Non-classical effects of vitamin D: Non-bone effects of vitamin D

Vitamin D Status and Behavioral Impulsivity in Anorexia Nervosa: Insights from a Longitudinal Study

Anorexia nervosa (AN) is a severe psychiatric disorder marked by extreme weight control behaviors and significant impacts on physical and psychosocial health. This study explores the relationship between vitamin D (Vit-D) levels and impulsivity in women with AN. Forty-six cisgender White women participants were assessed upon admission and before discharge from a specialized eating disorder treatment center, with an average duration of 2.5 ± 0.10 months. Methods included self-reported questionnaires and behavioral tasks to measure impulsivity, alongside serum Vit-D levels. Our results showed significant improvements in Vit-D levels and certain impulsivity measures, such as faster reaction times and fewer errors on the go/no-go task, correlating with higher Vit-D levels. However, no significant correlations were found between Vit-D levels and self-reported impulsivity. These findings suggest that adequate Vit-D levels may enhance cognitive functions related to impulse control in AN. Given this study's limitations, including its exclusive focus on women and small sample size, future research should involve larger, more diverse populations and randomized clinical trials to better understand the causal relationships and therapeutic potential of Vit-D in managing AN-related impulsivity.

The Importance of Determining the Level of Bone Metabolism Markers and Vitamin D in the First Year of Life in the Kazakh Population

OBJECTIVE

The research aimed to determine the importance of vitamin D and markers of bone metabolism in the overall assessment of bone mineralization during a child's first year of life.

METHODS

The 198 children were selected by screening all infants seen at our pediatric clinic over a 2-year period from 2020-2022 and including those who met the eligibility criteria of being aged 0 to 1 year, healthy with no chronic conditions, and not on vitamin D supplementation. Children were divided into 3 groups depending on the content of vitamin D in the blood serum: sufficient, insufficient, and deficient. The markers of bone tissue status included: markers of mineral metabolism (calcium, phosphorus, parathyroid hormone, calcitonin), a marker of bone formation (osteocalcin), resorption marker (deoxypyridinoline). Laboratory values were obtained at the time of study enrollment during the initial study visit. Labs were not repeated during the course of the study.

RESULTS

A quarter of the infants exhibited vitamin D deficiency at enrollment with serum 25OHD concentrations below 20 ng/mL, which showed a positive correlation with serum calcium and phosphorus -concentrations and a negative correlation with PTH, while osteocalcin and deoxypyridinoline concentrations remained consistent regardless of vitamin D status.

CONCLUSIONS

The study's practical significance allows for the recommendation of using vitamin D -concentrations as a marker to detect bone formation and mineral metabolism disorders in children during their first year of life. By identifying and addressing these issues early on, the health care system aims to ensure better musculoskeletal health for children.

Vitamin D and its role in gynecology: emerging importance of checking vitamin D status in certain gynecological entities

Among non-bone effects of vitamin D, the three main chronological stages in gynecology ‒ menarche, reproductive stage and menopause/postmenopause - are possibly impacted by vitamin D deficiency. A large amount of emerging data show that vitamin D is a confounding factor in these parameters. Gynecology stays at the crossroads with endocrinology and, in the light of the rising knowledge about the involvement of vitamin D in many gynecological disorders, it is worth to investigate the exact role of vitamin D in this area. Especially since vitamin D is easy to substitute in case of deficiency. Authors present some emerging data on the role of vitamin D in gynecology, suggesting when it is necessary to check vitamin D status to intervene with vitamin D supplementation and raising gynecologists' awareness of the need for further clinical studies.

Correlation between serum vitamin D level and uterine volume in girls with idiopathic central precocious puberty

OBJECTIVES

Investigate serum vitamin D (vit D) levels' relation to uterine volume in idiopathic central precocious puberty (ICPP) girls and compare findings with normal peers.

METHODS

Analyzed 278 ICPP cases from January 2017 to September 2022 alongside 239 normally developing girls. Collected clinical data and lab markers and performed subgroup analysis based on vit D levels. Correlation and regression analyses were conducted.

RESULTS

The ICPP group exhibited elevated uterine volume and lower serum vit D compared to controls (p<0.05). A weak negative correlation was noted between vit D and uterine volume in ICPP (r=-0.193, p=0.004), and no such correlation in controls (r=-0.073, p=0.319). The ICPP vit D deficiency subgroup displayed higher uterine volume than the insufficiency and sufficiency subgroups (p<0.05). Uterine volume in the insufficiency subgroup exceeded the sufficiency subgroup (p<0.05). After adjusting for confounders, lower vit D is linked to increased ICPP uterine volume (non-standardized regression coefficient β=-25.55, 95 % CI= -46.23, -4.87, p=0.016). A Limited correlation between vit D and uterine volume was seen in girls with normal pubertal timing.

CONCLUSIONS

We demonstrated a correlation between vit D and uterine volume in ICPP girls, absent in normal peers. ICPP girls often exhibit lower vit D levels and increased uterine volume. Further research is vital for understanding vit D's role in ICPP pathogenesis and guiding prevention and treatment strategies.

Mini-Review on Vitamin D in Pediatric Population and its Role in Respiratory and Atopic Disorders

In recent years, our comprehension of the function of vitamin D has significantly evolved. The ubiquitous presence of the vitamin D receptor (Vitamin D Receptor- VDR) in the body has led to its redefinition from a steroidal hormone primarily involved in skeletal functions to a hormone with pleiotropic effects, exerting its influence on the circulatory, nervous, and immune systems. This has prompted investigations into its potential use in preventing and treating chronic metabolic disorders, cardiovascular diseases, infections, and allergic and autoimmune diseases. This comprehensive review explores the various aspects of vitamin D, including its sources, synthesis, functions, and its impact on different physiological systems. It delves into the epidemiology of vitamin D deficiency, highlighting its occurrence among various age demographics and geographic regions. The impact of vitamin D on the immune system is also explored, elucidating its immunomodulatory and anti-inflammatory properties, particularly in the context of respiratory infections. The review discusses emerging evidence concerning the potential advantages of vitamin D in respiratory diseases, pediatric asthma and atopic dermatitis. It also addresses vitamin D supplementation recommendations for various pediatric populations, including term and preterm infants. The growing concern regarding the global health impacts of insufficient vitamin D levels necessitates further research to bridge gaps in knowledge, particularly in enhancing screening, prevention, and approaches to address vitamin D deficiency from birth onwards. In summary, this comprehensive overview underscores the vital role of vitamin D, highlighting the significance of understanding its multifaceted functions and the need for tailored supplementation strategies, especially in vulnerable populations.

Obstructive sleep apnea and vitamin D: an updated systematic review and meta-analysis

PURPOSE  : Obstructive sleep apnea (OSA) is a chronic, sleep-related breathing disorder which leads to increased cardiovascular risks. Vitamin D deficiency is associated with various cardiometabolic complications, including increased cardiovascular morbidity and mortality. We aimed to analyze the difference in serum 25-hydroxyvitamin D (25-OHD) level, prevalence of vitamin D insufficiency and deficiency, and the effect of CPAP treatment on serum 25-OHD levels among adult patients with OSA.

METHODS

We pooled data from 18 observational studies involving 5592 individuals. Baseline parameters that might have contributed to the significant differences observed were also analyzed.

RESULTS

Patients with OSA had significantly lower serum 25-OHD levels (pooled d +  - 0.74 [95% CI: - 1.19 to - 0.28], p < 0.01) and higher prevalence of vitamin D deficiency (pooled log (odds ratio) 0.98 [95% CI: 0.30 to 1.67], p < 0.01) compared to those without OSA. Subgroup analysis demonstrated that these differences were significant only in moderate OSA and severe OSA. Neither age nor BMI nor geographical latitude contributed significantly to the differences observed in serum 25-OHD levels. The use of CPAP did not lead to significant changes in serum 25-OHD levels.

CONCLUSION

Patients with OSA have lower serum 25-OHD levels with a higher prevalence of vitamin D deficiency, regardless of age or BMI, pointing to an independent association between vitamin D and OSA.

Effect of vitamin D metabolites and gene expression of vitamin D receptor, and 1-alpha-hydroxylase related to the sperm quality

The incidence of male fertility disorders has increased greatly due to various genetic and lifestyle factors. Recently, it has been hypothesized that vitamin D may be involved with idiopathic infertility. The goal of the study was to determine the effect and relationship between blood vitamin D metabolites, intracellular sperm vitamin D levels, and gene expression of 1-α-hydroxylase and VDR, with regard to semen quality. Seventy volunteers aged 25-45 were involved in the study. According to spermogram analysis, participants were stratified into normozoospermic control group, non-normozoospermic target group, and oligoasthenoteratozoospermic group. Vitamin D metabolites (total 25-hydroxycholecalciferol, 1,25-dihydroxycholecalciferol) in blood and spermatozoa were determined by ELISA. Free and bioavailable 25-hydroxycholecalciferol were calculated using the Vermeulen equation. mRNA expression of VDR and 1-α hydroxylase was evaluated by qPCR. Free and bioavailable 25-hydroxycholecalciferol were significantly higher in the control group compared to the target group and compared to the oligoasthenoteratozoospermic group . Intracellular sperm 1,25-dihydroxycholecalciferol was higher in the control group compared to the target group. The mRNA levels of 1- α-hydroxylase were significantly higher in the control samples, while VDR expression was significantly higher in the target group. Significant positive correlations were established between free and bioavailable 25-hydroxycholecalciferol with sperm motility and morphology. Vitamin D metabolites in blood and intracellular sperm 1,25-dihydroxycholecalciferol seem to exert beneficial effects on sperm motility and morphology. Regarding sperm quality, these effects are more pronounced in the free and bioavailable 25OHD compared to the total 25OHD in blood. Higher expression of 1-α-hydroxylase likely leads to higher intracellular levels of 1,25-dihydroxycholecalciferol, which could contribute to sperm motility and morphology. Higher VDR expression may be a compensatory mechanism related to lower intracellular sperm 1,25-dihydroxycholecalciferol.

A Scoping Review of Vitamin D for Nonskeletal Health: A Framework for Evidence-Based Clinical Practice

BACKGROUND

Low serum 25-hydroxy-vitamin D [25(OH)D] levels are prevalent worldwide. Although the benefits of vitamin D supplementation have focused on skeletal disorders (eg, rickets, osteomalacia, osteoporosis), emerging evidence for nonskeletal health merits further discussion.

PURPOSE

The purpose of this review was to critically examine the vitamin D supplementation literature pertaining to nonskeletal health to help guide clinicians.

METHODS

A scoping review that included observational studies and randomized clinical trials (RCTs) was performed. Evidence from meta-analyses and individual RCTs are discussed, and controversies and future directions are considered.

FINDINGS

25(OH)D deficiency is a ubiquitous condition associated with multiple nonskeletal diseases, including cardiometabolic (heart disease, diabetes, and kidney disease), immune (HIV/AIDS and cancer), lung (from traditional chronic disorders to coronavirus disease 2019), and gut diseases. Vitamin D deficiency also affects health across the life span (children, pregnant, and elderly), mental illness, and reproduction in both men and women. In contrast, vitamin D supplementation does not necessarily improve major medical outcomes, even when low 25(OH)D levels are treated. Screening for 25(OH)D status remains an important practice, primarily for high-risk patients (eg, elderly, women with osteoporosis, people with low exposure to sunlight). It is reasonable to supplement with vitamin D to treat 25(OH)D deficiency, such that if beneficial nonskeletal health occurs, this may be considered as a coadjutant instead of the central tenet of the disease. Furthermore, optimizing dosing regimens is an important clinical consideration.

IMPLICATIONS

Although 25(OH)D deficiency is prevalent in nonskeletal diseases, there is no uniform evidence that vitamin D supplementation improves major medical outcomes, even when low 25(OH)D levels are corrected. Findings from RCTs warrant caution due to possible selection bias. Overall, vitamin D supplementation must be guided by circulating levels as a reasonable medical practice to correct 25(OH)D deficiency.

Vitamin D from UV-Irradiated Mushrooms as a Way for Vitamin D Supplementation: A Systematic Review on Classic and Nonclassic Effects in Human and Animal Models

Recent literature has shown that vitamin D, in addition to its well-known activity on the skeleton, has many positive effects on health. Unfortunately, it is not easy to meet intake needs solely with food. Mushrooms could provide a valid way to achieve this goal, because they are one of the few sources of vitamin D. The aim of this systematic review was to summarize what has been reported in the literature on the treatment of animal and human models with irradiated commercial mushrooms, with particular attention paid to the effects on clinical outcomes associated with the classical and nonclassical vitamin D functions. A total of 18 articles were selected. Six studies were conducted on human samples, while twelve were focused on animal models. The six studies conducted in humans involved a large number of subjects (663), but the treatment period was relatively short (1–6 months). Furthermore, the treatment dosage was different in the various groups (600–3800 IU/day). Probably for this reason, the studies did not demonstrate clinical efficacy on the parameters evaluated (cognitive functions, muscle system/function, metabolic syndrome). Indeed, those studies demonstrated an efficacy in increasing the blood levels of 25(OH)D2, but not in increasing the levels of 25(OH)D total. In 9 of 12 studies conducted on the animal model, however, a clinical efficacy on bone metabolism, inflammation, and cognitive performance was demonstrated. The results of this systematic review indicate that the intake of vitamin D from irradiated mushrooms could possibly help to meet vitamin D needs, but the dosage and the time of treatment tested need to be evaluated. Therefore, studies conducted in humans for longer periods than the studies carried out up to now are necessary, with defined dosages, in order to also evaluate the clinical efficacy demonstrated in animal models both for the classical (bone metabolism) and nonclassical (muscle function, cognitive performance, anti-inflammatory, and antioxidant activities) effects of vitamin D.

Immunoceuticals: Harnessing Their Immunomodulatory Potential to Promote Health and Wellness

Knowledge that certain nutraceuticals can modulate the immune system is not new. These naturally occurring compounds are known as immunoceuticals, which is a novel term that refers to products and systems that naturally improve an individual’s immuno-competence. Examples of immunoceuticals include vitamin D3, mushroom glycans, flavonols, quercetin, omega-3 fatty acids, carotenoids, and micronutrients (e.g., zinc and selenium), to name a few. The immune system is a complex and highly intricate system comprising molecules, cells, tissues, and organs that are regulated by many different genetic and environmental factors. There are instances, such as pathological conditions, in which a normal immune response is suboptimal or inappropriate and thus augmentation or tuning of the immune response by immunoceuticals may be desired. With infectious diseases, cancers, autoimmune disorders, inflammatory conditions, and allergies on the rise in both humans and animals, the importance of the use of immunoceuticals to prevent, treat, or augment the treatment of these conditions is becoming more evident as a natural and often economical approach to support wellness. The global nutraceuticals market, which includes immunoceuticals, is a multi-billion-dollar industry, with a market size value of USD 454.55 billion in 2021, which is expected to reach USD 991.09 billion by 2030. This review will provide an overview of the immune system, the importance of immunomodulation, and defining and testing for immunocompetence, followed by a discussion of several key immunoceuticals with clinically proven and evidence-based immunomodulatory properties.

Reconsidering vitamin D optimal values based on parathyroid hormone levels in a North Algerian cohort: stratification by gender and season

"Health-based threshold value" is used to define the optimal cutoff of vitamin D. This approach is based on the hypothesis of a secondary hyperparathyroidism associated with hypovitaminosis D. We define the optimal values in a North Algerian population. The optimal value is 25.0 ng/ml in men and 30.0 ng/ml in women.

PURPOSE/INTRODUCTION

There is no consensus defining the vitamin D optimal values. The aim of this study is to establish vitamin D optimal values in the Northern Algerian population, based on its skeletal effects as represented by the inverse relationship between 25-hydroxy vitamin D (25(OH) D) and parathyroid hormone (PTH).

METHODS

451 healthy volunteers of both genders, aged 19 to 79 years, were enrolled in a cross-sectional study conducted at the medical analysis laboratory of the University Hospital of Blida, Algeria. 25(OH) D was assessed by a sequential competitive immuno-fluoroassay technique. Determination of vitamin D optimal values was performed based on the kinetic relationship between 25(OH) D and PTH, as explored by inverse nonlinear regression on a spline plots curve. The optimal value represents the 25(OH) D level at which PTH ceases to increase and reaches a virtual plateau.

RESULTS

In men and women, respectively, the 25 (OH) D thresholds are estimated at 25.0 ng/ml and 30 ng/ml, above this value, PTH stabilizes in a virtual plateau, estimated at 22.3 pg/ml and 26.8 pg/ml. In warm and cold seasons, respectively, the 25 (OH) D cut-offs are estimated at 30.0 ng/ml and 25.0 ng/ml, from these values, the PTH stabilizes in a virtual plateau, estimated at 21.5 pg/ml and 27.7 pg/ml.

CONCLUSION

In this study, the optimal values of 25(OH) D were defined for the first time in a North Algerian adult population. The optimal value is 25.0 ng/ml in men and 30.0 ng/ml in women.

Vitamin D3 Metabolic Enzymes in the Porcine Uterus: Expression, Localization and Autoregulation by 1,25(OH)2D3 In Vitro

The role of vitamin D₃ has been confirmed in female reproductive organs. This study aimed to examine vitamin D₃ metabolic enzymes, i.e., CYP27B1 and CYP24A1, mRNA transcript and protein abundance, and protein localization in the uterus of pigs on days 2–5, 10–12, 15–16 and 18–20 of the estrous cycle. Additionally, we determined 1,25(OH)₂D₃ concentration in uterine flushings and the effect of 1,25(OH)₂D₃ (10, 50 and 100 ng/mL) in vitro on CYP27B1 and CYP24A1 mRNA transcript abundance in endometrial and myometrial slices. In the endometrium, a greater CYP27B1 mRNA transcript abundance was noted on days 10–12 and 18–20 than on days 15–16, whereas encoded protein abundance was greater on days 18–20 when compared to days 15–16. Endometrial CYP24A1 mRNA transcript abundance was greater on days 18–20 than on days 10–12 and 15–16. In the myometrium, CYP27B1 mRNA transcript abundance was greater on days 18–20 than on days 2–5 and 15–16, while protein abundance was larger in slices collected on days 18–20 than on days 15–16. Neither CYP24A1 mRNA transcript nor encoded protein abundance were detected in the myometrium. The highest 1,25(OH)₂D₃ concentration in uterine flushings was observed on days 18–20. Furthermore, the 1,25(OH)₂D₃ increased the abundance of the CYP24A1 mRNA transcript in endometrial slices. Overall, our results suggest that porcine uterus is an extra-renal site of vitamin D₃ metabolism. Both the endometrium and the myometrium possess the ability to synthesize vitamin D₃, while only the endometrium contributes to its catabolism.

Vitamin D Dosing: Basic Principles and a Brief Algorithm (2021 Update)

Nowadays, in modern societies, many people can be at high risk to have low vitamin D levels. Therefore, testing of serum 25-hydroxy-vitamin D (25OH-D) levels should be performed before prescribing them vitamin D supplementation. However, in some cases the 25OH-D level assessment is not available at the right moment, e.g., due to mandatory quarantine of COVID-19 outpatients. Therefore, such patients could be advised to start taking moderate vitamin D doses (e.g., 4000 IU/day for adults), and their 25-OH-D levels could be checked later. The proposed algorithm also comprises vitamin D dosing principles when baseline 25OH-D levels are known.

The Role of Dietary Nutrients in Peripheral Nerve Regeneration

Peripheral nerves are highly susceptible to injuries induced from everyday activities such as falling or work and sport accidents as well as more severe incidents such as car and motorcycle accidents. Many efforts have been made to improve nerve regeneration, but a satisfactory outcome is still unachieved, highlighting the need for easy to apply supportive strategies for stimulating nerve growth and functional recovery. Recent focus has been made on the effect of the consumed diet and its relation to healthy and well-functioning body systems. Normally, a balanced, healthy daily diet should provide our body with all the needed nutritional elements for maintaining correct function. The health of the central and peripheral nervous system is largely dependent on balanced nutrients supply. While already addressed in many reviews with different focus, we comprehensively review here the possible role of different nutrients in maintaining a healthy peripheral nervous system and their possible role in supporting the process of peripheral nerve regeneration. In fact, many dietary supplements have already demonstrated an important role in peripheral nerve development and regeneration; thus, a tailored dietary plan supplied to a patient following nerve injury could play a non-negotiable role in accelerating and promoting the process of nerve regeneration.