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

Understanding the Biological Activities of Vitamin D in Type 1 Neurofibromatosis: New Insights into Disease Pathogenesis and Therapeutic Design

Vitamin D is a fat-soluble steroid hormone playing a pivotal role in calcium and phosphate homeostasis as well as in bone health. Vitamin D levels are not exclusively dependent on food intake. Indeed, the endogenous production-occurring in the skin and dependent on sun exposure-contributes to the majority amount of vitamin D present in the body. Since vitamin D receptors (VDRs) are ubiquitous and drive the expression of hundreds of genes, the interest in vitamin D has tremendously grown and its role in different diseases has been extensively studied. Several investigations indicated that vitamin D action extends far beyond bone health and calcium metabolism, showing broad effects on a variety of critical illnesses, including cancer, infections, cardiovascular and autoimmune diseases. Epidemiological studies indicated that low circulating vitamin D levels inversely correlate with cutaneous manifestations and bone abnormalities, clinical hallmarks of neurofibromatosis type 1 (NF1). NF1 is an autosomal dominant tumour predisposition syndrome causing significant pain and morbidity, for which limited treatment options are available. In this context, vitamin D or its analogues have been used to treat both skin and bone lesions in NF1 patients, alone or combined with other therapeutic agents. Here we provide an overview of vitamin D, its characteristic nutritional properties relevant for health benefits and its role in NF1 disorder. We focus on preclinical and clinical studies that demonstrated the clinical correlation between vitamin D status and NF1 disease, thus providing important insights into disease pathogenesis and new opportunities for targeted therapy.

Nutritional Enhancement of Farmed Salmon Meat via Non-GMO Nannochloropsis Gaditana: Eicosapentaenoic Acid (EPA, 20:5 n-3), Docosapentaenoic Acid (DPA, 22:5 n-3) and Vitamin D3 for Human Health

Omega-3 long-chain polyunsaturated fatty acids (n-3 LC PUFAs) and vitamin D3 are essential components of human nutrition. A regular human diet is highly deficient in n-3 LC PUFAs. Fish like salmon are highly recommended in the human diet as they are a major source of high-value n-3 LC PUFAs and vitamin D3. The levels of these nutrients have been decreasing over the last few years in farmed salmon, whose production urgently needs sustainable sources of these nutrients. The microalga Nannochloropsis gaditana (NG) is known for its naturally high potential for the production of eicosapentaenoic (EPA, 20:5 n-3) fatty acid. A commercial diet for Atlantic salmon was supplemented with 1% and 10% of spray-dried NG grown under controlled conditions for a high EPA content. Salmon were harvested on day 49, following which, boneless and skinless salmon meat was recovered from fish and analyzed for the fatty acid profile, total fat, and vitamin D3. Vitamin D3, EPA, and docosapentaenoic fatty acid (DPA, 22:5 n-3) levels were significantly increased (p < 0.05) by supplementing the basal diet with 10% NG, thus, NG represents a novel, functional, natural ingredient and a sustainable source of n-3 LC-PUFAs that can raise the levels of healthy fats and vitamin D3 in farmed salmon meat.

Pleiotropic actions of Vitamin D in composite musculoskeletal trauma

Composite tissue injuries are the result of high energy impacts caused by motor vehicle accidents, gunshot wounds or blasts. These are highly traumatic injuries characterized by wide-spread, penetrating wounds affecting the entire musculoskeletal system, and are generally defined by frank volumetric muscle loss with concomitant segmental bone defects. At the tissue level, the breadth of damage to multiple tissue systems, and potential for infection from penetration, have been shown to lead to an exaggerated, often chronic inflammatory response with subsequent dysregulation of normal musculoskeletal healing mechanisms. Aside from the direct effects of inflammation on myogenesis and osteogenesis, frank muscle loss has been shown to directly impair fracture union and ultimately contribute to failed wound regeneration. Care for these injuries requires extensive surgical intervention and acute care strategies. However, often these interventions do not adequately mitigate inflammation or promote proper musculoskeletal injury repair and force amputation of the limb. Therefore, identification of factors that can promote tissue regeneration and mitigate inflammation could be key to restoring wound healing after composite tissue injury. One such factor that may directly affect both inflammation and tissue regeneration in response to these multi-tissue injuries may be Vitamin D. Beyond traditional roles, the pleiotropic and localized actions of Vitamin D are increasingly being recognized in most aspects of wound healing in complex tissue injuries - e.g., regulation of inflammation, myogenesis, fracture callus mineralization and remodeling. Conversely, pre-existing Vitamin D deficiency leads to musculoskeletal dysfunction, increased fracture risk or fracture non-unions, decreased strength/function and reduced capacity to heal wounds through increased inflammation. This Vitamin D deficient state requires acute supplementation in order to quickly restore circulating levels to an optimal level, thereby facilitating a robust wound healing response. Herein, the purpose of this review is to address the roles and critical functions of Vitamin D throughout the wound healing process. Findings from this review suggest that careful monitoring and/or supplementation of Vitamin D may be critical for wound regeneration in composite tissue injuries.

Why do so many trials of vitamin D supplementation fail?

Our knowledge of vitamin D has come a long way since the 100 years it took for doctors to accept, between 1860 and 1890, that both sunlight and cod liver oil (a well-known folk remedy) cured and prevented rickets. Vitamins D2/D3 were discovered exactly a hundred years ago, and over the last 50 years vitamin D has been found to have many effects on virtually all human tissues and not just on bone health, while mechanisms affecting the actions of vitamin D at the cellular level are increasingly understood, but deficiency persists globally. Observational studies in humans have shown that better provision of vitamin D is strongly associated, dose-wise, with reductions in current and future health risks in line with the known actions of vitamin D. Randomised controlled trials, commonly accepted as providing a 'gold standard' for assessing the efficacy of new forms of treatment, have frequently failed to provide supportive evidence for the expected health benefits of supplementation. Such RCTs, however, have used designs evolved for testing drugs while vitamin D is a nutrient; the appreciation of this difference is critical to identifying health benefits from existing RCT data and for improving future RCT design. This report aims, therefore, to provide a brief overview of the evidence for a range of non-bony health benefits of vitamin D repletion; to discuss specific aspects of vitamin D biology that can confound RCT design and how to allow for them.

Role of vitamin D in preventing of COVID-19 infection, progression and severity

The outbreak of COVID-19 has created a global public health crisis. Little is known about the protective factors of this infection. Therefore, preventive health measures that can reduce the risk of infection, progression and severity are desperately needed. This review discussed the possible roles of vitamin D in reducing the risk of COVID-19 and other acute respiratory tract infections and severity. Moreover, this study determined the correlation of vitamin D levels with COVID-19 cases and deaths in 20 European countries as of 20 May 2020. A significant negative correlation (p=0.033) has been observed between mean vitamin D levels and COVID-19 cases per one million population in European countries. However, the correlation of vitamin D with COVID-19 deaths of these countries was not significant. Some retrospective studies demonstrated a correlation between vitamin D status and COVID-19 severity and mortality, while other studies did not find the correlation when confounding variables are adjusted. Several studies demonstrated the role of vitamin D in reducing the risk of acute viral respiratory tract infections and pneumonia. These include direct inhibition with viral replication or with anti-inflammatory or immunomodulatory ways. In the meta-analysis, vitamin D supplementation has been shown as safe and effective against acute respiratory tract infections. Thus, people who are at higher risk of vitamin D deficiency during this global pandemic should consider taking vitamin D supplements to maintain the circulating 25(OH)D in the optimal levels (75-125nmol/L). In conclusion, there is not enough evidence on the association between vitamin D levels and COVID-19 severity and mortality. Therefore, randomized control trials and cohort studies are necessary to test this hypothesis.

Null association between serum 25-hydroxyvitamin D levels with allergic rhinitis, allergic sensitization and non-allergic rhinitis: A Mendelian randomization study

BACKGROUND

Previous observational studies have not found a conclusive association between serum 25-hydroxyvitamin D (25(OH)D) levels and allergic rhinitis (AR) or allergic sensitization (AS).

OBJECTIVE

To investigate a causal association between 25(OH)D levels with risk of AR and AS, using a two-sample Mendelian randomization (MR) approach.

METHODS

Seven single nucleotide polymorphisms (SNPs), previously shown to be associated with serum 25(OH)D levels, were identified as instrumental variables. The primary outcome was AR, and the secondary outcomes were AS and non-allergic rhinitis (NAR). The genome-wide association (GWA) summary statistics of the outcomes were obtained from two cohort studies (EAGLE Consortium and UK Biobank). An MR analysis with random-effects inverse-variance weighted method was performed as the primary analysis to estimate overall effect size (odds ratio [OR] and 95% confidence interval [CI]). Sensitivity analysis using weighted median method and MR-Egger regression method was conducted. A subgroup analysis based on 25(OH)D synthesis-related SNPs was further applied.

RESULTS

Serum 25(OH)D levels were not causally associated with risk of AR (OR: 0.960; 95% CI: 0.779-1.184), AS (OR: 1.059; 95% CI: 0.686 to 1.634) or NAR (OR: 0.937; 95% CI: 0.588-1.491). Subgroup analysis also showed null association between 25(OH)D synthesis-related SNPs and the outcomes. Sensitivity analyses yielded similar results.

CONCLUSIONS AND CLINICAL RELEVANCE

This MR study found no evidence supporting a causal association between serum 25(OH)D levels and risk of AR, AS and NAR in European-ancestry population. This argues against the previous postulation that vitamin D supplementation is effective in prevention of allergic diseases.

Effect of Vitamin D Supplement on Vulvovaginal Atrophy of the Menopause

The effects of oral vitamin D supplements on vaginal health in postmenopausal women with vulvovaginal atrophy (VVA) was evaluated. A double-blinded, randomized placebo-controlled trial was conducted for 12 weeks to investigate changes on vaginal maturation index (VMI), vaginal pH, and the visual analog scale (VAS) of VVA symptoms. The vitamin D group received oral ergocalciferol, at 40,000 IU per week, while the placebo group received an identical placebo capsule. Eighty postmenopausal women were enrolled. There were no significant differences in baseline characteristics between both groups. In an intention-to-treat analysis, VMI, vaginal pH, and VAS of VVA symptoms showed no significant differences between both groups at the six and 12 weeks. However, the mean difference of VMI in the vitamin D group between baseline and at six weeks showed significant improvement (5.5 + 16.27, p <0.05). Moreover, the mean vaginal pH and VAS of VVA patients in the vitamin D group were significantly improved at both six and 12 weeks compared to baseline. The oral vitamin D supplementation for 12 weeks potentially improves vaginal health outcomes in postmenopausal women with VVA symptoms, demonstrated by the improved mean VMI, vaginal pH, and VAS at six and 12 weeks between baseline, however, no significant differences were observed from the placebo treatment.

Vitamin D Deficiency in Autism Spectrum Disorder: A Cross-Sectional Study

Vitamin D plays a role in central nervous system (CNS) development. Recent literature focused on vitamin D status in children and adolescents with autism spectrum disorder (ASD), but with inconsistent results. Our case-control study is aimed at evaluating serum 25-hydroxyl-vitamin D (25(OH)D) concentration in children with ASD (ASD group, n = 54) compared to children affected by other neurological and psychiatric disorders (non-ASD group, n = 36). All patients were admitted at the Complex Operative Unit of Child Neuropsychiatry, Polyclinic of Bari, Italy. 25(OH)D was quantified by chemiluminescence immunoassay and level defined as: deficiency (<20 ng/mL); insufficiency (20-30); normality (30-100); toxicity (>100). Statistical analysis was performed using SPSS20 (significance < 0.05). The ASD group showed 25(OH)D a mean level significantly lower than control (p = 0.014). Multivariable logistic regression analysis showed an association between ASD and vitamin D deficiency (p = 0.006). The nature of such association is unclear. Vitamin D deficiency may probably act as a risk factor for the development of ASD. Further studies are needed to unravel the role of vitamin D in ASD etiology and investigate its therapeutic potential.

Vitamin D Metabolism and Profiling in Veterinary Species

The demand for vitamin D analysis in veterinary species is increasing with the growing knowledge of the extra-skeletal role vitamin D plays in health and disease. The circulating 25-hydroxyvitamin-D (25(OH)D) metabolite is used to assess vitamin D status, and the benefits of analysing other metabolites in the complex vitamin D pathway are being discovered in humans. Profiling of the vitamin D pathway by liquid chromatography tandem mass spectrometry (LC-MS/MS) facilitates simultaneous analysis of multiple metabolites in a single sample and over wide dynamic ranges, and this method is now considered the gold-standard for quantifying vitamin D metabolites. However, very few studies report using LC-MS/MS for the analysis of vitamin D metabolites in veterinary species. Given the complexity of the vitamin D pathway and the similarities in the roles of vitamin D in health and disease between humans and companion animals, there is a clear need to establish a comprehensive, reliable method for veterinary analysis that is comparable to that used in human clinical practice. In this review, we highlight the differences in vitamin D metabolism between veterinary species and the benefits of measuring vitamin D metabolites beyond 25(OH)D. Finally, we discuss the analytical challenges in profiling vitamin D in veterinary species with a focus on LC-MS/MS methods.

Exploring the effect of vitamin D3 supplementation on surrogate biomarkers of cholesterol absorption and endogenous synthesis in patients with type 2 diabetes-randomized controlled trial

BACKGROUND

Inverse associations have been reported between serum 25-hydroxyvitamin D [25(OH)D] and circulating cholesterol concentrations in observational studies. Postulated mechanisms include reduced bioavailability of intestinal cholesterol and alterations in endogenous cholesterol synthesis.

OBJECTIVE

To explore the effect of daily supplementation with 4000 IU/d vitamin D3 for 24 wk on surrogate biomarkers of cholesterol absorption (campesterol and β-sitosterol) and endogenous synthesis (lathosterol and desmosterol).

METHODS

Ancillary study of The Vitamin D for Established Type 2 Diabetes (DDM2) trial. Patients with established type 2 diabetes (N = 127, 25-75 y, BMI 23-42 kg/m2) were randomly assigned to receive either 4000 IU vitamin D3 or placebo daily for 24 wk. Of participants without changes in cholesterol-lowering medications (n = 114), plasma surrogate cholesterol absorption and endogenous synthesis biomarker concentrations were measured and merged with available measures of serum LDL cholesterol and HDL cholesterol concentrations.

RESULTS

At week 24, vitamin D3 supplementation significantly increased 25(OH)D concentrations (+21.5 ± 13.4 ng/mL) but not insulin secretion rates (primary outcome of the parent study) as reported previously. In this ancillary study there was no significant effect of vitamin D3 supplementation on serum cholesterol profile or surrogate biomarkers of cholesterol absorption and endogenous synthesis. Compared with participants not treated with cholesterol-lowering medications, those who were treated exhibited a greater reduction in plasma campesterol concentrations in the vitamin D3 but not placebo group (P-interaction = 0.011). Analyzing the data on the basis of cholesterol absorption status (hypo- versus hyperabsorbers) or cholesterol synthesis status (hypo- versus hypersynthesizers) did not alter these results.

CONCLUSIONS

Vitamin D3 supplementation for 24 wk had no significant effect on surrogate biomarkers of cholesterol absorption or endogenous synthesis, consistent with the lack of effect on serum cholesterol profile. Vitamin D3 supplementation resulted in greater reduction in campesterol concentrations in participants not using compared with those using cholesterol-lowering medications. Further studies are required.This trial was registered at clinicaltrials.gov as NCT01736865.

Low plasma 25(OH) vitamin D level is associated with increased risk of COVID-19 infection: an Israeli population-based study

Vitamin D deficiency is a worldwide pandemic. The aim of this study was to evaluate associations of plasma 25(OH)D levels with the likelihood of coronavirus disease 2019 (COVID‐19) infection and hospitalization. The study population included the 14 000 members of Leumit Health Services, who were tested for COVID‐19 infection from February 1^st to April 30^th, 2020, and who had at least one previous blood test for the plasma 25(OH)D level. ‘Suboptimal’ or ‘low’ plasma 25(OH)D level was defined as plasma 25‐hydroxyvitamin D, or 25(OH)D, concentration below the level of 30 ng/mL. Of 7807 individuals, 782 (10.02%) were COVID‐19‐positive, and 7025 (89.98%) COVID‐19‐negative. The mean plasma vitamin D level was significantly lower among those who tested positive than negative for COVID‐19 [19.00 ng/mL (95% confidence interval (CI) 18.41–19.59) vs. 20.55 (95% CI: 20.32–20.78)]. Univariate analysis demonstrated an association between the low plasma 25(OH)D level and increased likelihood of COVID‐19 infection [crude odds ratio (OR) of 1.58 (95% CI: 1.24–2.01, P < 0.001)], and of hospitalization due to the SARS‐CoV‐2 virus [crude OR of 2.09 (95% CI: 1.01–4.30, P < 0.05)]. In multivariate analyses that controlled for demographic variables, and psychiatric and somatic disorders, the adjusted OR of COVID‐19 infection [1.45 (95% CI: 1.08–1.95, P < 0.001)] and of hospitalization due to the SARS‐CoV‐2 virus [1.95 (95% CI: 0.98–4.845, P = 0.061)] were preserved. In the multivariate analyses, age over 50 years, male gender and low–medium socioeconomic status were also positively associated with the risk of COVID‐19 infection; age over 50 years was positively associated with the likelihood of hospitalization due to COVID‐19. We concluded that low plasma 25(OH)D levels appear to be an independent risk factor for COVID‐19 infection and hospitalization.

Low vitamin D status is associated with obesity but no other cardiovascular risk factors in Chinese children and adolescents

BACKGROUND AND AIMS

Evidence on relationship between vitamin D status and cardiovascular health in childhood remains inconsistent. This study aimed to investigate vitamin D status and its relationship with cardiovascular risk factors in Chinese children and adolescents.

METHODS AND RESULTS

Cross-sectional data were obtained from 2680 children and adolescents aged 7-18 y in Guangzhou, South China. Anthropometric and socioeconomic characters, concentration of serum 25-hydroxyvitamin D [25(OH)D], fasting blood glucose and lipids, as well as information about diet and physical activity were measured and collected. Logistic regression model was adopted to analyze the associations between 25(OH)D levels and cardiovascular risk factors including obesity, high blood pressure, dyslipidemia, hyperglycemia, and metabolic syndrome. Overall, median level of 25(OH)D was 19.74 ng/mL. The prevalence rates of vitamin D deficiency and inadequacy were 7.5% and 44.4%, both of which were highest among adolescents aged 14-18 y (14.5% and 51.6%, respectively). As vitamin D level increased, an upward trend in fasting glucose concentrations was observed in subjects with normal fasting glucose level, but not in subjects with hyperglycemia. Among the assessed cardiovascular risk factors, vitamin D status was only inversely associated with general obesity, and the adjusted odds ratio was 1.95 (95% CI: 1.08-3.49), comparing the lowest 25(OH)D quartile with the highest one.

CONCLUSIONS

Vitamin D deficiency and inadequacy remain a concern among school-aged children and adolescents in Guangzhou, South China, particularly in adolescents aged 14-18 y. However, low vitamin D status was found only associated with general obesity but no other cardiovascular risk factors.

The Role of Polymorphisms in Vitamin D-Related Genes in Response to Vitamin D Supplementation

Background. Vitamin D deficiency represents a major healthcare problem. Vitamin D status is influenced by genetic and environmental determinants. Several observational studies have evaluated the association of single-nucleotide polymorphisms (SNPs) in vitamin D-related genes and vitamin D levels. Nevertheless, little is known about the role of these SNPs in the response to vitamin D supplementation. We conducted an interventional study to define the association between SNPs in vitamin D-related genes and the response to vitamin D supplementation in 100 self-reported healthy women of Arab ancestry for the majority. Methods. A total of 100 healthy female subjects received a weekly oral dose of 50,000 IU vitamin D for 12 weeks. Serum vitamin D concentration and metabolic profiles were measured at baseline and 12 weeks post-vitamin D supplementation. The genotypes of 37 SNPs selected from previously reported vitamin D-related genes have been assessed by Fluidigm genotyping assay. Results. Rs731236 (VDR gene) and rs7116978 (CYP2R1 gene) showed a significant association with vitamin D status. The rs731236 GG genotype and the rs7116978 CC genotype were associated with a “vitamin D sufficiency” state. Rs731236 GG and rs7116978 CC genotypes showed a higher response to vitamin D supplementation. Transcription factor binding site prediction analysis showed altered binding sites for transcription factors according to the different rs7116978 alleles. Interestingly, the 37 SNPs previously established to play a role in vitamin D-related pathways explained very little of the response to vitamin D supplementation in our cohort, suggesting the existence of alternative loci whose number and effect size need to be investigated in future studies. Conclusion. In this paper, we present novel data on vitamin D-related SNPs and response to vitamin D supplementation demonstrating the feasibility of applying functional genomic approaches in interventional studies to assess individual-level responses to vitamin D supplementation.

Nuclear Receptors as Potential Therapeutic Targets for Myeloid Leukemia

The nuclear receptor (NR) superfamily has been studied extensively in many solid tumors and some receptors have been targeted to develop therapies. However, their roles in leukemia are less clear and vary considerably among different types of leukemia. Some NRs participate in mediating the differentiation of myeloid cells, making them attractive therapeutic targets for myeloid leukemia. To date, the success of all-trans retinoic acid (ATRA) in treating acute promyelocytic leukemia (APL) remains a classical and unsurpassable example of cancer differentiation therapy. ATRA targets retinoic acid receptor (RAR) and forces differentiation and/or apoptosis of leukemic cells. In addition, ligands/agonists of vitamin D receptor (VDR) and peroxisome proliferator-activated receptor (PPAR) have also been shown to inhibit proliferation, induce differentiation, and promote apoptosis of leukemic cells. Encouragingly, combining different NR agonists or the addition of NR agonists to chemotherapies have shown some synergistic anti-leukemic effects. This review will summarize recent research findings and discuss the therapeutic potential of selected NRs in acute and chronic myeloid leukemia, focusing on RAR, VDR, PPAR, and retinoid X receptor (RXR). We believe that more mechanistic studies in this field will not only shed new lights on the roles of NRs in leukemia, but also further expand the clinical applications of existing therapeutic agents targeting NRs.

Sociodemographic disparity in the nutritional status among children and adolescents in Zhejiang Province

OBJECTIVE

To explore the sociodemographic disparity in the nutritional status including BMI, vitamin D and vitamin A status among children and adolescents in Zhejiang Province.

METHODS

Weight, height serum 25-hydroxyvitamin D, and serum retinol were assessed in 2818 children and adolescents (6-17 years of age), using ten investigation sites in Zhejiang Province including urban and rural areas data from the China National Nutritional Study 2016-2017, which is a nationally representative cross-sectional study, to form provincial representative sample of Zhejiang Province. Sociodemographic disparity was explored.

RESULTS

The prevalence of low weight, eutrophic, overweight and obese were 6.7%, 70.4%, 11.6%, and 11.2%, respectively. Significant difference was observed on BMI between males and females (P < 0.05), and between urban and rural areas (P < 0.05). The prevalence of vitamin D deficiency, inadequacy, normal and appropriate were 1.8%, 34.9%, 46.4% and 16.9%, respectively. Significant difference was observed on the concentration of 25-hydroxyvitamin D (25(OH)D) both between genders and between living areas (P < 0.05). The prevalence of vitamin A deficiency, marginal deficiency and appropriate were 4.5%, 24.7%, and 70.9%, respectively. Significant difference was observed on the concentration of retinol between living area (P < 0.05).

CONCLUSIONS

Overweight and obesity, deficiency and inadequacy of vitamin D, deficiency and marginal deficiency of vitamin A were prevalent among children and adolescents. There were disparities between genders and between living areas on the nutritional status. Regional and sex-specific guidelines and public health policies for children and adolescent nutrition are needed.

Ionizing Radiation as a Source of Oxidative Stress-The Protective Role of Melatonin and Vitamin D

Ionizing radiation (IR) has found widespread application in modern medicine, including medical imaging and radiotherapy. As a result, both patients and healthcare professionals are exposed to various IR doses. To minimize the negative side effects of radiation associated with oxidative imbalance, antioxidant therapy has been considered. In this review, studies on the effects of melatonin and vitamin D on radiation-induced oxidative stress are discussed. According to the research data, both substances meet the conditions for use as agents that protect humans against IR-induced tissue damage. Numerous studies have confirmed that melatonin, a hydro- and lipophilic hormone with strong antioxidant properties, can potentially be used as a radioprotectant in humans. Less is known about the radioprotective effects of vitamin D, but the results to date have been promising. Deficiencies in melatonin and vitamin D are common in modern societies and may contribute to the severity of adverse side effects of medical IR exposure. Hence, supporting supplementation with both substances seems to be of first importance. Interestingly, both melatonin and vitamin D have been found to selectively radiosensitise cancer cells, which makes them promising adjuvants in radiotherapy. More research is needed in this area, especially in humans.

Association of Alopecia Areata with Vitamin D and Calcium Levels: A Systematic Review and Meta-analysis

Introduction

To investigate the associations of alopecia areata (AA) with serum vitamin D and calcium levels.

Methods

A systematic review of all relevant articles published up to February 2020 in PubMed, Embase, and Cochrane Library databases was conducted. Primary endpoints were serum 25-hydroxyvitamin D [25(OH)D] levels and vitamin D deficiency, and the secondary endpoint was serum calcium level. Odds ratio (OR) and standardized mean difference (SMD) with 95% CI across studies were analyzed.

Results

Data on 1585 patients with AA and 1114 controls from 16 case–control studies and three cross-sectional studies were included in this meta-analysis. A pooled meta-analysis was conducted using the random-effects model because of inter-study heterogeneity (vitamin D level, I² = 87.90%; vitamin D deficiency, I² = 81.10%; serum calcium level, I² = 83.80%). A combined analysis revealed that patients with AA had significantly lower mean serum 25(OH)D level compared with control (WMD − 9.08, 95% CI − 11.65, − 6.50, p < 0.001), and were more likely to have vitamin D deficiency (OR 4.14, 95% CI 2.34, 7.35, p < 0.001). However, the pooled analysis revealed that patients with AA did not have significantly lower serum calcium levels compared with control (WMD − 0.17, 95% CI − 0.40, 0.06, p = 0.143). Subgroup analysis suggested that matched control, mean age, and country might contribute to the heterogeneity of serum vitamin D level, while study design, matched control, and country might contribute to the heterogeneity of vitamin D deficiency.

Conclusion

Deficiency of serum 25(OH)D level, rather than calcium level, was present in patients with AA. Screening for vitamin D deficiency and vitamin D supplementation may be beneficial in the treatment of patients with AA.

Electronic supplementary material

The online version of this article (10.1007/s13555-020-00433-4) contains supplementary material, which is available to authorized users.

Early Nutritional Interventions with Zinc, Selenium and Vitamin D for Raising Anti-Viral Resistance Against Progressive COVID-19

OBJECTIVES

The novel coronavirus infection (COVID-19) conveys a serious threat globally to health and economy because of a lack of vaccines and specific treatments. A common factor for conditions that predispose for serious progress is a low-grade inflammation, e.g., as seen in metabolic syndrome, diabetes, and heart failure, to which micronutrient deficiencies may contribute. The aim of the present article was to explore the usefulness of early micronutrient intervention, with focus on zinc, selenium, and vitamin D, to relieve escalation of COVID-19.

METHODS

We conducted an online search for articles published in the period 2010-2020 on zinc, selenium, and vitamin D, and corona and related virus infections.

RESULTS

There were a few studies providing direct evidence on associations between zinc, selenium, and vitamin D, and COVID-19. Adequate supply of zinc, selenium, and vitamin D is essential for resistance to other viral infections, immune function, and reduced inflammation. Hence, it is suggested that nutrition intervention securing an adequate status might protect against the novel coronavirus SARS-CoV-2 (Severe Acute Respiratory Syndrome - coronavirus-2) and mitigate the course of COVID-19.

CONCLUSION

We recommended initiation of adequate supplementation in high-risk areas and/or soon after the time of suspected infection with SARS-CoV-2. Subjects in high-risk groups should have high priority as regards this nutritive adjuvant therapy, which should be started prior to administration of specific and supportive medical measures.

Vitamin D screening

At present, there is no need and no sufficient evidence to support universal screening for vitamin D status. There are four categories of subjects in whom there is no requirement for screening, since a number of studies indicate beneficial effects of vitamin D supplementation; these are represented by children and adolescents, pregnant women, patients taking bone active drugs and subjects with documented hypovitaminosis D. In the remaining subjects, the utilization of adequate questionnaires will target with sufficient sensitivity and specificity those with hypovitaminosis D. These must be first supplemented and, at a later time, serum 25(OH)D assay should be requested to confirm attainment of sufficiency, independently of the threshold chosen. This strategy will cut costs deriving from both widespread use of vitamin D assays and vitamin D supplementation.

Role of vitamin D3 in selected malignant neoplasms

Vitamin D₃ is a fat-soluble essential nutrient that affects multiple biologic functions in the organism through calcitriol and the vitamin D₃ receptor. This review article focuses on the results of studies on the relationship between the level of vitamin D₃ and cancer incidence or mortality, but also on the anticancer properties of vitamin D₃ that support its significant role in the prevention, clinical course, and overall survival rates of selected cancers (colorectal, prostate, breast, ovarian, endometrial, bladder, and malignant melanoma). The mechanisms of vitamin D₃ action involve, among others, polymorphism of vitamin D₃ receptor, cell cycle, caspases, and cancer stem cells. The level of vitamin D₃ has been also demonstrated to serve as a biomarker in some cancers, and high levels of vitamin D₃ can be conducive to successful cancer therapy.

Low energy irradiation of narrow-range UV-LED prevents osteosarcopenia associated with vitamin D deficiency in senescence-accelerated mouse prone 6

Deficiency of vitamin D is an important cause of osteosarcopenia. The purpose of this study is to examine the effects of low energy narrow-range UV-LED on osteosarcopenia in animal models of senescence-accelerated mouse prone 6 (SAMP6). Preliminary experiments specified the minimum irradiance intensity and dose efficacy for vitamin D production (316 nm, 0.16 mW/cm², 1,000 J/m²). we set a total of 4 groups (n = 8 per group); vitamin D-repletion without UV irradiation (Vit.D+UV-), vitamin D-repletion with UV irradiation (Vit.D+UV +), vitamin D-deficiency without UV irradiation, (Vit.D-UV-), and vitamin D-deficiency with UV irradiation (Vit.D-UV +). Serum levels of 25(OH)D at 28 and 36 weeks of age were increased in Vit.D-UV+ group as compared with Vit.D-UV- group. Trabecular bone mineral density on micro-CT was higher in Vit.D-UV+ group than in Vit.D-UV- group at 36 weeks of age. In the histological assay, fewer osteoclasts were observed in Vit.D-UV+ group than in Vit.D-UV- group. Grip strength and muscle mass were higher in Vit.D-UV+ group than in Vit.D-UV- group at 36 weeks of age. Signs of severe damage induced by UV irradiation was not found in skin histology. Low energy narrow-range UV irradiation may improve osteosarcopenia associated with vitamin D deficiency in SAMP6.

Prevalence of Vitamin D Deficiency in a Large Newborn Cohort from Northern United States and Effect of Intrauterine Drug Exposure

Vitamin D is not only a vital element in bone health but is also a prohormone. Data regarding distribution of vitamin D status among preterm and term neonates in the United States are limited. There are no data on the effect of intrauterine drug exposure on vitamin D status. Our objective was to determine the distribution of vitamin D levels among preterm and term neonates and the effect of intrauterine illicit drug exposure. We did a retrospective chart review of neonates admitted from 2009 to 2016 to our neonatal intensive care unit with serum 25-hydroxycholecalciferol (25[OH]D) levels measured during the hospital stay. Of 1517 neonates, the median 25[OH]D level was 19 ng/mL with 31% deficient and 49% insufficient, even though 75% of mothers took prenatal vitamins. In pregnant women, 38% were vitamin-D-deficient and 44% were vitamin-D-insufficient. Four hundred seventy-one neonates had intrauterine drug exposure, with a median 25[OH]D level of 22.9 ng/mL versus 17.8 ng/mL in nonexposed neonates (p = 0.001). Despite maternal prenatal vitamin intake, neonates are at risk of vitamin D deficiency. Maternal illicit drug use was not related to lower 25[OH]D levels in neonates.

Can Vitamin D and L-Cysteine Co-Supplementation Reduce 25(OH)-Vitamin D Deficiency and the Mortality Associated with COVID-19 in African Americans?

Early reports indicate an association between the severity of the COVID-19 infection and the widespread 25-hydroxy vitamin D deficiency known to exist in populations around the world. Vitamin D deficiency is extremely common among African American (AA) communities, where the COVID-19 infection rate is three-fold higher, and the mortality rate nearly six-fold higher, compared with rates in predominantly white communities. COVID-19 infection primarily affects the lungs and airways. Previous reports have linked 25-hydroxy vitamin D deficiency with subclinical interstitial lung disease. AA are at risk for lower cellular glutathione (GSH) levels, and GSH deficiency epigenetically impairs VD biosynthesis pathway genes. Compared with vitamin D alone, co-supplementation of vitamin D and L-cysteine (a GSH precursor) showed a better efficacy in improving levels of GSH and VD-regulatory genes at the cellular/tissue level, increasing 25(OH) vitamin D levels, and reducing inflammation biomarkers in the blood in mice studies. We propose that randomized clinical trials are needed to examine the potential of co-supplementation with anti-inflammatory antioxidants, vitamin D and L-cysteine in correcting the 25(OH)VD deficiency and preventing the 'cytokine storm,' one of the most severe consequences of infection with COVID-19, thereby preventing the adverse clinical effects of COVID-19 infection in the vulnerable AA population.

Impact of the Local Inflammatory Environment on Mucosal Vitamin D Metabolism and Signaling in Chronic Inflammatory Lung Diseases

Vitamin D plays an active role in the modulation of innate and adaptive immune responses as well as in the protection against respiratory pathogens. Evidence for this immunomodulatory and protective role is derived from observational studies showing an association between vitamin D deficiency, chronic airway diseases and respiratory infections, and is supported by a range of experimental studies using cell culture and animal models. Furthermore, recent intervention studies have now shown that vitamin D supplementation reduces exacerbation rates in vitamin D-deficient patients with chronic obstructive pulmonary disease (COPD) or asthma and decreases the incidence of acute respiratory tract infections. The active vitamin D metabolite, 1,25-dihydroxy-vitamin D (1,25(OH)₂D), is known to contribute to the integrity of the mucosal barrier, promote killing of pathogens (via the induction of antimicrobial peptides), and to modulate inflammation and immune responses. These mechanisms may partly explain its protective role against infections and exacerbations in COPD and asthma patients. The respiratory mucosa is an important site of local 1,25(OH)₂D synthesis, degradation and signaling, a process that can be affected by exposure to inflammatory mediators. As a consequence, mucosal inflammation and other disease-associated factors, as observed in e.g., COPD and asthma, may modulate the protective actions of 1,25(OH)₂D. Here, we discuss the potential consequences of various disease-associated processes such as inflammation and exposure to pathogens and inhaled toxicants on vitamin D metabolism and local responses to 1,25(OH)₂D in both immune- and epithelial cells. We furthermore discuss potential consequences of disturbed local levels of 25(OH)D and 1,25(OH)₂D for chronic lung diseases. Additional insight into the relationship between disease-associated mechanisms and local effects of 1,25(OH)₂D is expected to contribute to the design of future strategies aimed at improving local levels of 1,25(OH)₂D and signaling in chronic inflammatory lung diseases.

Diabetes Mellitus and Vitamin D Deficiency:Comparable Effect on Survival and a DeadlyAssociation after a Myocardial Infarction

Survivors after a myocardial infarction (MI), especially those with diabetes mellitus (DM),remain at high risk of further events. Identifying and treating factors that may influence survivalmay open new therapeutic strategies. We assessed the impact on prognosis of DM andhypovitaminosis D (hypovitD), alone or combined. In this prospective, observational study, 1081patients were enrolled surviving an MI and divided into four groups according to their diabetic andVitD status. The primary end-point was composite of all-cause mortality, angina/MI and heartfailure (HF). Secondary outcomes were mortality, HF and angina/MI. During a follow-up of 26.1months (IQR 6.6-64.5), 391 subjects experienced the primary end-point. Patients with DM orhypovitD had similar rate of the composite end-point. Patients with only hypovitD or DM did notdiffer regarding components of composite end-point (angina p = 0.97, HF p = 0.29, mortality p = 0.62).DM and VitD deficiency had similarly adjusted risks for primary end-point (HR 1.3, 95%CI 1.05-1.61; HR 1.3, 95% CI 1.04-1.64). The adjusted HR for primary composite end-point for patients withhypovitD and DM was 1.69 (95%CI 1.25-2.29, p = 0.001) in comparison to patients with neitherhypoD nor DM. In conclusion, DM and hypovitD, individually and synergistically, are associatedwith a worse outcome after MI.

Vitamin D Status and Gastric Cancer: A Cross-Sectional Study in Koreans

Sufficient vitamin D levels are associated with reduced Helicobacter pylori infections, which can cause gastric carcinogenesis. We examined associations between vitamin D concentrations and gastric cancer (GC) prevalence in a Korean population. We analyzed data of 33,119 adults using serum 25-hydroxyvitamin D (25(OH)D) concentrations as a biomarker of vitamin D status. Participants were classified with GC if previously diagnosed as such by a physician. After controlling for age, sex and body mass index (model A), odds ratio (OR) for GC was 0.81 (95% confidence interval [CI]: 0.70, 0.95), with a 5-ng/mL increment in total 25(OH)D concentrations. In fully adjusted models (model B), the OR for GC was 0.84 (95% CI: 0.72, 0.98), with a 5-ng/mL increment in total vitamin D. Following the classification of vitamin D concentrations into three categories or for GC in model A was 0.52 (95% CI: 0.30, 0.92) comparing between higher (≥20 ng/mL) and lower (<12 ng/mL) total 25(OH)D concentrations. In model B OR for GC was 0.57 (95% CI: 0.32, 1.00) comparing between higher and lower total 25(OH)D concentrations. Our results suggested that high vitamin D concentration was associated with lower ORs of GC in Korean adults.

Activity of vitamin D receptor agonists against dengue virus

Infections with the mosquito-transmitted dengue virus (DENV) are a pressing public health problem in many parts of the world. The recently released commercial vaccine for DENV has encountered some problems, and there is still no effective drug to treat infections. Vitamin D has a well characterized role in calcium and phosphorus homeostasis, but additionally has a role in the immune response to bacterial and viral pathogens. In this study a number of fused bicyclic derivatives of 1H-pyrrolo[1,2]imidazol-1-one with vitamin D receptor (VDR) agonist activity were evaluated for possible anti-DENV activity. The results showed that five of the compounds were able to significantly inhibit DENV infection. The most effective compound, ZD-3, had an EC₅₀ value of 7.47 μM and a selective index of 52.75. The compounds were only effective when used as a post-infection treatment and treatment significantly reduced levels of infection, virus output, DENV protein expression and genome copy number. These results suggest that these VDR agonists have the potential for future development as effective anti-DENV agents.

Vitamin D and PTH: data from a cross-sectional study in an equatorial population

OBJECTIVE

Investigate the prevalence of vitamin D deficiency in an equatorial population through a large-sample study.

METHODS

Cross-sectional study with 30,224 healthy individuals from the North Region, in Brazil (Amazônia - state of Pará), who had 25-hydroxy-vitamin D (25(OH)D) and intact parathyroid hormone (PTH) serum levels measured by immunoassay method. Those with history of acute or chronic diseases were excluded. Abnormal levels of calcium, creatinine, glycemia and albumin were also exclusion criteria.

RESULTS

25(OH)D levels were 29.1 ± 8.2 ng/mL and values <12.7 ng/mL were equal to < -2 s.d. below average. Hypovitaminosis D was present in 10% of subjects according to the Institute of Medicine (values <20 ng/mL) and in 59%, in consonance with Endocrine Society (values 20-30 ng/mL as insufficiency and <20 ng/mL as deficiency) criteria. Individuals were divided according to four age brackets: children, adolescents, adults and elderly, and their 25(OH)D levels were: 33 ± 9; 28.5 ± 7.4; 28.3 ± 7.7; 29.3 ± 8.5 ng/mL, respectively. All groups differed in 25(OH)D, except adolescents vs adults. Regression model showed BMI, sex, living zone (urban or rural) and age as independent variables to 25(OH)D levels. Comparing subjects with vitamin D deficiency (<20 ng/mL) to those with vitamin D insufficiency (20-30 ng/mL), a difference between PTH levels in these two groups was observed (95.9 ± 24.7 pg/mL vs 44.2 ± 64.5 pg/mL; P < 0.01). Additionally, the most accurate predictive vitamin D level for subclinical hyperparathyroidism in ROC curve was 26 ng/mL.

CONCLUSION

Our equatorial population showed low prevalence of vitamin D hypovitaminosis ranging with age bracket. The insufficient category by Endocrine Society was corroborated by our PTH data.

A systematic review and meta-analysis of the effect of Vitamin D-fortified food on glycemic indices

Some reports indicated that Vitamin D may improve glycaemia indices in diabetic patients. The aim of this systematic and meta-analysis was to evaluate effects of Vitamin D fortification on indices of glycemic control. Six databases (PubMed/Medline, ISI Web of Knowledge, Cochrane Library, Science Direct, Scopus, and Google Scholar) were searched, for randomized controlled trials that were published up to September 2018 and that compared the effect of Vitamin D-fortified food versus regular diet in relation to glycemic control. Of the 4,379 studies originally found, 11 articles remained to be assessed for meta-analysis. Vitamin D fortification was associated with a significant improvement in fasting serum glucose (mean difference [MD]: -2.772; 95% confidence interval [CI]: -5.435 to -0.109) and fasting serum insulin (MD: -2.937; 95% CI: -4.695 to -1.178) in patients with Type 2 diabetes mellitus. A diet with food enriched with Vitamin D was associated with a significant improvement in homeostatic model assessment of insulin resistance (MD: -1.608; 95% CI: -3.138 to -0.079) but was not associated with a significant reduction in hemoglobin A1C (MD: 0.034; 95% CI: -0.655 to 0.069). This meta-analysis indicates that Vitamin D fortification improves indices of glycemic control. Hence, food fortified with Vitamin D may be of potential therapeutic value in diabetic patients, as an adjuvant therapy.

Association between vitamin D deficiency and common variants of Vitamin D binding protein gene among Mexican Mestizo and indigenous postmenopausal women

PURPOSE

Vitamin D deficiency (VDD) and polymorphisms in the group-specific component (GC) gene are known to be associated in different populations. However, the effects of such genetic variants may vary across different populations. Thus, the objective of this study was to estimate the association between Vitamin D-Binding Protein (VDBP) haplotypes and VDD in mestizo postmenopausal women and Mexican Amerindian ethnic groups.

METHODS

This was a cross-sectional study of 726 postmenopausal Mexican women from the Health Workers Cohort Study (HWCS) and 166 postmenopausal women from the Metabolic Analysis in an Indigenous Sample (MAIS) cohort in Mexico. GC polymorphisms (rs7045 and rs4588) were analyzed by TaqMan probes. Serum 25-hydroxyvitamin D [25(OH)D] levels were measured by Chemiluminescent Microparticle Immuno Assay.

RESULTS

The prevalence of VDD serum 25(OH)D < 20 ng/mL was 43.7% in mestizo women and 44.6% in indigenous women. In HWCS, the single nucleotide polymorphisms (SNPs) rs7041 and rs4588 were associated with VDD. In addition, women from the HWCS, carrying the haplotypes GC2/2 and GC1f/2 had higher odds of VDD (OR = 2.83, 95% CI 1.14, 7.02; and OR = 2.30, 95% CI 1.40, 3.78, respectively) compared to women with haplotype 1f/1 s. These associations were not statistically significant in the MAIS cohort.

CONCLUSIONS

Our results show genetic association of the analyzed SNPs and related haplotypes, on the GC gene, with VDD in mestizo Mexican postmenopausal women. Moreover, a high prevalence of VDD with high genetic variability within the country was observed. Our results support the need for national policies for preventing VDD.

Nutrihealth Study: Seasonal Variation in Vitamin D Status Among the Slovenian Adult and Elderly Population

Several studies conducted around the world showed substantial vitamin D insufficiency and deficiency among different population groups. Sources of vitamin D in the human body include ultraviolet B (UVB)-light-induced biosynthesis and dietary intake, but people's diets are often poor in vitamin D. Furthermore, in many regions, sun exposure and the intensity of UVB irradiation during wintertime are not sufficient for vitamin D biosynthesis. In Slovenia, epidemiological data about vitamin D status in the population were investigated through a national Nutrihealth study-an extension to the national dietary survey SI.Menu (2017/18). The study was conducted on a representative sample of 125 adult (18-64 years) and 155 elderly (65-74 years old) subjects, enrolled in the study in different seasons. Their vitamin D status was determined by measuring the serum 25-hydroxy-vitamin D (25(OH)D) concentration. Thresholds for vitamin D deficiency and insufficiency were 25(OH)D levels below 30 and 50 nmol/L, respectively. Altogether, 24.9% of the adults and 23.5% of the elderly were found to be vitamin D deficient, while an insufficient status was found in 58.2% and 62.9%, respectively. A particularly concerning situation was observed during extended wintertime (November-April); vitamin D deficiency was found in 40.8% and 34.6%, and insufficient serum 25(OH)D levels were observed in 81.6% and 78.8%, respectively. The results of the study showed high seasonal variation in serum 25(OH)D levels in both the adult and elderly population, with deficiency being especially pronounced during wintertime. The prevalence of this deficiency in Slovenia is among the highest in Europe and poses a possible public health risk that needs to be addressed with appropriate recommendations and/or policy interventions.

Emirati Adults Have a Higher Overall Knowledge on Vitamin D Compared to Tourists

Objectives

In the last decade, vitamin D deficiency has become a major global issue. One of the main functions of vitamin D is the proper absorption of calcium in the gastrointestinal track. Optimal vitamin D levels are mandatory for adequate calcium absorption and bone health. The purpose of this study was to assess the level of knowledge of vitamin D, calcium, and physical activity among Emirati and tourist adults in Abu Dhabi.

Methods

This is a cross-sectional study that took place in three different malls in Abu Dhabi and included Emirati and tourist adults. Participants were asked to fill in a questionnaire consisting of 32 questions. These included questions on vitamin D, calcium, supplement, and physical activity knowledge. Another section of the questionnaire included general information on age, sex, education, weight, and height. The collected data were statistically analyzed using descriptive statistics using IBM SPSS statistics for Windows version 26.0 (SPSS Inc., Chicago, IL, United States). Statistical significance was set at P < 0.05.

Results

Out of 147 adults, 113 were females and 34 males. The mean age, height, and weight were 27.9 ± 8.6 years, 162.7 ± 10.4 cm, and 66.5 ± 19.5 kg, respectively. Emiratis had statistically significant higher basic knowledge on vitamin D compared to tourists (44.9 vs 27.1%), respectively. More than 66% of the whole sample was aware that vitamin D deficiency can affect muscle strength, as well as that calcium may affect osteoporosis. In a multiple regression model to analyze the possible effects of other factors to knowledge, it was found that only age (Beta: 0.045, P < 0.014) and nationality (Beta: 0.750, P < 0.018) were independently and significantly associated to vitamin D.

Conclusion

Emirati participants showed a higher overall vitamin D knowledge than their tourist counterparts. Both groups had low/medium level of knowledge when it comes to physical activity and calcium and vitamin D supplements.

Ultrasonographic measurements of the skin, fat and muscle in vitamin D deficiency

BACKGROUND

Vitamin D is a steroid hormone and it is essential for the musculoskeletal system health. The relationship among vitamin D levels and adiposity was shown. However, there is only one study seems to have examined the relationship between skinfold thickness and vitamin D levels.

METHODS

A total of 116 healthy subjects who had a recent vitamin D measurement were included. Skin, subcutaneous fat and muscle thicknesses were measured by ultrasound (US). Hand grip strength and usual gait speed were evaluated.

RESULTS

Subjects were classified into two groups according to 25-OH vitamin D levels. Skin thicknesses of anterior forearm in women and of anterior tibia in men, and trochanteric fat thicknesses of both genders were higher in lower 25-OH vitamin D group (both P < .05). There were no differences between the groups regarding muscle thicknesses, grip strength and gait speed (all P > .05). For identifying vitamin D deficiency (≤20 ng/mL); optimal skin thickness value was 1.25 mm in women (sensitivity: 91.3%, specificity: 54.7%), and optimal trochanteric fat thickness was 1.79 cm in men (sensitivity: 87.5%, specificity: 76.9). The specificity was increased to 79.2% if the cut-off value was taken as 1.35 mm for anterior forearm skin thickness in women.

CONCLUSION

We imply that skin thicknesses (anterior forearm and tibia) and subcutaneous fat (trochanteric region) increase in subjects with low vitamin D levels. Having also ascertained the relevant cut-off values, we underscore the possible role of these measurements as regards the assessment of vitamin D status.

Does Vitamin D play a role in the management of Covid-19 in Brazil?

The study discusses the possible role of adequate vitamin D status in plasma or serum for preventing acute respiratory infections during the Covid-19 pandemic. Our arguments respond to an article, published in Italy, that describes the high prevalence of hypovitaminosis D in older Italian women and raises the possible preventive and therapeutic role of optimal vitamin D levels. Based on literature review, we highlight the findings regarding the protective role of vitamin D for infectious diseases of the respiratory system. However, randomized controlled trials are currently lacking. Adequate vitamin D status is obtained from sun exposure and foods rich in vitamin D. Studies in Brazil have shown that hypovitaminosis D is quite common in spite of high insolation. Authors recommend ecological, epidemiological and randomized controlled trials studies to verify this hypothesis.

Vitamin D supplementation rescues simvastatin induced myopathy in mice via improving mitochondrial cristae shape

Statin induced myopathy (SIM) is a main deleterious effect leading to the poor treatment compliance, while the preventive or therapeutic treatments are absent. Mounting evidences demonstrated that vitamin D plays a vital role in muscle as a direct modulator. The deficiency of vitamin D was considered as a cause of muscle dysfunction, whereas the supplementation resulted in a remission. However, there is no causal proof that vitamin D supplementation rescues SIM. Here, using the mice model of simvastatin-induced myopathy, we investigated the role of vitamin D supplementation and the mechanisms associated with mitochondria. Results indicated that simvastatin administration (80 mg/kg) impaired skeletal muscle with the increased serum creatine kinase (CK) level and the declined grip strength, which were alleviated by vitamin D supplementation. Moreover, vitamin D supplementation rescued the energy metabolism dysfunction in simvastatin-treated mice gastrocnemius by reducing the abnormal aggregation of muscular glycogen and lactic acid. Mitochondrial homeostasis plays a key role in the process of energy metabolism. Thus, the mitochondrial dysfunction is a mortal damage for the highly energy-requiring tissue. In our study, the mitochondrial cristae observed under transmission electron microscope (TEM) were lytic in simvastatin-treated gastrocnemius. Interestingly, vitamin D supplementation improved the mitochondrial cristae shape by regulating the expression of mitofusin-1/2 (MFN1/2), optic atrophy 1 (OPA1) and dynamin-related protein 1 (Drp1). As expected, the mitochondrial dysfunction and oxidative stress was mitigated by vitamin D supplementation. In conclusion, these findings suggested that moderate vitamin D supplementation rescued simvastatin induced myopathy via improving the mitochondrial cristae shape and function.

The routine chemiluminescence assay for plasma 25-hydroxyvitamin D analysis does not overestimate the prevalence of vitamin D deficiency in adolescents

Vitamin D deficiency (VDD) is a global public health problem. Inaccurate methods for measuring plasma 25-hydroxyvitamin D (25[OH]D) may have contributed to the reported high prevalence of VDD. We hypothesized that the most commonly used assay for vitamin D status, chemiluminescence immunoassay (CLIA), underestimates 25(OH)D levels and thus overestimates VDD. Using both liquid chromatography-tandem mass spectrometry and CLIA for plasma 25(OH)D, we evaluated the prevalence of VDD in adolescents (11-16 years-old; n = 410) by both methods in a cross-sectional study. Subjects were selected from public middle schools from all the 6 Governorates of Kuwait using stratified multistage cluster random sampling. Cohen κ agreement, linear regression, and Bland-Altman plots were used to evaluate the classification of VDD by the 2 methods. VDD (25[OH]D < 50 nmol/L) was 85.9% with CLIA and 81.2% with liquid chromatography-tandem mass spectrometry. There was a good agreement between the 2 methods in classifying the study subjects as deficient, insufficient, or sufficient (κ = 85.1%, P < .001). The between-assay bias was very small with a mean percentage difference < 1% from the mean value of the 25(OH)D as assessed by the 2 methods. These data did not support our hypothesis, and we conclude that the routine methods used for plasma 25(OH)D levels have no or little impact on evaluating VDD as a public health problem or in clinical management.

Cytochrome P450 expression patterns in human osteoblasts during osteogenic differentiation with or without TNFα treatment

BACKGROUND

Recently the expression patterns of several cytochrome P450 (CYP) genes in different human osteoblast models were reported. However, the various expression patterns of CYPs in human osteoblasts during different stages of osteogenic differentiation have not been investigated and the effect of inflammatory cytokines on CYPs expression in osteoblasts is unknown.

METHODS

The expression levels of nine different CYP genes in the human osteoblast cell line MG63 and in primary human osteoblasts (HOB) during osteogenic differentiation with or without treatment with tumor necrosis factor-α (TNFα) were analyzed by quantitative real-time PCR.

RESULTS

The expression levels of most CYPs under study show a significant time dependence during osteogenic differentiation. Overall, more highly significant CYP expression level changes occur in HOB than in MG63 cells. Treatment with TNFα causes a variety of CYP expression level changes in both HOB and MG63 cells.

CONCLUSIONS

Our findings indicate that TNFα treatment reduces steroid hormone production in MG63 cells (but not in HOB) at the level of lanosterol-demethylation during cholesterol biosynthesis. By contrast, TNFα treatment of HOB cells (but not in MG63) leads to the upregulation of several key enzymes involved in the biosynthesis of sex steroids, which is proposed to lead to higher levels of estrogen production. These data also suggest that at least with respect to the topic of this study the cell line MG63 is not a good representative for osteoblasts and that it is preferential to use primary osteoblasts instead.

Is First Trimester Maternal 25-Hydroxyvitamin D Level Related to Adverse Maternal and Neonatal Pregnancy Outcomes? A Prospective Cohort Study among Malaysian Women

Information on the role of 25-hydroxyvitamin D (25(OH)D) in preventing adverse pregnancy/neonatal outcomes is limited in Malaysia. This study aims to determine the relationship between the level of maternal 25(OH)D in the first trimester of pregnant women and their pregnancy/neonatal outcomes. A total of 60 pregnant women in the first trimester were recruited and followed until the end of their pregnancy. The occurrence of any antenatal, delivery, and neonatal complications was recorded. Their blood was collected in the first trimester for total serum 25(OH)D determination using enzyme-linked immunosorbent assay. Overall, 10% of the women had vitamin D deficiency, while 57% had vitamin D insufficiency in their first trimester. No statistically significant difference in 25(OH)D level/status was observed between women with or without antenatal and delivery complications (p > 0.05). No difference in maternal serum 25(OH)D level and vitamin D status was observed between neonates with or without complications (p > 0.05). In conclusion, there is a high prevalence of vitamin D insufficiency among Malaysian pregnant women, but it is not associated with adverse maternal and neonatal outcomes. More comprehensive studies should be planned to verify this relationship.

A Brief Review of the Effects of Vitamin D on Multiple Sclerosis

Multiple sclerosis (MS) is characterized as an autoimmune disease affecting the central nervous system. It is one of the most common neurological disorders in young adults. Over the past decades, increasing evidence suggested that hypovitaminosis D is a contributing factor to the risk of developing MS. From different risk factors contributing to the development of MS, vitamin D status is of particular interest since it is not only a modifiable risk factor but is also associated with MS disease activity. MS patients with lower serum vitamin D concentrations were shown to have higher disease activity. However, this finding does not demonstrate causality. In this regard, prospective vitamin D supplementation studies missed statistical significance in its primary endpoints but showed promising results in secondary outcome measures or post hoc analyses. An explanation for missed primary endpoints may be underpowered trials. Besides vitamin D supplementation as a potential add-on to long-term immunotherapeutic treatment, a recent laboratory study of our group pointed toward a beneficial effect of vitamin D to improve the efficacy of glucocorticoids in relapse therapy. In the following article, we will briefly review the effects of vitamin D on MS by outlining its effects on the immune and nervous system and by reviewing the association between vitamin D and MS risk as well as MS disease activity. We will also review the effects of vitamin D supplementation on MS risk and MS disease activity.

Metabolic effects of cholecalciferol supplementation in patients with calcium nephrolithiasis and vitamin D deficiency

INTRODUCTION

In this paper, we investigated whether cholecalciferol supplementation may increase the risk of stone recurrence in patients with calcium nephrolithiasis and Vitamin D deficiency.

METHODS

Thirty-three stone formers (56 ± 17 years old, 12 males) with 25(OH)D < 20 ng/mL were considered. Calcium excretion and urine supersaturation with calcium oxalate (ßCaOx) and brushite (ßbsh) were evaluated, both before and after cholecalciferol supplementation. Values of ß > 1 mean supersaturation. Cholecalciferol was prescribed as oral bolus of 100,000-200,000 IU, followed by weekly (5000-10,000 IU) or monthly (25,000-50,000 IU) doses. Calcium intake varied between 800 and 1000 mg/day. In urine, total nitrogen (TNE) was taken as an index of protein intake, sodium as a marker of dietary intake, and net acid excretion (NAE) as an index of acid-base balance.

RESULTS

TNE, sodium, and NAE did not change during the study (p = ns). Compared to baseline values, after cholecalciferol, both serum calcium and phosphate did not vary (p = ns); 25(OH)D increased from 11.8 ± 5.5 to 40.2 ± 12.2 ng/mL (p < 0.01); 1.25(OH)₂D increased from 41.6 ± 17.6 to 54 ± 16 pg/mL (p < 0.01); PTH decreased from 75 ± 27.2 to 56.7 ± 21.1 pg/mL (p < 0.01); urinary calcium increased from 2.7 ± 1.5 to 3.6 ± 1.6 mg/Kg b.w. (p < 0.01); ßbsh increased from 0.9 ± 0.7 to 1.3 ± 1.3 (p = 0.02); whereas ßCaOx varied but not significantly. Before cholecalciferol supplementation, 6/33 patients were hypercalciuric (i.e., urine Ca ≥ 4 mg/Kg b.w.) and increased to 13/33 after cholecalciferol supplementation (pX² = 0.03).

CONCLUSIONS

Cholecalciferol supplementation may increase calcium excretion, or reveal an underlying condition of absorptive hypercalciuria. This may increase both urine supersaturation with calcium salts and stone-forming risk.

Daily and seasonal mitochondrial protection: Unraveling common possible mechanisms involving vitamin D and melatonin

From an evolutionary point of view, vitamin D and melatonin appeared very early and share functions related to defense mechanisms. In the current clinical setting, vitamin D is exclusively associated with phosphocalcic metabolism. Meanwhile, melatonin has chronobiological effects and influences the sleep-wake cycle. Scientific evidence, however, has identified new actions of both molecules in different physiological and pathological settings. The biosynthetic pathways of vitamin D and melatonin are inversely related relative to sun exposure. A deficiency of these molecules has been associated with the pathogenesis of cardiovascular diseases, including arterial hypertension, neurodegenerative diseases, sleep disorders, kidney diseases, cancer, psychiatric disorders, bone diseases, metabolic syndrome, and diabetes, among others. During aging, the intake and cutaneous synthesis of vitamin D, as well as the endogenous synthesis of melatonin are remarkably depleted, therefore, producing a state characterized by an increase of oxidative stress, inflammation, and mitochondrial dysfunction. Both molecules are involved in the homeostatic functioning of the mitochondria. Given the presence of specific receptors in the organelle, the antagonism of the renin-angiotensin-aldosterone system (RAAS), the decrease of reactive species of oxygen (ROS), in conjunction with modifications in autophagy and apoptosis, anti-inflammatory properties inter alia, mitochondria emerge as the final common target for melatonin and vitamin D. The primary purpose of this review is to elucidate the common molecular mechanisms by which vitamin D and melatonin might share a synergistic effect in the protection of proper mitochondrial functioning.

Vitamin D deficiency in Kazakhstan: Cross-Sectional study

Vitamin D deficiency (VDD) is one of the serious and highly debatable public health problems affecting at least one billion of world population. This study objected to evaluate Vitamin D status in adult population of both sexes residing in different geographical areas of Kazakhstan and to elucidate the possible contributing factors related to VDD. This cross-sectional study covered 6 regions of Kazakhstan and applied the systematic random sampling to recruit 1347 healthy adults (of whom 819 were females) with mean age 44 ± 14 years. The concentration of 25-hydroxy vitamin D (25-OHD) was measured from May 2018 to August 2018 with Architect 25OH Vitamin D assay (Abbott Ireland Diagnostics Division Lisnamuck, Longford Co. Longford Ireland). Vitamin D deficiency was defined as 25-OHD values not exceeding 20 ng/mL as a reference threshold in healthy population. The median serum 25(OH)D concentrations in all studied regions of Kazakhstan were below the reference threshold (20 ng/mL). The lowest range of vitamin D (<10 ng/mL) was observed more commonly in females (34.6 % - 283) as compared to males (16.7 % - 88) and was significantly higher in Asians (33.2 % - 352) in contrast with Caucasians (6.7 % - 19) (χ2 = 177,939; D.f. = 3; p-value=<0,001). The proportion of severe VDD was higher in individuals with low body mass index (31.1 % - 188) vs. individuals with high body mass index (18.7 % - 50). In this study individuals aged 60 years and older had the most favorable situation with 25-OHD concentrations since these were normal in 14.4 % of observations (χ2 = 26,589; D.f. = 6; p-value=<0001). Studying the prevalence of VDD is an important public health task. Further research is needed to understand the epidemiology of VDD in more details to tailor intervention programs.

Vitamin D Supplementation and Blood Pressure in Children and Adolescents: A Systematic Review and Meta-Analysis

Suboptimal vitamin D status is associated with elevated blood pressure (BP) in children and adolescents. Whether vitamin D supplementation reduces BP remains unclear. To systematically review whether vitamin D supplementation reduces BP in children and adolescents, we conducted a literature review according to the PRISMA statement. We included vitamin-D supplementation human interventions studies that reported on BP as an outcome. We searched PUBMED, MEDLINE, CINAHL, EMBASE, the Cochrane Library, and the clinical trials website. We also hand searched the references of the included articles and previous reviews of vitamin D therapy. No language or time restrictions were applied. We extracted data on population characteristics, baseline and endline vitamin D and BP values, and assessed the risk of bias of the included studies. We performed a narrative review of the findings, conducted a meta-analysis when possible, and performed sensitivity analyses to test the robustness of our results. We assessed the overall quality of the evidence produced in the meta-analysis. We included eight studies in our review and five studies in the meta-analysis, none of which included hypertensive only participants. The risk of bias was variable. In non-randomized studies, no effect of vitamin D supplementation was seen on systolic BP (SBP) (mean difference: 0.39 (95% confidence interval (CI): -0.9; 1.68) mmHg; p = 0.55; I2 = 0%). Only a significant decrease in diastolic BP (DBP) (mean difference: -1.87 (95% CI: -3.02; -0.72) mmHg; p = 0.001; I2 = 0%) was noted. Both analyses had a low quality of evidence. In randomized controlled trials (RCTs), no effect was noted on SBP (mean difference: -2.04 (95% CI: -5.12; 1.04) mmHg; p = 0.19; I2 = 71%) nor DBP (mean difference: 0.01 (95% CI: -1.09; 1.12) mmHg; p = 0.98; I2 = 0%). The final quality of evidence ranged between low and moderate. Sensitivity analyses did not affect the results. Vitamin D supplementation was found to be ineffective in lowering SBP and DBP in children and adolescents.