Antioxidant Role of Vitamin D in Mice With Alloxan-Induced Diabetes

In vivo and computational investigation of butin against alloxan-induced diabetes via biochemical, histopathological, and molecular interactions

Herbs have been used as medicines since antiquity, and it has been discovered that the human body responds well to herbal remedies. Research on the effect of butin was conducted in the current study in the alloxan-induced diabetic rat paradigm. A total of 30 Wistar rats were randomly assigned into the following groups (n = 6): I-Normal; II-Alloxan-induced (50 mg/kg); III-Alloxan + butin 25 mg/kg; IV-Alloxan + butin 50 mg/kg; V-Butin per se 50 mg/kg. Various diabetic parameters (blood glucose, insulin, HbA1c), lipid profile, inflammatory (TNF-α, IL-1β, IL-6 and NF-κB), antioxidant enzymes (CAT, SOD and GSH), oxidative stress indicators (MDA), apoptosis marker (caspase-3), hepatic markers (ALT and AST), and histopathological changes were assessed. Additionally, molecular docking and dynamics were performed to evaluate the interaction of butin with target proteins. Butin treatment, at both doses, significantly restored biochemical parameters and preserved pancreatic histopathology in diabetic rats. It effectively modulated blood parameters, lipid profiles, inflammatory markers, apoptosis, antioxidant enzyme activity, oxidative stress, and hepatic markers. Molecular docking revealed that butin binds to proteins such as caspase-3 (1NME), NF-κB (1SVC), and serum insulin (4IBM) with binding affinities of - 7.4, - 6.5, and - 8.2 kcal/mol, respectively. Molecular dynamics simulations further suggested that butin induces significant conformational changes in these proteins. Butin exhibits potential effects against alloxan-induced diabetic rats by restoring biochemical balance, reducing inflammation, and protecting pancreatic tissue. Its binding to key proteins involved in apoptosis and inflammation highlights its therapeutic potential in diabetes management.

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

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

Cardioprotective effect of vitamin D3 on cisplatin-induced cardiotoxicity in male mice: role of oxidative stress

Cisplatin (CP) is a chemotherapy drug used in a broad spectrum of cancer. The current study investigated the protective effect of vitamin D3 (vit-D3) on CP-induced cardiotoxicity. Forty-two male Balb-c mice (20-25 g) were divided into seven groups (GP), 6 per/group were included: GP1 was considered the control group, GP2 received a single dose of I.V. injection of cisplatin (10 mg/kg). Seven days before cisplatin injection on GP3 and GP4 as pre-treatment, vit-D3 was injected I.P. with the doses of 500 IU/kg and 1000 IU/kg, respectively. GP5 and GP6 were considered the treatment groups, were injected cisplatin (10 mg/kg, I.V), and 15 days later, received vit-D3 (500 IU/kg and 1000 IU/kg, I.P) for 7 days. GP7 was the positive control group, which received vit-D3 at a dose of 500 IU/kg (I.P.) for 7 days. Tissues samples and blood serum were collected for biochemical and histopathological investigations. CP injection significantly increased (p < 0.001) LDH, Troponin I, CK-MB, malondialdehyde (MDA), and nitric oxide (NO) levels, but total antioxidant capacity (TAC) levels were significantly reduced. Histological findings showed cardiac muscle rupture, myocardial fiber necrosis, edema, and pyknotic nuclei, indicating cardiac damage. In both pre-treatment and treatment protocol, vit-D3 could improve the histological and biochemical parameters and prevented from the CP toxicity. Vit-D3 significantly could prevent the CP cardiotoxicity in pre-treatment groups, and partially improve the damage of chemotherapy in treatment group. However, further research is necessary to establish the potential of vit-D3 in preventing or ameliorating cisplatin-induced cardiotoxicity.

Antiglycation, antifibrillation and antioxidative effects of para coumaric acid and vitamin D; an in-vitro and in-silico comparative-cum-synergistic approach

Diabetes Mellitus is a metabolic disorder that results in impaired utilization of carbohydrates, lipids, and proteins. Severe hyperglycemia is its principal clinical symptom. Human serum albumin (HSA) is used as a model protein since it is viewed as a sign of glycaemic management because it is more likely to get glycated in diabetic people than other proteins. Para-coumaric acid (pCA), a phenolic acid, and Vitamin D (vit-D) are used as protective agents. In the present work, we deduce a synergistic-cum-comparative effect of pCA and vit-D, expecting some improvement in the efficacy of pCA when combined with vit-D. Methods employed are DPPH radical scavenging activity, In-vitro glycation of HSA, UV-vis spectroscopy, fluorescence analysis, and circular dichroism measurement. After treatment, increasein the absorbance and fluorescence intensity were reduced along with normalization of CD value. . The glycation-mediated fibrillation assessed by Congo-Red and Thioflavin T (ThT) were found to be diminishedwhen HSA was treated with equimolar concentration of p-CA and vit-D- treatment. Fructosamine adduct formation and lysine modificationwas also decreased, while inhibition to hemolysis and lipid peroxidation was found to increase upon treatment. The reactive oxygen species generation detection was also performed in lymphocytes treated with various protein samples. Docking results further confirmed theblocking some glycation-prone amino acids by both compounds. The study shows that the combination in the ratio of 1:1 has provided higher overall protection comparable to aminoguanidine (AG), the molecule which is utilized as a positive control.

Vitamin D Status in Critically Ill Patients with SIRS and Its Relationship with Circulating Zn and Related Parameters during ICU Stay

Critically ill patients are exposed to different stressors which may generate Systemic Inflammatory Response Syndrome (SIRS). This situation hinders the assessment of micronutrients status, such as vitamin D or Zinc (Zn), potentially affecting patients’ treatment and recovery. The aim of the present study was to assess the evolution of circulating 25–Hydroxyvitamin D (25–OH–D) levels after seven days of Intensive Care Unit (ICU) stay and the influence on changes in plasma and erythrocyte Zn levels, as well as other parameters related to phosphorus–calcium metabolism. A prospective analytical study was conducted on 65 critically ill patients (42% women) aged 31–77 years with SIRS. Total 25–OH–D levels were measured in plasma samples by liquid chromatography-tandem mass spectrometry, and Zn content was analyzed by flame atomic absorption spectrometry. Both 25–OH–D and 25–OH–D₃ levels were directly associated with erythrocyte Zn concentration at follow-up (p = 0.046 and p = 0.011, respectively). A relationship between erythrocyte and plasma Zn was also found at this follow-up point. No such clear associations were found when considering 25–OH–D₂. Different disturbances in levels of phosphorus–calcium metabolism parameters were found, suggesting a relationship between the changes of 25–OH–D₃ levels and parathormone (p = 0.019) and phosphorus (p = 0.005). The findings of the present study suggest an interaction between vitamin D and Zn, in which the correct status of these micronutrients could be a potentially modifiable factor and a beneficial approach in the recovery of critically ill patients.

Association of keratoconus with serum levels of 25-hydroxyvitamin D and antioxidant trace elements: A systematic review and meta-analysis

The aim of this systematic review and meta-analysis was to summarize and compare the available evidence on the level of vitamin D and antioxidant trace elements between the keratoconus (KC) patients and healthy controls. Seven case-control studies with 830 subjects were found eligible with a systematic search using PubMed, SCOPUS, Web of Science, and EMBASE till November 21, 2021. Data were synthesized with a DerSimonian and Laird random-effects method of meta-analysis. The mean serum vitamin D level was significantly lower in the patients with KC [standardized mean difference (SMD): -0.71; P < 0.001] as compared with the control group. The mean serum vitamin D level decreased more in the progressive patients (SMD: -0.80; P = 0.016) than in the stable patients (SMD: -0.66; P < 0.001) when compared with the control group. The mean serum zinc level was found significantly lower in the patients with KC compared with the control group (SMD: -1.98; P = 0.005). Pooled analysis based on the two studies showed significantly lower mean selenium levels in the KC patients (SMD: -0.34; P = 0.003). Regular evaluation of serum vitamin D, zinc, and selenium levels among the patients with KC at disease onset and future follow-ups could be promising in predicting the progressive disease and disease severity.

Chronic vitamin D3 supplementation alleviates cognition impairment via inhibition of oxidative stress regulated by PI3K/AKT/Nrf2 in APP/PS1 transgenic mice

Oxidative stress plays essential role in the pathogenesis of Alzheimer's disease, and vitamin D₃ (VD₃) is a nutrient with neuroprotective and antioxidant activities. The present study aimed to confirm the neuroprotective effect and the ameliorative effect of cortical oxidative stress of VD₃ in APP/PS1 transgenic mice. APP/PS1 mice were treated with VD₃ for 20 weeks. After treatment, Morris Water Maze test was used to evaluate cognitive level. Western blotting was used to determine APP, p-tau, tau and PI3K/AKT/Nrf2 pathway-related protein expression levels. Immunohistochemical staining was performed to determine the levels of β amyloid peptide (Aβ) deposition. Enzyme linked immunosorbent assay was used to determine the 25(OH)D₃ levels and oxidative stress status. Our results showed that treatment with VD₃ ameliorated behavioral deficits of APP/PS1 mice. In addition, the administration of VD₃ significantly increased the cortical 25(OH)D₃ levels, while reducing the levels of cortical Aβ deposition and decreasing the expression levels of cortical APP, tau and p-tau in APP/PS1 mice. Moreover, VD₃ protected the cortex against oxidative stress by enhancing the levels of superoxide dismutase, glutathione and total antioxidant capacity, and downregulating the malondialdehyde levels. Furthermore, VD₃ clearly activated the PI3K/AKT/Nrf2 pathway, thereby elevating the expression levels of HO1 and NQO1. We concluded that VD₃ improved cognitive function and cortical Alzheimer-like pathology of APP/PS1 mice, which may be related to the inhibition of oxidative stress via activation the PI3K/AKT/Nrf2 pathway.

Current landscape of preclinical models of diabetic cardiomyopathy

Patients with diabetes have an increased risk of developing heart failure, preceded by (often asymptomatic) cardiac abnormalities, collectively called diabetic cardiomyopathy (DC). Diabetic heart failure lacks effective treatment, remaining an urgent, unmet clinical need. Although structural and functional characteristics of the diabetic human heart are well defined, clinical studies lack the ability to pinpoint the specific mechanisms responsible for DC. Preclinical animal models represent a vital component for understanding disease aetiology, which is essential for the discovery of new targeted treatments for diabetes-induced heart failure. In this review, we describe the current landscape of preclinical DC models (genetic, pharmacologically induced, and diet-induced models), highlighting their strengths and weaknesses and alignment to features of the human disease. Finally, we provide tools, resources, and recommendations to assist future preclinical translation addressing this knowledge gap.

Vitamin D3 intake as modulator for the early biomarkers of myocardial tissue injury in diabetic hyperlipidaemic rats

CONTEXT

Myocardial cell death occurs within hours following the onset of myocardial ischaemia and its chief cause is atherosclerosis. There is a link between vitamin D3 deficiency and many cardiovascular risk factors.

OBJECTIVE

This study compared the effect of vitamin D3 on early biomarkers of myocardial injury, to that of atorvastatin.

METHODS

Diabetic hyperlipidaemia was induced in Wistar rats, which were divided into 3 groups: diabetic hyperlipidaemic control, diabetic hyperlipidaemic rats treated with atorvastatin and diabetic hyperlipidaemic rats treated with vitamin D3. Blood glucose, glycated haemoglobin and lipid profile were evaluated. Markers of myocardial injury were examined including cardiac troponin, heart fatty acid binding protein (HFABP) and C-terminal pro-endothelin-1 (CT-pro-ET-1).

RESULTS

Vitamin D3 and atorvastatin intake improved lipid profile and glucose homeostasis, and reduced levels of predictive biomarkers of myocardial injury.

CONCLUSION

Vitamin D3 can be used in a suitable dose as a safe and protective candidate against myocardial injury.

Combined exposure to fine particulate matter and high glucose aggravates endothelial damage by increasing inflammation and mitophagy: the involvement of vitamin D

Background

Cardiovascular diseases (CVDs) are related to particulate matter (PM_2.5) exposure. Researchers have not clearly determined whether hyperglycemia, a hallmark of diabetes, exacerbates PM_2.5-induced endothelial damage. Thus, this study aimed to investigate the combined effects of PM_2.5 and high glucose on endothelial damage.

Results

Here, we treated human umbilical vein endothelial cells (HUVECs) with 30 mM high glucose and 50 μg/mL PM (HG + PM) to simulate endothelial cells exposed to hyperglycemia and air pollution. First, we showed that HUVECs exposed to PM under high glucose conditions exhibited significant increases in cell damage and apoptosis compared with HUVECs exposed to PM or HG alone. In addition, PM significantly increased the production of reactive oxygen species (ROS) in HUVECs and mitochondria treated with HG and decreased the expression of superoxide dismutase 1 (SOD1), a free radical scavenging enzyme. The coexposure group exhibited significantly increased ROS production in cells and mitochondria, a lower mitochondrial membrane potential, and increased levels of the autophagy-related proteins p62, microtubule-associated protein 1 light chain 3β (LC3B), and mitophagy-related protein BCL2 interacting protein 3 (Bnip3). Moreover, autophagosome-like structures were observed in the HG + PM group using transmission electron microscopy. The expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) were also increased through the JNK/p38 signaling pathway in the HG + PM group. As a ROS scavenger, vitamin D treatment effectively protected cells under HG and PM conditions by increasing cell viability, reducing mitochondrial ROS production, and suppressing the formation of mitophagy and inflammation. Furthermore, diabetes was induced in mice by administering streptozotocin (STZ). Mice were treated with PM by intratracheal injection. Vitamin D effectively alleviated oxidative stress, mitophagy, and inflammation in the aortas of mice treated with STZ and PM.

Conclusion

Taken together, simultaneous exposure to PM and high glucose exerts significant harmful effects on endothelial cells by inducing ROS production, mitophagy, and inflammation, while vitamin D reverses these effects.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12989-022-00462-1.

Vitamin D as therapeutic modulator in cerebrovascular diseases: a mechanistic perspectives

Vitamin D deficiency has been linked to several major chronic diseases, such as cardiovascular and neurodegenerative diseases, diabetes, and cancer, linked to oxidative stress, inflammation, and aging. Vitamin D deficiency appears to be particularly harmful to the cardiovascular system, as it can cause endothelial dysfunctioning and vascular abnormalities through the modulation of various downstream mechanisms. As a result, new research indicates that therapeutic approaches targeting vitamin D inadequacies or its significant downstream effects, such as impaired autophagy, abnormal pro-inflammatory and pro-oxidant reactions, may delay the onset and severity of major cerebrovascular disorders such as stroke and neurologic malformations. Vitamin D modulates the various molecular pathways, i.e., Nitric Oxide, PI3K-Akt Pathway, cAMP pathway, NF-kB Pathway, Sirtuin 1, Nrf2, FOXO, in cerebrovascular disorder. The current review shows evidence for vitamin D's mitigating or slowing the progression of these cerebrovascular disorders, which are significant causes of disability and death worldwide.

Metal ion homeostasis with emphasis on zinc and copper: Potential crucial link to explain the non-classical antioxidative properties of vitamin D and melatonin

Metal ion homeostasis is an essential physiological mechanism necessary for achieving an adequate balance of these ions' concentrations in the different cellular compartments. This fact is of great importance because both an excess and a deficiency of cellular metal ion levels are usually equally harmful due to the exacerbated increase in oxidative stress that may occur in both cases. Metal ion homeostasis ensures an equilibrium among multiple functions associated with the body's antioxidative defense network controlled by metallic micronutrients such as zinc and copper, some of the central regulators of redox processes. These micronutrients significantly modulate the activity of some isoforms of superoxide dismutase (SOD) and other enzymes such as metallothioneins (MTs) and ceruloplasmin (CP), which are directly or indirectly involved in the regulation of redox homeostasis. Although it is well known that both melatonin (MEL) and vitamin D have important roles as natural antioxidants, often some of these effects are related to their actions on antioxidative processes dependent on metal ions. Thus, in addition to their classical antioxidative properties usually associated with mitochondrial effects, it is known that MEL and vitamin D modulate the expression and activity of Cu/Zn-dependent SOD isoforms, MTs and CP; function as copper chelators and regulate genomic and non-genomic mechanisms related to the zinc transport. This review summarizes the main findings related to the crucial participation of zinc and copper in physiological antioxidative status and their relationship with the non-classical antioxidant effects of MEL and vitamin D, suggesting a potential synergism among these four micronutrients.

Mechanistic insight into glycation inhibition of human serum albumin by vitamin B9: Multispectroscopic and molecular docking approach

Advanced glycation end products (AGEs) formation produces free radicals that play a role in diabetes mellitus; hence inhibition of glycation plays a part in minimizing diabetes-related complications. This study was intended to examine the AGEs formation of HSA upon prolonged incubation of 28 days at 37 °C and further investigate the antiglycation potential of folic acid (FA). FA shows a significant binding affinity to the HSA with a binding constant (K) of 10⁴ M^-1. The evaluation of enthalpy change (∆H⁰) and entropy change (∆S^o) implied that the HSA-FA complex is stabilized primarily by hydrophobic interaction and hydrogen bonding. Molecular docking analysis depicted that FA binds with HSA in subdomain IIA (Sudlow's site I) with a binding energy of -7.0 kcal mol^-1. AGEs were characterized by free lysine and thiol groups, carbonyl content, and AGEs specific fluorescence. The presence of FA significantly decreased glycation from free lysine and carbonyl content estimation and AGEs specific fluorescence. Multispectroscopic observations and molecular docking and examination of various biomarkers demonstrate the antiglycation activity of FA and its capacity to prevent disease progression in diabetes.

Effect of vitamin D receptor polymorphisms on plasma oxidative stress and apoptotic biomarkers among breast cancer survivors supplemented vitamin D3

We investigated whether plasma oxidative stress and apoptotic biomarkers were associated with the VDR polymorphisms in breast cancer survivors supplemented with vitamin D3. Two hundred fourteen breast cancer survivors received 4000 IU of vitamin D3 daily for 12 weeks. Linear regression was used to analyze whether the effect of vitamin D3 supplementation on response variables was associated with the selected VDR single nucleotide polymorphisms executing by 'association' function in the R package 'SNPassoc'. Linear regression analyses adjusted for age, BMI and on-study plasma 25(OH)D changes indicated that the aa genotype of the ApaI [codominant model (aa vs. AA): -0.21 (-0.39 to -0.03); recessive model (aa vs. AA and Aa): -0.20 (-0.37 to -0.03)] and bb genotypes of the BsmI [recessive model (bb vs. BB and Bb): -0.20 (-0.39 to -0.01)] on VDR were associated with greater decrease in plasma Bcl2. Our findings indicated that, the Ff genotype of FokI was accompanied by higher increase in plasma MDA levels [codominant model (Ff vs. FF): 0.64 (0.18-1.11); dominant model (ff and Ff vs. FF): 0.52 (0.09-0.05)]. This observed association was not remained statistically significant after correction for multiple testing. Haplotype score analyses revealed statistically significant association between the FokI BsmI ApaI haplotype and circulating MDA changes (P-value for global score = 0.001) after false-discovery rate correction. Our study suggests that genetic variations in the VDR do not powerfully modify the effects of vitamin D3 intake on biomarkers associated with antioxidant activity, oxidative stress and apoptosis in breast cancer survivors.

Genome-Protecting Compounds as Potential Geroprotectors

Throughout life, organisms are exposed to various exogenous and endogenous factors that cause DNA damages and somatic mutations provoking genomic instability. At a young age, compensatory mechanisms of genome protection are activated to prevent phenotypic and functional changes. However, the increasing stress and age-related deterioration in the functioning of these mechanisms result in damage accumulation, overcoming the functional threshold. This leads to aging and the development of age-related diseases. There are several ways to counteract these changes: 1) prevention of DNA damage through stimulation of antioxidant and detoxification systems, as well as transition metal chelation; 2) regulation of DNA methylation, chromatin structure, non-coding RNA activity and prevention of nuclear architecture alterations; 3) improving DNA damage response and repair; 4) selective removal of damaged non-functional and senescent cells. In the article, we have reviewed data about the effects of various trace elements, vitamins, polyphenols, terpenes, and other phytochemicals, as well as a number of synthetic pharmacological substances in these ways. Most of the compounds demonstrate the geroprotective potential and increase the lifespan in model organisms. However, their genome-protecting effects are non-selective and often are conditioned by hormesis. Consequently, the development of selective drugs targeting genome protection is an advanced direction.

Beneficial Impact of Semicarbazide-Sensitive Amine Oxidase Inhibition on the Potential Cytotoxicity of Creatine Supplementation in Type 2 Diabetes Mellitus

Creatine supplementation of the population with type 2 diabetes mellitus (T2DM) combined with an exercise program is known to be a possible therapy adjuvant with hypoglycemic effects. However, excessive administration of creatine leads to the production of methylamine which is deaminated by the enzyme semicarbazide-sensitive amine oxidase (SSAO) and as a result, cytotoxic compounds are produced. SSAO activity and reaction products are increased in the serum of T2DM patients. Creatine supplementation by diabetics will further augment the activity of SSAO. The current review aims to find a feasible way to ameliorate T2DM for patients who exercise and desire to consume creatine. Several natural agents present in food which are involved in the regulation of SSAO activity directly or indirectly are reviewed. Particularly, zinc-α2-glycoprotein (ZAG), zinc (Zn), copper (Cu), histamine/histidine, caffeine, iron (Fe), and vitamin D are discussed. Inhibiting SSAO activity by natural agents might reduce the potential adverse effects of creatine metabolism in population of T2DM.

Vitamin D Deficiency and the Risk of Cerebrovascular Disease

Vitamin D deficiency has been clearly linked to major chronic diseases associated with oxidative stress, inflammation, and aging, including cardiovascular and neurodegenerative diseases, diabetes, and cancer. In particular, the cardiovascular system appears to be highly sensitive to vitamin D deficiency, as this may result in endothelial dysfunction and vascular defects via multiple mechanisms. Accordingly, recent research developments have led to the proposal that pharmacological interventions targeting either vitamin D deficiency or its key downstream effects, including defective autophagy and abnormal pro-oxidant and pro-inflammatory responses, may be able to limit the onset and severity of major cerebrovascular diseases, such as stroke and cerebrovascular malformations. Here we review the available evidence supporting the role of vitamin D in preventing or limiting the development of these cerebrovascular diseases, which are leading causes of disability and death all over the world.

Association between calcitriol and paricalcitol with oxidative stress in patients with hemodialysis

Background: The pathophysiological basis of chronic kidney disease and its complications, including cardiovascular disease, are associated with chronic inflammation and oxidative stress. We investigated the effects of active vitamin D (calcitriol) and synthetic vitamin D analog (paricalcitol) on oxidative stress in hemodialysis patients. Methods: This cross-sectional study was composed of 83 patients with a minimum hemodialysis vintage of one year. Patients with a history of any infection, malignancy, and chronic inflammatory disease were excluded. Oxidative markers (total oxidant and antioxidant status) and inflammation markers (C-reactive protein and interleukin-6) were analyzed. Results: A total of 47% (39/83) patients were using active or analog vitamin D. Total antioxidant status was significantly higher in patients with using active or analog vitamin D than those who did not use (p = 0.006). Whereas, total oxidant status and oxidative stress index were significantly higher in patients with not using vitamin D when compared with the patients who were using vitamin D preparation (p = 0.005 and p = 0.004, respectively). On the other hand, total antioxidant status, total oxidant status, and oxidative stress index were similar between patients who used active vitamin D or vitamin D analog (p = 0.6; p = 0.4 and p = 0.7, respectively). Conclusion: The use of active or selective vitamin D analog in these patients decreases total oxidant status and increases total antioxidant status. Also, paricalcitol is as effective as calcitriol in decreasing total oxidant status and increasing total antioxidant status in patients with chronic kidney disease.

Serum 25-Hydroxyvitamin D, Selenium, Zinc and Copper in Patients with Keratoconus

PURPOSE

To assess the possible association between keratoconus (KC) and serum levels of 25-hydroxyvitamin D (25OHD), Selenium (Se), Zinc (Zn), and Copper (Cu) and to compare it with age-matched healthy subjects.

METHODS

One hundred patients with KC and 100 normal subjects were included. The two groups were compared for serum 25OHD and serum levels of three trace elements: Se, Zn, and Cu. These factors were also compared between groups with different KC stages.

RESULTS

Serum levels of vitamin D, Zn, Cu, and Se were significantly different between the KC and normal groups (P = 0.006, P = 0.015, P = 0.004, and P = 0.038, respectively). Although a lower level of 25OHD was found in severe stages of KC, it was not significantly different among different KC groups (P = 0.441). KC stage groups were not significantly different for mean serum Zn, Cu, and Se (P = 0.130, P = 0.98, P = 0.113, respectively). Although the Cu/Zn ratio was higher in cases than in controls, there was no significant difference between the two groups and between KC stages (P = 0.168, P = 0.143, respectively).

CONCLUSION

Lower serum 25OHD, Cu, Zn, and Se were found in the KC group compared to the control group. The results of this study suggest that a lower antioxidative activity may be involved in the possible etiology of KC.