Does vitamin D improve liver enzymes, oxidative stress, and inflammatory biomarkers in adults with non-alcoholic fatty liver disease? A randomized clinical trial

Decreasing the burden of non-alcoholic fatty liver disease: From therapeutic targets to drug discovery opportunities

Non-alcoholic fatty liver disease (NAFLD) presents a pervasive global pandemic, affecting approximately 25 % of the world's population. This grave health issue not only demands urgent attention but also stands as a significant economic concern on a global scale. The genesis of NAFLD can be primarily attributed to unhealthy dietary habits and a sedentary lifestyle, albeit certain genetic factors have also been recorded to contribute to its occurrence. NAFLD is characterized by fat accumulation in more than 5 % of hepatocytes according to histological analysis, or >5.6 % of lipid volume fraction in total liver weight in patients. The pathophysiology of NAFLD/non-alcoholic steatohepatitis (NASH) is multifactorial and the mechanisms underlying the progression to advanced forms remain unclear, thereby representing a challenge to disease therapy. Despite the substantial efforts from the scientific community and the large number of pre-clinical and clinical trials performed so far, only one drug was approved by the Food and Drug Administration (FDA) to treat NAFLD/NASH specifically. This review provides an overview of available information concerning emerging molecular targets and drug candidates tested in clinical studies for the treatment of NAFLD/NASH. Improving our understanding of NAFLD pathophysiology and pharmacotherapy is crucial not only to explore new molecular targets, but also to potentiate drug discovery programs to develop new therapeutic strategies. This knowledge endeavours scientific efforts to reduce the time for achieving a specific and effective drug for NAFLD or NASH management and improve patients' quality of life.

The beneficial influences of vitamin D intake on inflammation and oxidative stress in infertile women with polycystic ovary syndrome

Objective

Oxidative stress and inflammation play a vital function in the pathophysiology of polycystic ovary syndrome (PCOS) and infertility. The aim of this work was to control the impacts of vitamin D intake on metabolic profiles in infertile subjects with PCOS.

Trial design and methods

This randomized, double-blinded, placebo-controlled clinical trial was carried out among 40 infertile women with PCOS. Subjects were randomly divided into two intervention groups to take either 50 000 IU vitamin D (n=20) or placebo (n=20) weekly for 8 weeks. Metabolic profiles and few inflammatory cytokines expression evaluated on peripheral blood mononuclear cells (PBMCs) of participants, using real-time polymerase chain reaction (RT-PCR) method.

Results

Vitamin D intake decreased high-sensitivity C-reactive protein (hs-CRP) (-0.9±1.1 vs. 0.3±0.9 mg/l, P=0.002) and elevated total antioxidant capacity (TAC) levels (49.2±60.2 vs. -50.6±161.8 mmol/l, P=0.02) compared with placebo; but no significant effects on other metabolic parameters were observed. Moreover, a significant downregulation of tumor necrosis factor alpha (TNF-α) expression (P=0.03) was observed after taking vitamin D compared with the placebo.

Conclusions

Overall, vitamin D intake for eight weeks had beneficial impacts on hs-CRP, TAC, and TNF-α among infertile women with PCOS.

Vitamin D ameliorates celecoxib cardiotoxicity in a doxorubicin heart failure rat model via enhancement of the antioxidant defense and minimizing mitochondrial dysfunction

Recent evidence suggests the mechanistic role of mitochondria and oxidative stress in the development of celecoxib-induced cardiotoxicity. On the other, it has reported the positive effects of vitamin D on oxidative stress and the maintenance of mitochondrial functions. This current study examined the cardiac effects of celecoxib, doxorubicin, vitamin D, and a combination of them in rats. The effect of 10 days of celecoxib (100 mg/kg/day), doxorubicin (2.5 mg/kg), vitamin D (60,000 U/kg), and their combination was studied on cardiac function according to serum lactate dehydrogenase (LDH), creatine kinase (CK), glutathione (GSH), and malondialdehyde (MDA) levels as well as mitochondrial succinate dehydrogenases (SDH) activity, reactive oxygen species (ROS) production, mitochondrial swelling, and mitochondrial membrane potential (MMP). Results showed that celecoxib and its combination with doxorubicin led to abnormality in paws and limbs, increased pressure in the eyes, blindness and animal death (in about 75% of the animals under study). Moreover, celecoxib and its combination with doxorubicin significantly increased cardiotoxicity biomarkers, oxidative stress markers (GSH and MDA), and mitochondrial toxicity parameters (SDH, ROS formation, MMP collapse, mitochondrial swelling). However, the combination of vitamin D with celecoxib and celecoxib + doxorubicin caused a significant reversal of deformity in paws and limbs, increased pressure in the eye, blindness, and animal death, as well as cardiotoxicity, oxidative stress, and mitochondrial parameters. This study proved for the first time the beneficial effect of vitamin D on celecoxib-induced cardiotoxicity, which is aggravated in the presence of doxorubicin through the maintenance of mitochondrial functions and its antioxidant potential.

A Narrative Review of Oxidative Stress and Liver Disease in Pregnancy: The Role of Antioxidants

Pregnancy brings numerous physiological changes to the body of the pregnant woman. Liver diseases in pregnancy contribute to increased oxidative stress, disrupting the delicate balance between reactive oxygen species and antioxidant defence. Antioxidant supplementation may have potential benefits in addressing pregnancy-related liver disorders, such as HELLP (haemolysis, elevated liver enzymes, low platelet count) and preeclampsia-associated liver dysfunction in pregnancy. The purpose of this narrative review is to review the evidence regarding oxidative stress in liver disorders during pregnancy and the role of antioxidants in alleviating oxidative stress and its effect on maternal and foetal outcomes. A narrative review study design involved a comprehensive search across three scientific databases: PubMed, Embase, and MEDLINE, published in the last 20 years. The searches were performed up to January 2024. Thirty-two studies were included in the narrative review. The most studied antioxidants were vitamins (vitamin C and E) for their role in clinical treatment, prophylaxis, and clearing surrogate oxidative stress markers. The majority of studies were on preeclampsia. Though the existing literature is not robust, available evidence suggests that antioxidant supplementation may have potential benefits in addressing pregnancy-related liver disorders, such as HELLP and preeclampsia-associated liver dysfunction in pregnancy. However, there is a need to establish consistent protocols, ethical standards, and well-designed clinical trials to clarify the timing and dosage of antioxidants in pregnancy. Antioxidants may alleviate the oxidative stress in various liver disorders during pregnancy, which still needs to be studied further for their clinical relevance.

Longitudinal Plasma Metabolome Patterns and Relation to Kidney Function and Proteinuria in Pediatric CKD

Key Points

Longitudinal untargeted metabolomics. Children with CKD have a circulating metabolome that changes over time.

Background

Understanding plasma metabolome patterns in relation to changing kidney function in pediatric CKD is important for continued research for identifying novel biomarkers, characterizing biochemical pathophysiology, and developing targeted interventions. There are a limited number of studies of longitudinal metabolomics and virtually none in pediatric CKD.

Methods

The CKD in Children study is a multi-institutional, prospective cohort that enrolled children aged 6 months to 16 years with eGFR 30–90 ml/min per 1.73 m2. Untargeted metabolomics profiling was performed on plasma samples from the baseline, 2-, and 4-year study visits. There were technologic updates in the metabolomic profiling platform used between the baseline and follow-up assays. Statistical approaches were adopted to avoid direct comparison of baseline and follow-up measurements. To identify metabolite associations with eGFR or urine protein-creatinine ratio (UPCR) among all three time points, we applied linear mixed-effects (LME) models. To identify metabolites associated with time, we applied LME models to the 2- and 4-year follow-up data. We applied linear regression analysis to examine associations between change in metabolite level over time (∆level) and change in eGFR (∆eGFR) and UPCR (∆UPCR). We reported significance on the basis of both the false discovery rate (FDR) <0.05 and P < 0.05.

Results

There were 1156 person-visits (N : baseline=626, 2-year=254, 4-year=276) included. There were 622 metabolites with standardized measurements at all three time points. In LME modeling, 406 and 343 metabolites associated with eGFR and UPCR at FDR <0.05, respectively. Among 530 follow-up person-visits, 158 metabolites showed differences over time at FDR <0.05. For participants with complete data at both follow-up visits (n =123), we report 35 metabolites with ∆level–∆eGFR associations significant at FDR <0.05. There were no metabolites with significant ∆level–∆UPCR associations at FDR <0.05. We report 16 metabolites with ∆level–∆UPCR associations at P < 0.05 and associations with UPCR in LME modeling at FDR <0.05.

Conclusions

We characterized longitudinal plasma metabolomic patterns associated with eGFR and UPCR in a large pediatric CKD population. Many of these metabolite signals have been associated with CKD progression, etiology, and proteinuria in previous CKD Biomarkers Consortium studies. There were also novel metabolite associations with eGFR and proteinuria detected.

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.

Oxidative Stress as a Target for Non-Pharmacological Intervention in MAFLD: Could There Be a Role for EVOO?

Oxidative stress plays a central role in most chronic liver diseases and, in particular, in metabolic dysfunction-associated fatty liver disease (MAFLD), the new definition of an old condition known as non-alcoholic fatty liver disease (NAFLD). The mechanisms leading to hepatocellular fat accumulation in genetically predisposed individuals who adopt a sedentary lifestyle and consume an obesogenic diet progress through mitochondrial and endoplasmic reticulum dysfunction, which amplifies reactive oxygen species (ROS) production, lipid peroxidation, malondialdehyde (MDA) formation, and influence the release of chronic inflammation and liver damage biomarkers, such as pro-inflammatory cytokines. This close pathogenetic link has been a key stimulus in the search for therapeutic approaches targeting oxidative stress to treat steatosis, and a number of clinical trials have been conducted to date on subjects with NAFLD using drugs as well as supplements or nutraceutical products. Vitamin E, Vitamin D, and Silybin are the most studied substances, but several non-pharmacological approaches have also been explored, especially lifestyle and diet modifications. Among the dietary approaches, the Mediterranean Diet (MD) seems to be the most reliable for affecting liver steatosis, probably with the added value of the presence of extra virgin olive oil (EVOO), a healthy food with a high content of monounsaturated fatty acids, especially oleic acid, and variable concentrations of phenols (oleocanthal) and phenolic alcohols, such as hydroxytyrosol (HT) and tyrosol (Tyr). In this review, we focus on non-pharmacological interventions in MAFLD treatment that target oxidative stress and, in particular, on the role of EVOO as one of the main antioxidant components of the MD.

Anthocyanins: Potential phytochemical candidates for the amelioration of non-alcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is described by too much hepatic fat deposition causing steatosis, which further develops into nonalcoholic steatohepatitis (NASH), defined by necroinflammation and fibrosis, progressing further to hepatic cirrhosis, hepatocellular carcinoma, and liver failure. NAFLD is linked to different aspects of the metabolic syndrome like obesity, insulin resistance, hypertension, and dyslipidemia, and its pathogenesis involves several elements including diet, obesity, disruption of lipid homeostasis, and a high buildup of triglycerides and other lipids in liver cells. It is therefore linked to an increase in the susceptibility to developing diabetes mellitus and cardiovascular diseases. Several interventions exist regarding its management, but the availability of natural sources through diet will be a benefit in dealing with the disorder due to the immensely growing dependence of the population worldwide on natural sources owing to their ability to treat the root cause of the disease. Anthocyanins (ACNs) are naturally occurring polyphenolic pigments that exist in the form of glycosides, which are the glucosides of anthocyanidins and are produced from flavonoids via the phenyl propanoid pathway. To understand their mode of action in NAFLD and their therapeutic potential, the literature on in vitro, in vivo, and clinical trials on naturally occurring ACN-rich sources was exhaustively reviewed. It was concluded that ACNs show their potential in the treatment of NAFLD through their antioxidant properties and their efficacy to control lipid metabolism, glucose homeostasis, transcription factors, and inflammation. This led to the conclusion that ACNs possess efficacy in the amelioration of NAFLD and the various features associated with it. However, additional clinical trials are required to justify the potential of ACNs in NAFLD.

Vitamin D and Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD): Novel Mechanistic Insights

Metabolic dysfunction-associated steatotic liver disease (MASLD) is an increasingly prevalent condition characterized by abnormal fat accumulation in the liver, often associated with metabolic disorders. Emerging evidence suggests a potential link between vitamin D deficiency and the development and progression of MASLD. The current review provides a concise overview of recent studies uncovering novel mechanistic insights into the interplay between vitamin D and MASLD. Several epidemiological studies have highlighted a significant association between low vitamin D levels and an increased risk of MASLD. Vitamin D, traditionally known for its role in bone health, has now been recognized as a key player in various physiological processes, including immune regulation and inflammation. Experimental studies using animal models have demonstrated that vitamin D deficiency exacerbates liver steatosis and inflammation, suggesting a potential protective role against MASLD. Mechanistically, vitamin D appears to modulate MASLD through multiple pathways. Firstly, the vitamin D receptor (VDR) is abundantly expressed in liver cells, indicating a direct regulatory role in hepatic function. Activation of the VDR has been shown to suppress hepatic lipid accumulation and inflammation, providing a mechanistic basis for the observed protective effects. Additionally, vitamin D influences insulin sensitivity, a critical factor in MASLD pathogenesis. Improved insulin sensitivity may mitigate the excessive accumulation of fat in the liver, thus attenuating MASLD progression. In parallel, vitamin D exhibits anti-inflammatory properties by inhibiting pro-inflammatory cytokines implicated in MASLD pathophysiology. Experimental evidence suggests that the immunomodulatory effects of vitamin D extend to the liver, reducing inflammation and oxidative stress, key drivers of MASLD, and the likelihood of hepatocyte injury and fibrosis. Understanding the complex interplay between vitamin D and MASLD provides a basis for exploring targeted therapeutic strategies and preventive interventions. As vitamin D deficiency is a modifiable risk factor, addressing this nutritional concern may prove beneficial in mitigating the burden of MASLD and associated metabolic disorders.

Vitamin D3 exacerbates steatosis while calcipotriol inhibits inflammation in non-alcoholic fatty liver disease in Sod1 knockout mice: a comparative study of two forms of vitamin D

The role of vitamin D (VD) in non-alcoholic fatty liver disease (NAFLD) remains controversial, possibly due to the differential effects of various forms of VD. In our study, Sod1 gene knockout (SKO) mice were utilized as lean NAFLD models, which were administered 15 000 IU VD3 per kg diet, or intraperitoneally injected with the active VD analog calcipotriol for 12 weeks. We found that VD3 exacerbated hepatic steatosis in SKO mice, with an increase in the levels of Cd36, Fatp2, Dgat2, and CEBPA. However, calcipotriol exerted no significant effect on hepatic steatosis. Calcipotriol inhibited the expression of Il-1a, Il-1b, Il-6, Adgre1, and TNF, with a reduction of NFκB phosphorylation in SKO mice. No effect was observed by either VD3 or calcipotriol on hepatocyte injury and hepatic fibrosis. Co-immunofluorescence stains of CD68, a liver macrophage marker, and VDR showed that calcipotriol reduced CD68 positive cells, and increased the colocalization of VDR with CD68. However, VD3 elevated hepatocyte VDR expression, with no substantial effect on the colocalization of VDR with CD68. Finally, we found that VD3 increased the levels of serum 25(OH)D3 and 24,25(OH)2D3, whereas calcipotriol decreased both. Both VD3 and calcipotriol did not disturb serum calcium and phosphate levels. In summary, our study found that VD3 accentuated hepatic steatosis, while calcipotriol diminished inflammation levels in SKO mice, and the difference might stem from their distinct cellular selectivity in activating VDR. This study provides a reference for the application of VD in the treatment of lean NAFLD.

Multivitamins co-intake can reduce the prevalence of kidney stones: a large-scale cross-sectional study

BACKGROUND

This research aimed to explore the association between changes in the intake of common individual vitamins and combinations of vitamins and the prevalence of kidney calculi.

METHODS

We used data from NHANES to investigate the association between nine common vitamins and kidney stone prevalence. Participants were clustered into several vitamin exposure patterns using an unsupervised K-means clustering method. We used logistic regression models and restrictive cubic spline curves to explore the influence of vitamins.

RESULTS

The regression model exposed that compared to lower intake, high intake of vitamin B6 [Q4: OR (95% CI) = 0.76 (0.62, 0.93)], vitamin C [Q4: OR (95% CI) = 0.73 (0.59, 0.90)] and vitamin D [Q4: OR (95% CI) = 0.77 (0.64, 0.94)] individually exerted protective effects against the prevalence of kidney stones. Furthermore, the restrictive cubic spline analysis showed that the protective effect against the prevalence of kidney stones is enhanced as the take of vitamin B6 and vitamin D increased. Moreover, with the increase in vitamin C intake, its protective effect may turn into a risk factor. Regarding mixed exposure, Cluster 4 exhibited a significant protective effect against kidney stones compared with Cluster 1 [Model 3: OR (95% CI) = 0.79 (0.64, 0.98)].

CONCLUSIONS

Our research revealed that high levels of vitamin B6 and vitamin D intake were linked to a lower prevalence of kidney stone. With the gradual increase intake of vitamin C, the prevalence of kidney calculi decreased first and then increased. In addition, the co-exposure of nine vitamins is a protective factor for kidney stone disease.

The contribution of vitamin D insufficiency to the onset of steatotic liver disease among individuals with metabolic dysfunction

The interplay between fatty liver disease (FLD) and metabolic dysfunction has given rise to the concept of metabolic associated fatty liver disease (MAFLD). With vitamin D insufficiency frequently co-occurring with FLD and linked to metabolic abnormalities, this study investigates the potential role of vitamin D in the development of MAFLD. In this cross-sectional analysis, 22,476 participants with baseline metabolic dysfunction and known serum 25-OH-vitamin D3 levels were examined. The fatty liver index (FLI) was utilized to predict FLD, dividing subjects into MAFLD and non-MAFLD groups. Further stratification by vitamin D levels (sufficient vs. insufficient) and gender provided a detailed assessment through binary logistic regression to determine the association of vitamin D status with MAFLD incidence. Vitamin D insufficiency correlated with a higher MAFLD incidence in metabolically impaired individuals. Post-adjustment, the correlation was stronger (men: aOR = 1.32, 95% CI = 1.22-1.43, P < 0.001; women: aOR = 1.53, 95% CI = 1.18-1.98, P = 0.001). Lower serum 25-OH-vitamin D3 levels were found in MAFLD patients across genders (men: P = 0.003; women: P = 0.014), with a higher prevalence of insufficiency in MAFLD cases (men: P = 0.007; women: P = 0.003). The vitamin D-MAFLD link was stable across subgroups and using varying FLI criteria. Our findings indicate a clear association between vitamin D insufficiency and increased MAFLD incidence, underscoring the potential of vitamin D as an anti-lipogenic and anti-fibrotic agent.

Aerobic training with moderate or high doses of vitamin D improve liver enzymes, LXRα and PGC-1α levels in rats with T2DM

Dysregulation of key transcription factors involved in hepatic energy metabolism, such as peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) and liver X receptor alpha (LXRα), has been observed in T2DM. The present study aims to investigate the effects of aerobic training and vitamin D supplementation on liver enzyme levels and the levels of PGC-1α and LXRα proteins in hepatocytes, in a rat model of T2DM. The study involved 56 male Wistar rats, divided into two groups: one was non-diabetic and acted as a control group (n = 8), and the other had induced diabetes (n = 48). The diabetic rats were then split into six subgroups: two groups received high or moderate doses of vitamin D and aerobic training (D + AT + HD and D + AT + MD); two groups received high or moderate doses of vitamin D alone (D + HD and D + MD); one group underwent aerobic training with vehicle (sesame oil; D + AT + oil), and one group was a diabetic control receiving only sesame oil (oil-receiving). The D + AT + HD and D + HD groups received 10,000 IU of vitamin D, while the D + AT + MD and D + MD groups received 5000 IU of vitamin D once a week by injection. The D + AT + oil group and the sham group received sesame oil. After eight weeks of treatment, body weight, BMI, food intake, serum insulin, glucose, 25-hydroxyvitamin D, ALT, AST, and visceral fat were measured. The levels of PGC-1α and LXRα proteins in the liver was assessed by western blotting. Statistical analysis was performed using the paired t-test, one-way analysis of variance (ANOVA), and the Tukey post hoc test at a significance level of P < 0.05. Body weight, food intake, and BMI decreased significantly in the D + AT + HD, D + AT + MD, D + AT + oil, D + HD, and D + MD groups with the highest reduction being observed in body weight and BMI in the D + AT + HD group. The D + AT + HD group exhibited the lowest levels of insulin, glucose, and HOMA-IR while the D + C group exhibited the highest levels among the diabetic groups. The D + AT + HD and D + AT + MD groups had lower levels of ALT and AST enzymes compared to the other groups with no significant difference between D + AT + HD and D + AT + MD. D + AT + HD (p = 0.001), D + AT + MD (p = 0.001), D + HD (p = 0.023), D + MD (p = 0.029), and D + AT + oil (p = 0.011) upregulated LXRα compared to D + C. Among these groups, D + AT + HD exhibited a more profound upregulation of LXRα than D + AT + MD, D + AT + oil, D + HD, and D + MD (p = 0.005; p = 0.002, p = 0.001, and p = 0.001, respectively). Similarly, D + AT + HD showed a more notable upregulation of PGC-1α compared to D + AT + oil, D + HD, and D + MD (p = 0.002; p = 0.001, and p = 0.001, respectively). Pearson correlation tests showed significant and negative correlations between serum 25-hydroxyvitamin levels and both visceral fat (r = - 0.365; p = 0.005) and HOMA-IR (r = - 0.118; p = 0.009); while positive and significant correlations between the liver-to-bodyweight ratio with both ALT and AST enzymes and also between QUICKI levels with LXRα (r = 0.578; p = 0.001) and PGC-1α (r = 0.628; p = 0.001). Combined administration of aerobic training and vitamin D supplementation potentially improves liver enzymes in type-2 diabetic rats that were simultaneous with upregulating the levels of PGC-1α and LXRα proteins in hepatocytes. These improvements were more significant when combining exercise with high-dose vitamin D supplementation. This study highlights the potential of this combination therapy as a new diabetes treatment strategy.

Effects of vitamin D supplementation on liver fibrogenic factors, vitamin D receptor and liver fibrogenic microRNAs in metabolic dysfunction-associated steatotic liver disease (MASLD) patients: an exploratory randomized clinical trial

BACKGROUND AND AIMS

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a global metabolic problem which can lead to irreversible liver fibrosis. It has been shown that vitamin D and its receptors contribute to fibrogenic pathways in the liver. However, the effect of vitamin D supplementation on liver fibrosis related factors have not been examined. This double blinded placebo controlled clinical trial was designed to investigate the effects on vitamin D supplementation on serum levels of VDR, fibrogenic factors and fibrogenic MicroRNAs in MASLD patients.

METHODS

Forty six MASLD patients after block matching for sex and BMI were randomly assigned to receive 4000 IU/d vitamin D or placebo for 12 weeks. Weight, height and waist circumference were measured. Serum fibrogenic microRNAs, laminin, collagen type IV, hyaluronic acid, vitamin D, VDR, PTH, blood fasting glucose, serum fasting insulin, lipid profile, ALT and AST were determined at the baseline and at the end of the trial. Insulin resistance and insulin sensitivity were calculated using the HOMA-IR and QUICKI equation.

RESULTS

Supplementation with vitamin D for 12 weeks led to the significant increases in serum 25(OH) vitamin D, VDR and HDL-C compared to placebo (P < 0.001, P = 0.008 and P < 0.001). There were significant decreases in ALT, AST, FBS and LDL-C levels in the vitamin D group as compared to the placebo (P < 0.05). Laminin and hyaluronic acid concentrations were significantly decreased in the vitamin D group as compared to the placebo group, by -10.6 and - 28.7 ng/mL, respectively. Supplementation with vitamin D for 12 weeks resulted in a significant lower MiR-21 and MiR-122 gene expressions compared to the placebo group (P = 0.01 and P < 0.001, respectively).

DISCUSSION

As the first randomized controlled trial on the effect of vitamin D supplementation on serum levels of VDR, fibrogenic factors and fibrogenic MicroRNAs in MASLD patients, we found a significant reduction in some liver fibrogenic factors, in liver transaminases and corresponding changes in some fibrosis-related MiRs and some metabolic factors. Further clinical trials with larger sample sizes and direct measures of liver fibrosis are needed to confirm these findings.

TRIAL REGISTRATION NUMBER

(available at: http://www.irct.ir , identifier: IRCT201405251485N13), Registration date: 14-03-2017.

Effect of vitamin D supplementation on symptoms severity in vitamin D insufficient women with premenstrual syndrome: A randomized controlled trial

BACKGROUND

Premenstrual syndrome (PMS) is one of the most prevalent disorders among reproductive women worldwide that negatively impact women's quality of life. This study aimed to investigate the effect of vitamin D supplementation on the severity of PMS symptoms in vitamin D insufficient women with PMS.

METHODS

In this randomized, double-blind clinical trial, 44 vitamin D insufficient women with PMS received either 50,000 IU vitamin D or a placebo fortnightly for 16 weeks. Participants completed the PMS Daily Symptoms Rating form at beginning and during the last two months of the intervention, and their blood samples were collected to assess 25(OH)D serum levels.

RESULTS

After the four months' intervention, the serum level of 25(OH)D in the vitamin D group raised from 21 ± 8 ng/ml to 40 ± 8 ng/ml (P < 0.001), while in the placebo group it raised from 21 ± 7 ng/ml to 23 ± 7 ng/ml (P = 0.03). Indeed, serum vitamin D levels in the placebo group could not reach a sufficient level. At the end of the intervention, the mean score of total PMS symptoms showed significant improvement in the vitamin supplemented group compared to the controls (p < 0.001). By grouping the PMS symptoms into five subgroups, the mean score of all five subgroups decreased post-supplementation compared to the baseline; however, the highest and lowest decrease were in depression (53 %) and water retention subgroups (28 %), respectively. This indicates a greater improvement in the mean scores of mood symptoms compared to physical symptoms in this study (p < 0.001).

CONCLUSION

Results obtained in this clinical trial represent the helpful effects of vitamin D supplementation on total, physical and mood symptoms in vitamin D insufficient women with PMS.

TRIAL REGISTRATION

This randomized controlled trial at IRCT.ir on 2018-06-20 with Registration No: IRCT20180525039822N1.

The protective impact of curcumin, vitamin D and E along with manganese oxide and Iron (III) oxide nanoparticles in rats with scrotal hyperthermia: Role of apoptotic genes, miRNA and circRNA

BACKGROUND

Infertility is one of the major factors affecting most people around the world. Short-term exposure to high temperatures can cause hyperthermia, which is one of the causes of male infertility. The aim of this study was to investigate the protective effect of curcumin, vitamins D and E along with Iron (III) oxide nanoparticles (Fe2O3-NPs) and manganese oxide nanoparticles (MnO2-NPs) on semen parameters and its effect on miRNA21 and circRNA0001518 expression.

MATERIAL AND METHODS

In this study, the lower part of the rat was exposed to 43 °C for 5 weeks every other day for 5 weeks. Then the animals were killed. Tissue samples were collected for sperm parameters analysis, and tissue samples were taken for evaluation of apoptosis levels in germ cells, and RNA extraction in order to examine the expression of Bax, Bcl-2, miRNA, and CircRNA genes.

RESULTS

The results of this study showed that administration of curcumin, vitamin D, and vitamin E with Fe2O3-NPs and MnO2-NPs can improve the parameters of semen, Bax gene expression, Bcl-2 as well as miRNA and CircRNA in rats with testicular hyperthermia. In addition, curcumin by reducing the toxicity of Fe2O3 nanoparticles was able to reduce its negative effects and also reduce apoptosis in germ cells. This decrease in apoptosis was attributed to decreased Bcl-2 gene expression and increased expression of Bax, miRNA-21, and circRNA0001518.

CONCLUSION

All the results of this study confirmed that Fe2O3-NPs and Mno2-NPs containing antioxidants or vitamins are useful in improving fertility in rats due to scrotal hyperthermia. Although Fe2O3-NPs and Mno2-NPs containing both antioxidants and vitamins had a greater effect on improving fertility and reducing the toxic effects of nanoparticles.

Circulating Metabolomic Associations with Neurocognitive Outcomes in Pediatric CKD

BACKGROUND

Children with CKD are at risk for impaired neurocognitive functioning. We investigated metabolomic associations with neurocognition in children with CKD.

METHODS

We leveraged data from the Chronic Kidney Disease in Children (CKiD) study and the Neurocognitive Assessment and Magnetic Resonance Imaging Analysis of Children and Young Adults with Chronic Kidney Disease (NiCK) study. CKiD is a multi-institutional cohort that enrolled children aged 6 months to 16 years with eGFR 30-90 ml/min per 1.73 m 2 ( n =569). NiCK is a single-center cross-sectional study of participants aged 8-25 years with eGFR<90 ml/min per 1.73 m 2 ( n =60) and matched healthy controls ( n =67). Untargeted metabolomic quantification was performed on plasma (CKiD, 622 metabolites) and serum (NiCK, 825 metabolites) samples. Four neurocognitive domains were assessed: intelligence, attention regulation, working memory, and parent ratings of executive function. Repeat assessments were performed in CKiD at 2-year intervals. Linear regression and linear mixed-effects regression analyses adjusting for age, sex, delivery history, hypertension, proteinuria, CKD duration, and glomerular versus nonglomerular diagnosis were used to identify metabolites associated with neurocognitive z-scores. Analyses were performed with and without adjustment for eGFR.

RESULTS

There were multiple metabolite associations with neurocognition observed in at least two of the analytic samples (CKiD baseline, CKiD follow-up, and NiCK CKD). Most of these metabolites were significantly elevated in children with CKD compared with healthy controls in NiCK. Notable signals included associations with parental ratings of executive function: phenylacetylglutamine, indoleacetylglutamine, and trimethylamine N-oxide-and with intelligence: γ -glutamyl amino acids and aconitate.

CONCLUSIONS

Several metabolites were associated with neurocognitive dysfunction in pediatric CKD, implicating gut microbiome-derived substances, mitochondrial dysfunction, and altered energy metabolism, circulating toxins, and redox homeostasis.

PODCAST

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Insights into the role of vitamin D in targeting the culprits of non-alcoholic fatty liver disease

Vitamin D (VD) is a secosteroid hormone that is renowned for its crucial role in phospho-calcium homeostasis upon binding to the nuclear vitamin D receptor (VDR). Over and above, the pleiotropic immunomodulatory, anti-inflammatory, and metabolic roles VD plays in different disease settings started to surface in the past few decades. On the other hand, a growing body of evidence suggests a correlation between non-alcoholic fatty liver disease (NAFLD) and its progressive inflammatory form non-alcoholic steatohepatitis (NASH) with vitamin D deficiency (VDD) owing to the former's ingrained link with obesity and metabolic syndrome. Accordingly, a better understanding of the contribution of disrupted VDR signalling to NAFLD incidence and progression would provide further insights into its diagnosis, treatment modalities, and prognosis. This is especially significant as, hitherto, no drug for NAFLD has been approved. This review, therefore, sought to set forth the likely contribution of VDR signalling in NAFLD and how it might influence its multiple drivers.

The Association between Vitamin D Deficiency and Hepatosteatosis in Children and Adolescents with Obesity

INTRODUCTION

Increasingly, research groups have been studying the association of serum vitamin D and metabolic health indicators, especially in patients with obesity. We compared the serum 25-hydroxyvitamin D (25(OH)D) concentrations in children and adolescents who had obesity and hepatosteatosis with children and adolescents who had obesity without hepatosteatosis and investigated the relationship between serum 25(OH)D concentrations and severity of hepatosteatosis. We also aimed to assess the effect of vitamin D treatment after 6 months on hepatosteatosis and liver biochemistry.

METHODS

One hundred thirty-three patients with obesity (body mass index [BMI] >+2 standard deviations [SDs] for their age and gender) and vitamin D deficiency (serum 25(OH)D <12 ng/mL) were recruited. Anthropometric measurements, biochemical parameters (serum calcium, phosphate, alkaline phosphatase, parathyroid hormone, 25(OH)D, glucose and insulin concentrations), and ultrasonographic findings of hepatosteatosis were recorded before and 6 months after Vitamin D treatment. χ2, Student's t tests, and multivariate analysis were performed.

RESULTS

Grade 1, 2, and 3 hepatosteatosis at baseline was present in 51 (38.4%), 43 (32.3%), and 10 (7.5%) subjects, respectively. Mean (± SD) serum 25(OH)D concentrations were significantly lower in those with hepatosteatosis (8.4 ± 2.4 ng/mL) compared with those without hepatosteatosis (9.9 ± 2.4 ng/mL, p < 0.005). Multivariable logistic regression analysis showed serum 25(OH)D concentration was the independent predictor for hepatosteatosis (p < 0.005), whereas age, sex, weight SD, BMI SD, and homeostasis model of assessment (HOMA)-insulin resistance (IR) were not (p > 0.05). There was no significant difference in BMI SD, HOMA-IR, and liver enzymes between subjects with and without hepatosteatosis (p > 0.05). Despite improvement in serum 25(OH)D concentrations at 6 months post-treatment (34.7 ± 10.6 ng/mL vs. 8.7 ± 2.4 ng/mL; p < 0.0001), there was no significant difference in the proportion of patients with different severity of hepatosteatosis as compared to before treatment (p = 0.88).

CONCLUSION

Serum 25(OH)D concentrations were lower in children and adolescents with obesity and hepatic steatosis as compared to those without hepatic steatosis, with an inverse association between the severity of hepatosteatosis and serum 25(OH)D concentrations. Vitamin D treatment in children and adolescents with obesity and hypovitaminosis D did not improve severity of hepatic steatosis on ultrasonography at 6 months.

The effects of low-fat dairy products fortified with 1500 IU vitamin D3 on serum liver function biomarkers in adults with abdominal obesity: a randomized controlled trial

INTRODUCTION

Vitamin D deficiency has been reported to affect liver function biomarkers. This study was aimed to investigate the effect of consuming vitamin D fortified low-fat dairy products on liver function tests in adults with abdominal obesity.

METHODS

This total blinded randomized controlled trial was undertaken on otherwise healthy abdominally obese adults living in Mashhad, Iran. Milk and yogurt were fortified with 1500 IU vitamin D3 nano-capsules. Participants were randomized to receive fortified milk (n = 73), plain milk (n = 73), fortified yogurt (n = 69), and plain yogurt (n = 74) for 10 weeks. Blood samples were taken at baseline and at the end of the study to assess serum levels of vitamin D, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase (ALP), and Gamma glutamyl transferase.

RESULTS

A total of 289 participants completed the study (54% female). The groups were homogenous in terms of age, sex, weight, energy intake, and physical activity level (p-value > 0.05). After the trial, vitamin D serum levels were significantly increased in both groups receiving fortified products (both p < 0.001). There was a significant time*group effect only in serum ALP (p < 0.001).

CONCLUSION

Consumption of dairy products fortified by 1500 IU vitamin D3 might have detrimental effects on serum levels of some liver enzymes in individuals with abdominal obesity. Further studies needed to determine these effects and underlying mechanisms.

TRIAL REGISTRATION

IRCT20101130005280N27 .

Calcium signalling in hepatic metabolism: Health and diseases

The flexibility between the wide array of hepatic functions relies on calcium (Ca2+) signalling. Indeed, Ca2+ is implicated in the control of many intracellular functions as well as intercellular communication. Thus, hepatocytes adapt their Ca2+ signalling depending on their nutritional and hormonal environment, leading to opposite cellular functions, such as glucose storage or synthesis. Interestingly, hepatic metabolic diseases, such as obesity, type 2 diabetes and non-alcoholic fatty liver diseases, are associated with impaired Ca2+ signalling. Here, we present the hepatocytes' toolkit for Ca2+ signalling, complete with regulation systems and signalling pathways activated by nutrients and hormones. We further discuss the current knowledge on the molecular mechanisms leading to alterations of Ca2+ signalling in hepatic metabolic diseases, and review the literature on the clinical impact of Ca2+-targeting therapeutics.

Vitamin D/vitamin D receptor pathway in non-alcoholic fatty liver disease

INTRODUCTION

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease worldwide, but underlying mechanisms are not fully understood. In recent years, a growing body of evidence has emphasized the therapeutic role of vitamin D in NAFLD, but the specific mechanism remains to be investigated.

AREAS COVERED

This review summarized the roles of vitamin D/VDR (vitamin D receptor) pathway in different types of liver cells (such as hepatocytes, hepatic stellate cells, liver macrophages, T lymphocytes, and other hepatic immune cells) in case of NAFLD. Meanwhile, the effects of pathways in the gut-liver axis, adipose tissue-liver axis, and skeletal muscle-liver axis on the development of NAFLD were further reviewed. Relevant literature was searched on PubMed for the writing of this review.

EXPERT OPINION

The precise regulation of regional vitamin D/VDR signaling pathway based on cell-specific or tissue-specific function will help clarify the potential mechanism of vitamin D in NAFLD, which may provide new therapeutic targets to improve the safety and efficacy of vitamin D based drugs.

Exploring the Impact of Nutrition on Non-Alcoholic Fatty Liver Disease Management: Unveiling the Roles of Various Foods, Food Components, and Compounds

There is a need to introduce standardized treatment options for non-alcoholic fatty liver disease (NAFLD) due to its global prevalence and the complications of this disease. Many studies have revealed that food-derived substances may be beneficial in dealing with this disease. Therefore, this review aims to evaluate the recently published studies on the food-derived treatment options for NAFLD. A comprehensive search of the PubMed database using keywords such as "NAFLD", "nutrition", "food", "derived", "therapy", and "guidelines" yielded 219 relevant papers for our analysis, published from 2004 to 2023. The results show the significant benefits of food-derived treatment in NAFLD therapy, including improvements in liver histology, hepatic fat amounts, anthropometric measures, lipid profile, and other metabolic measures. The availability of the substances discussed makes them a significant adjuvant in the treatment of this disease. The usefulness of Viusid as additional therapy to diet and physical activity should be emphasized due to improvements in liver histology; however, many other substances lead to a decrease in liver fat amounts including, e.g., berberine or omega-3 fatty acids. In addition, the synbiotic Protexin seems to be useful in terms of NAFLD treatment, especially because it is effective in both obese and lean subjects. Based on the latest research results, we suggest revising the therapeutic recommendations for patients suffering from NAFLD.

The Effect of Bioactive Aliment Compounds and Micronutrients on Non-Alcoholic Fatty Liver Disease

In the current review, we focused on identifying aliment compounds and micronutrients, as well as addressed promising bioactive nutrients that may interfere with NAFLD advance and ultimately affect this disease progress. In this regard, we targeted: 1. Potential bioactive nutrients that may interfere with NAFLD, specifically dark chocolate, cocoa butter, and peanut butter which may be involved in decreasing cholesterol concentrations. 2. The role of sweeteners used in coffee and other frequent beverages; in this sense, stevia has proven to be adequate for improving carbohydrate metabolism, liver steatosis, and liver fibrosis. 3. Additional compounds were shown to exert a beneficial action on NAFLD, namely glutathione, soy lecithin, silymarin, Aquamin, and cannabinoids which were shown to lower the serum concentration of triglycerides. 4. The effects of micronutrients, especially vitamins, on NAFLD. Even if most studies demonstrate the beneficial role of vitamins in this pathology, there are exceptions. 5. We provide information regarding the modulation of the activity of some enzymes related to NAFLD and their effect on this disease. We conclude that NAFLD can be prevented or improved by different factors through their involvement in the signaling, genetic, and biochemical pathways that underlie NAFLD. Therefore, exposing this vast knowledge to the public is particularly important.

Role of Nutrition in the Etiopathogenesis and Prevention of Nonalcoholic Fatty Liver Disease (NAFLD) in a Group of Obese Adults

Nonalcoholic fatty liver disease (NAFLD) is liver damage characterized by an accumulation of triglycerides in hepatocytes of >5% (due to an alteration of the balance of the lipid metabolism in favour of lipogenesis compared to lipolysis) that is not induced by the consumption of alcohol. The pathology includes simple steatosis and nonalcoholic steatohepatitis, or NASH (steatosis associated with microinflammatory activities), which can evolve in 15% of subjects with hepatic fibrosis to cirrhosis and the development of hepatocellular carcinoma. The aim of this study is to report the role of macro- and micronutrients in the pathogenesis and prevention of NAFLD in obese subjects. A total of 22 obese or overweight patients with hepatic steatosis were monitored periodically, evaluating their eating habits, fasting glycaemia, lipid picture, liver enzymes, anthropometric parameters, nutrition status, liver ultrasound, oxidative stress, and adherence to the Mediterranean diet. A statistical analysis shows a significant positive relationship between total cholesterol and the Mediterranean adequacy index (MAI) (r = -0.57; p = 0.005) and a significant negative relationship between ALT transaminases and the MAI (r = -0.56; p = 0.007). Nutrition and diet are important factors in the pathogenesis and prevention of NAFLD. The dietary model, based on the canons of the Mediterranean diet, prevents and reduces the accumulation of fat in hepatocytes. Therefore, in agreement with other studies in the literature, we can state that a dietary model characterized by foods rich in fibre, carotenoids, polyphenols, ω3 fatty acids, folic acid, and numerous other molecules is inversely correlated with the serum levels of ALT transaminases, an enzyme whose level increases when the liver is damaged and before the most obvious symptoms of organ damage appear.

The effect of high oral loading dose of cholecalciferol in non-alcoholic fatty liver disease patients. A randomized placebo controlled trial

Background and Aim: Non-alcoholic fatty liver (NAFLD) is one of the most common progressive metabolic disorders worldwide. There are increasing scientific interests nowadays for the association between vitamin D status and Non-alcoholic fatty liver. Earlier studies have revealed that vitamin D deficiency is highly prevalent in Non-alcoholic fatty liver patients that contributes to poor outcomes. Hence, the present study aimed to assess the efficacy and safety of oral cholecalciferol on Non-alcoholic fatty liver patients.

Subjects and Methods: This study was conducted on 140 patients that were randomized either to group 1 that received the standard conventional therapy in addition to placebo or group 2 that received the standard conventional therapy in addition to cholecalciferol during the 4 months study period.

Results: At the end of the study group 2 revealed significant decrease (p &lt; 0.05) in the mean serum level of TG, LDL-C, TC, hsCRP as compared to their baseline results and group 1 results. Additionally, a significant improvement in the serum levels of ALT (p = 0.001) was seen in group 2 at the end of the study when compared to group 1. Whereas group 1 did not show any change in these parameters when compared to group 2 and their baseline results.

Conclusion: Cholecalciferol was shown to have beneficial effects on serum ALT levels, hsCRP levels and lipid profile of NAFLD patients.

Clinical Trial Registration:https://prsinfo.clinicaltrials.gov/prs-users-guide.html, identifier NCT05613192

Therapeutic potential of vitamin D against bisphenol A-induced spleen injury in Swiss albino mice

Bisphenol A (BPA), a ubiquitous plasticizer, is capable of producing oxidative splenic injury, and ultimately led to spleen pathology. Further, a link between VitD levels and oxidative stress was reported. Hence the role of VitD in BPA-induced oxidative splenic injury was investigated in this study. Sixty male and female Swiss albino mice (3.5 weeks old) were randomly divided into control and treated groups 12 mice in each (six males and six females). The control groups were further divided into sham (no treatment) and vehicle (sterile corn oil), whereas the treatment group was divided into VitD (2,195 IU/kg), BPA (50 μg/kg), and BPA+VitD (50 μg/kg + 2,195 IU/kg) groups. For six weeks, the animals were dosed intraperitoneally (i.p). One week later, at 10.5 weeks old, mice were sacrificed for biochemical and histological analyses. Findings showed BPA triggered neurobehavioral abnormalities and spleen injury with increased apoptotic indices (e.g. DNA fragmentation) in both sexes. A significant increase was found in lipid peroxidation marker, MDA in splenic tissue, and leukocytosis. Conversely, VitD treatment altered this scenario into motor performance preservation, reducing oxidative splenic injury with a decrease in the percent apoptotic index. This protection was significantly correlated with preserving leukocyte counts and reduced MDA levels in both genders. It can be concluded from the above findings that VitD treatment has an ameliorative effect on oxidative splenic injury induced by BPA, highlighting the continuous crosstalk between oxidative stress and the VitD signaling pathway.

Functional foods and dietary supplements in the management of non-alcoholic fatty liver disease: A systematic review and meta-analysis

Objective

In this systematic review and meta-analysis, we aimed to clarify the overall effects of functional foods and dietary supplements in non-alcoholic fatty liver disease (NAFLD) patients.

Methods

Randomized controlled trials (RCTs) published in PubMed, ISI Web of Science, Cochrane library, and Embase from January 1, 2000 to January 31, 2022 were systematically searched to assess the effects of functional foods and dietary supplements in patients with NAFLD. The primary outcomes were liver-related measures, such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), and hepatic fibrosis and steatosis, while the secondary outcomes included body mass index (BMI), waist circumference (WC), triacylglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C). These indexes were all continuous variables, so the mean difference (MD) was used for calculating the effect size. Random-effects or fixed-effects models were used to estimate the mean difference (MD). The risk of bias in all studies was assessed with guidance provided in the Cochrane Handbook for Systematic Reviews of Interventions.

Results

Twenty-nine articles investigating functional foods and dietary supplements [antioxidants (phytonutrients and coenzyme Q10) = 18, probiotics/symbiotic/prebiotic = 6, fatty acids = 3, vitamin D = 1, and whole grain = 1] met the eligibility criteria. Our results showed that antioxidants could significantly reduce WC (MD: -1.28 cm; 95% CI: -1.58, -0.99, P < 0.05), ALT (MD: -7.65 IU/L; 95% CI: -11.14, -4.16, P < 0.001), AST (MD: -4.26 IU/L; 95% CI: -5.76, -2.76, P < 0.001), and LDL-C (MD: -0.24 mg/dL; 95% CI: -0.46, -0.02, P < 0.05) increased in patients with NAFLD but had no effect on BMI, TG, and TC. Probiotic/symbiotic/prebiotic supplementation could decrease BMI (MD: -0.57 kg/m2; 95% CI: -0.72, -0.42, P < 0.05), ALT (MD: -3.96 IU/L; 95% CI: -5.24, -2.69, P < 0.001), and AST (MD: -2.76; 95% CI: -3.97, -1.56, P < 0.0001) levels but did not have beneficial effects on serum lipid levels compared to the control group. Moreover, the efficacy of fatty acids for treating NAFLD was full of discrepancies. Additionally, vitamin D had no significant effect on BMI, liver transaminase, and serum lipids, while whole grain could reduce ALT and AST but did not affect serum lipid levels.

Conclusion

The current study suggests that antioxidant and probiotic/symbiotic/prebiotic supplements may be a promising regimen for NAFLD patients. However, the usage of fatty acids, vitamin D, and whole grain in clinical treatment is uncertain. Further exploration of the efficacy ranks of functional foods and dietary supplements is needed to provide a reliable basis for clinical application.

Systematic review registration

https://www.crd.york.ac.uk/prospero, identifier: CRD42022351763.

The association of vitamin D status with oxidative stress biomarkers and matrix metalloproteinases in patients with knee osteoarthritis

Objective

The association of vitamin D status with osteoarthritis (OA) has been demonstrated previously. The current study was performed to examine the association of vitamin D status with oxidative stress markers and matrix metalloproteinases (MMPs) in patients with knee OA.

Methods

This case-control study was conducted on 124 subjects with mild to moderate knee OA and 65 healthy controls. Demographic data was collected from all participants at baseline. Serum levels of vitamin D as well as markers of oxidative stress including malondialdehyde (MDA), total oxidant status (TOS), superoxide dismutase (SOD), oxidative stress index (OSI), paraoxonase-1 (PON-1), glutathione peroxidase (GPX), catalase (CAT), and total antioxidant capacity (TAC) were evaluated for each participant. Furthermore, serum concentrations of MMP-1, MMP-3, MMP-13, and cartilage oligomeric matrix protein (COMP) were measured.

Results

The results of the present study indicated that individuals with vitamin D insufficiency had higher levels of MDA, TOS, SOD, and OSI as well as lower levels of PON-1 and TAC. Based on the linear regression analysis, serum vitamin D levels were inversely correlated with MDA, TOS, SOD, OSI, MMP-1, and MMP-13 and positively associated with TAC levels (p < 0.0001). Patients with sufficient vitamin D levels had lower MMP-1 and MMP-13 levels compared to patients with vitamin D insufficiency (p < 0.001 and p < 0.001, respectively).

Conclusion

Findings from this study showed a strong association between vitamin D deficiency and increased oxidative stress and MMPs activity in patients with knee OA.

Inverse Association Between Serum 25-Hydroxyvitamin D and Nonalcoholic Fatty Liver Disease

BACKGROUND & AIMS

Serum 25-hydroxyvitamin D [S-25(OH)D] and nonalcoholic fatty liver disease (NAFLD) are correlated in many observational studies, whereas the causality of this association is uncertain, especially in European populations. We conducted a bidirectional Mendelian randomization study to determine the association between S-25(OH)D and NAFLD.

METHODS

Seven and 6 independent genetic variants associated with S-25(OH)D and NAFLD at the genome-wide-significance level, respectively, were selected as instrumental variables. Summary-level data for S-25(OH)D were obtained from the Study of Underlying Genetic Determinants of Vitamin D and Highly Related Traits consortium including 79,366 individuals. Summary-level data for NAFLD were available from a genome-wide association meta-analysis (1483 cases and 17,781 controls), the FinnGen consortium (894 cases and 217,898 controls), and the UK Biobank study (275 cases and 360,919 controls). Summary-level data for 4 liver enzymes were obtained from the UK Biobank.

RESULTS

There were genetic correlations of S-25(OH)D with NAFLD and certain liver enzymes. Genetically predicted higher levels of S-25(OH)D were consistently associated with a decreased risk of NAFLD in the 3 sources. For a 1-SD increase in genetically predicted S-25(OH)D levels, the combined odds ratio of NAFLD was 0.78 (95% confidence interval [CI], 0.69 to 0.89). Genetically predicted higher levels of S-25(OH)D showed a borderline association with aspartate aminotransferase levels (change -1.17; 95% CI, -1.36 to 0.01). Genetic predisposition to NAFLD was not associated with S-25(OH)D (change 0.13; 95% CI, -1.26 to 0.53).

CONCLUSIONS

Our findings have clinical implications as they suggest that increased vitamin D levels may play a role in NAFLD prevention in European populations.

Association between serum 25-hydroxy vitamin D concentrations and mortality among individuals with metabolic dysfunction-associated fatty liver disease: a prospective cohort study

BACKGROUND

The association between serum 25-hydroxy vitamin D (25(OH)D) concentrations and mortality remains unclear among patients with metabolic dysfunction-associated fatty liver disease (MAFLD) or non-alcoholic fatty liver disease (NAFLD).

OBJECTIVES

To evaluate the association between serum 25(OH)D concentrations and mortality among individuals with MAFLD/NAFLD.

METHODS

The study included 4651 individuals with fatty liver disease (FLD) (3964 had MAFLD and 3968 had NAFLD) from the Third National Health and Nutrition Examination Survey. Fatty liver disease was identified by ultrasonographic detection of hepatic steatosis. Mortality was ascertained by linkage to the National Death Index up to 31 December 2019. Cox proportional hazards models were used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) with adjustment of potential confounders.

RESULTS

Of 4651 individuals with FLD, 3427 individuals (69.7%) had both MAFLD and NAFLD. During median follow-ups of 25.8 and 26.1 years, we identified 1809 and 1665 deaths among 3964 participants with MAFLD and 3968 participants with NAFLD, respectively. Compared with participants with serum 25(OH)D concentrations ≤30.0 nmol/L, the multivariable-adjusted HR and 95% CI of all-cause mortality were 0.62 (0.43, 0.89) for participants with MAFLD having serum 25(OH)D >75.0 nmol/L (P-trend = 0.001), and 0.63 (0.42, 0.95) for participants with NAFLD having serum 25(OH)D >75.0 nmol/L (P-trend = 0.002). A nonlinearly inverse association was observed between serum 25(OH)D concentrations and all-cause mortality among participants with MAFLD (Poverall <0.001; Pnonlinear = 0.003) or NAFLD (Poverall <0.001; Pnonlinear = 0.009), with a threshold effect at around 50.0 nmol/L. The inverse association was stronger among participants with MAFLD aged <60 years (P-interaction = 0.001).

CONCLUSIONS

This study suggested a nonlinearly inverse association between serum 25(OH)D concentrations and all-cause mortality among patients with MAFLD/NAFLD, with a threshold effect at around 50.0 nmol/L of serum 25(OH)D.

The Role of Vitamin D and Vitamin D Binding Protein in Chronic Liver Diseases

Vitamin D (calciferol) is a fat-soluble vitamin that has a significant role in phospho-calcium metabolism, maintaining normal calcium levels and bone health development. The most important compounds of vitamin D are cholecalciferol (vitamin D3, or VD3) and ergocalciferol (vitamin D2, or VD2). Besides its major role in maintaining an adequate level of calcium and phosphate concentrations, vitamin D is involved in cell growth and differentiation and immune function. Recently, the association between vitamin D deficiency and the progression of fibrosis in chronic liver disease (CLD) was confirmed, given the hepatic activation process and high prevalence of vitamin D deficiency in these diseases. There are reports of vitamin D deficiency in CLD regardless of the etiology (chronic viral hepatitis, alcoholic cirrhosis, non-alcoholic fatty liver disease, primary biliary cirrhosis, or autoimmune hepatitis). Vitamin D binding protein (VDBP) is synthesized by the liver and has the role of binding and transporting vitamin D and its metabolites to the target organs. VDBP also plays an important role in inflammatory response secondary to tissue damage, being involved in the degradation of actin. As intense research during the last decades revealed the possible role of vitamin D in liver diseases, a deeper understanding of the vitamin D, vitamin D receptors (VDRs), and VDBP involvement in liver inflammation and fibrogenesis could represent the basis for the development of new strategies for diagnosis, prognosis, and treatment of liver diseases. This narrative review presents an overview of the evidence of the role of vitamin D and VDBP in CLD, both at the experimental and clinical levels.

Role of Vitamin D in Liver Disease and Complications of Advanced Chronic Liver Disease

Vitamin D is a crucial nutrient with many pleiotropic effects on health and various chronic diseases. The purpose of this review is to provide a detailed report on the pathophysiological mechanisms underlying vitamin D deficiency in patients with chronic liver disease, addressing the different liver etiologies and the condition of advanced chronic liver disease (cirrhosis) with related complications. To date, patients with liver disease, regardless of underlying etiology, have been shown to have reduced levels of vitamin D. There is also evidence of the predictive role of vitamin D values in complications and progression of advanced disease. However, specific indications of vitamin D supplementation are not conclusive concerning what is already recommended in the general population. Future studies should make an effort to unify and validate the role of vitamin D supplementation in chronic liver disease.

Vitamin D–VDR Novel Anti-Inflammatory Molecules—New Insights into Their Effects on Liver Diseases

There is consistent evidence that vitamin D deficiency is strongly associated with liver dysfunction, disease severity, and poor prognosis in patients with liver disease. Vitamin D and its receptor (VDR) contribute to the regulation of innate and adaptive immune responses. The presence of genetic variants of vitamin D- and VDR-associated genes has been associated with liver disease progression. In our recent work, we summarized the progress in understanding the molecular mechanisms involved in vitamin D–VDR signaling and discussed the functional significance of VDR signaling in specific cell populations in liver disease. The current review focuses on the complex interaction between immune and liver cells in the maintenance of liver homeostasis and the development of liver injury, the interplay of vitamin D and VDR in the development and outcome of liver disease, the role of vitamin D- and VDR-associated genetic variants in modulating the occurrence and severity of liver disease, and the therapeutic value of vitamin D supplementation in various liver diseases. The association of the vitamin D–VDR complex with liver dysfunction shows great potential for clinical application and supports its use as a prognostic index and diagnostic tool.

Resolution of, and Risk of Incident Non-alcoholic Fatty Liver Disease With Changes in Serum 25-hydroxy Vitamin D Status

CONTEXT

A protective or causative role of vitamin D status on the risk of nonalcoholic fatty liver disease (NAFLD) remains inconclusive.

OBJECTIVE

To evaluate the association between changes in serum 25-hydroxyvitamin D [25(OH)D] status during follow-up and the risk of incident NAFLD and resolution of preexisting NAFLD.

DESIGN

A retrospective cohort study.

SETTING

Kangbuk Samsung Health Study based on routine health screening examinations.

PARTICIPANTS

Korean adults (mean age, 36.8 years; range, 18-96 years) who underwent comprehensive health examinations including assessment of serum 25(OH)D levels.

MAIN OUTCOME MEASURES

The main outcomes were (1) incidence and (2) resolution of NAFLD assessed by liver ultrasound. Cox proportional hazard models were used to estimate hazard ratios (HRs) with 95% CIs for outcomes according to serum 25(OH)D levels.

RESULTS

Among 139 599 participants without NAFLD at baseline, 27 531 developed NAFLD during follow-up. Serum 25(OH)D levels were significantly and inversely associated with NAFLD development. Among 48 702 participants with NAFLD at baseline, 13 449 showed NAFLD resolution. Multivariable-adjusted HR (95% CI) for NAFLD resolution comparing 25(OH)D 10 to <20, 20 to <30, and ≥30 ng/mL to <10 ng/mL were 1.09 (1.03-1.15), 1.13 (1.06-1.21), and 1.21 (1.09-1.35), respectively. Additionally, an increase in 25(OH)D levels between baseline and the subsequent visit (median, 1.8 years) was associated with decreased NAFLD incidence, while persistently adequate 25(OH)D levels over time was associated with decreased incidence and increased resolution of NAFLD.

CONCLUSIONS

Maintaining adequate serum 25(OH)D concentrations may be beneficial for both prevention as well as resolution of NAFLD.

Modulation of Oxidative Stress-Induced Senescence during Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease is characterized by disturbed lipid metabolism and increased oxidative stress. These conditions lead to the activation of different cellular response mechanisms, including senescence. Cellular senescence constitutes an important response to injury in the liver. Recent findings show that chronic oxidative stress can induce senescence, and this might be a driving mechanism for NAFLD progression, aggravating the disturbance of lipid metabolism, organelle dysfunction, pro-inflammatory response and hepatocellular damage. In this context, the modulation of cellular senescence can be beneficial to ameliorate oxidative stress-related damage during NAFLD progression. This review focuses on the role of oxidative stress and senescence in the mechanisms leading to NAFLD and discusses the possibilities to modulate senescence as a therapeutic strategy in the treatment of NAFLD.

Additional treatment of vitamin D for improvement of insulin resistance in non-alcoholic fatty liver disease patients: a systematic review and meta-analysis

Insulin resistance provides an important role in the pathogenesis of non-alcoholic fatty liver disease (NAFLD). Several studies already evaluate vitamin D supplementation for NAFLD patients in relation to insulin resistance. The results obtained still carry conflicting results. This study aimed to evaluate the effect of additional treatment of vitamin D for the improvement of insulin resistance in NAFLD patients. Relevant literatures were obtained from PubMed, Google Scholar, COCHRANE, and Science Direct database. The obtained studies were analyzed using fixed effect model or random effect model. Seven eligible studies with a total of 735 participants were included. Vitamin D supplementation improves insulin resistance in NAFLD patients, marked by reduced Homeostatic Model Assessment for Insulin Resistance (HOMA-IR), with pooled mean difference - 1.06 (p = 0.0006; 95% CI - 1.66 to - 0.45). Vitamin D supplementation increase the level of vitamin D serum with pooled mean difference of 17.45 (p = 0.0002; 95% CI 8.33 to 26.56). Vitamin D supplementation decrease ALT levels, with pooled mean difference of - 4.44 (p = 0.02; 95% CI - 8.24 to - 0.65). No effect was observed for AST levels. Vitamin D supplementation provides beneficial effects on the improvement of insulin resistance in NAFLD patients. This supplementation may reduce HOMA-IR in such patients. It may serve as a potential adjunctive treatment for NAFLD patients.

Effect of Vitamin D on Paraxonase-1, Total Antioxidant Capacity, and 8-Isoprostan in Children with Attention Deficit Hyperactivity Disorder

METHOD

In this double-blind, randomized, placebo-controlled trial, 75 children (aged 6-12) diagnosed with ADHD were randomly assigned into two groups. The supplementation group received vitamin D3 (2000 IU), and the control group received a placebo for 3 months. Blood samples were collected at baseline and after intervention to analyze the 25(OH)D, paraxonase-1 activity (PON-1), Total Antioxidant Capacity (TAC), and 8-isoprostan levels.

RESULTS

A significant rise in circulating 25(OH)D was observed in the vitamin D group versus the placebo group at the end of the study. There was no reduction in 8-isoprostan levels in the vitamin D group compared to the placebo group. Serum paraxonase-1 and TAC concentration decreased in both groups, but these alterations were not statistically significant in the treatment group versus the placebo group at the end of the intervention.

CONCLUSION

Vitamin D supplementation for 3 months did not have beneficial effects on biomarkers of oxidative stress status. To confirm these findings, further studies on children are suggested.

Assessing Oxidative Stress by Thiol/Disulfide Homeostasis Among Vitamin D-Deficient Patients

Objective: Thiol/disulfide (T/DS) homeostasis represents a promising new approach to evaluate oxidative stress. Therefore, we aimed to examine T/DS homeostasis in vitamin D (VitD)-deficient patients.

Methods: We enrolled 154 patients with VitD deficiency and 154 healthy control subjects in the study. For both groups, native thiol, total thiol, and disulfide values were measured. Additionally, considering the obtained 25-hydroxycholecalciferol [25(OH)D] levels, the patient group was further divided into two subgroups (Group 1: <10 ng/mL, Group 2: 10-20 ng/mL), which were compared in more depth according to the specified parameters.

Results: Values of native thiol, total thiol, and disulfide measured in the combination of Groups 1 and 2, comprising individuals with VitD deficiency, proved to be higher in comparison to the control group with statistical significance (p=0.007, p=0.028, and p<0.001, respectively). When subgroups were considered according to VitD classifications, native thiol and total thiol were again higher in Group 1 in comparison to the values obtained for control subjects (p=0.022; p<0.001). While the total thiol level of Group 2 was higher than that of controls (p<0.001), no difference with statistical significance was obtained in the comparison of disulfide levels among the indviduals of Group 1, Group 2, and the controls (p=0.081).

Conclusion: In this study, among patients with VitD deficiency, we have confirmed that values of native thiol and total thiol were increased, while the T/DS balance was found to have shifted in favor of the thiol level.

The Effects of Vitamin D Supplementation on Anthropometric and Biochemical Indices in Patients With Non-alcoholic Fatty Liver Disease: A Systematic Review and Meta-analysis

Background: Vitamin D was reported to be associated with non-alcoholic fatty liver disease (NAFLD). This systematic review and meta-analysis aimed to investigate the effects of the vitamin D supplementation on anthropometric and biochemical indices in patient with NAFLD. Methods: PubMed, Web of science, Scopus, and Embase databases were explored to identify all randomized controlled trial (RCT) investigating the effects of vitamin D supplementation on anthropometric and biochemical indices in patients with NAFLD. A random-effects model was used to pool weighted mean difference (WMD) and corresponding 95% confidence intervals (CIs). The statistical heterogeneity among the studies was assessed using I2 statistic (high ≥ 50%, low < 50%) and Cochran's Q-test. Results: Sixteen RCTs were included in this meta-analysis. The results identified that high-density lipoprotein-cholesterol (HDL-C) level significantly increased following vitamin D supplementation (P = 0.008). Vitamin D reduced body weight (P = 0.007), body mass index (P = 0.002), waist circumstance (WC) (P = 0.02), serum alanine transaminase (ALT) (P = 0.01), fasting blood sugar (FBS) (P = 0.01), homeostatic model assessment for insulin resistance (HOMA-IR) (P = 0.004), and calcium (P = 0.01). No significant changes were found on body fat, triglyceride (TG), total cholesterol, low-density lipoprotein-cholesterol (LDL-C), aspartate transaminase, alkaline phosphatase, gamma-glutamyl transferase, and adiponectin following vitamin D supplementation. Conclusion: Vitamin D had significant effects on anthropometric and biochemical indices including HDL-C, body weight, BMI, WC, serum ALT, serum FBS, HOMA-IR, and calcium. Vitamin D supplementation can be considered as an effective strategy in management of patients with NAFLD. Systematic Review Registration: [website], identifier [registration number].

Could Vitamin D Be Effective in Prevention of Preeclampsia?

Prevention of preeclampsia (PE) remains one of the most significant problems in perinatal medicine. Due to the possible unpredictable course of hypertension in pregnancy, primarily PE and the high complication rate for the mother and fetus/newborn, it is urgent to offer pregnant women in high-risk groups effective methods of preventing the PE development or delaying its appearance. In addition, due to the association of PE with an increased risk of developing cardiovascular diseases (CVD) in later life, effective preeclampsia prevention could also be important in reducing their incidence. Ideal PE prophylaxis should target the pathogenetic changes leading to the development of PE and be safe for the mother and fetus, inexpensive and freely available. Currently, the only recognized method of PE prevention recommended by many institutions around the world is the use of a small dose of acetylsalicylic acid in pregnant women with risk factors. Unfortunately, some cases of PE are diagnosed in women without recognized risk factors and in those in whom prophylaxis with acetylsalicylic acid is not adequate. Hence, new drugs which would target pathogenetic elements in the development of preeclampsia are studied. Vitamin D (Vit D) seems to be a promising agent due to its beneficial effect on placental implantation, the immune system, and angiogenic factors. Studies published so far emphasize the relationship of its deficiency with the development of PE, but the data on the benefits of its supplementation to reduce the risk of PE are inconclusive. In the light of current research, the key issue is determining the protective concentration of Vit D in a pregnant woman. The study aims to present the possibility of using Vit D to prevent PE, emphasizing its impact on the pathogenetic elements of preeclampsia development.

Vitamin D3 Supplementation Effects on Spermatogram and Oxidative Stress Biomarkers in Asthenozoospermia Infertile Men: a Randomized, Triple-Blind, Placebo-Controlled Clinical Trial

The objective is to evaluate the effects of vitamin D3 (VD3) on sperm parameters and seminal and serum oxidative stress (OS) biomarkers in asthenozoospermia infertile men. This randomized, triple-masking, placebo-controlled clinical trial conducted on 86 asthenozoospermia infertile men with serum 25 hydroxy vitamin D3 (25-OH-D3) < 30 ng/ml in the infertility clinic of Ahvaz Jahad Daneshgahi, Iran. Patients were randomly allocated to groups A and B, who received daily 4000 IU vitamin D3 (VD3) and matching placebo respectively for 3 months. Demographic data, dietary intake, physical activity, sun exposure, anthropometric indices, serum and seminal levels of MDA (Malondialdehyde), 8-hydroxy-2- Dioxy Guanosine (8-OHDG), total antioxidant capacity (TAC) and calcium, sperm DNA fragmentation index (DFI), serum 25-OH-D3, parathyroid hormone (PTH), phosphorus, and sperm parameters were assessed. VD3 supplementation had no significant effects on body weight, body mass index (BMI), waist circumference (WC), body fat (BF), 8-OHDG, DFI, semen volume, sperm count, and normal sperm morphology, but increased post-intervention mean and mean change of serum 25-OH-D3 (P < 0.001, P < 0.001), PTH (P < 0.001, P < 0.001) and phosphorus (P = 0.009, P = 0.049) and seminal calcium (P = 0.035, P = 0.038) and serum calcium (P = 0.008, P = 0.009), seminal TAC (P < 0.001, P < 0.001), and serum TAC (P = 0.007, P = 005), total sperm motility (P < 0.001, P < 0.001) and progressive sperm motility (P < 0.001, P < 0.001) and decreased seminal MDA (P = 0.017, P = 0.004) and serum MDA (P = 006, P = 0.005) significantly compared to the baseline and placebo group respectively. VD3 supplementation may modulate OS and affect sperm motility in men with asthenozoospermia and serum 25-OH-D3 < 30 ng/ml. Iran Clinical Trials Registry, ID: IRCT20151128025274N4, registered on 28 March 2018, URL of trial registry record: https://www.irct.ir/trial/29983.

Chromium picolinate balances the metabolic and clinical markers in nonalcoholic fatty liver disease: a randomized, double-blind, placebo-controlled trial

OBJECTIVE

Nonalcoholic fatty liver disease (NAFLD) is a complicated disease and is considered as a severe global health problem affecting 30% of adults worldwide. The present study aimed to evaluate changes in oxidative stress, adipokines, liver enzyme, and body composition following treatment with chromium picolinate (CrPic) among patients with NAFLD.

PARTICIPANTS AND METHODS

The current randomized, double-blind, placebo-controlled study was conducted on 46 NAFLD patients with the age range of 20-65 years. Patients were randomly classified into two groups, receiving either 400 µg CrPic tablets in two divided doses of 200 µg (23 patients) or placebo (23 patients) daily for 12 weeks. The participants' body composition and biochemical parameters were evaluated at the baseline and after 12 weeks.

RESULTS

Serum levels of liver enzymes reduced significantly only in the CrPic group (P < 0.05 for all), but not between the groups after the intervention. Besides, there were significant differences between the study groups regarding body weight and body fat mass, total antioxidant capacity, superoxide dismutase, malondialdehyde, leptin, and adiponectin post-intervention (P = 0.017, P = 0.032, P = 0.003, P = 0.023, P = 0.012, P = 0.003, and P = 0.042, respectively). However, glutathione peroxidase and resistin levels did not differ significantly between groups (P = 0.127 and P = 0.688, respectively).

DISCUSSION AND CONCLUSION

This study showed that consuming 400 µg/day of CrPic for 12 weeks in patients with NAFLD causes a significant change in leptin, adiponectin, oxidative stress (expect glutathione peroxidase), and body weight, compared to baseline. Nevertheless, it does not affect liver enzymes. Therefore, the CrPic supplementation may improve adipokines, some anthropometric indices, and oxidative stress in patients with NAFLD.

Chronic liver disease and oxidative stress - a narrative review

Introduction: Oxidative stress underlies the pathophysiology of various etiologies of chronic liver disease and contributes to the development of hepatocarcinogenesis.Areas covered: This review focuses on the impact of oxidative stress in various etiologies of chronic liver disease such as alcoholic liver disease (ALD), nonalcoholic steatohepatitis (NASH), hepatitis B virus (HBV), and hepatitis C virus (HCV) infection. The efficacy of antioxidants in laboratory, animal, and clinical studies in chronic liver disease is also reviewed.Expert opinion: Currently, there are limited targeted pharmacotherapeutics for NASH and no pharmacotherapeutics for ALD and antioxidant supplementation may be useful in these conditions to improve liver function and reverse fibrosis. Antioxidants may also be used in patients with HBV or HCV infection to supplement antiviral therapies. Specific genotypes of antioxidant and prooxidant genes render patients more susceptible to liver cirrhosis and hepatocellular carcinoma while other individual characteristics like age, genotype, and metabolomic profiling can influence the efficacy of antioxidants on CLD. More research needs to be done to establish the safety, efficacy, and dosage of antioxidants and to establish the ideal patient profile that will benefit the most from antioxidant treatment.

Vitamin D supplementation for chronic liver diseases in adults

BACKGROUND

Vitamin D deficiency is often reported in people with chronic liver diseases. Improving vitamin D status could therefore be beneficial for people with chronic liver diseases.

OBJECTIVES

To assess the beneficial and harmful effects of vitamin D supplementation in adults with chronic liver diseases.

SEARCH METHODS

We searched the Cochrane Hepato-Biliary Group Controlled Trials Register, CENTRAL, MEDLINE Ovid, Embase Ovid, LILACS, Science Citation Index Expanded, and Conference Proceedings Citation Index-Science. We also searched ClinicalTrials.gov  and the World Health Organization International Clinical Trials Registry Platform. We scanned bibliographies of relevant publications and enquired experts and pharmaceutical companies as to additional trials. All searches were up to November 2020.

SELECTION CRITERIA

Randomised clinical trials that compared vitamin D at any dose, duration, and route of administration versus placebo or no intervention in adults with chronic liver diseases. Vitamin D could have been administered as supplemental vitamin D (vitamin D₃ (cholecalciferol) or vitamin D₂ (ergocalciferol)), or an active form of vitamin D (1α-hydroxyvitamin D (alfacalcidol), 25-hydroxyvitamin D (calcidiol), or 1,25-dihydroxyvitamin D (calcitriol)).

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. We used GRADE to assess the certainty of evidence.

MAIN RESULTS

We included 27 randomised clinical trials with 1979 adult participants. This review update added 12 trials with 945 participants. We assessed all trials as at high risk of bias. All trials had a parallel-group design. Eleven trials were conducted in high-income countries and 16 trials in middle-income countries. Ten trials included participants with chronic hepatitis C, five trials participants with liver cirrhosis, 11 trials participants with non-alcoholic fatty liver disease, and one trial liver transplant recipients. All of the included trials reported the baseline vitamin D status of participants. Participants in nine trials had baseline serum 25-hydroxyvitamin D levels at or above vitamin D adequacy (20 ng/mL), whilst participants in the remaining 18 trials were vitamin D insufficient (less than 20 ng/mL). Twenty-four trials administered vitamin D orally, two trials intramuscularly, and one trial intramuscularly and orally. In all 27 trials, the mean duration of vitamin D supplementation was 6 months, and the mean follow-up of participants from randomisation was 7 months. Twenty trials (1592 participants; 44% women; mean age 48 years) tested vitamin D₃ (cholecalciferol); three trials (156 participants; 28% women; mean age 54 years) tested vitamin D₂; four trials (291 participants; 60% women; mean age 52 years) tested 1,25-dihydroxyvitamin D; and one trial (18 participants; 0% women; mean age 52 years) tested 25-hydroxyvitamin D. One trial did not report the form of vitamin D. Twelve trials used a placebo, whilst the other 15 trials used no intervention in the control group. Fourteen trials appeared to be free of vested interest. Eleven trials did not provide any information on clinical trial support or sponsorship. Two trials were funded by industry. We are very uncertain regarding the effect of vitamin D versus placebo or no intervention on all-cause mortality (risk ratio (RR) 0.86, 95% confidence interval (CI) 0.51 to 1.45; 27 trials; 1979 participants). The mean follow-up was 7 months (range 1 to 18 months). We are very uncertain regarding the effect of vitamin D versus placebo or no intervention on liver-related mortality (RR 1.62, 95% CI 0.08 to 34.66; 1 trial; 18 participants) (follow-up: 12 months); serious adverse events such as hypercalcaemia (RR 5.00, 95% CI 0.25 to 100.8; 1 trial; 76 participants); myocardial infarction (RR 0.75, 95% CI 0.08 to 6.81; 2 trials; 86 participants); thyroiditis (RR 0.33, 95% CI 0.01 to 7.91; 1 trial; 68 participants); circular haemorrhoidal prolapse (RR 3.00, 95% CI 0.14 to 65.9; 1 trial; 20 participants); bronchopneumonia (RR 0.33, 95% CI 0.02 to 7.32; 1 trial 20 participants); and non-serious adverse events. The certainty of evidence for all outcomes is very low. We found no data on liver-related morbidity such as gastrointestinal bleeding, hepatic encephalopathy, hepatorenal syndrome, ascites, or liver cancer. There were also no data on health-related quality of life. The evidence is also very uncertain regarding the effect of vitamin D versus placebo or no intervention on rapid, early, and sustained virological response in people with chronic hepatitis C.

AUTHORS' CONCLUSIONS

Given the high risk of bias and insufficient power of the included trials and the very low certainty of the available evidence, vitamin D supplementation versus placebo or no intervention may increase or reduce all-cause mortality, liver-related mortality, serious adverse events, or non-serious adverse events in adults with chronic liver diseases. There is a lack of data on liver-related morbidity and health-related quality of life. Further evidence on clinically important outcomes analysed in this review is needed.

Advanced glycation end product: A potential biomarker for risk stratification of non-alcoholic fatty liver disease in ELSA-Brasil study

BACKGROUND

Liver diseases are associated with the excess formation of advanced glycation end products (AGEs), which induce tissue inflammation and oxidative damage. However, the trend of oxidative marker levels according to the steatosis grade in non-alcoholic fatty liver disease (NAFLD) is unclear.

AIM

To compare serum AGE levels between participants with NAFLD accordingly to steatosis severity in the baseline ELSA-Brasil population.

METHODS

In 305 individuals at baseline ELSA-Brasil, NAFLD-associated steatosis was classified by ultrasound hepatic attenuation. The participants were grouped according to the severity of steatosis: mild and moderate/severe pooled. The measurement of serum fluorescent AGE concentrations was based on spectrofluorimetric detection. Serum AGE content and clinical and laboratory characteristics of the participants were compared between groups. The correlation between serum AGE levels and the grade of steatosis was analyzed. Logistic regression analysis was used to investigate the relationship between serum AGE levels and steatosis severity. A P value < 0.05 was considered statistically significant.

RESULTS

According to the steatosis severity spectrum in NAFLD, from mild to moderate/severe, individuals with the most severe steatosis grade had a higher incidence of metabolic syndrome (63% vs 34%, P ≤ 0.001), diabetes mellitus (37% vs 14%, P ≤ 0.001), and high cholesterol levels (51% vs 33%, P < 0.001). Moreover, individuals with increasing severity of steatosis presented increasing waist circumference, body mass index, systolic and diastolic blood pressure, fasting blood glucose, glycated hemoglobin, insulin, triglycerides, alanine aminotransferase, gamma-glutamyl transferase, C-reactive protein, and uric acid levels and lower high-density lipoprotein. Higher serum AGE content was present in the moderate/severe group of individuals than in the mild group (P = 0.008). In addition, the serum AGE levels were correlated with the steatosis grade in the overall sample (rho = 0.146, P = 0.010). Logistic regression analysis, after adjusting for confounding variables, showed that subjects with higher serum AGE content had a 4.6-fold increased chance of having moderate or severe steatosis when compared to low levels of serum AGEs. According to the results of the receiver operator characteristic curves analyses (areas under the curve, AUC = 0.83), AGEs could be a good marker of steatosis severity in patients with NAFLD and might be a potential biomarker in predicting NAFLD progression, strengthening the involvement of AGE in NAFLD pathogenesis.

CONCLUSION

NAFLD-associated steatosis was associated with serum AGE levels; therefore, plasmatic fluorescent AGE quantification by spectroscopy could be a promising alternative method to monitor progression from mild to severe NAFLD accordingly to steatosis grade.

Nutritional supplementation for nonalcohol-related fatty liver disease: a network meta-analysis

BACKGROUND

The prevalence of non-alcohol-related fatty liver disease (NAFLD) varies between 19% and 33% in different populations. NAFLD decreases life expectancy and increases risks of liver cirrhosis, hepatocellular carcinoma, and the requirement for liver transplantation. Uncertainty surrounds relative benefits and harms of various nutritional supplements in NAFLD. Currently no nutritional supplement is recommended for people with NAFLD.

OBJECTIVES

• To assess the benefits and harms of different nutritional supplements for treatment of NAFLD through a network meta-analysis • To generate rankings of different nutritional supplements according to their safety and efficacy SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, Science Citation Index Expanded, Conference Proceedings Citation Index-Science, the World Health Organization International Clinical Trials Registry Platform, and trials registers until February 2021 to identify randomised clinical trials in people with NAFLD.

SELECTION CRITERIA

We included only randomised clinical trials (irrespective of language, blinding, or status) for people with NAFLD, irrespective of method of diagnosis, age and diabetic status of participants, or presence of non-alcoholic steatohepatitis (NASH). We excluded randomised clinical trials in which participants had previously undergone liver transplantation.

DATA COLLECTION AND ANALYSIS

We performed a network meta-analysis with OpenBUGS using Bayesian methods whenever possible and calculated differences in treatments using hazard ratios (HRs), odds ratios (ORs), and rate ratios with 95% credible intervals (CrIs) based on an available-case analysis, according to National Institute of Health and Care Excellence Decision Support Unit guidance.

MAIN RESULTS

We included in the review a total of 202 randomised clinical trials (14,200 participants). Nineteen trials were at low risk of bias. A total of 32 different interventions were compared in these trials. A total of 115 trials (7732 participants) were included in one or more comparisons. The remaining trials did not report any of the outcomes of interest for this review. Follow-up ranged from 1 month to 28 months. The follow-up period in trials that reported clinical outcomes was 2 months to 28 months. During this follow-up period, clinical events related to NAFLD such as mortality, liver cirrhosis, liver decompensation, liver transplantation, hepatocellular carcinoma, and liver-related mortality were sparse. We did not calculate effect estimates for mortality because of sparse data (zero events for at least one of the groups in the trial). None of the trials reported that they measured overall health-related quality of life using a validated scale. The evidence is very uncertain about effects of interventions on serious adverse events (number of people or number of events). We are very uncertain about effects on adverse events of most of the supplements that we investigated, as the evidence is of very low certainty. However, people taking PUFA (polyunsaturated fatty acid) may be more likely to experience an adverse event than those not receiving an active intervention (network meta-analysis results: OR 4.44, 95% CrI 2.40 to 8.48; low-certainty evidence; 4 trials, 203 participants; direct evidence: OR 4.43, 95% CrI 2.43 to 8.42). People who take other supplements (a category that includes nutritional supplements other than vitamins, fatty acids, phospholipids, and antioxidants) had higher numbers of adverse events than those not receiving an active intervention (network meta-analysis: rate ratio 1.73, 95% CrI 1.26 to 2.41; 6 trials, 291 participants; direct evidence: rate ratio 1.72, 95% CrI 1.25 to 2.40; low-certainty evidence). Data were sparse (zero events in all groups in the trial) for liver transplantation, liver decompensation, and hepatocellular carcinoma. So, we did not perform formal analysis for these outcomes. The evidence is very uncertain about effects of other antioxidants (antioxidants other than vitamins) compared to no active intervention on liver cirrhosis (HR 1.68, 95% CrI 0.23 to 15.10; 1 trial, 99 participants; very low-certainty evidence). The evidence is very uncertain about effects of interventions in any of the remaining comparisons, or data were sparse (with zero events in at least one of the groups), precluding formal calculations of effect estimates. Data were probably because of the very short follow-up period (2 months to 28 months). It takes follow-up of 8 to 28 years to detect differences in mortality between people with NAFLD and the general population. Therefore, it is unlikely that differences in clinical outcomes are noted in trials providing less than 5 to 10 years of follow-up.

AUTHORS' CONCLUSIONS

The evidence indicates considerable uncertainty about effects of nutritional supplementation compared to no additional intervention on all clinical outcomes for people with non-alcohol-related fatty liver disease. Accordingly, high-quality randomised comparative clinical trials with adequate follow-up are needed. We propose registry-based randomised clinical trials or cohort multiple randomised clinical trials (study design in which multiple interventions are trialed within large longitudinal cohorts of patients to gain efficiencies and align trials more closely to standard clinical practice) comparing interventions such as vitamin E, prebiotics/probiotics/synbiotics, PUFAs, and no nutritional supplementation. The reason for the choice of interventions is the impact of these interventions on indirect outcomes, which may translate to clinical benefit. Outcomes in such trials should be mortality, health-related quality of life, decompensated liver cirrhosis, liver transplantation, and resource utilisation measures including costs of intervention and decreased healthcare utilisation after minimum follow-up of 8 years (to find meaningful differences in clinically important outcomes).

A Lipid-Based Nanocarrier Containing Active Vitamin D3 Ameliorates NASH in Mice via Direct and Intestine-Mediated Effects on Liver Inflammation

The gut-liver axis may be involved in non-alcoholic steatohepatitis (NASH) progression. Pathogen-associated molecular patterns leak through the intestinal barrier to the liver via the portal vein to contribute to NASH development. Active vitamin D₃ (1,25(OH)₂D₃) is a potential therapeutic agent to enhance the intestinal barrier. Active vitamin D₃ also suppresses inflammation and fibrosis in the liver. However, the adverse effects of active vitamin D₃ such as hypercalcemia limit its clinical use. We created a nano-structured lipid carrier (NLC) containing active vitamin D₃ to deliver active vitamin D₃ to the intestine and liver to elicit NASH treatment. We found a suppressive effect of the NLC on the lipopolysaccharide-induced increase in permeability of an epithelial layer in vitro. Using mice in which NASH was induced by a methionine and choline-deficient diet, we discovered that oral application of the NLC ameliorated the permeability increase in the intestinal barrier and attenuated steatosis, inflammation and fibrosis in liver at a safe dose of active vitamin D₃ at which the free form of active vitamin D₃ did not show a therapeutic effect. These data suggest that the NLC is a novel therapeutic agent for NASH.

Lifestyle modifications for nonalcohol-related fatty liver disease: a network meta-analysis

BACKGROUND

The prevalence of nonalcohol-related fatty liver disease (NAFLD) varies between 19% and 33% in different populations. NAFLD decreases life expectancy and increases the risks of liver cirrhosis, hepatocellular carcinoma, and requirement for liver transplantation. There is uncertainty surrounding the relative benefits and harms of various lifestyle interventions for people with NAFLD.

OBJECTIVES

To assess the comparative benefits and harms of different lifestyle interventions in the treatment of NAFLD through a network meta-analysis, and to generate rankings of the different lifestyle interventions according to their safety and efficacy.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, Science Citation Index Expanded, Conference Proceedings Citation Index - Science, World Health Organization International Clinical Trials Registry Platform, and trials registers until February 2021 to identify randomised clinical trials in people with NAFLD.

SELECTION CRITERIA

We included only randomised clinical trials (irrespective of language, blinding, or status) in people with NAFLD, whatever the method of diagnosis, age, and diabetic status of participants, or presence of non-alcoholic steatohepatitis (NASH). We excluded randomised clinical trials in which participants had previously undergone liver transplantation.

DATA COLLECTION AND ANALYSIS

We planned to perform a network meta-analysis with OpenBUGS using Bayesian methods and to calculate the differences in treatments using hazard ratios (HRs), odds ratios (ORs), and rate ratios (RaRs) with 95% credible intervals (CrIs) based on an available-participant analysis, according to National Institute of Health and Care Excellence Decision Support Unit guidance. However, the data were too sparse for the clinical outcomes. We therefore performed only direct comparisons (head-to-head comparisons) with OpenBUGS using Bayesian methods.

MAIN RESULTS

We included a total of 59 randomised clinical trials (3631 participants) in the review. All but two trials were at high risk of bias. A total of 33 different interventions, ranging from advice to supervised exercise and special diets, or a combination of these and no additional intervention were compared in these trials. The reference treatment was no active intervention. Twenty-eight trials (1942 participants) were included in one or more comparisons. The follow-up ranged from 1 month to 24 months. The remaining trials did not report any of the outcomes of interest for this review. The follow-up period in the trials that reported clinical outcomes was 2 months to 24 months. During this short follow-up period, clinical events related to NAFLD such as mortality, liver cirrhosis, liver decompensation, liver transplantation, hepatocellular carcinoma, and liver-related mortality were sparse. This is probably because of the very short follow-up periods. It takes a follow-up of 8 years to 28 years to detect differences in mortality between people with NAFLD and the general population. It is therefore unlikely that differences by clinical outcomes will be noted in trials with less than 5 years to 10 years of follow-up. In one trial, one participant developed an adverse event. There were no adverse events in any of the remaining participants in this trial, or in any of the remaining trials, which seemed to be directly related to the intervention.

AUTHORS' CONCLUSIONS

The evidence indicates considerable uncertainty about the effects of the lifestyle interventions compared with no additional intervention (to general public health advice) on any of the clinical outcomes after a short follow-up period of 2 months to 24 months in people with nonalcohol-related fatty liver disease. Accordingly, high-quality randomised clinical trials with adequate follow-up are needed. We propose registry-based randomised clinical trials or cohort multiple randomised clinical trials (a study design in which multiple interventions are trialed within large longitudinal cohorts of participants to gain efficiencies and align trials more closely to standard clinical practice), comparing aerobic exercise and dietary advice versus standard of care (exercise and dietary advice received as part of national health promotion). The reason for the choice of aerobic exercise and dietary advice is the impact of these interventions on indirect outcomes which may translate to clinical benefit. The outcomes in such trials should be mortality, health-related quality of life, decompensated liver cirrhosis, liver transplantation, and resource use measures including costs of intervention and decreased healthcare use after a minimum follow-up of eight years, to find meaningful differences in the clinically important outcomes.