users increased from 45 to 78% (mean dose 41 μg) and of calcium supplement users from 40 to 72% (mean dose 769 mg) (both P=0.002). Among those having blood sampled at both baseline and endpoint (n = 30), mean vitamin D status increased from 66.6 ± 31.7 nmol/L to 82.8 ± 26.3 nmol/L (P < 0.001), and more residents were vitamin D sufficient at endpoint (90 vs. 63%, P=0.021). Endpoint vitamin D status among supplement users was 88.2 ± 22.2 nmol/L, which was higher compared to nonsupplement users (55.3 ± 30.4 nmol/L, P < 0.01). No effects were seen on muscle strength or physical functioning.

Conclusions

Increased supplementation with vitamin D using The Model for Improvement positively affected vitamin D status and prevalence of vitamin D sufficiency but did not affect muscle strength or physical functioning. Longer-term studies involving more residents are needed to investigate effects of improved adherence on these outcomes. This trial is registered with NCT04956705.

Integrative Geriatric Oncology: A Review of Current Practices

PURPOSE OF REVIEW

This article aims to offer a comprehensive review of optimal integrative medicine practices for geriatric oncology patients. Given the aging population and the global rise in cancer incidence, it is crucial to identify evidence-based modalities and employ an integrated approach to enhance cancer outcomes and quality of life in older adults.

RECENT FINDINGS

It has been predicted that 20.5% (6.9 million) of new cancer cases in 2050 will occur in adults over 80 years old.1 The increasing focus on lifestyle factors in healthy aging has shed light on various overlooked areas of significance. Notably, anti-inflammatory diets and the promotion of a healthy gut microbiome have demonstrated significant impacts on overall health outcomes, bolstering the body's innate capacity to combat disease. This review delves into further evidence and extrapolation concerning integrative approaches and their influence on cancer outcomes and older adults quality of life. The complexity and unique nature of cancer in older adults requires a wide range of support from medical providers. Incorporating various integrative techniques as part of cancer treatment and side effect support can improve health outcomes and patient's quality of life. Familiarity with the lifestyle interventions and other topics explored in this review equips healthcare providers to offer tailored and holistic care to geriatric patients navigating cancer.

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

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

Patterns of Dietary Supplement Use during the COVID-19 Pandemic in Poland: Focus on Vitamin D and Magnesium

Background: The COVID-19 pandemic has brought significant attention to the role of dietary supplements, particularly Vitamin D, in enhancing immunity and possibly mitigating the severity of the disease. The pandemic has highlighted the importance of nutritional health in preventing severe outcomes from infections. Objective: This study aimed to assess consumption patterns of dietary supplements, with a focus on Vitamin D, among the Polish population during the COVID-19 pandemic and to identify the demographic factors influencing these patterns. Methods: An anonymous survey was conducted in March 2021 among 926 pharmacy patients in Poland. The study analyzed the use of dietary supplements such as vitamin D, magnesium, and others in relation to variables like age, gender, and education level. Statistical analyses were performed using the Pearson chi-square test. Results: The study revealed that 77.1% of the respondents reported using dietary supplements, with Vitamin D being the most frequently mentioned, used by 64.6% of participants. Magnesium was also widely used, with a higher overall prevalence of 67.3%, making it the most commonly consumed supplement. The use of supplements was significantly higher among women and individuals with higher education. Younger age groups, particularly those aged 18-30, were more likely to use supplements. Conclusions: The use of supplements was significantly higher among women, individuals with higher education, and those aged 18-30. However, the findings also indicate a growing awareness and increased use across the general population. This trend reflects increased public awareness of the potential health benefits of these supplements in boosting immunity. However, the study also highlights the need for public education on the risks of over-supplementation and the importance of appropriate dosages.

Can Vitamin D Levels Influence Bone Metabolism and Osseointegration of Dental Implants? An Umbrella Review

INTRODUCTION

Due to the large amount of scientific evidence on the subject and the limitations and incongruities in previous reviews, the primary aim of this umbrella review is to gather all the information regarding the importance of vitamin D levels in the osseointegration of dental implants.

METHODS

The literature search was performed in PubMed, Web of Science, CINAHL Plus, Cochrane Library, and Academic Search Complete throughout the search expression ["vitamin D" AND ("dental implant" OR "dental implants")].

RESULTS

The initial search yielded 351 results, but at the end of the process, only five systematic reviews were selected.

CONCLUSIONS

Vitamin D seems to have a positive effect on the osseointegration of dental implants and on the reduction of dental implant failures; however, it is recommended that future studies take into account the limitations mentioned in this study in order to increase the validity and quality of scientific evidence on the subject.

The complex relationship between vitamin D and kidney stones: balance, risks, and prevention strategies

The association between vitamin D and kidney stones is characterized by a remarkable multi-dimensional complexity involving numerous physiological and metabolic pathways. Vitamin D is pivotal in maintaining calcium-phosphorus metabolic homeostasis and bone health. However, fluctuations in its intake, whether excessive or insufficient, May potentially increase the risk of kidney stones. Vitamin D exerts its influence on kidney stone formation indirectly by increasing the efficiency of intestinal calcium absorption and regulating renal calcium excretion. Moreover, there is a robust correlation between various states of vitamin D, particularly its active form, 1,25-dihydroxyvitamin D, and the development of numerous kidney stones. This finding underscores the necessity of individualized medical treatment in vitamin D supplementation and kidney stone prevention. When developing treatment strategies, it is essential to consider the patient's genetic background, lifestyle, environmental factors, and overall health. To prevent the formation of kidney stones, it is recommended that patients adopt a comprehensive approach, which May include measures such as moderate sun exposure, dietary modification, moderate exercise, and weight management. These preventive measures are designed to maintain healthy calcium and phosphorus metabolism and reduce kidney stone formation risk. Future studies should aim to elucidate the detailed mechanisms of vitamin D metabolism, individual differences, and the role of genes in this process. Furthermore, the role of lifestyle interventions in preventing kidney stones requires greater attention. Moreover, the implementation of large-scale, long-term prospective studies and randomized controlled trials will facilitate the assessment of the actual effects of diverse vitamin D supplementation strategies, thereby providing a robust scientific foundation for advancing more precise prevention strategies and clinical guidelines.

Consensus Statement on Vitamin D Status Assessment and Supplementation: Whys, Whens, and Hows

The 6th International Conference, "Controversies in Vitamin D," was convened to discuss controversial topics, such as vitamin D metabolism, assessment, actions, and supplementation. Novel insights into vitamin D mechanisms of action suggest links with conditions that do not depend only on reduced solar exposure or diet intake and that can be detected with distinctive noncanonical vitamin D metabolites. Optimal 25-hydroxyvitamin D (25(OH)D) levels remain debated. Varying recommendations from different societies arise from evaluating different clinical or public health approaches. The lack of assay standardization also poses challenges in interpreting data from available studies, hindering rational data pooling and meta-analyses. Beyond the well-known skeletal features, interest in vitamin D's extraskeletal effects has led to clinical trials on cancer, cardiovascular risk, respiratory effects, autoimmune diseases, diabetes, and mortality. The initial negative results are likely due to enrollment of vitamin D-replete individuals. Subsequent post hoc analyses have suggested, nevertheless, potential benefits in reducing cancer incidence, autoimmune diseases, cardiovascular events, and diabetes. Oral administration of vitamin D is the preferred route. Parenteral administration is reserved for specific clinical situations. Cholecalciferol is favored due to safety and minimal monitoring requirements. Calcifediol may be used in certain conditions, while calcitriol should be limited to specific disorders in which the active metabolite is not readily produced in vivo. Further studies are needed to investigate vitamin D effects in relation to the different recommended 25(OH)D levels and the efficacy of the different supplementary formulations in achieving biochemical and clinical outcomes within the multifaced skeletal and extraskeletal potential effects of vitamin D.

Vitamin D and Sarcopenia in the Senior People: A Review of Mechanisms and Comprehensive Prevention and Treatment Strategies

This article reviews the mechanisms and prevention strategies associated with vitamin D and sarcopenia in older adults. As a geriatric syndrome, sarcopenia is defined by a notable decline in skeletal muscle mass and strength, which increases the risk of adverse health outcomes such as falls and fractures. Vitamin D, an essential fat-soluble vitamin, is pivotal in skeletal muscle health. It affects muscle function through various mechanisms, including regulating calcium and phosphorus metabolism, promoting muscle protein synthesis, and modulation of muscle cell proliferation and differentiation. A deficiency in vitamin D has been identified as a significant risk factor for the development of sarcopenia in older adults. Many studies have demonstrated that low serum vitamin D levels are significantly associated with an increased risk of sarcopenia. While there is inconsistency in the findings, most studies support the importance of vitamin D in maintaining skeletal muscle health. Vitamin D influences the onset and progression of sarcopenia through various pathways, including the promotion of muscle protein synthesis, the regulation of mitochondrial function, and the modulation of immune and inflammatory responses. Regarding the prevention and treatment of sarcopenia, a combination of nutritional, exercise, and pharmacological interventions is recommended. Further research should be conducted to elucidate the molecular mechanism of vitamin D in sarcopenia, to study genes related to sarcopenia, to perform large-scale clinical trials, to investigate special populations, and to examine the combined application of vitamin D with other nutrients or drugs. A comprehensive investigation of the interconnection between vitamin D and sarcopenia will furnish a novel scientific foundation and productive strategies for preventing and treating sarcopenia. This, in turn, will enhance the senior people's quality of life and health.

The effect of vitamin D3 and omega-3 combination, taken orally, on triglycerides, lining of intestine, and the biodiversity of gut microbiota in healthy rats

AIM

The gut microbiota plays a key role in host health. An intake of omega-3 and vitamin D3 in a separate manner is vital for maintaining good health of gut microbiota and controlling some illness manifestations. The aim of this study is to investigate the potential change in biodiversity of the gut microbiome in healthy rats supplemented with vitamin D3, omega-3 alone and their combination and to reflect onto the triglyceride levels in serum and fecal samples.

METHODS AND RESULTS

Using the 16S rRNA gene Miseq Illumina NGS, and monitoring triglyceride levels in serum and fecal samples coupled with several clinical parameters, we examined the effect of orally taken combination of omega-3 and vitamin D3 alongside the separate intake of supplements on gut microbiota in 24 healthy white Wistar rats for six weeks. The study findings showed that combination treatment encouraged the growth of opportunistic Clostridia class during day 21 and 42 of treatment by 7.7 and 7.4 folds, respectively, exhibited incomplete absorption levels for both supplements when used concomitantly, demonstrated a damaging effect on the gut intestinal lining wall thickness (126 µm) when compared to control group (158  µm), increasing lumen diameter (400 µm), and showed higher triglyceride level in fecal samples.

CONCLUSIONS

These findings indicate that omega-3 and vitamin D3 supplements as combination intake reveal unfavorable effects, thus, it is advised to conduct further in-depth studies to clarify the presence or absence of any chemical interaction between both supplements' molecules and to investigate based on human model to attain a superior perspective.

A multi-omics analysis reveals vitamin D supplementation since childhood modulates molecules for signal transductions in the mouse striatum

Vitamin D is a critical fat-soluble vitamin for the nervous system. Research suggests a potential link between vitamin D deficiency and attention-deficit hyperactivity disorder (ADHD), particularly in children and adolescents. The core symptoms of ADHD are associated with deficits in striatal functions, and maintaining sufficient levels of vitamin D may help prevent or alleviate ADHD symptoms. However, the molecular changes in the striatum caused by vitamin D supplementation that may contribute to the brain processes linked to ADHD symptoms remain unclear. In this study, we established a mouse model fed diets with three different dose gradients of vitamin D3 (0, 500, and 2000 IU/kg·day) from postnatal day 21 (P21) to 14 weeks of age. Striatal tissues from mice with gradient vitamin D3 intake were subjected to reduced representation bisulfite sequencing (RRBS), RNA-sequencing, and neurotransmitter profiling by liquid chromatography-mass spectrometry (LC-MS). Our findings indicate that vitamin D supplementation since childhood influenced the overall landscape of DNA methylations and the expression of many genes involved in critical neurological functions in a dose-dependent manner. Additionally, our data demonstrate how vitamin D modulated neuropeptide signaling pathways, as well as cholinergic and dopaminergic synapses in the striatum, through an orchestrated mechanism involving epigenetic and transcriptional regulations. Furthermore, we observed a synergistic effect of vitamin D on dopamine release following acute methylphenidate injection into our mouse model. In summary, this study provides mechanistic insights into how dietary vitamin D supplementation since childhood can modulate specific signal transductions among striatal cells, underscoring the importance of vitamin D supplementation for ADHD management.

Antioxidant Functions of Vitamin D and CYP11A1-Derived Vitamin D, Tachysterol, and Lumisterol Metabolites: Mechanisms, Clinical Implications, and Future Directions

Evidence is increasing that vitamin D and CYP11A1-derived vitamin D, tachysterol, and lumisterol metabolites play a significant antioxidant role beyond its classical functions in bone health and calcium metabolism. Several recent studies have linked these elements to reduced oxidative stress as well as improved immune, cardiovascular, and neurological functions as a result of chronic kidney disease and cancer. Additionally, supplementation with this vitamin has been shown to be one of the most cost-effective micronutrient interventions worldwide, highlighting its potential as a therapeutic approach. The underlying mechanisms and implications of this antioxidant function of vitamin D or CYP11A1-derived vitamin D, tachysterol, and lumisterol metabolites are not well understood. This comprehensive and narrative review is aimed at summarizing the current evidence regarding the molecular mechanisms implicated in this antioxidant function of vitamin D, as well as to provide a general overview and to identify key research areas for the future, offering an extensive perspective that can guide both researchers and clinicians in the management of diseases associated with oxidative stress and/or insufficient vitamin D status.

Unraveling the Relationship Between Vitamin D and Oxidative Stress: A Cross-Sectional Study

INTRODUCTION

Vitamin D, beyond bone metabolism, has played a significant role in various physiological processes, including modulation of oxidative stress and maintenance of vascular architecture. Oxidative stress, a state of altered balance between reactive oxygen species (ROS) and antioxidants, is a critical factor in the pathogenesis of various chronic diseases. Our study aims to explore the intricate relationship between serum vitamin D levels and markers of oxidative stress in normotensive and hypertensive individuals.

MATERIALS AND METHODS

A total of 108 age-matched participants (35 to 50 years) of both genders (54 males and 54 females) were included in this cross-sectional study according to the study design and assessed for their serum vitamin D level by using enzyme-linked immunosorbent assay (ELISA) method and serum malondialdehyde (MDA) level by using a spectrophotometer at 540 nm after measurement of the blood pressure. The data were entered in a Microsoft Excel sheet and analyzed using Statistical Package for Social Science (SPSS) software version 20.

RESULTS

Our findings demonstrate a significant inverse correlation between serum vitamin D levels and MDA (r = -0.71, p < 0.001), indicating lower lipid peroxidation with higher vitamin D levels. Our study concludes by evident higher serum vitamin D levels associated with reduced oxidative stress, reflected by lower MDA.

CONCLUSION

These findings suggest a potential protective role of vitamin D against oxidative damage, which could have implications for the prevention of oxidative stress-related diseases.

Positive Effect of 25-Hydroxyvitamin D (25(OH)D) Levels in Follicular Fluid on Embryonic Developmental Potential in Diminished Ovarian Reserve (DOR) Patients Undergoing Microstimulation

OBJECTIVE

This study aimed to explore the effect of 25-hydroxyvitamin D (25(OH)D) levels in follicular fluid (FF) on the embryo outcome with diminished ovarian reserve (DOR) patients undergoing in vitro fertilization (IVF) by microstimulation protocol.

METHODS

A prospective cohort study of 79 patients with DOR who underwent IVF using the microstimulation protocol was conducted. Based on the level of 25(OH)D in follicular fluid (25(OH)D-FF), the patients were divided into a high-value group (25(OH)D-FF>11.1, n = 50) and a low-value group (25(OH)D-FF>11.1, n = 29). Correlation analysis was conducted between the level of 25(OH)D-FF and the rate of high-quality embryos on day 3 (D3). Logistic regression analysis of factors affecting the presence or absence of D3-available embryos in patients with DOR was conducted.

RESULTS

The number of oocytes retrieved, mature oocytes (MII), normal fertilization rate, number of available embryos on D3, and high-quality embryo rate were lower in the low-value group than in the high-value group (p = 0.000, p = 0.000, p = 0.009, p = 0.000, p = 0.001). The clinical pregnancy rate of frozen embryo transfer (FET) between the two groups was no statistically significant difference (p > 0.05); correlation analysis between the 25(OH)D-FF level and the rate of high-quality embryos was performed using Spearman's rank-sum test, and there was a positive correlation (R = 0.271, P<0.01). Logistic analysis showed that 25(OH)D-FF level was a protective factor for embryonic outcome (odds ratio (OR) > 1, P<0.01).

CONCLUSION

The 25(OH)D level in FF has a positive effect on embryonic outcomes in DOR patients with IVF using the microstimulation protocol. Vitamin D (VD) supplementation can be used to increase the number of available embryos and improve the quality of embryos for patients with DOR who are undergoing microstimulation of IVF.

Vitamin D Supplementation May Prevent or Treat Deficiency After Total Knee Arthroplasty: A Retrospective Cohort Analysis

BACKGROUND

Vitamin D deficiency is associated with poorer functional outcomes and increased complication rates after total knee arthroplasty (TKA). Yet, there is no longer term study evaluating vitamin D levels and supplementation after TKA. Our study aimed to compare quantitative vitamin D levels and supplementation regimens after TKA stratified by patient sex and race.

METHODS

A retrospective cohort study of primary TKA patients at a single hospital from 2015 to 2022 was conducted. We analyzed vitamin D preoperatively and postoperatively up to 2 years. Vitamin D deficiency was defined as <30 ng/mL. A subgroup analysis was conducted in patients with vitamin D <21 ng/mL. Supplementation categories included none, low (<1,001 IU), medium (1,001 to 5,000 IU), and high (>5,000 IU).

RESULTS

A total of 400 (66.0% female) patients who underwent 430 primary TKA procedures were included, and 65.3% received supplementation. Patients who were vitamin D sufficient preoperatively demonstrated higher vitamin D levels and ability to maintain sufficiency postoperatively using low-dose supplementation compared with no supplementation (P = 0.004). Those who were vitamin D deficient preoperatively demonstrated higher vitamin D levels postoperatively using medium to high doses (P = 0.02). For patients who became deficient postoperatively, supplementation was associated with achieving repletion at an average of 10.2 months (P < 0.001). Black patients demonstrated 2.8 times higher odds of having a vitamin D level less than 30 ng/mL (P = 0.03).

CONCLUSION

Our study demonstrated that low-dose vitamin D supplementation (<1,001 IU) was beneficial for vitamin D-sufficient TKA patients to achieve higher levels and maintain vitamin D sufficiency. Vitamin D-deficient TKA patients benefitted from medium-to-high dose supplementation (1,001 to 5,000+), but only 33.7% achieved vitamin D repletion. This work highlights the need to continue vitamin D surveillance postoperatively and the need to continue vitamin D repletion.

Association Among Vitamin D Supplementation, Serum 25(OH)D Concentrations, and Mortality Risk: A Prospective Cohort Study Using NHANES 2007-2018 Data

BACKGROUND

To determine the associations among self-reported vitamin D (VD) supplementation, measured serum 25-hydroxyvitamin D (25[OH]D) concentrations, and all-cause and cause-specific mortality risks.

METHODS

Self-reported VD supplementation, serum 25(OH)D concentration, and all-cause and cause-specific mortality data from the National Health and Nutrition Examination Survey 2007-2018 were examined for 10,793 adults ≥20 years from the United States. VD dosage was categorized as <800 or ≥800 IU/d. The mortality status and causes of mortality up to 2019 were determined using the National Death Index. The relationships among VD, 25(OH)D levels, and mortality were analyzed using Cox regression before and after propensity score matching (PSM).

RESULTS

Over a median of 6.6 years, 915 deaths were recorded, 230 because of cardiovascular disease (CVD), 240 because of cancer, and 445 because of other specific causes. Mortality risk did not differ between VD <800 IU/d and ≥800 IU/d before or after PSM. However, serum 25(OH)D concentrations were statistically different before and after PSM. The upper 2 quartiles of 25(OH)D levels were associated with lower all-cause mortality, and the fourth quartile was associated with reduced other-specific mortality before and after PSM. No correlation was found between the 25(OH)D concentration and CVD- or cancer-specific mortality after PSM. The inverse 25(OH)D-mortality relationship was consistent across subgroups.

CONCLUSIONS

Based on this large cohort study, higher 25(OH)D levels are robustly associated with reduced all-cause and other specific mortality but not CVD- or cancer-specific mortality. These findings support the benefits of maintaining adequate VD status for longevity. Further research is required to elucidate these mechanisms and define the optimal VD concentration to reduce mortality. These results underscore the importance of public health strategies for preventing VD deficiency.

Postoperative Vitamin D Surveillance and Supplementation in Revision Total Knee Arthroplasty Patients: A Retrospective Cohort Analysis

This study was a retrospective cohort analysis of 20 patients who underwent 23 revision total knee arthroplasty procedures in a single geographic region of the United States from January 2015 to February 2023. We analyzed their 25-OH vitamin D levels preoperatively and postoperatively at 1 month, 3 months, 6 months, 1 year, and 2 years. We categorized their supplementation regimens by dose: none, low dose (1000 IU and below), medium dose (1001-5000 IU), and high dose (>5000 IU). We found that there was a high incidence of vitamin D deficiency in this patient population.

Vitamin D Deficiency as a Risk Factor of Tinnitus: An Epidemiological Study

OBJECTIVES

Vitamin D deficiency as a risk factor of tinnitus has not been well known. We tried to evaluate the association between the serum 25-(OH) vitamin D levels and tinnitus among the Korean population to propose the possible role of serum vitamin D in patients with tinnitus.

METHODS

This cross-sectional study investigated the potential risk factors of tinnitus in relation to serum 25(OH)D levels within the Korean population. It encompassed a health interview, nutrition assessment, and a health examination. Data was sourced from the KNHANES V (2010-2012), conducted by the Division of Health and Nutritional Survey under the Korean Centers for Disease Control and Prevention (KCDCP). Participants were chosen from various sampling units categorized by geography, gender, and age group. The selection was facilitated through household registries using a stratified, multistage, clustered probability sampling approach.

RESULTS

Data of 16 408 subjects were collected in this study. There were significant differences in gender, economic status, educational level, and sun exposure duration between the tinnitus and non-tinnitus groups. Serum 25(OH) vitamin D level between hearing loss and normal hearing was also significantly different. The logistic regression models with serum 25(OH) vitamin D quartile and tinnitus as the dependent variable, which were controlled for age, sex, smoking status, BMI, diabetes, hypertension, sun exposure, regular exercise, income, and education, eventually demonstrated that serum vitamin D deficiency and low sun exposure duration significantly increased the risk of tinnitus development.

CONCLUSION

This study demonstrated a significant association between serum vitamin D levels and tinnitus, driven by large epidemiological data. The results of our study provide baseline data for further research to investigate the role of vitamin D in the pathogenesis and management of tinnitus.

Vitamin D and Atherosclerosis: Unraveling the Impact on Macrophage Function

Vitamin D plays a crucial role in preventing atherosclerosis and in the regulation of macrophage function. This review aims to provide a comprehensive summary of the clinical evidence regarding the impact of vitamin D on atherosclerotic cardiovascular disease, atherosclerotic cerebrovascular disease, peripheral arterial disease, and associated risk factors. Additionally, it explores the mechanistic studies investigating the influence of vitamin D on macrophage function in atherosclerosis. Numerous findings indicate that vitamin D inhibits monocyte or macrophage recruitment, macrophage cholesterol uptake, and esterification. Moreover, it induces autophagy of lipid droplets in macrophages, promotes cholesterol efflux from macrophages, and regulates macrophage polarization. This review particularly focuses on analyzing the molecular mechanisms and signaling pathways through which vitamin D modulates macrophage function in atherosclerosis. It claims that vitamin D has a direct inhibitory effect on the formation, adhesion, and migration of lipid-loaded monocytes, thus exerting anti-atherosclerotic effects. Therefore, this review emphasizes the crucial role of vitamin D in regulating macrophage function and preventing the development of atherosclerosis.

Vitamin D Levels in Patients with Noninfectious Uveitis: A Systematic Review and Meta-Analysis

PURPOSE

Vitamin D deficiency has been associated with higher rates of autoimmune disease, including noninfectious uveitis. This PRISMA-compliant review and meta-analysis aimed to analyze the correlation between noninfectious uveitis and vitamin D levels.

METHODS

We searched PubMed, Embase, Cochrane, and Web of Science databases for studies, published in English, assessing vitamin D levels in patients diagnosed with noninfectious uveitis. The outcomes of interest were vitamin D deficiency, vitamin D mean level, vitamin D supplementation, and smoking rates. A subgroup analysis of inactive uveitis and active uveitis was performed. The heterogeneity was assessed with Cochrane Q-test and I2 statistics; p > 0.10 and I2 > 50% were considered significant for heterogeneity. Statistical analysis was conducted using Review Manager 5.3.

RESULTS

9 studies were included in the meta-analysis comprising a total of 10 711 patients, of whom 1,368 were diagnosed with noninfectious uveitis. Patients with noninfectious uveitis had worse results regarding vitamin D deficiency when compared with the control group (OR 0.58; CI 95% 0.44 to 0.77; p = 0.0002; I2 = 61%). Patients with inactive uveitis had better results towards vitamin D deficiency when compared with active uveitis (OR 5.00; CI 95% 2.84 to 8.81; p < 0.001; I2 = 0%).

CONCLUSION

Our research supports the increasing evidence that associates vitamin D deficiency with noninfectious uveitis and its activity. Further investigation into the efficacy of vitamin D screening and supplementation in reducing the recurrence of uveitis is necessary.

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.

Recommendations for nutritional supplements for dry eye disease: current advances

Dry eye disease (DED) represents a prevalent ocular surface disease. The development of effective nutritional management strategies for DED is crucial due to its association with various factors such as inflammation, oxidative stress, deficiencies in polyunsaturated fatty acids (PUFAs), imbalanced PUFA ratios, and vitamin insufficiencies. Extensive research has explored the impact of oral nutritional supplements, varying in composition and dosage, on the symptoms of DED. The main components of these supplements include fish oils (Omega-3 fatty acids), vitamins, trace elements, and phytochemical extracts. Beyond these well-known nutrients, it is necessary to explore whether novel nutrients might contribute to more effective DED management. This review provides a comprehensive update on the therapeutic potential of nutrients and presents new perspectives for combination supplements in DED treatment.

Physiology of Vitamin D-Focusing on Disease Prevention

Vitamin D is a crucial micronutrient, critical to human health, and influences many physiological processes. Oral and skin-derived vitamin D is hydroxylated to form calcifediol (25(OH)D) in the liver, then to 1,25(OH)2D (calcitriol) in the kidney. Alongside the parathyroid hormone, calcitriol regulates neuro-musculoskeletal activities by tightly controlling blood-ionized calcium concentrations through intestinal calcium absorption, renal tubular reabsorption, and skeletal mineralization. Beyond its classical roles, evidence underscores the impact of vitamin D on the prevention and reduction of the severity of diverse conditions such as cardiovascular and metabolic diseases, autoimmune disorders, infection, and cancer. Peripheral target cells, like immune cells, obtain vitamin D and 25(OH)D through concentration-dependent diffusion from the circulation. Calcitriol is synthesized intracellularly in these cells from these precursors, which is crucial for their protective physiological actions. Its deficiency exacerbates inflammation, oxidative stress, and increased susceptibility to metabolic disorders and infections; deficiency also causes premature deaths. Thus, maintaining optimal serum levels above 40 ng/mL is vital for health and disease prevention. However, achieving it requires several times more than the government's recommended vitamin D doses. Despite extensive published research, recommended daily intake and therapeutic serum 25(OH)D concentrations have lagged and are outdated, preventing people from benefiting. Evidence suggests that maintaining the 25(OH)D concentrations above 40 ng/mL with a range of 40-80 ng/mL in the population is optimal for disease prevention and reducing morbidities and mortality without adverse effects. The recommendation for individuals is to maintain serum 25(OH)D concentrations above 50 ng/mL (125 nmol/L) for optimal clinical outcomes. Insights from metabolomics, transcriptomics, and epigenetics offer promise for better clinical outcomes from vitamin D sufficiency. Given its broader positive impact on human health with minimal cost and little adverse effects, proactively integrating vitamin D assessment and supplementation into clinical practice promises significant benefits, including reduced healthcare costs. This review synthesized recent novel findings related to the physiology of vitamin D that have significant implications for disease prevention.

Manifestations and Treatment of Hypovitaminosis in Oral Diseases: A Systematic Review

This review's objective is to examine the findings from various studies on oral signs and symptoms related to vitamin deficiency. In October 2023, two electronic databases (Scopus and PubMed) were searched for published scientific articles following PRISMA principles. Articles eligible for inclusion in this review had to be published in English between 2017 and 2023, be original studies, and involve human subjects. Fifteen studies were included in this review: three examining oral symptoms of vitamin B12 deficiency; one assessing vitamin B complex and vitamin E for recurrent oral ulcers; one investigating serum vitamin D levels in recurrent aphthous stomatitis patients; three exploring hypovitaminosis effects on dental caries; two measuring blood serum vitamin D levels; one evaluating vitamin B12 hypovitaminosis; three investigating hypovitaminosis as indicative of gingival disease; one focusing on vitamin deficiencies and enamel developmental abnormalities; one assessing vitamin deficiencies in oral cancer patients; one examining vitamin K as an oral anticoagulant and its role in perioperative hemorrhage; and one evaluating vitamin effects on burning mouth syndrome. Despite some limitations, evidence suggests a correlation between vitamin deficiencies and oral symptoms. This systematic review was registered in the International Platform of Registered Systematic Review and Meta-analysis Protocols (INPLASY) database (202430039).

Relationship between Vitamin D3 Deficiency, Metabolic Syndrome and VDR, GC, and CYP2R1 Gene Polymorphisms

The presence of vitamin D3 deficiency associated with the presence of metabolic syndrome (MS) has important public health effects. This study aims to investigate the relationship between vitamin D3 deficiency, MS and vitamin D3 receptor (VDR), GC Vitamin D binding protein (GC), and cytochrome P450 family 2 subfamily R member 1 (CYP2R1) gene polymorphisms, and genes whose encoded proteins are responsible for vitamin D3 metabolism and transport. A total of 58 participants were included in this study (age 39 ± 12 years) and were selected over a 12-month period. They were divided into four groups, depending on the presence of polymorphisms in VDR, GC, and CYP2R1 genes and their weight status. At baseline, in months 3, 6, and 12, biochemical parameters including 25(OH)D3, total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides, and homeostatic model assessment (HOMA index), the insulin resistance indicator were measured. Our results show that all subjects in the polymorphism group supplemented with vitamin D3 reached an optimal level of vitamin D3 associated with high concentrations of 25(OH)D3. Weight loss was most significant in patients in the POW group (overweight patients).

The Role of Vitamins in Mitigating the Effects of Various Stress Factors in Pigs Breeding

Good practices in farm animal care are crucial for upholding animal well-being, efficiency, and health. Pigs, like other farm animals, are exposed to various stressors, including environmental, nutritional, chemical, psychological, physiological, and metabolic stressors, which can disrupt their internal balance and compromise their well-being. Oxidative stress can adversely affect animal performance, fertility, and immunity, leading to economic losses for farmers. Dietary considerations are hugely important in attaining these objectives. This paper reviews studies investigating the impact of additional vitamin supplementation on stress reduction in pigs. Vitamin A can be beneficial in counteracting viral and parasitic threats. Vitamin B can be a potential solution for reproductive issues, but it might also be beneficial in reducing the effects of inappropriate nutrition. Vitamin C plays a vital role in reducing the effects of heat stress or exposure to toxins in pigs. Vitamin D proves to be beneficial in addressing stress induced mostly by infections and weaning, while vitamin E has been shown to mitigate the effects of toxins, heat stress, or transport stress. This review highlights the potential benefits of these dietary antioxidants in maintaining pig health, enhancing productivity, and counteracting the adverse effects of various stressors. Understanding the role of vitamins in pig nutrition and stress management is vital for optimising farm animal welfare and production efficiency.

The association between serum 25-hydroxyvitamin D levels and psoriasis in a large population-based cohort: a cross-sectional analysis of The Tromsø Study 2015-16

BACKGROUND

Case-control studies indicate an association between lower serum 25-hydroxyvitamin D [25(OH)D] levels and psoriasis. Data from larger population-based cohorts including mild cases are sparse.

OBJECTIVES

To investigate the association between 25(OH)D and psoriasis in a large population-based cohort, and assess possible effect modification by overweight.

METHODS

Data from the Tromsø Study 2015-16 (Tromsø7), which included 19 520 participants from the general population aged 40-79 years, were subjected to a cross-sectional analysis. We assessed the shapes of the relationships between 25(OH)D and psoriasis using fractional polynomials. Odds ratios (ORs) for lifetime and active psoriasis were estimated using logistic regression. Adjusted models included month of blood sampling, body mass index (BMI), age and sex. Two-way and additive interaction between BMI and 25(OH)D were explored.

RESULTS

From a total of 19 520 participants [10 203 women (52.3%); mean age 56.3 years (SD 10.4); mean 25[OH]D, 63.4 nmol L-1 (SD 21.9)], 2088 (10.7%) reported lifetime psoriasis and 1179 (6.0%) reported active psoriasis the past 12 months. There was no association between 25(OH)D and lifetime psoriasis [OR per 10 nmol L-1 increase in 25(OH)D 1.02, 95% confidence interval (CI) 0.99-1.04]. The relationship between 25(OH)D and active psoriasis was suggested to be nonlinear, but the model was not significant (P = 0.098). There was evidence for a superadditive effect (i.e. larger than the sum of the factors) of BMI > 27.5 kg m-2 and 25(OH)D < 25 nmol L-1 on the odds for active psoriasis (OR 1.92, 95% CI 1.18-3.12), but not for lifetime psoriasis (OR 1.41, 95% CI 0.93-2.15). There was no evidence for two-way interaction between BMI and 25(OH)D.

CONCLUSIONS

This large population-based study found no significant relationship between 25(OH)D and psoriasis. The analysis may have been underpowered to detect a threshold effect in the lower 25(OH)D spectrum. Interaction analysis indicates that high BMI and vitamin D deficiency combined increase the odds of active psoriasis more than the sum of these factors, with an estimated 92% higher odds for active psoriasis in participants with BMI > 27.5 kg m-2 and 25(OH)D < 25 nmol L-1. Providing advice to prevent vitamin D deficiency may be considered in the follow-up of overweight patients with psoriasis.

Dietary intake of polish organic and conventional fruit growers and their life partners - a pilot study

Diet is one of the elements that contribute to health and quality of life. There are significant discrepancies between the diets of people living in different regions, with different beliefs, or with different approaches to sustainability and ecology. There is a lack of research on dietary intake among organic and conventional fruit growers. The aim of our study was to examine the diets of orchardists and their immediate life partners in terms of meeting energy requirements, nutrient intake and fulfillment of dietary recommendations in this group. Fifty-three participants (28 in the organic group and 25 in the conventional group) took part in the study. Dietary data were obtained using the 3-day dietary record. Body mass and height were measured and BMI was calculated. Physical activity was estimated using a questionnaire method. The study group was aged 44 ± 8 years, with a body weight of 84 ± 16 kg and a height of 172 ± 9 cm. The mean BMI was 28 ± 4 kg/m2. Mean energy intake with diet was 2170 ± 606 kcal/day with needs of 3002 (1991-5144) kcal/day. A significant proportion of the study group did not fulfill their calcium and vitamin D requirements. In addition, a significant proportion of the conventional fruit growers did not cover their needs for potassium, magnesium and vitamins: E, C, and folate. Both groups had too high an intake of cholesterol and saturated fatty acids, and too low an intake of polyunsaturated fatty acids. In conclusion, the orchardists' diets mostly provided adequate amounts of nutrients, with inadequate intakes of calcium, vitamin D, cholesterol, and fatty acids. The diets of organic fruit growers were significantly richer in selected nutrients.

Comparative Performance Assessment of Novel Fluorescence Immunoassay POCTs for Measuring Circulating Levels of Vitamin-D

Vitamin D (Vit D) is a fat-soluble molecule acting like a hormone, and it is involved in several biological mechanisms such as gene expression, calcium homeostasis, bone metabolism, immune modulation, viral protection, and neuromuscular functions. Vit D deficiency can lead to chronic hypocalcemia, hyperparathyroidism, and many other pathological conditions; in this context, low and very low levels of 25-hydroxy-vitamin D (25-OH-D) were found to be associated with an increased risk of COVID-19 infection and the likelihood of many severe diseases. For all these reasons, it is important to quantify and monitor 25-OH-D levels to ensure that the serum/blood concentrations are not clinically suboptimal. Serum concentration of 25-OH-D is currently the main indicator of Vit D status, and it is currently performed by different assays, but the most common quantitation techniques involve immunometric methods or chromatography. Nevertheless, other quantitation techniques and instruments are now emerging, such as AFIAS-1® and AFIAS-10® (Boditech and Menarini) based on the immunofluorescence analyzer, that guarantee an automated system with cartridges able to give quick and reliable results as a point-of-care test (POCT). This work aims to compare AFIAS-1® and AFIAS-10® (Boditech and Menarini) Vit D quantitation with Ultra High-Performance Liquid Chromatography coupled with tandem mass spectrometry that currently represents the gold standard technique for Vit D quantitation. The analyses were performed in parallel on 56 samples and in different conditions (from fresh and frozen plasma) to assess the reliability of the results. Any statistically significant differences in methods, the fixed error, and the error proportional to concentration were reported. Results obtained in all conditions showed a good correlation between both AFIAS® instruments and LC-MS/MS, and we can affirm that AFIAS-1® and AFIAS-10® are reliable instruments for measuring 25-OH-D with accuracy and in a fast manner.

Evolution of Vitamin D Status and Vitamin D Receptor Gene Expression Among Professional Handball Athletes During a Competitive Period. Relationship with Body Composition, Calcium, Magnesium and Phosphorous

INTRODUCTION

A generalized risk of vitamin D deficiency exists worldwide affecting also professional and elite athletes. This study assesses the evolution of vitamin D status and vitamin D receptor (VDR) gene expression and their relationship with body composition, calcium (Ca), magnesium (Mg) and phosphorous (P) among professional handball athletes during a competitive period.

METHODS

A total of 26 male subjects were recruited: 13 professional handball athletes and 13 non-athlete controls. An observational follow-up study was conducted in 2 time points over a 16-week period. Nutritional intake, body composition, and routinary biochemical parameters were measured via 24-hours recall, bioimpedance and enzyme immunoassay, respectively. Ca and Mg were measured by flame atomic absorption spectrophotometry and P was determined with the colorimetric method of Fiske-Subbarow. 25-hydroxyvitamin-D (25(OH)D) levels and its forms (i.e., 25(OH)D3 and 25(OH)D2) were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS), whereas VDR gene expression was measured by quantitative real time-polymerase chain reaction (qRT-PCR).

RESULTS

A total of 54% of the athletes showed deficient vitamin D status. Moreover, a prevalence of insufficient vitamin D status in handball players affected 46% at baseline, reaching 61% after 16 weeks. Vitamin D showed no evolution during the competitive period and no differences between groups were observed (all p ≥ 0.05). Handball players increased the VDR expression, enhanced body composition, Ca and Mg levels at 16-weeks follow-up (all p < 0.05). VDR gene expression was positively related with body mass and body mass index at follow-up in athletes (all p ≤ 0.038; r ≥ 0.579) and with Ca at baseline in controls (p = 0.026; r = 0.648). Finally, 25(OH)D2 form was directly associated with P in athletes at 16 weeks of study (p = 0.034; r = 0.588).

CONCLUSION

Players of indoor team sports such as handball would be a population at risk of vitamin D deficiency. The 16-weeks competition improved VDR gene expression, body composition, Ca and Mg levels. The associations observed between VDR gene expression and the variables of the study evidenced the importance of this receptor as a marker involved in health status in handball athletes despite vitamin D - although in a deficient status -, Ca, Mg and P showed no remarkable changes during the competition period.

Association between vitamin D status, physical performance, sex, and lifestyle factors: a cross-sectional study of community-dwelling Kosovar adults aged 40 years and older

PURPOSE

Vitamin D status and its association with age-related decline in physical performance and strength have already been highlighted in various ways, but data on the situation in developing countries are scarce. This study aimed to investigate vitamin D status, its association with muscle mass and function, and other potential determinants such as age, sex, lifestyle factors (physical activity, dietary behavior), self-perceived health status, medication intake, education and financial situation in adults from Kosovo.

METHODS

This cross-sectional study included 297 participants (54.5% women), aged ≥ 40 years. Serum 25-hydroxyvitamin D (25(OH)D) concentration, hand grip strength and physical performance tests, body composition, vitamin D dietary intake and knowledge were assessed. The interaction between serum 25(OH)D status, lifestyle factors and muscle traits was investigated.

RESULTS

Vitamin D deficiency (< 50 nmol/L) was observed in 47.5% of the total population, of whom 14.7% of them were severely deficient (< 30 nmol/L). No associations were found between 25(OH)D concentration and age. Daily dietary intake of vitamin D was low (1.89 ± 0.67 µg) and 87.6% of individuals did not take vitamin D supplements. However, vitamin D supplementation was the only variable that added statistical significance (p < 0.05) to the prediction of vitamin D status (3.8%). On the other hand, age, medication intake and vitamin D level contributed significantly to the overall regression model, explaining 24.9% of the 30-s chair stand performance as an indicator of lower-body strength endurance.

CONCLUSION

Vitamin D deficiency is highly prevalent among community-dwelling adults in Kosovo and low serum 25(OH)D has been associated with low muscle strength. This implies an urgent need for the development of comprehensive prevention strategies, focusing on pharmacological (supplementation) but also on non-pharmacological strategies such as education, food fortification or lifestyle advices.

VDR and deubiquitination control neuronal oxidative stress and microglial inflammation in Parkinson's disease

Close correlation between vitamin D (VitD) deficiency and Parkinson's Disease (PD) risk, VitD as an adjuvant treatment promising to improve PD progression. However, VitD excessive intake could induce hypercalcemia and renal damage. Therefore, upregulation of vitD receptor (VDR) is considered a compensatory strategy to overcome VitD insufficiency and alleviate PD symptoms. In this study, we discovered that VDR played antioxidative roles in dopaminergic neurons by decreasing reactive oxygen species (ROS) and maintaining mitochondrial membrane potential. Further, we newly identified VDR downstream events in C. elegans, including glutathione S-transferase (gst) and forkhead box transcription factor class O (daf-16) mediated oxidative stress resistance. VDR upregulation also mitigated microglial activation through inhibition of NLRP3/caspase-1-mediated inflammation and membrane permeabilization. These findings highlight the multifaceted protective effects of VDR in both neurons and microglia against the development of PD. Importantly, we discovered a novel deubiquitinase DUB3, whose N-terminal catalytic domain interacted with the C-terminal ligand-binding domain of VDR to reduce VDR ubiquitination. Identification of DUB3 as an essential player in the deubiquitinating mechanism of VDR provides valuable insights into VDR regulation and its potential as a therapeutic target for PD.

Association between serum 25-hydroxyvitamin D and vitamin D dietary supplementation and risk of all-cause and cardiovascular mortality among adults with hypertension

BACKGROUND

The relationship between vitamin D status and mortality among adults with hypertension remains unclear.

METHODS

This prospective cohort study involved a sample of 19,500 adults with hypertension who participated in the National Health and Nutrition Examination Survey (NHANES) from 2001 to 2018. We utilized a weighted COX proportional hazard model to assess the association between vitamin D status and mortality. This statistical model calculates hazard ratios (HR) and their corresponding 95% confidence intervals (95% CI).

RESULTS

The study indicated that lower serum 25(OH)D concentration was associated with an increased risk of all-cause mortality among individuals with hypertension. Specially. Those with concentrations between 25.0 and 49.9 nmol/L (HR = 1.71, 95%CI = 1.22-2.40) and less than 25.0 nmol/L (HR = 1.97, 95%CI = 1.15-3.39) had higher hazard ratios for all-cause mortality. Individuals with hypertension who took vitamin D supplements had a lower risk of all-cause mortality, but not the risk of CVD mortality (HR 0.75, 95%CI 0.54-1.03), compared to those who did not supplement (HR = 0.76, 95%CI = 0.61-0.94). Subgroup analysis further revealed that vitamin D supplementation was associated with a reduced risk of all-cause mortality among individuals without diabetes (HR = 0.65, 95%CI = 0.52-0.81) and individuals without CVD (HR = 0.75, 95%CI = 0.58-0.97), and a decreased risk of CVD mortality among individuals without diabetes (HR = 0.63, 95%CI = 0.45-0.88) and without CVD (HR = 0.61, 95%CI = 0.40-0.92). Furthermore, higher-dose vitamin D supplementation was also associated with a greater reduction in all-cause mortality among hypertensive individuals, and there was the potential synergistic effect of combining normal-dose calcium and vitamin D supplementation, showing a superior effect on mortality compared to low-dose supplementation in adults with hypertension.

CONCLUSIONS

This prospective cohort study demonstrated a significant association between lower serum 25 (OH)D concentration and increased all-cause mortality among adults with hypertension. Furthermore, the study found that vitamin D supplementation had a strong and significantly positive correlation with reduced all-cause and CVD mortality among hypertensive individuals without diabetes or CVD. This positive correlation suggests that vitamin D supplementation could potentially be an effective strategy to reduce the risk of mortality in this specific group of people.

The prevalence of vitamin D deficiency and associated factors in first-episode psychosis

AIM

Vitamin D deficiency is prevalent in people with established psychotic disorders, but less is known about vitamin D levels in people with first-episode psychosis (FEP). This study aimed to determine the prevalence of vitamin D deficiency in people with FEP and identify the factors associated with vitamin D status.

METHODS

This was a prospective cohort study nested within a randomized controlled trial, which included 37 young people with an FEP with minimal antipsychotic medication exposure.

RESULTS

Twenty-four percent of participants were vitamin D deficient, and a further 30% were vitamin D insufficient. There was no association between vitamin D and demographic factors or clinical symptoms (positive, negative, general psychopathology and depressive symptoms) or cognition and functioning. However, vitamin D levels were associated with season of sampling.

CONCLUSIONS

Considering the longer-term adverse effects associated with vitamin D deficiency, it is warranted to ensure this clinical population receives supplementation if indicated.

[Association between preoperative cholecalciferol therapy and hypocalcemia after parathyroidectomy in patients with primary hyperparathyroidism]

BACKGROUND

Primary hyperparathyroidism (PHPT) is a endocrine disorder characterized by excessive secretion of parathyroid hormone (PTH) from parathyroid gland tumors. Parathyroidectomy (PTE) is the main treatment for PHPT, but it can lead to hypocalcemia in up to 46% of cases. Hypocalcemia is associated with seizures and life-threatening cardiac arrhythmias, and vitamin D deficiency can exacerbate PHPT severity and contribute to «hungry bones syndrome,» resulting in severe and persistent postoperative hypocalcemia.

AIM

To evaluate the association and determine the strength of the relationship between preoperative cholecalciferol therapy and the occurrence of hypocalcemia within 1-3 days after PTE in patients with PHPT.

MATERIALS AND METHODS

The study was conducted at the Endocrinology Research Centre, during the periods of 1993-2010 and 2017-2020. The inclusion criteria consisted of patients diagnosed with PHPT who required PTE, had a serum 25-hydroxyvitamin D (25(OH)D) level below 20 ng/mL, and a serum total calcium level below 3 mmol/L. The exclusion criterion was the use of medications that affect calcium-phosphorus metabolism, including cinacalcet, denosumab, or bisphosphonates, either as monotherapy or as part of combination therapy.

RESULTS

There were 117 patients, including 110 (94%) females and 7 (6%) males. The median age and interquartile range were 58 [49; 65] years. Among the participants, 21 (18%) received cholecalciferol supplementation for a duration of 2 weeks to 2 months prior to PTE, aiming to address vitamin D deficiency. The remaining 96 (82%) participants did not receive -cholecalciferol supplementation. Both groups, i.e., participants receiving cholecalciferol and those who did not, were similar in terms of anthropometric factors (sex and age at the time of surgery), preoperative clinical characteristics (BMD decrease), and laboratory parameters (PTH, total calcium, phosphorus, ALP, OC, CTX-1, and 25(OH)D levels). The occurrence of postoperative hypocalcemia was significantly lower in participants who received cholecalciferol supplementation (10% vs. 63%, p<0,001, FET2). Cholecalciferol intake showed a negative association with hypocalcemia development (RR=0,15, 95% CI (0,03; 0,51)).

CONCLUSION

Preoperative cholecalciferol supplementation for 2 weeks to 2 months before PTE reduces the risk of postoperative hypocalcemia in patients with PHPT by 2-33 times.

Accurate Clinical Detection of Vitamin D by Mass Spectrometry: A Review

Vitamin D deficiency is thought to be associated with a wide range of diseases, including diabetes, cancer, depression, neurodegenerative diseases, and cardiovascular and cerebrovascular diseases. This vitamin D deficiency is a global epidemic affecting both developing and developed countries and therefore qualitative and quantitative analysis of vitamin D in a clinical context is essential. Mass spectrometry has played an increasingly important role in the clinical analysis of vitamin D because of its accuracy, sensitivity, specificity, and the ability to detect multiple substances at the same time. Despite their many advantages, mass spectrometry-based methods are not without analytical challenges. Front-end and back-end challenges such as protein precipitation, analyte extraction, derivatization, mass spectrometer functionality, must be carefully considered to provide accurate and robust analysis of vitamin D through a well-designed approach with continuous control by internal and external quality control. Therefore, the aim of this review is to provide a comprehensive overview of the development of mass spectrometry methods for vitamin D accurate analysis, including emphasis on status markers, deleterious effects of biological matrices, derivatization reactions, effects of ionization sources, contribution of epimers, standardization of assays between laboratories.

No evidence of a causal relationship between miscarriage and 25-hydroxyvitamin D: a Mendelian randomization study

STUDY QUESTION

Is there a causal relationship between 25-hydroxyvitamin D (25OHD) and miscarriage?

SUMMARY ANSWER

In this study, little evidence of a causal relationship was found between low serum 25OHD concentration or vitamin D deficiency and the risk of miscarriages.

WHAT IS KNOWN ALREADY

Associations between low vitamin D levels and increased risk of miscarriage have been reported, but causality is unclear.

STUDY DESIGN SIZE DURATION

The latest and largest genome-wide association studies (GWAS) for serum 25OHD concentration (n = 417 580), vitamin D deficiency (426 cases and 354 812 controls), miscarriage (16 906 cases and 149 622 controls), and the number of miscarriages (n = 78 700) were used to explore the causal association between serum vitamin D levels and miscarriage by two-sample Mendelian randomization analysis.

PARTICIPANTS/MATERIALS SETTING METHODS

This study was based on summary GWAS results from the FinnGen database and the UK Biobank. The random-effect inverse-variance weighted method was regarded as the primary analysis; MR-Egger, weighted median, weighted mode, simple mode, and MR-pleiotropy residual sum and outlier (MR-PRESSO) were further employed as complementary methods. MR-Egger intercept analysis and MR-PRESSO were employed to test pleiotropy, and Cochran's Q statistic and leave-one-out sensitivity analysis were used to determine the heterogeneity and robustness of the overall estimates, respectively.

MAIN RESULTS AND THE ROLE OF CHANCE

There was insufficient evidence of causal associations between serum 25OHD concentration and miscarriage (odds ratio (OR) = 0.995, 95% CI: 0.888 to 1.114, P = 0.927), or the number of miscarriages (β = -0.004, 95% CI: -0.040 to 0.032, P = 0.829). Furthermore, little evidence of causality between genetically determined vitamin D deficiency to miscarriage (OR = 0.993, 95% CI: 0.966 to 1.021, P = 0.624), or the number of miscarriages (β = 0.001, 95% CI: -0.009 to 0.011, P = 0.828), was observed. The results of the sensitivity analysis were robust, and no significant heterogeneity or horizontal pleiotropy was found.

LIMITATIONS REASONS FOR CAUTION

This study is limited by the absence of female-specific GWAS data and the limited amount of GWAS data available for this study, as well as the need for caution in generalizing the findings to non-European ethnic groups.

WIDER IMPLICATIONS OF THE FINDINGS

These findings enhance the current understanding of the intricate association between vitamin D and pregnancy outcomes, challenging prevailing beliefs regarding the strong association with miscarriage. The results provide a special perspective that may prompt further exploration and potentially offer insights for guiding future research and informing clinical guidelines pertaining to the management of miscarriage.

STUDY FUNDING/COMPETING INTERESTS

This project was supported by the Hubei Provincial Natural Science Foundation Program General Surface Project (2022CFB200), the Key Research & Developmental Program of of Hubei Province (2022BCA042), the Fundamental Research Funds for the Central Universities (2042022gf0007, 2042022kf1210), and the Interdisciplinary Innovative Talents Foundation from Renmin Hospital of Wuhan University (JCRCWL-2022-001, JCRCYG-2022-009). All authors have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

Retrospective Analysis of Vitamin D Deficiency in an Adult Population of Arad County, Western Romania (2019-2022)

Vitamin D, a steroid hormone synthesized primarily in the skin upon exposure to ultraviolet light, is widely deficient across global populations. This study aimed to fill the data gap in Western Romania by measuring 25-hydroxy-vitamin D levels in a cohort of 7141 from Arad County. It was observed that women, younger adults (18-29 years), and older adults (70-79 years) had notably lower vitamin D levels compared to the average population. Additionally, there was a rise in vitamin D levels over the four-year span of 2018-2022, coinciding with the COVID-19 pandemic. Our research provides fresh data on those most susceptible to vitamin D deficiency and lays the groundwork for educational campaigns on vitamin D supplementation benefits.

Bone Formation and Maintenance in Oral Surgery: The Decisive Role of the Immune System-A Narrative Review of Mechanisms and Solutions

Based on the evidence of a significant communication and connection pathway between the bone and immune systems, a new science has emerged: osteoimmunology. Indeed, the immune system has a considerable impact on bone health and diseases, as well as on bone formation during grafts and its stability over time. Chronic inflammation induces the excessive production of oxidants. An imbalance between the levels of oxidants and antioxidants is called oxidative stress. This physio-pathological state causes both molecular and cellular damage, which leads to DNA alterations, genetic mutations and cell apoptosis, and thus, impaired immunity followed by delayed or compromised wound healing. Oxidative stress levels experienced by the body affect bone regeneration and maintenance around teeth and dental implants. As the immune system and bone remodeling are interconnected, bone loss is a consequence of immune dysregulation. Therefore, oral tissue deficiencies such as periodontitis and peri-implantitis should be regarded as immune diseases. Bone management strategies should include both biological and surgical solutions. These protocols tend to improve immunity through antioxidant production to enhance bone formation and prevent bone loss. This narrative review aims to highlight the relationship between inflammation, oxidation, immunity and bone health in the oral cavity. It intends to help clinicians to detect high-risk situations in oral surgery and to propose biological and clinical solutions that will enhance patients' immune responses and surgical treatment outcomes.

An overview of nutritional factors in the aetiopathogenesis of myocardial fibrosis in great apes

The main cause of mortality in great apes in zoological settings is cardiovascular disease (CVD), affecting all four taxa: chimpanzee (Pan troglodytes), bonobo (Pan paniscus), gorilla (Gorilla spp.) and orangutan (Pongo spp.). Myocardial fibrosis, the most typical histological characterisation of CVD in great apes, is non-specific, making it challenging to understand the aetiopathogenesis. A multifactorial origin of disease is assumed whereby many potential causative factors are directly or indirectly related to the diet, which in wild-living great apes mainly consists of high-fibre, low-carbohydrate and very low-sodium components. Diets of great apes housed in zoological settings are often different compared with the situation in the wild. Moreover, low circulating vitamin D levels have recently been recognised in great apes housed in more northern regions. Evaluation of current supplementation guidelines shows that, despite implementation of different dietary strategies, animals stay vitamin D insufficient. Therefore, recent hypotheses designate vitamin D deficiency as a potential underlying factor in the pathogenesis of myocardial fibrosis. The aim of this literature review is to: (i) examine important differences in nutritional factors between zoological and wild great ape populations; (ii) explain the potential detrimental effects of the highlighted dietary discrepancies on cardiovascular function in great apes; and (iii) elucidate specific nutrition-related pathophysiological mechanisms that may underlie the development of myocardial fibrosis. This information may contribute to understanding the aetiopathogenesis of myocardial fibrosis in great apes and pave the way for future clinical studies and a more preventive approach to great ape CVD management.

Evaluation of diagnostic potential of CD38 in rickets

BACKGROUND

Rickets occurs in infants and children (aged 2 months to 3 years), compromising their skeletal development and damaging nervous, hematopoietic, immune, and other system functions. This study aimed to explore the significance of CD38 in rickets.

METHODS

The microarray dataset GSE22523 was analyzed to obtain differentially expressed genes in rickets patients. A total of 36 rickets patients and healthy controls were recruited for the study, and their blood samples were collected, followed by detecting mRNA levels of CD38 using quantitative real-time polymerase chain reaction (qRT-PCR). Moreover, the significance of CD38 in rickets patients was analyzed by receiver operating characteristic (ROC) analysis, while the correlation between CD38 and 25-hydroxy-vitamin D (25OHD)/parathyroid hormone (PTH) was analyzed with Pearson's correlation.

RESULTS

Results showed that CD38 mRNA levels and PTH contents were significantly increased in the rickets patients while 25OHD contents were decreased. Correlation analysis indicated that CD38 was positively correlated with PTH and negatively correlated with 25OHD in both serum and plasma samples of rickets patients. Moreover, ROC analysis showed that serum CD38 was 0.9005 (95 % CI: 0.8313-0.9696), and the AUCs of plasma CD38 was 0.7215 (95 % CI: 0.6031-0.8398) in differentiating rickets patients from healthy persons, advocating serum CD38 had better diagnostic value.

CONCLUSION

CD38 mRNA levels were upregulated in rickets patients and closely correlated with PTH and 25OHD contents, indicating CD38 might be a diagnostic marker of rickets patients. Further research on the diagnostic utility of CD38 is necessary for the diagnosis and treatment of ricketsin rickets in the future.

Emerging factors affecting peri-implant bone metabolism

Implant dentistry has evolved to the point that standard implant osseointegration is predictable. This is attributed in part to the advancements in material sciences that have led toward improvements in implant surface technology and characteristics. Nonetheless, there remain several cases where implant therapy fails (specifically at early time points), most commonly attributed to factors affecting bone metabolism. Among these patients, smokers are known to have impaired bone metabolism and thus be subject to higher risks of early implant failure and/or late complications related to the stability of the peri-implant bone and mucosal tissues. Notably, however, emerging data have unveiled other critical factors affecting osseointegration, namely, those related to the metabolism of bone tissues. The aim of this review is to shed light on the effects of implant-related factors, like implant surface or titanium particle release; surgical-related factors, like osseodensification or implanted biomaterials; various drugs, like selective serotonin reuptake inhibitors, proton pump inhibitors, anti-hypertensives, nonsteroidal anti-inflammatory medication, and statins, and host-related factors, like smoking, diet, and metabolic syndrome on bone metabolism, and aseptic peri-implant bone loss. Despite the infectious nature of peri-implant biological complications, these factors must be surveyed for the effective prevention and management of peri-implantitis.

The effects of 12 weeks resistance training and vitamin D administration on neuromuscular joint, muscle strength and power in postmenopausal women

BACKGROUND

This study aimed to examine the effects of 12 weeks of resistance training (RT) and vitamin D (VitD) supplementation on muscle strength and C-terminal agrin fragment (CAF) and Neurotrophin-3 (NT-3) concentrations as potential biomarkers in postmenopausal women.

METHODS

This was a randomized double-blind placebo-controlled study. Forty-four healthy postmenopausal women (55.84 ± 4.70 years and 29.61 ± 4.26 kg/m2) were randomly assigned into four groups: (1) Resistance training + placebo (RT + PLA), (2) Vitamin D supplementation (VitD), (3) Resistance training + vitamin D (RT + VitD), and (4) Placebo (PLA). VitD was supplemented as an oral capsule containing 50000 IU of cholecalciferol every two weeks. RT involved leg press, chest press, leg extension, leg curl, and shoulder press exercises, performed with 3-4 sets at 70-85 % of 1RM, three times a week.

RESULTS

Circulating levels of CAF and NT-3 did not significantly change following the intervention period in the study groups (p > 0.05). There were significant increases in upper and lower body muscle strength and power for RT + VitD and RT + PLA ( < 0.05), but not for VitD or PLA (p > 0.05). The muscle function gains for RT + VitD and RT + PLA were higher than those for VitD and PLA but did not differ between them.

CONCLUSION

12-week of RT interventions resulted in significant increases in muscle strength and power in postmenopausal women. However, VitD supplementation did not result in any additional benefits. The positive changes in muscle function promoted by RT do not seem to be associated with changes in the neuromuscular joint via the CAF or NT-3 as potential biomarkers.

Prevalence and determinants of insufficient vitamin D status in young Canadian Inuit children from Nunavik

Background: Vitamin D deficiency has reached pandemic levels affecting over one billion people worldwide. However, limited data is available on the prevalence and determinants of vitamin D status of Canadian Indigenous children and no study has been reported in Inuit children from Nunavik. Aim: Therefore, using data collected between 2006 and 2010, we aimed to investigate the prevalence and main determinants of insufficient serum 25-hydroxyvitamin D (s25(OH)D) concentrations in Inuit children attending childcare centres in Nunavik. Methods: This study included 245 Inuit children aged 11 to 54 months. s25(OH)D concentrations were measured by radioimmunoassay. Dietary intakes were assessed using 24-hour recalls. Usual dietary intakes were estimated using the National Cancer Institute method. We used a multiple imputation technique to replace missing values when performing regression analysis. Results: Our findings revealed that 64.5% of children had a s25(OH)D concentration < 75 nmol/L, while 78.1% did not meet the estimated average requirement (EAR) for vitamin D. Vitamin D intake and fluid milk consumption were positively associated with s25(OH)D concentrations, while negative associations were observed with children' energy intake, non-alcoholic beverage consumption, body weight, breastfeeding duration and, biological/adoptive/foster parents' educational level. Conclusion: Vitamin D inadequacy was highly prevalent and closely aligned with levels observed over the years in non-Indigenous children. Breastfed children who do not receive vitamin D supplementation, overweight and obese children, and children with inadequate milk consumption were at high risk of vitamin D insufficiency. Eating vitamin D rich foods such as fluid milk and seafood along with vitamin D supplementation when needed are recommended.

Vitamin D and cancer

The role of vitamin D in the prevention of chronic diseases including cancer, has received a great deal of attention during the past few decades. The term "Cancer" represents multiple disease states with varying biological complexities. The strongest link between vitamin D and cancer is provided by ecological and studies like observational, in preclinical models. It is apparent that vitamin D exerts diverse biological responses in a tissue specific manner. Moreover, several human factors could affect bioactivity of vitamin D. The mechanism(s) underlying vitamin D initiated anti-carcinogenic effects are diverse and includes changes at the muti-system levels. The oncogenic environment could easily corrupt the traditional role of vitamin D or could ensure resistance to vitamin D mediated responses. Several researchers have identified gaps in our knowledge pertaining to the role of vitamin D in cancer. Further areas are identified to solidify the role of vitamin D in cancer control strategies.

Efficacy and Safety of Calcifediol in Young Adults with Vitamin D Deficiency: A Phase I, Multicentre, Clinical Trial-POSCAL Study

Vitamin D deficiency is highly prevalent, and recent evidence suggests a possible association between vitamin D deficiency and various health conditions. The aim of this study was to assess monthly calcifediol treatments for vitamin D deficiency (or biweekly, if the deficiency was severe) in a young adult population with no associated comorbidities. This multicentre phase I trial started with a four month open-label treatment phase (TP) that included 101 participants (65% women with mean age 29.8 years). Eighty-two percent of the subjects (79/96) achieved 25(OH)D levels within the target range (20-60 ng/mL) by the end of the TP, and they were subsequently randomised and subjected to a double-blind, placebo-controlled, five month follow-up phase (FP). At the end of the FP, 89% of participants maintained vitamin D levels of >20 ng/mL with calcifediol, versus 49% with placebo (p < 0.001). Subjects receiving monthly calcifediol during both phases (n = 32) maintained 25(OH)D levels >20 ng/mL, whereas those on the placebo during the FP (n = 38) exhibited deficiency levels of 25(OH)D by the end of the study. No clinically relevant changes in bone metabolism parameters or toxic 25(OH)D levels were observed, and no serious adverse events were reported throughout the study. Calcifediol is a safe and effective treatment for vitamin D deficiency in the young adult population, but long-term use may be required to sustain optimal 25(OH)D levels.

Has a High Dose of Vitamin D3 Impacted Health Conditions in Older Adults?-A Systematic Review and Meta-Analysis Focusing on Dose 100,000 IU

BACKGROUND

Older adults are prone to vitamin D3 (VD3) deficiency, which may impair their health. A high dose of VD3 (HDVD3 = 100,000 IU) could improve their 25-hydroxyvitamin D3 [25(OH)D] level and health outcomes. However, evidence for such a beneficial effect of HDVD3 in older adults coming from clinical trials is mixed.

OBJECTIVE

To review the literature on the efficacy of a single dose of 100,000 IU of VD3 in older people.

METHODS

We searched PubMed/Medline, Science Direct, and NIH's clinical trials registry for clinical studies on the effect of a single high dose of VD3 on various health outcomes in older people. We also performed a meta-analysis using the standardized mean difference to assess the effect of VD3 on its blood level. Due to expected high heterogeneity, its amount (i.e., tau2) was estimated using the DerSimonian-Laird estimator. To estimate tau2, the Q-test for heterogeneity and the I2 statistic were calculated.

RESULTS

Search results identify 13 studies that reported diverse health outcomes, such as lung and cardiovascular function, skin cancer progression, intensive care unit mortality, immune system response, and bone density. The meta-analysis showed a significant increase in 25(OH)D blood levels after treatment in 10 studies, with an average standardized mean difference of 2.60 ng/mL (95% CI: 2.07 to 3.13). Their results suggested that a single high dose of VD3 may benefit intensive care unit patients and skin cancer patients in remission. However, evidence for other beneficial health effects of HDVD3 was mixed due to high heterogeneity among studies.

CONCLUSIONS

A single high dose of VD3 may positively affect some health outcomes in older people, possibly due to its pleiotropic and immunomodulatory effects. However, the evidence needs to be more extensive and consistent, and more rigorous studies are required to confirm the benefits and safety of VD3 high doses in older patients.

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.

Effects of Vitamin D Supplementation in Elite Athletes: A Systematic Review

Background

Deficiency in vitamin D has been shown to increase the risk of injury.

Purpose

To synthesize current placebo-controlled randomized trials investigating the effect of vitamin D supplementation in elite athletes on (1) aerobic capacity; (2) anaerobic measures, such as strength, speed, and anaerobic power; (3) serum biomarkers of inflammation; and (4) bone health.

Study Design

Systematic review; Level of evidence, 1.

Methods

A literature search was conducted on November 30, 2022, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Included were randomized, placebo-controlled studies of longer than 2 weeks on subjects with active participation in organized sport. Excluded were nonrandomized controlled trial study designs, vitamin D administration routes other than oral, studies that did not use vitamin D supplementation as the sole intervention, and studies with nonathletic or military populations.

Results

Out of 2331 initial studies, 14 studies (482 athletes) were included. Of the 3 studies that assessed aerobic capacity, 2 demonstrated significantly greater improvements in maximal oxygen uptake and physical working capacity-170 (P < .05) in supplemented versus nonsupplemented athletes. Measurements of anaerobic power and strength were consistently increased in supplemented groups compared with nonsupplemented groups in 5 out of the 7 studies that assessed this. Of the 6 studies that assessed sprint speed, 4 found no significant difference between supplemented and nonsupplemented groups. Aside from 1 study that found significantly lower interleukin-6 levels in supplemented athletes, measures of other inflammatory cytokines were not affected consistently by supplementation. The 4 studies that assessed markers of bone health were conflicting regarding benefits of supplementation. One study found demonstrated improvements in bone mineral density in response to supplementation (P = .02) compared with control whereas another found no significant difference between supplemented and nonsupplemented groups. However, in 3 other studies, serum biomarkers of bone turnover such as bone-specific alkaline phosphatase, parathyroid hormone, and N-terminal telopeptide appeared to be higher in subjects with lower serum vitamin D levels (P < .05).

Conclusion

Results of this systematic review indicated that the greatest benefit of vitamin D supplementation in elite athletes may be improving aerobic endurance, anaerobic power, and strength. More research is needed to determine the effect of vitamin D supplementation on bone health and injury risk in this population.