scholarly journals Role of Vitamin D in Insulin Resistance

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Chih-Chien Sung ◽  
Min-Tser Liao ◽  
Kuo-Cheng Lu ◽  
Chia-Chao Wu
Keyword(s):  
Insulin Resistance ◽  
Vitamin D ◽  
Vitamin D Deficiency ◽  
Mineral Metabolism ◽  
Serum Levels ◽  
Underlying Mechanism ◽  
Vitamin D Receptors ◽  
Cell Proliferation And Differentiation ◽  
Increase Insulin Resistance

Vitamin D is characterized as a regulator of homeostasis of bone and mineral metabolism, but it can also provide nonskeletal actions because vitamin D receptors have been found in various tissues including the brain, prostate, breast, colon, pancreas, and immune cells. Bone metabolism, modulation of the immune response, and regulation of cell proliferation and differentiation are all biological functions of vitamin D. Vitamin D may play an important role in modifying the risk of cardiometabolic outcomes, including diabetes mellitus (DM), hypertension, and cardiovascular disease. The incidence of type 2 DM is increasing worldwide and results from a lack of insulin or inadequate insulin secretion following increases in insulin resistance. Therefore, it has been proposed that vitamin D deficiency plays an important role in insulin resistance resulting in diabetes. The potential role of vitamin D deficiency in insulin resistance has been proposed to be associated with inherited gene polymorphisms including vitamin D-binding protein, vitamin D receptor, and vitamin D 1alpha-hydroxylase gene. Other roles have been proposed to involve immunoregulatory function by activating innate and adaptive immunity and cytokine release, activating inflammation by upregulation of nuclear factorκB and inducing tumor necrosis factorα, and other molecular actions to maintain glucose homeostasis and mediate insulin sensitivity by a low calcium status, obesity, or by elevating serum levels of parathyroid hormone. These effects of vitamin D deficiency, either acting in concert or alone, all serve to increase insulin resistance. Although there is evidence to support a relationship between vitamin D status and insulin resistance, the underlying mechanism requires further exploration. The purpose of this paper was to review the current information available concerning the role of vitamin D in insulin resistance.

Vitamin D and Sleep Regulation: Is there a Role for Vitamin D?

2020 ◽  
Vol 26 (21) ◽  
pp. 2492-2496 ◽  
Author(s):  
Fiammetta Romano ◽  
Giovanna Muscogiuri ◽  
Elea Di Benedetto ◽  
Volha V. Zhukouskaya ◽  
Luigi Barrea ◽  
...  
Keyword(s):  
Vitamin D ◽  
Sleep Disorders ◽  
Vitamin D Deficiency ◽  
Sleep Apnea Syndrome ◽  
Regulatory Mechanisms ◽  
Sleep Regulation ◽  
Vitamin D Receptors ◽  
Obstructive Sleep ◽  
The Impact

Background: Vitamin D exerts multiple pleiotropic effects beyond its role in calcium-phosphate metabolism. Growing evidence suggests an association between hypovitaminosis D and sleep disorders, thus increasing the interest in the role of this vitamin in the regulatory mechanisms of the sleep-wake cycle. Objective: The study aimed to explore and summarize the current knowledge about the role of vitamin D in sleep regulation and the impact of vitamin D deficiency on sleep disorders. Methods: The main regulatory mechanisms of vitamin D on sleep are explained in this study. The literature was scanned to identify clinical trials and correlation studies showing an association between vitamin D deficiency and sleep disorders. Results: Vitamin D receptors and the enzymes that control their activation and degradation are expressed in several areas of the brain involved in sleep regulation. Vitamin D is also involved in the pathways of production of Melatonin, the hormone involved in the regulation of human circadian rhythms and sleep. Furthermore, vitamin D can affect sleep indirectly through non-specific pain disorders, correlated with alterations in sleep quality, such as restless legs syndrome and obstructive sleep apnea syndrome. Conclusions: : Vitamin D has both a direct and an indirect role in the regulation of sleep. Although vitamin D deficiency has been associated to sleep disorders, there is still scant evidence to concretely support the role of vitamin D supplementation in the prevention or treatment of sleep disturbances; indeed, more intervention studies are needed to better clarify these aspects.

P–662 Study on D-vitamin, AMH and insulin interrelation in Polycystic Ovary Syndrome (PCOS) patients

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
A Coc. Lizarraga ◽  
S Lindenberg ◽  
G Juu. Almind ◽  
F Lindenberg
Keyword(s):  
Insulin Resistance ◽  
Vitamin D ◽  
Vitamin D Deficiency ◽  
Serum Vitamin ◽  
Serum Vitamin D ◽  
Vitamin D Levels ◽  
Group A ◽  
D Values ◽  
Group B

Abstract Study question Is vitamin D deficiency more prevalent in PCOS patients? Is there a link between vitamin D levels and metabolic status in PCOS subjects? Summary answer An inverse relationship between vitamin D levels and metabolic status was demonstrated and it is thought to be responsible of its pathogenesis. What is known already PCOS is a multifactorial condition, characterised by failure in oogenesis and anovulation. Obesity is a common condition linked to its clinical features and studies have reported inverse associations between BMI and severity of the condition. Furthermore, 67–85% of PCOS patients have vitamin D deficiency. Low levels of vitamin D have been found to be closely related to insulin resistance, obesity, or hyperandrogenism and there is a significant association between serum vitamin D levels and reproductive function. Other factors such as AMH have also been described as possibly involved in the pathophysiology. Study design, size, duration We performed a retrospective, analytical and observational study in the Copenhagen Fertility Center. Patients referred with cycle abnormalities, hirsutism, and infertility were evaluated. A total of 778 women were enrolled consecutively from January 2019 to October 2020. Subjects who had major medical disorders were excluded. We selected those in which vitamin D was measured in the baseline analysis selecting a total of 396 patients. The further analysis has been carried out from 100 randomly selected patients. Participants/materials, setting, methods Blood samples were drawn after overnight fasting. They were all assayed in the same laboratory. Biochemical parameters were analyzed using descriptive statistics. Same parameters were studied after dividing into vitamin D deficiency group or optimal levels using a multiple t-test. Correlation between variables was determined. Graphpad Prism program version 8 was used to perform the calculations. The level of statistical significance was set at P-value < 0.05. Main results and the role of chance A total of 100 subjects fulfilling the inclusion criteria were selected randomly from 396 PCOS women. Serum vitamin D concentrations were highly variable ranging from 16 nmol/L to 175 nmol/L. The prevalence of vitamin D deficiency was 24% and 41% of the subjects were classified as vitamin D insufficient. Only 35% of our patients had optimal vitamin D values. We compared data between the group with optimal values of vitamin D (Group A) versus the group with insufficient/deficient vitamin D values (Group B). We found statistical difference between groups in PTH values, being notably higher in group B compared with group A. Despite no statistically significant difference was obtained, it is important to highlight that the mean of SHBG was lower in group B and the mean of androstenedione, AMH, FAI and HOMA-IR were much higher in this group as well. Following the HOMA-IR criteria, 55% of patients had insulin resistance. Specifically, 26% had moderate insulin resistance and 29% severe insulin resistance. Levels of vitamin D were negatively correlated with FAI, AMH and HOMA-IR and positively correlated with HDL-Cholesterol and SHBG. Statistically significant differences were evidenced in the correlation between vitamin D and FAI and SHBG. Limitations, reasons for caution This is a retrospective observational study on a consecutive admitted patient group with a lack of a control group. Another limitation is the small sample size. It is difficult to generalize with other degrees of severity. We didn’t assess seasonal variability or if they were taking any vitamin D supplementation. Wider implications of the findings: Properly randomized clinical trials are mandatory to achieve more conclusive results about the role of vitamin D. Available evidence is promising but not sufficient to draw final conclusions. The aim is to better understand the pathophysiology of the condition and the factors involved and to find new target treatments. Trial registration number 1

scholarly journals Insulin resistance in an animal model of polycystic ovary disease is aggravated by vitamin D deficiency: Vascular consequences

2018 ◽  
Vol 15 (4) ◽  
pp. 294-301 ◽  
Author(s):  
Leila Hadjadj ◽  
Szabolcs Várbíró ◽  
Eszter Mária Horváth ◽  
Anna Monori-Kiss ◽  
Éva Pál ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Vitamin D ◽  
Glucose Tolerance ◽  
Vitamin D Deficiency ◽  
Vascular Tissue ◽  
Female Rats ◽  
Oral Glucose ◽  
Model Assessment ◽  
Coronary Resistance ◽  
Vitamin D Receptors

Hyperandrogenic state in females is accompanied with metabolic syndrome, insulin resistance and vascular pathologies. A total of 67%–85% of hyperandrogenic women suffer also from vitamin D deficiency. We aimed to check a potential interplay between hyperandrogenism and vitamin D deficiency in producing insulin resistance and effects on coronary resistance arteries. Adolescent female rats were divided into four groups, 11–12 animals in each. Transdermal testosterone-treated and vehicle-treated animals were kept either on vitamin D-deficient or on vitamin D-supplemented diet for 8 weeks. Plasma sexual steroid, insulin, leptin and vitamin D plasma levels were measured, and oral glucose tolerance test was performed. In coronary arterioles, insulin receptor and vitamin D receptor expressions were tested by immunohistochemistry, and insulin-induced relaxation was measured in vitro on isolated coronary resistance artery segments. Testosterone impaired glucose tolerance, and it diminished insulin relaxation but did not affect the expression of insulin and vitamin D receptors in vascular tissue. Vitamin D deficiency elevated postprandial insulin levels and homeostatic model assessment insulin resistance. It also diminished insulin-induced coronary arteriole relaxation, while it raised the expression of vitamin D and insulin receptors in the endothelial and medial layers. Our conclusion is that both hyperandrogenism and vitamin D deficiency reduce sensitivity of coronary vascular tissue to insulin, but they do it with different mechanisms.

scholarly journals Are Vitamin D Levels Associated With Risk of Deep Neck Infection?

2019 ◽  
pp. 014556131986549
Author(s):  
Mustafa Sıtkı Gozeler ◽  
Muhammed Sedat Sakat ◽  
Korhan Kilic ◽  
Abdulkadir Sahin ◽  
Arzu Tatar ◽  
...  
Keyword(s):  
Vitamin D ◽  
Immune System ◽  
Vitamin D Deficiency ◽  
Serum Levels ◽  
Control Group ◽  
Deep Neck Infection ◽  
Neck Infection ◽  
Vitamin D Receptors ◽  
Vitamin D Levels ◽  
25 Hydroxy Vitamin D

Deep neck infection (DNI) refers to infections in spaces created by superficial and deep cervical fascia around the muscles and organs in the neck. Vitamin D is highly important for an effective immune system. Vitamin D receptors (VDR) have been identified in immune system cells, and particularly in T and B lymphocytes, macrophages, and dendritic cells. Vitamin D deficiency is thought to result in impaired immune response, decreased leukocyte chemotaxis, and an increased disposition to infection. The purpose of this study was to investigate whether vitamin D deficiency is an underlying occult factor in the development of DNI. Sixty-five patients aged 6 to 90, diagnosed with DNI, and 70 healthy age- and sex-compatible cases were included in the study. Serum levels of calcium, phosphorus, parathyroid hormone, and 25-hydroxy vitamin D (25(OH)D) were determined in each case. 25-hydroxy vitamin D levels above 20 ng/mL were regarded as normal, 12 to 20 ng/mL as insufficient, 5 to 12 ng/mL as deficient, and less than 5 ng/mL as severely deficient. Mean serum 25(OH)D levels were 10.4 (6.2) ng/mL in the patient group and 15.5 (6.4) ng/mL in the control group ( P < .01). This difference was statistically significant ( P < .01). Vitamin D was within normal limits in 9.2% (n = 6) of cases in the study group, insufficient in 29.2% (n = 19), deficient in 35.3% (n = 23), and severely deficient in 26.2% (n = 17). The equivalent values in the control group were 21.4% (n = 15), 48.5% (n = 34), 30% (n = 21), and 0% (n = 0). Serum 25(OH)D levels were significantly lower in patients with DNI compared to the healthy cases; 25(OH)D levels may be a factor in the development of DNI.

scholarly journals Vitamin D testing and treatment: a narrative review of current evidence

2019 ◽  
Vol 8 (2) ◽  
pp. R27-R43 ◽  
Author(s):  
Stefan Pilz ◽  
Armin Zittermann ◽  
Christian Trummer ◽  
Verena Theiler-Schwetz ◽  
Elisabeth Lerchbaum ◽  
...  
Keyword(s):  
Public Health ◽  
Vitamin D ◽  
Vitamin D Deficiency ◽  
Human Health ◽  
Mineral Metabolism ◽  
Narrative Review ◽  
Current Evidence ◽  
Scientific Debate ◽  
Hydroxyvitamin D

Vitamin D testing and treatment is a subject of controversial scientific discussions, and it is challenging to navigate through the expanding vitamin D literature with heterogeneous and partially opposed opinions and recommendations. In this narrative review, we aim to provide an update on vitamin D guidelines and the current evidence on the role of vitamin D for human health with its subsequent implications for patient care and public health issues. Vitamin D is critical for bone and mineral metabolism, and it is established that vitamin D deficiency can cause rickets and osteomalacia. While many guidelines recommend target serum 25-hydroxyvitamin D (25[OH]D) concentrations of ≥50 nmol/L (20 ng/mL), the minimum consensus in the scientific community is that serum 25(OH)D concentrations below 25–30 nmol/L (10–12 ng/mL) must be prevented and treated. Using this latter threshold of serum 25(OH)D concentrations, it has been documented that there is a high worldwide prevalence of vitamin D deficiency that may require public health actions such as vitamin D food fortification. On the other hand, there is also reason for concern that an exploding rate of vitamin D testing and supplementation increases costs and might potentially be harmful. In the scientific debate on vitamin D, we should consider that nutrient trials differ from drug trials and that apart from the opposed positions regarding indications for vitamin D treatment we still have to better characterize the precise role of vitamin D for human health.

scholarly journals Non-Musculoskeletal Benefits of Vitamin D beyond the Musculoskeletal System

2021 ◽  
Vol 22 (4) ◽  
pp. 2128
Author(s):  
Sicheng Zhang ◽  
Duane D. Miller ◽  
Wei Li
Keyword(s):  
Risk Factors ◽  
Vitamin D ◽  
Vitamin D Deficiency ◽  
Musculoskeletal System ◽  
Neurological Disorders ◽  
The Body ◽  
Health Maintenance ◽  
Vitamin D Receptors ◽  
Beneficial Effects

Vitamin D, a fat-soluble prohormone, is endogenously synthesized in response to sunlight or taken from dietary supplements. Since vitamin D receptors are present in most tissues and cells in the body, the mounting understanding of the role of vitamin D in humans indicates that it does not only play an important role in the musculoskeletal system, but has beneficial effects elsewhere as well. This review summarizes the metabolism of vitamin D, the research regarding the possible risk factors leading to vitamin D deficiency, and the relationships between vitamin D deficiency and numerous illnesses, including rickets, osteoporosis and osteomalacia, muscle weakness and falls, autoimmune disorders, infectious diseases, cardiovascular diseases (CVDs), cancers, and neurological disorders. The system-wide effects of vitamin D and the mechanisms of the diseases are also discussed. Although accumulating evidence supports associations of vitamin D deficiency with physical and mental disorders and beneficial effects of vitamin D with health maintenance and disease prevention, there continue to be controversies over the beneficial effects of vitamin D. Thus, more well-designed and statistically powered trials are required to enable the assessment of vitamin D’s role in optimizing health and preventing disease.

scholarly journals The Relationship Between the Serum Level of Vitamin D and Hypocalcemia After Total Thyroidectomy

2021 ◽  
Author(s):  
Behrang Motamed ◽  
Hossein Hemmati ◽  
Mehdi Pursafar ◽  
Mohaya Farzin ◽  
Zakiyeh Jafaryparvar ◽  
...  
Keyword(s):  
Vitamin D ◽  
Total Thyroidectomy ◽  
Vitamin D Deficiency ◽  
Significant Relationship ◽  
Serum Levels ◽  
Vitamin D Supplementation ◽  
Severe Form ◽  
Benign Goiter ◽  
Male Patients

Vitamin D plays a crucial role in calcium metabolism through the parathormone-dependent process. The deficiency of this important nutrient may be associated with hypocalcemia after thyroidectomy. To evaluate the role of vitamin D in predicting hypocalcemia following total thyroidectomy. In this study, sixty-two patients who underwent total thyroidectomy for benign or malignant thyroid disease were included in this prospective study. Preoperative vitamin D serum levels and parathormone (PTH) levels were determined. The association between preoperative vitamin D status and the development of hypocalcemia was investigated. In this study, 62 patients were evaluated. The mean age of the subjects was 47 years. Of the 62 patients studied, of which 9 were male patients (14.5%), and 53 were female (85.5%), the results of our study showed. In both groups with and without vitamin D deficiency, calcium levels decreased significantly (P=0.01). In our study, it was found that there was no significant relationship between postoperative hypocalcemia and vitamin D deficiency. (P=0.441). After reviewing the data and according to Spearman correlation statistical test, no significant relationship was observed between serum parathyroid hormone (PTH) and calcium after thyroidectomy (P=0.340). Vitamin D deficiency is a risk factor of hypocalcemia after total thyroidectomy for benign goiter. Although post thyroidectomy hypocalcemia is multifactorial, vitamin D deficiency, particularly severe form, is significantly associated with the development of biochemical and clinical hypocalcemia. Vitamin D supplementation can prevent this unwanted complication in such patients.

Vitamin D and Vascular Disease

2020 ◽  
Vol 19 (3) ◽  
pp. 250-268 ◽  
Author(s):  
Ioanna Gouni-Berthold ◽  
Heiner K. Berthold
Keyword(s):  
Risk Factors ◽  
Vitamin D ◽  
Vitamin D Deficiency ◽  
Vitamin D Supplementation ◽  
Plasma Vitamin ◽  
Cvd Risk ◽  
Vitamin D Receptors ◽  
Cell Proliferation And Differentiation ◽  
Increased Risk ◽  
Vitamin D Levels

: Cardiovascular disease (CVD) is a major cause of morbidity and mortality worldwide. Vitamin D deficiency has been identified as a potential risk factor for a number of diseases unrelated to the classical skeletal pathophysiology, such as cancer and CVD, but the effects of vitamin D supplementation are less clear. Purpose of this narrative review is to discuss the evidence suggesting an association between vitamin D status and CVD as well as the results of supplementation studies. Vitamin D deficiency has been associated with CVD risk factors such as hypertension, dyslipidemia and diabetes mellitus as well as with cardiovascular events such as myocardial infarction, stroke and heart failure. While vitamin D deficiency might contribute to the development of CVD through its association with risk factors, direct effects of vitamin D on the cardiovascular system may also be involved. Vitamin D receptors are expressed in a variety of tissues, including cardiomyocytes, vascular smooth muscle cells and endothelial cells. Moreover, vitamin D has been shown to affect inflammation, cell proliferation and differentiation. While observational studies support an association between low plasma vitamin D levels and increased risk of CVD, Mendelian randomization studies do not support a causal association between the two. At present, high quality randomized trials do not find evidence of significant effects on CVD endpoints and do not support supplementation of vitamin D to decrease CVD events.

scholarly journals Impact of Vitamin D on Physical Efficiency and Exercise Performance—A Review

Nutrients ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2826 ◽  
Author(s):  
Michał Wiciński ◽  
Dawid Adamkiewicz ◽  
Monika Adamkiewicz ◽  
Maciej Śniegocki ◽  
Marta Podhorecka ◽  
...  
Keyword(s):  
Vitamin D ◽  
Exercise Performance ◽  
Strong Relationship ◽  
High Quality Research ◽  
Vitamin D Receptors ◽  
Cell Proliferation And Differentiation ◽  
Proliferation And Differentiation ◽  
Strongly Connected ◽  
The Impact

Vitamin D deficiency amongst athletes and the general population seems to be a prominent problem. The most recognized role of vitamin D is its regulation of calcium homeostasis; there is a strong relationship between vitamin D and bone health. Moreover, its concentrations are associated with muscle function and immune response in both the general and athletic populations. Vitamin D level is strongly connected with the presence of VDRs (vitamin D receptors) in most human extraskeletal cells. Expression of multiple myogenic transcription factors enhancing muscle cell proliferation and differentiation is caused by an exposure of skeletal muscles to vitamin D. The aim of this review is to summarize current understanding of the significance of vitamin D on exercise performance and physical efficiency, as well to analyze the impact of vitamin D on multiple potential mechanisms. More high-quality research studies, considering free 25(OH)D as a better marker of vitamin D status, the baseline level of 25(OH)D and multiple pathways of vitamin D acting and usage in athletes are required.

scholarly journals Vitamin D Metabolism and Its Role in Mineral and Bone Disorders in Chronic Kidney Disease in Humans, Dogs and Cats

Metabolites ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 499
Author(s):  
Fernanda C. Chacar ◽  
Márcia M. Kogika ◽  
Rafael V. A. Zafalon ◽  
Marcio A. Brunetto
Keyword(s):  
Chronic Kidney Disease ◽  
Vitamin D ◽  
Kidney Disease ◽  
Secondary Hyperparathyroidism ◽  
Vitamin D Deficiency ◽  
Comparative Studies ◽  
Mineral Metabolism ◽  
Vitamin D Metabolism ◽  
Bone Disorders

Some differences regarding Vitamin D metabolism are described in dogs and cats in comparison with humans, which may be explained by an evolutionary drive among these species. Similarly, vitamin D is one of the most important regulators of mineral metabolism in dogs and cats, as well as in humans. Mineral metabolism is intrinsically related to bone metabolism, thus disturbances in vitamin D have been implicated in the development of chronic kidney disease mineral and bone disorders (CKD-MBD) in people, in addition to dogs and cats. Vitamin D deficiency may be associated with Renal Secondary Hyperparathyroidism (RSHPT), which is the most common mineral disorder in later stages of CKD in dogs and cats. Herein, we review the peculiarities of vitamin D metabolism in these species in comparison with humans, and the role of vitamin D disturbances in the development of CKD-MBD among dogs, cats, and people. Comparative studies may offer some evidence to help further research about vitamin D metabolism and bone disorders in CKD.

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