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1.
Roles of Vitamin D in Reproductive Systems and Assisted Reproductive Technology.
Chen, Y, Zhi, X
Endocrinology. 2020;(4)
Abstract
Vitamin D, an essential steroid hormone in the human body, plays an important role in not only the regulation of calcium and phosphorus metabolism, but also in various physiological processes, such as cell differentiation and apoptosis, inflammation, and insulin resistance. Vitamin D receptors are widely distributed in male and female reproductive systems, suggesting that vitamin D is essential for fertility. Because vitamin D deficiency is highly prevalent around the world, this review aims to discuss the potential functions of vitamin D in male and female reproductive systems and the associations between vitamin D and assisted reproductive technology (ART) outcomes. Vitamin D is involved in many physiological reproductive processes, including steroidogenesis, spermatogenesis, and acrosome reaction. It is correlated with sperm quality, ovarian reserve, polycystic ovarian syndrome, and endometriosis, among others. Controversial clinical findings on vitamin D levels and ART outcomes were revealed in this review, and demonstrations of efficacy for human fertility in randomized controlled trials of vitamin D supplementation are notably lacking. Thus, further studies are highly required involving molecular mechanisms among different species and human populations, as well as randomized controlled trials.
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2.
Vitamin D status and the immune assessment in 22q11.2 deletion syndrome.
Legitimo, A, Bertini, V, Costagliola, G, Baroncelli, GI, Morganti, R, Valetto, A, Consolini, R
Clinical and experimental immunology. 2020;(3):272-286
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Abstract
22q11.2 deletion syndrome (22q11.2DS) is characterized by a heterogeneous phenotype, including alterations in phospho-calcium metabolism and immunodeficiency. We analyzed vitamin D status and the immune assessment, focusing on T cell subpopulations and dendritic cells (DCs) in a cohort of 17 pediatric 22q11.2DS patients and 17 age-matched healthy subjects. As antigen-presenting cells, DCs are the main target of vitamin D, promoting a tolerogenic T cell response. Patients were subdivided into three groups according to the parameters of phospho-calcium metabolism and serum levels of 25OHD: normal values, vitamin D deficiency and hypoparathyroidism. Different degrees of T cell deficiency, ranging from normal to partial T cell numbers, were observed in the cohort of patients. The group with vitamin D deficiency showed a significant reduction of naive T cells and a significant increase of central memory T cells compared to controls. In this group the number of circulating DCs was significantly reduced. DC decrease affected both myeloid and plasmacytoid DC subsets (mDCs and pDCs), with the most relevant reduction involving pDCs. A direct correlation between 25OHD levels and recent thymic emigrant (RTE) and DC number was identified. Despite the limited cohort analyzed, our results show that deficiency of the pDC subset in patients with 22q11.2DS may be included among the causative factors of the progressive increase of risk of autoimmune diseases in these patients. As most patients suffer from increased susceptibility to infections and heightened prevalence of autoimmune disorders, we suggest a potential role of vitamin D supplementation in preventing autoimmune or proinflammatory diseases in 22q11.2DS.
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Clinical Significance of Analysis of Vitamin D Status in Various Diseases.
Kowalówka, M, Główka, AK, Karaźniewicz-Łada, M, Kosewski, G
Nutrients. 2020;(9)
Abstract
Vitamin D plays a role not only in the proper functioning of the skeletal system and the calcium-phosphate equilibrium, but also in the immune system, the cardiovascular system and the growth and division of cells. Although numerous studies have reported on the analysis of vitamin D status in various groups of patients, the clinical significance of measurements of vitamin D forms and metabolites remains ambiguous. This article reviews the reports analyzing the status of vitamin D in various chronic states. Particular attention is given to factors affecting measurement of vitamin D forms and metabolites. Relevant papers published during recent years were identified by an extensive PubMed search using appropriate keywords. Measurement of vitamin D status proved to be a useful tool in diagnosis and progression of metabolic syndrome, neurological disorders and cancer. High performance liquid chromatography coupled with tandem mass spectrometry has become the preferred method for analyzing the various forms and metabolites of vitamin D in biological fluids. Factors influencing vitamin D concentration, including socio-demographic and biochemical factors as well as the genetic polymorphism of the vitamin D receptor, along with vitamin D transporters and enzymes participating in vitamin D metabolism should be considered as potential confounders of the interpretation of plasma total 25(OH)D concentrations.
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Bone Metabolism and Vitamin D Implication in Gastroenteropancreatic Neuroendocrine Tumors.
Altieri, B, Di Dato, C, Modica, R, Bottiglieri, F, Di Sarno, A, Pittaway, JFH, Martini, C, Faggiano, A, Colao, A
Nutrients. 2020;(4)
Abstract
Patients affected by gastroenteropancreatic-neuroendocrine tumors (GEP-NETs) have an increased risk of developing osteopenia and osteoporosis, as several factors impact on bone metabolism in these patients. In fact, besides the direct effect of bone metastasis, bone health can be affected by hormone hypersecretion (including serotonin, cortisol, and parathyroid hormone-related protein), specific microRNAs, nutritional status (which in turn could be affected by medical and surgical treatments), and vitamin D deficiency. In patients with multiple endocrine neoplasia type 1 (MEN1), a hereditary syndrome associated with NET occurrence, bone damage may carry other consequences. Osteoporosis may negatively impact on the quality of life of these patients and can increment the cost of medical care since these patients usually live with their disease for a long time. However, recommendations suggesting screening to assess bone health in GEP-NET patients are missing. The aim of this review is to critically analyze evidence on the mechanisms that could have a potential impact on bone health in patients affected by GEP-NET, focusing on vitamin D and its role in GEP-NET, as well as on factors associated with MEN1 that could have an impact on bone homeostasis.
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Effects of Vitamin D Supplementation on Lipid Profile in Adults with the Metabolic Syndrome: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.
AlAnouti, F, Abboud, M, Papandreou, D, Mahboub, N, Haidar, S, Rizk, R
Nutrients. 2020;(11)
Abstract
BACKGROUND Metabolic syndrome (MetS) increases the risk of cardiovascular disease, with atherogenic dyslipidemia being a major contributing factor. METHODS A systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement to assess whether vitamin D supplementation (VDS) alleviates dyslipidemia in adults with MetS. Scientific databases (PUBMED, MEDLINE, CINAHL, EMBASE, Cochrane Library, ClinicalTrials.gov, International Clinical Trials Registry Platform) and the gray literature were searched for randomized controlled trials of VDS, reporting on blood lipids. A narrative review, meta-analyses, sensitivity analyses, and appraisal of the risk of bias and overall quality of evidence produced were conducted. RESULTS Seven studies were included, and four were meta-analyzed. The risk of bias was generally low, and the final quality of evidence was low or very low. VDS, whether in high or low dose, significantly increased endline vitamin D blood levels; did not affect total, low-density, high-density cholesterol levels, and novel lipid-related biomarkers; yet, significantly increased triglycerides (TG) levels compared with placebo (MD: 30.67 (95%CI: 4.89-56.45) mg/dL; p = 0.02 for low-dose VDS; and MD: 27.33 (95%CI: 2.06-52.59) mg/dL; p = 0.03 for high-dose VDS). Pertaining heterogeneity was high (I2 = 86%; and I2 = 51%, respectively), and some included studies had significantly higher baseline TG in the intervention arm. The sensitivity analyses revealed robust results. CONCLUSION VDS seems not to affect blood lipids in adults with MetS.
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Effectiveness and safety of routine calcium supplementation in postmenopausal women. A narrative review.
Heidari, B, Hajian-Tilaki, K, Babaei, M
Diabetes & metabolic syndrome. 2020;(4):435-442
Abstract
BACKGROUND To determine whether routine administration of calcium supplementation is useful in postmenopausal women, while it is associated with an increased risk of cardiovascular complications. METHODS A literature search was performed using Medline/PubMed, Scopus and Google Scholar by using relevant keywords. RESULTS Calcium supplement exerts a small protective effect against bone loss which disappears after cessation. Antifracture effect of supplemental calcium is limited to older frail women or community-dwelling residents who are vitamin D deficient and have inadequate dietary calcium intake. The results of studies on the association between calcium supplementation and cardiovascular complications are contradictory and do not lead to a decisive conclusion CONCLUSION Current data do not support routine calcium supplementation to all postmenopausal women for prevention of bone loss or bone fracture.
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Efficacy of oral Vitamin D supplementation in reducing body mass index and lipid profile in adolescents and young adults in Colombia: A pilot clinical trial protocol nested in the SIMBA cohort.
Serrano, NC, Romero, SL, Suárez, DP, Rojas, LZ, Gamboa-Delgado, EM, Forero, M, Guio, E, Quintero-Lesmes, DC
Medicine. 2020;(35):e21722
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Abstract
BACKGROUND In recent years, the role of vitamin D (VD) as a protective factor in cardiovascular disease has been recognized. Thus, there is a need to study the effect of vitamin D supplementation in the control of different cardiovascular risk factors and metabolic syndrome, especially in young populations where few studies have been conducted. METHODS Pilot study of a randomized, parallel two-arm, triple-blind clinical controlled trial in 150 adolescents and young adults in the city of Bucaramanga-Colombia. The intervention group will receive 1000 IU of VD and the control group 200 IU of VD daily for 15 weeks. The main outcomes are: serum calcifediol levels (25(OH) D), body mass index and lipid profile; secondary outcomes are complementary to the previous ones (skin folds, waist-hip ratio). Other variables will be analyzed such as assessment of dietary intake, physical activity, sun exposure, cigarette and tobacco consumption and compliance with VD supplementation. DISCUSSION This study is innovative since there is little evidence from clinical trials in adolescents and young adults; similar studies are not known in our context. The results of this study may facilitate the recommendation of oral vitamin D supplementation in the population of interest. In addition, it is a low-cost and easy-to-apply intervention that could contribute to the formulation and implementation of health policies. TRIAL REGISTRATION NCT04377386.
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Effects of vitamin D supplementation in women with polycystic ovary syndrome: a review.
Menichini, D, Facchinetti, F
Gynecological endocrinology : the official journal of the International Society of Gynecological Endocrinology. 2020;(1):1-5
Abstract
Increasing evidence supports the contribution of vitamin D deficiency (VDD) in metabolic disturbances among women with polycystic ovary syndrome (PCOS). This review aims to assess the associations between vitamin D levels and metabolic/endocrine dysregulations and to determine the effects of vitamin D supplementation on glucose metabolism, insulin sensitivity, lipid profile, and hormones functionality in PCOS patients. We searched in PubMed human randomized controlled trials (RCTs) published in English between 2016 and 2019 on the effects of vitamin D supplementation on PCOS. Nine studies were included and analyzed. Vitamin D supplementation restored physiological serum 25(OH)D levels in PCOS women in all the studies included. In six studies, it significantly decreased fasting plasma glucose and brought to improvements in insulin resistance (IR) and serum fasting insulin. In addition, four studies reported decreases of serum triglycerides, while discordant data are reported as far as LDL, HDL, and total cholesterol levels. High-doses of vitamin D (4000 IU), compared with low-dose (1000 IU), and placebo, showed beneficial effects on total testosterone, sex hormone-binding globulin (SHBG) and free androgen index (FAI). Vitamin D supplementation at high doses for a period of at least 12 weeks, may lead to improvement in terms of glucose level, insulin sensitivity, hyperlipidemia, and hormonal functionality in PCOS women.
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Directional Relationship Between Vitamin D Status and Prediabetes: A New Approach from Artificial Neural Network in a Cohort of Workers with Overweight-Obesity.
Vigna, L, Silvia Tirelli, A, Grossi, E, Turolo, S, Tomaino, L, Napolitano, F, Buscema, M, Riboldi, L
Journal of the American College of Nutrition. 2019;(8):681-692
Abstract
Objective: Despite the increasing literature on the association of diabetes with inflammation, cardiovascular risk, and vitamin D (25(OH)D) concentrations, strong evidence on the direction of causality among these factors is still lacking. This gap could be addressed by means of artificial neural networks (ANN) analysis.Methods: Retrospective observational study was carried out by means of an innovative data mining analysis-known as auto-contractive map (AutoCM)-and semantic mapping followed by Activation and Competition System on data of workers referring to an occupational-health outpatient clinic. Parameters analyzed included weight, height, waist circumference, body mass index (BMI), percentage of fat mass, glucose, insulin, glycated hemoglobin (HbA1c), creatinine, total cholesterol, low- and high-density lipoprotein cholesterol, triglycerides, uric acid, fibrinogen, homocysteine, C-reactive protein (CRP), diastolic and systolic blood pressure, and 25(OH)D.Results: The study included 309 workers. Of these, 23.6% were overweight, 40.5% were classified into the first class of obesity, 23.3% were in the second class, and 12.6% were in the third class (BMI > 40 kg/m ). All mean biochemical values were in normal range, except for total cholesterol, low- and high-density lipoprotein cholesterol, CRP, and 25(OH)D. HbA1c was between 39 and 46 mmol/mol in 51.78%. 25(OH)D levels were sufficient in only 12.6%. Highest inverse correlation for hyperglycemia onset was with BMI and waist circumference, suggesting a protective role of 25(OH)D against their increase. AutoCM processing and the semantic map evidenced direct association of 25(OH)D with high link strength (0.99) to low CRP levels and low high-density lipoprotein cholesterol levels. Low 25(OH)D led to changes in glucose, which affected metabolic syndrome biomarkers, first of which was homeostatic model assessment index and blood glucose, but not 25(OH)D.Conclusions: The use of ANN suggests a key role of 25(OH)D respect to all considered metabolic parameters in the development of diabetes and evidences a causation between low 25(OH)D and high glucose concentrations.
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Effects of vitamin D supplementation along with endurance physical activity on lipid profile in metabolic syndrome patients: A randomized controlled trial.
Farag, HAM, Hosseinzadeh-Attar, MJ, Muhammad, BA, Esmaillzadeh, A, Hamid El Bilbeisi, A
Diabetes & metabolic syndrome. 2019;(2):1093-1098
Abstract
BACKGROUND AND OBJECTIVES This study was conducted to determine the effects of vitamin D supplementation along with endurance physical activity on lipid profile among metabolic syndrome patients. MATERIALS AND METHODS In a parallel randomized placebo controlled trial, 70 metabolic syndrome patients, were randomly assigned into three groups. Biochemical tests were assessed as baseline and after 12 weeks of intervention. Statistical analysis was performed using SPSS version 20. RESULTS The mean vitamin D levels was increased significantly in both vitamin D and vitamin D plus physical activity groups (P value < 0.05). No significant change was observed in the placebo group. Additionally, there was a significant decrease in total cholesterol and LDL-C in vitamin D plus physical activity group (P value < 0.05). No significant differences in changes of triglycerides and HDL-C among the three groups (P value > 0.05). While, in vitamin D group a decreased in total cholesterol, HDL-C, LDL-C and increase in triglycerides were observed, but did not reach a statistically significant. CONCLUSION Daily supplementation of vitamin D for 12 weeks, along with moderate endurance physical activity, significantly increase vitamin D concentration and induce a significant reduction in lipid profile in metabolic syndrome patients.