The effect of vitamin d-calcium co-supplementation on inflammatory biomarkers: A systematic review and meta-analysis of randomized controlled trials

Effect of vitamin D on inflammatory and clinical outcomes in patients with rheumatoid arthritis: a systematic review and dose-response meta-analysis of randomized controlled trials

CONTEXT

Rheumatoid arthritis is a chronic inflammatory disease that causes synovitis. Vitamin D deficiency is common in rheumatoid arthritis.

OBJECTIVE

This systematic review and meta-analysis investigated whether vitamin D supplementation affects the inflammatory and clinical outcomes in patients with rheumatoid arthritis on the basis of randomized clinical trials.

DATA SOURCES

A literature search was performed in the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, MEDLINE, Embase, and Google Scholar for articles published until May 2022.

DATA EXTRACTION

The studies were selected according to PRISMA guidelines, and the risk of bias was assessed for randomized controlled trials.

DATA ANALYSIS

A random effects model was used to conduct a meta-analysis, and heterogeneity was assessed using the I2 statistic. Of 464 records, 11 studies were included from 3049 patients. Conclusion: Vitamin D supplementation did not significantly reduce C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), disease activity score in 28 joints (DAS28), or the health assessment questionnaire score; however, the response to supplementation was highly heterogeneous. The pooled analysis showed that vitamin D significantly reduced the pain-visual analogue scale (VAS) weighted mean difference (WMD = -1.30, 95% confidence interval [CI] [-2.34, -27], P = .01), DAS28-CRP (WMD = -.58, 95% CI [-.86, -.31], P < .0001), and DAS28-ESR (WMD = -.58, 95% CI [-.86, -.31], P = .0001). Subgroup analysis for vitamin D doses (>100 µg per day versus <100 µg per day) showed that the higher doses had a more significant effect on CRP than the lower doses (P < .05).

CONCLUSIONS

There was no significant difference between the effect of 2 vitamin D doses on ESR and DAS28. To minimize the high heterogeneity among studies in this meta-analysis, other confounding factors such as baseline vitamin D, age, dietary vitamin D, time of year, sun exposure, drug interaction, effect dosage, and power of study should be examined.

The Effects of L-Carnitine Supplementation on Blood Pressure in Adults: A Systematic Review and Dose-response Meta-analysis

PURPOSE

Hypertension stands as a prominent risk factor for cardiovascular disease, making it of utmost importance to address. Studies have shown that L-carnitine supplementation may lower blood pressure (BP) parameters in different populations. Therefore, we have conducted a systematic review and dose-response meta-analysis of published Randomized Controlled Trials (RCTs), including the most recent articles on the effect of L-carnitine supplementation on BP.

METHODS

PubMed, ISI Web of Science, Cochrane databases, and Scopus were used to collect RCT studies published up to October 2022 without limitations in language. Inclusion criteria were adult participants and recipients of L-carnitine in oral supplemental forms. The funnel plot test, Begg's test, and Egger's test were used to examine publication bias.

FINDINGS

After the search strategy, 22 RCTs (n = 1412) with 24 effect sizes fulfilled the criteria. It was found L-Carnitine supplementation did not have a significant effect on systolic blood pressure (SBP) (mm Hg) (weighted mean difference [WMD] = -1.22 mm Hg, 95% CI: -3.79, 1.35; P = 0.352; I2 = 85.0%, P < 0.001), and diastolic blood pressure (mm Hg) (WMD = -0.50 mm Hg, 95% CI: -1.49, 0.48; P = 0.318; I2 = 43.4%, P = 0.021) in the pooled analysis. Subgroup analyses have shown that L-carnitine supplementation had no lowering effect on SBP in any subgroup. However, there was a significant reduction in diastolic blood pressure in participants with a baseline body mass index >30 kg/m2 (WMD = -1.59 mm Hg; 95% CI: -3.11, -0.06; P = 0.041; I2 = 41.3%, P = 0.164). There was a significant nonlinear relationship between the duration of L-carnitine intervention and changes in SBP (coefficients = -6.83, P = 0.045).

IMPLICATIONS

L-carnitine supplementation in adults did not significantly affect BP. But anyway, more studies should be done in this field on different individuals.

Nutrition in chronic inflammatory conditions: Bypassing the mucosal block for micronutrients

Nutritional Immunity is one of the most ancient innate immune responses, during which the body can restrict nutrients availability to pathogens and restricts their uptake by the gut mucosa (mucosal block). Though this can be a beneficial strategy during infection, it also is associated with non-communicable diseases-where the pathogen is missing; leading to increased morbidity and mortality as micronutritional uptake and distribution in the body is hindered. Here, we discuss the acute immune response in respect to nutrients, the opposing nutritional demands of regulatory and inflammatory cells and particularly focus on some nutrients linked with inflammation such as iron, vitamins A, Bs, C, and other antioxidants. We propose that while the absorption of certain micronutrients is hindered during inflammation, the dietary lymph path remains available. As such, several clinical trials investigated the role of the lymphatic system during protein absorption, following a ketogenic diet and an increased intake of antioxidants, vitamins, and minerals, in reducing inflammation and ameliorating disease.

The effect of acarbose on lipid profiles in adults: a systematic review and meta-analysis of randomized clinical trials

PURPOSE

Dyslipidemia, characterized by elevated levels of triglycerides (TG), low-density lipoprotein (LDL), total cholesterol (TC), and reduced levels of high-density lipoprotein (HDL), is a major risk factor for cardiovascular diseases (CVD). Several studies have shown the potential of acarbose in improving serum lipid markers. However, there have been conflicting results on the topic in adults. Therefore, a comprehensive systematic review and meta-analysis was conducted to assess the impact of acarbose on lipid profiles.

METHODS

The random-effects approach was used to combine the data, and the results were provided as weighted mean difference (WMD) with 95% confidence intervals (CI).

RESULTS

Our meta-analysis included a total of 74 studies with a combined sample size of 7046 participants. The results of the analysis showed that acarbose resulted in a reduction in levels of TG (WMD = - 13.43 mg/dl, 95% CI: - 19.20, - 7.67; P < 0.001) and TC (WMD = - 1.93 mg/dl, 95% CI: - 3.71, - 0.15; P = 0.033), but did not affect other lipid markers. When conducting a nonlinear dose-response analysis, we found that acarbose was associated with an increase in levels of HDL (coefficients = 0.50, P = 0.012), with the highest increase observed at a dosage of 400 mg/d. Furthermore, our findings suggested a non-linear relationship between the duration of the intervention and TC (coefficients = - 18.00, P = 0.032), with a decline observed after 50 weeks of treatment.

CONCLUSION

The findings of this study suggest that acarbose can reduce serum levels of TG and TC. However, no significant effects were observed on LDL or HDL levels.

The effects of L-carnitine supplementation on inflammatory and anti-inflammatory markers in adults: a systematic review and dose-response meta-analysis

L-carnitine supplementation may be beneficial in improving inflammatory conditions and reducing the level of inflammatory cytokines. Therefore, according to the finding of randomized controlled trials (RCTs), the systematic review and meta-analysis aimed to investigate the effect of L-carnitine supplementation on inflammation in adults. To obtain acceptable articles up to October 2022, a thorough search was conducted in databases including PubMed, ISI Web of Science, the Cochrane Library, and Scopus. A random-effects model was used to estimate the weighted mean difference (WMD). We included the 48 RCTs (n = 3255) with 51 effect sizes in this study. L-carnitine supplementation had a significant effect on C-reactive protein (CRP) (p < 0.001), interleukin-6 (IL-6) (p = 0.001), tumor necrosis factor-α (TNF-α) (p = 0.002), malondialdehyde (MDA) (p = 0.001), total antioxidant capacity (TAC) (p = 0.029), alanine transaminase (ALT) (p < 0.001), and aspartate transaminase (AST) (p < 0.001) in intervention, compared to the placebo group. Subgroup analyses showed that L-carnitine supplementation had a lowering effect on CRP and TNF-α in trial duration ≥ 12 weeks in type 2 diabetes and BMI ≥ 25 kg/m2. L-carnitine supplementation reduced ALT levels in overweight and normal BMI subjects at any trial dose and trial duration ≥ 12 weeks and reduced AST levels in overweight subjects and trial dose ≥ 2 g/day. This meta-analysis revealed that L-carnitine supplementation effectively reduces the inflammatory state by increasing the level of TAC and decreasing the levels of CRP, IL-6, TNF-α and MDA in the serum.

The effects of acarbose treatment on cardiovascular risk factors in impaired glucose tolerance and diabetic patients: a systematic review and dose-response meta-analysis of randomized clinical trials

Acarbose (ACB) seems to be an effective drug in the management of cardiovascular risk factors. However, no previous meta-analysis of randomized controlled trials (RCTs) has been done to evaluate the effects of ACB on cardiovascular risk factors on impaired glucose tolerance (IGT), type 2 diabetes mellitus (T2D), and type 1 diabetes mellitus (T1D). We comprehensively searched electronic databases including Scopus, Web of Science, and PubMed for RCTs for related keywords up to September 2022. A random-effects model was used to estimate the weighted mean difference (WMD) and 95% confidence interval (CI). The pooled analysis demonstrated that ACB treatment had a significant effect on fasting blood glucose (FBG) (WMD = -3.55 mg/dL; 95%CI: -6.29, -0.81; p = 0.011), fasting insulin (WMD = -6.73 pmoL/L; 95%CI: -10.37, -3.10; p < 0.001), HbA1c [WMD = -0.32%; 95%CI: -0.45, -0.20; p < 0.001], body weight (WMD = -1.25 kg; 95%CI: -1.79, -0.75; p < 0.001), body mass index (BMI) (WMD = -0.64 kg/m2; 95%CI: -0.92, -0.37; p < 0.001), tumor necrosis factor-alpha (TNF-α) (WMD = -2.70 pg/mL, 95%CI: -5.25, -0.16; p = 0.037), leptin (WMD = -1.58 ng/mL; 95%CI: -2.82, -0.35; p = 0.012), alanine transaminase (ALT) (WMD = 0.71 U/L; 95%CI: -0.31, 1.85; p = 0.164), triglyceride (TG) (WMD = -13.89 mg/dL; 95%CI: -20.69, -7.09; p < 0.001), total cholesterol (TC) (WMD = -2.26 mg/dL; 95%CI: -4.18, -0.34; p = 0.021), systolic blood pressure (SBP) (WMD = -1.29 mmHg; 95%CI: -2.44, -0.15; p = 0.027), and diastolic blood pressure (DBP) (WMD = 0.02 mmHg; 95%CI: -0.41, 0.45; p = 0.925) in an intervention group, compared with a placebo group. The non-linear dose-response analysis showed that ACB reduces the TC in trial duration by >50 weeks, and 180 mg/day is more effective for the decrement of CRP. ACB can improve lipid profiles, glycemic indices, anthropometric indices, and inflammatory markers in T2D, T1D, and IGT patients.

Dairy products intake and the risk of postpartum depression among mothers: A pilot study

Introduction

Postpartum depression is a prevalent consequence of childbirth experienced by many women. There has been evidence linking dairy intake during pregnancy with a reduction in postpartum depression symptoms. However, there is still a lack of understanding regarding the effects of postpartum dairy consumption on postpartum depression.

Objectives

To examine whether dairy products intake and calcium in dairy is associated with postpartum depression.

Methods

A pilot study was conducted (n = 49 postpartum women). A food frequency questionnaire was used to evaluate the participants' consumption of calcium and dairy products during pregnancy, and the Edinburgh Postnatal Depression Scale was used to screen for postpartum depression symptoms.

Results

Of 49 participants, 26 (53%) were at risk for postpartum depression (Edinburgh Postnatal Depression Scale ⩾ 12). Consuming >1 serving of Laban per day is significantly associated with reduced risk of postpartum depression (odds ratio = 0.01, 95% confidence interval [0, 0.3]). Total dairy intake >1 serving per day is significantly associated with reduced risk of postpartum depression (odds ratio = 0.17, 95% confidence interval [0.03, 0.83]). No significant association was found between the postpartum intake of milk, cheese, yogurt, or calcium and postpartum depression.

Conclusion

Our findings indicate that higher total dairy intake was associated with a lower likelihood of postpartum depression. Further assessment with a larger sample size of participants could provide additional insight into the potential of dietary dairy to mitigate postpartum depression.

Effects of hypoxia-inducible factor prolyl hydroxylase inhibitors versus erythropoiesis-stimulating agents on iron metabolism and inflammation in patients undergoing dialysis: A systematic review and meta-analysis

Aims

This study aimed to evaluate the effects of hypoxia-inducible factor prolyl hydroxylase inhibitors (HIF-PHIs) on iron metabolism and inflammation in dialysis-dependent chronic kidney disease (DD-CKD) patients.

Methods

PubMed, Embase, Web of Science, Cochrane Library, and ClinicalTrials.gov websites were searched for randomized controlled trials (RCTs) investigating HIF-PHIs versus ESAs for DD-CKD patients.

Key findings

Twenty studies with 14,737 participants were included in the meta-analysis, which demonstrated no significant difference in the effect of transferrin saturation and ferritin between HIF-PHIs and the ESAs group (MD, 0.65; 95%CI, -0.45 to 1.75; very low certainty; SMD, -0.03; 95% CI, -0.13 to 0.07; low certainty). However, HIF-PHIs significantly increased the iron (MD, 2.30; 95% CI, 1.40 to 3.20; low certainty), total iron-binding capacity (SMD, 0.82; 95% CI, 0.66 to 0.98; low certainty), and transferrin (SMD, 0.90; 95%CI, 0.74 to 1.05; moderate certainty) levels when compared with the ESAs group. In contrast, the hepcidin level and dosage of intravenous iron were significantly decreased in the HIF-PHIs group compared with the ESAs group (MD, -15.06, 95%CI, -21.96 to -8.16; low certainty; MD, -18.07; 95% CI, -30.05 to -6.09; low certainty). The maintenance dose requirements of roxadustat were independent of baseline CRP or hsCRP levels with respect to the effect on inflammation.

Significance

HIF-PHIs promote iron utilization and reduce the use of intravenous iron therapy. Furthermore, HIF-PHIs, such as roxadustat, maintain the erythropoietic response independent of the inflammatory state. Thus, HIF-PHIs may be an alternative treatment strategy for anemia in DD-CKD patients, where ESA is hyporesponsive due to iron deficiency and inflammation.

The effects of L-carnitine supplementation on glycemic markers in adults: A systematic review and dose-response meta-analysis

Background and aims

Hyperglycemia and insulin resistance are concerns today worldwide. Recently, L-carnitine supplementation has been suggested as an effective adjunctive therapy in glycemic control. Therefore, it seems important to investigate its effect on glycemic markers.

Methods

PubMed, Scopus, Web of Science, and the Cochrane databases were searched in October 2022 for prospective studies on the effects of L-carnitine supplementation on glycemic markers. Inclusion criteria included adult participants and taking oral L-carnitine supplements for at least seven days. The pooled weighted mean difference (WMD) was calculated using a random-effects model.

Results

We included the 41 randomized controlled trials (RCTs) (n = 2900) with 44 effect sizes in this study. In the pooled analysis; L-carnitine supplementation had a significant effect on fasting blood glucose (FBG) (mg/dl) [WMD = -3.22 mg/dl; 95% CI, -5.21 to -1.23; p = 0.002; I ² = 88.6%, p < 0.001], hemoglobin A1c (HbA1c) (%) [WMD = -0.27%; 95% CI, -0.47 to -0.07; p = 0.007; I ² = 90.1%, p < 0.001] and homeostasis model assessment-estimate insulin resistance (HOMA-IR) [WMD = -0.73; 95% CI, -1.21 to -0.25; p = 0.003; I ² = 98.2%, p < 0.001] in the intervention compared to the control group. L-carnitine supplementation had a reducing effect on baseline FBG ≥100 mg/dl, trial duration ≥12 weeks, intervention dose ≥2 g/day, participants with overweight and obesity (baseline BMI 25-29.9 and >30 kg/m²), and diabetic patients. Also, L-carnitine significantly affected insulin (pmol/l), HOMA-IR (%), and HbA1c (%) in trial duration ≥12 weeks, intervention dose ≥2 g/day, and participants with obesity (baseline BMI >30 kg/m²). It also had a reducing effect on HOMA-IR in diabetic patients, non-diabetic patients, and just diabetic patients for insulin, and HbA1c. There was a significant nonlinear relationship between the duration of intervention and changes in FBG, HbA1c, and HOMA-IR. In addition, there was a significant nonlinear relationship between dose (≥2 g/day) and changes in insulin, as well as a significant linear relationship between the duration (weeks) (coefficients = -16.45, p = 0.004) of intervention and changes in HbA1C.

Conclusions

L-carnitine could reduce the levels of FBG, HbA1c, and HOMA-IR.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier: CRD42022358692.

The effects of saffron supplementation on cardiovascular risk factors in adults: A systematic review and dose-response meta-analysis

Introduction

Cardiovascular disease (CVD) is one of the leading causes of death and disability in the world and is estimated to involve more people in the next years. It is said that alternative remedies such as herbs can be used to manage the complications of this disease. For this reason, we aimed to conduct this meta-analysis to systematically assess and summarize the effects of saffron supplementation as an important herb on cardiovascular risk factors in adults.

Methods

A systematic search was done in PubMed, Scopus, and Web of Science to find eligible articles up to September 2022. Randomized controlled trials (RCTs) that evaluated the effects of saffron on lipid profiles, glycemic control, blood pressure, anthropometric measures, and inflammatory markers were included. In the meta-analysis, 32 studies were taken into account (n = 1674).

Results

Consumption of saffron significantly decreased triglyceride (TG) (WMD = -8.81 mg/dl, 95%CI: -14.33, -3.28; P = 0.002), total cholesterol (TC) (WMD = -6.87 mg/dl, 95%CI: -11.19, -2.56; P = 0.002), low density lipoprotein (LDL) (WMD = -6.71 mg/dl, 95%CI: -10.51, -2.91; P = 0.001), (P = 0.660), fasting blood glucose (FBG) level (WMD = -7.59 mg/dl, 95%CI: -11.88, -3.30; P = 0.001), HbA1c (WMD = -0.18%, 95%CI: -0.21, -0.07; P < 0.001), homeostasis model assessment-insulin resistance (HOMA-IR) (WMD = -0.49, 95%CI: -0.89, -0.09; P = 0.016), systolic blood pressure (SBP) (WMD = -3.42 mmHg, 95%CI: -5.80, -1.04; P = 0.005), tumor necrosis factor α (TNF-α) (WMD = -2.54 pg/ml, 95%CI: -4.43, -0.65; P = 0.008), waist circumference (WC) (WMD = -1.50 cm; 95%CI: -2.83, -0.18; P = 0.026), malondialdehyde (MDA) (WMD = -1.50 uM/L, 95%CI: -2.42, -0.57; P = 0.001), and alanine transferase (ALT) (WMD = -2.16 U/L, 95%CI: -4.10, -0.23; P = 0.028). Also, we observed that saffron had an increasing effect on total antioxidant capacity (TAC) (WMD = 0.07 mM/L, 95%CI: 0.01, 0.13; P = 0.032). There was linear regression between FBG and the duration of saffron intake. Additionally, the non-linear dose-response analysis has shown a significant association of saffron intervention with HDL (P = 0.049), HOMA-IR (P = 0.002), weight (P = 0.036), ALP (P = 0.016), FBG (P = 0.011), HbA1c (P = 0.002), and TNF-α (P = 0.042). A non-linear association between the length of the intervention and the level of HDL and DBP was also found.

Discussion

That seems saffron could effectively improve TG, TC, LDL, FBG, HbA1c, HOMA-IR, SBP, CRP, TNF-α, WC, MDA, TAC, and ALT.

The effects of conjugated linoleic acid supplementation on lipid profile in adults: A systematic review and dose-response meta-analysis

Background

The findings of trials investigating the effect of conjugated linoleic acid (CLA) administration on lipid profile are controversial. This meta-analysis of randomized controlled trials (RCTs) was performed to explore the effects of CLA supplementation on lipid profile.

Methods

Two authors independently searched electronic databases including PubMed, Web of Science, and Scopus until March 2022, in order to find relevant RCTs. The random effects model was used to evaluate the mean and standard deviation.

Results

In total, 56 RCTs with 73 effect sizes met the inclusion criteria and were eligible for the meta-analysis. CLA supplementation significantly alter triglycerides (TG) (WMD: 1.76; 95% CI: -1.65, 5.19), total cholesterols (TC) (WMD: 0.86; 95% CI: -0.42, 2.26), low-density lipoprotein cholesterols (LDL-C) (WMD: 0.49; 95% CI: -0.75, 2.74), apolipoprotein A (WMD: -3.15; 95% CI: -16.12, 9.81), and apolipoprotein B (WMD: -0.73; 95% CI: -9.87, 8.41) concentrations. However, CLA supplementation significantly increased the density lipoprotein cholesterol (HDL-C) (WMD: -0.40; 95% CI: -0.72, -0.07) concentrations.

Conclusion

CLA supplementation significantly improved HDL-C concentrations, however, increased concentrations of TG, TC, LDL-C, apolipoprotein A, and apolipoprotein B.

Systematic review registration

https://www.crd.york.ac.uk/prospero/#recordDetails, identifier: CRD42022331100.

The effects of berberine supplementation on cardiovascular risk factors in adults: A systematic review and dose-response meta-analysis

Cardiovascular disease (CVD) is a major concern today. Herbal medicine is one helping way to control CVD risks. One conclusive of herbal medicine is Berberine (BBR) and converse about it still exists, to clarify this issue, this meta-analysis was performed. PubMed/Medline, Scopus, and Web of Science were searched for RCTs in adults on the effect of BBR supplementation on CVD risk factors up to July 2022. The pooled results showed BBR significantly reduced triglyceride (WMD = -23.70 mg/dl; 95%CI -30.16, -17.25; P < 0.001), total cholesterol (WMD = -20.64 mg/dl; 95%CI -23.65, -17.63; P < 0.001), low-density lipoprotein WMD = -9.63 mg/dl; 95%CI, -13.87, -5.39; P < 0.001), fasting blood glucose (FBG) (WMD = -7.74 mg/dl; 95%CI -10.79, -4.70; P < 0.001), insulin (WMD = -3.27 mg/dl; 95%CI -4.46,-2.07; P < 0.001), HbA1c (WMD = -0.45%; 95%CI -0.68, -0.23; P < 0.001), HOMA-IR (WMD = -1.04; 95%CI -1.55, -0.52; P < 0.001), systolic blood pressure (WMD = -5.46 mmHg; 95%CI -8.17, -2.76; P < 0.001), weight (WMD = -0.84; 95%CI -1.34,-0.34; P < 0.001), body mass index (WMD = -0.25 kg/m2; 95%CI -0.46, -0.04; P = 0.020), while increased high-density lipoprotein (HDL) (WMD = 1.37 mg/dl; 95%CI 0.41,2.23; P = 0.005). The optimal dose of BBR was 1 g/day for TG, TC, and weight, 1.8 g/day for insulin and HOMA-IR, and 5 g/day for HDL. FBG's most efficient time frame was 40 weeks from the beginning of supplementation, whereas DBP and waist circumference was 50 weeks. In conclusion, the lipid profile, FBG balance, obesity parameters, and SBP were improved with BBR supplementation.

Systematic review registration

CRD42022347004.

Vitamin D and cardiovascular disease risk. A literature overview

BACKGROUND

Atherosclerosis and cerebro and cardiovascular disease associated represent the major cause of morbidity and mortality worldwide. Recently, vitamin D deficiency has been considered a new potential risk factor of these conditions.

METHODS AND RESULTS

In this reviw we briefly describe the biological role of vitamin D, analyze the pathophysiological associations between cardiovascular disease and vitamin D, summarize and synthesize the evidence from literature about the association between vitamin D and cardiovascular disease.

RESULTS

Vit D is an essential vitamin for bone metabolism and homeostasis. The maintenance of optimal blood levels contributes to the correct homeostasis by influencing different metabolic processes, including those underlying cardiovascular diseases. However, the evidence does not support vitamin D routine administration for the prevention and treatment of cardiovascular disease and intake to achieve specific cardiovascular effects. Evidence shows that maintaining optimal levels of vitamin D, ensures cardiovascular protection.

An Overview of Systematic Reviews of the Role of Vitamin D on Inflammation in Patients with Diabetes and the Potentiality of Its Application on Diabetic Patients with COVID-19

Almost two years have passed since the outbreak reported for the first time in Wuhan of coronavirus disease 2019 (COVID-19), due to severe acute respiratory syndrome (SARS)-CoV-2 coronavirus, rapidly evolved into a pandemic. This infectious disease has stressed global health care systems. The mortality rate is higher, particularly in elderly population and in patients with comorbidities such as hypertension, diabetes mellitus, cardiovascular disease, chronic lung disease, chronic renal disease, and malignancy. Among them, subjects with diabetes have a high risk of developing severe form of COVID-19 and show increased mortality. How diabetes contributes to COVID-19 severity remains unclear. It has been hypothesized that it may be correlated with the effects of hyperglycemia on systemic inflammatory responses and immune system dysfunction. Vitamin D (VD) is a modulator of immune-response. Data from literature showed that vitamin D deficiency in COVID-19 patients increases COVID-19 severity, likely because of its negative impact on immune and inflammatory responses. Therefore, the use of vitamin D might play a role in some aspects of the infection, particularly the inflammatory state and the immune system function of patients. Moreover, a piece of evidence highlighted a link among vitamin D deficiency, obesity and diabetes, all factors associated with COVID-19 severity. Given this background, we performed an overview of the systematic reviews to assess the association between vitamin D supplementation and inflammatory markers in patients with diabetes; furthermore, vitamin D’s possible role in COVID-19 patients was assessed as well. Three databases, namely MEDLINE, PubMed Central and the Cochrane Library of Systematic Reviews, were reviewed to retrieve the pertinent data. The aim of this review is to provide insight into the recent advances about the molecular basis of the relationship between vitamin D, immune response, inflammation, diabetes and COVID-19.

Effect of l-Arginine Supplementation on Blood Pressure in Adults: A Systematic Review and Dose-Response Meta-analysis of Randomized Clinical Trials

A decade-old meta-analytic work indicated that l-arginine supplementation might have a blood pressure (BP)-lowering effect in different populations. However, several relevant investigations have emerged in the last 10 y, and an up-to-date systematic review and meta-analysis on this topic is currently lacking. Therefore, we aimed to examine the impact of l-arginine supplementation on BP by conducting a systematic review and dose-response meta-analysis of randomized placebo-controlled clinical trials (RCTs). We searched online databases using relevant keywords up to April 2021 to identify RCTs using oral l-arginine on systolic BP (SBP) and diastolic BP (DBP) in adults. Inclusion criteria were adult participants and an intervention duration ≥4 d. Exclusion criteria were the use of l-arginine infusion and acute interventions. A random-effects model was used to estimate the weighted mean difference (WMD) and 95% CI. Twenty-two RCTs with 30 effect sizes were included in this meta-analysis. The pooled analysis demonstrated significant decreases in SBP (WMD = -6.40 mmHg; 95% CI: -8.74, -4.05; P < 0.001) and DBP (WMD = -2.64 mmHg; 95% CI: -3.94, -1.40; P < 0.001) after l-arginine supplementation. Subgroup analysis showed significant reductions in SBP and DBP regardless of baseline BP category (normotensive, hypertensive), study duration (≤24 d, >24 d), sex (female, male), health status (healthy, unhealthy), and BMI (normal, overweight, obese). No significant changes were observed with dosages >9 g/d, trial duration >24 d, or in obese individuals. l-Arginine supplementation also appears to decrease DBP more effectively in females than in males. Moreover, meta-regression analysis for DBP demonstrated a significant relation between the dose of l-arginine intake and changes in DBP (P = 0.020). In the nonlinear dose-response analysis, the effective dosage of l-arginine supplementation was detected to be ≥4 g/d for SBP (P = 0.034), independent of trial duration. Overall, l-arginine supplementation may be effective for decreasing BP. This study was registered at PROSPERO as CRD42021242772.

Randomized trial of vitamin D versus placebo supplementation on markers of systemic inflammation in hypertensive patients

BACKGROUND AND AIMS

Animal and cell models indicated that vitamin D modulates inflammatory activity, which is considered relevant in the pathogenesis of arterial hypertension and cardiovascular diseases. We therefore aimed to investigate the effect of vitamin D supplementation on systemic markers of inflammation in a cohort of hypertensive patients.

METHODS AND RESULTS

The Styrian Vitamin D Hypertension Trial is a single-centre, double-blind, placebo-controlled study conducted from 2011 to 2014 in Austria. We enrolled 200 study participants with arterial hypertension and 25-hydroxy-vitamin-D (25(OH)D) concentration below 30 ng/mL. Study participants were randomized to receive either 2800 IU of vitamin D₃ per day or placebo for 8 weeks. The present investigation is a post-hoc analysis using analysis of co-variance (ANCOVA). Outcome measures were biomarkers of inflammation including CRP, leukocytes including subtypes and leukocyte-to-lymphocyte ratio, leucine and kynurenic acid. A total of 187 participants (mean age 60.1 ± 11.3years; 47% women; mean baseline 25(OH)D 21.1 ± 5.6 ng/mL) completed the trial. ANCOVA revealed a mean treatment effect for none of the respective outcomes and no significant results were detected in various subgroup analyses.

CONCLUSION

Vitamin D₃ supplementation in hypertensive patients with insufficient 25(OH)D concentrations has no significant effect on lowering markers of systemic inflammation. Further studies investigating the effect of vitamin D on other inflammatory pathways and in populations with severe vitamin D deficiency and a significant inflammatory burden are required.

REGISTRATION

ClinicalTrials.gov Identifier: NCT02136771; EudraCT No. 2009-018,125-70. Start Date: 2011-04-06.

Effect of Vitamin D Deficiency and Supplementation in Lactation and Early Life on Allergic Airway Inflammation and the Expression of Autophagy-Related Genes in an Ovalbumin Mouse Model

Background and Objective

Vitamin D is involved in various physiological and pathological processes, including inflammation and autophagy. We aimed to investigate the effects of dietary vitamin D deficiency or supplementation initiated in lactation and early life on inflammation and autophagy in an ovalbumin (OVA) mouse model.

Methods

Female BALB/c were fed with vitamin D-deficient, sufficient or supplemented diets throughout lactation and their offspring followed the same diet after weaning. Offspring were then sensitized and challenged with OVA, airway resistance (R_L) was measured, and their serum, bronchoalveolar lavage fluid (BALF), and lung tissue were collected. Alveolar macrophages (AMs) were isolated from lung tissue and cultured with different concentrations of 1,25(OH)₂D₃. The expressions of autophagy-related (ATG) proteins including light-chain 3 (LC3), Beclin-1, and ATG5, and NF-κB p65 in lung tissue and AMs were measured.

Results

OVA sensitization and challenge induced dramatic allergic airway inflammation and higher R_L in the vitamin D-deficient group compared with vitamin D-sufficient or the supplemented group. The expression of ATGs including LC3, Beclin-1, and ATG5, and NF-κB p65 in lung tissue in the vitamin D-deficient OVA-mediated group was increased compared with vitamin D-supplemented OVA-mediated group. There was correlation between the expression of LC3 mRNA and inflammatory cell numbers and cytokines in BALF. In vitro, 1,25(OH)₂D₃ also regulated the expression of LC3, Beclin-1, ATG5, and NF-κB p65 mRNA in AMs in a time- and dose-dependent manner.

Conclusion

Deficiency of vitamin D in early life may aggravate allergic airway inflammation, and maintaining sufficient vitamin D during early life is necessary for lung health. Vitamin D may modulate autophagy in lungs of OVA sensitized/challenged mice, thus playing a protective role in OVA-induced allergic airway inflammation.

Does Evidence Exist to Blunt Inflammatory Response by Nutraceutical Supplementation during COVID-19 Pandemic? An Overview of Systematic Reviews of Vitamin D, Vitamin C, Melatonin, and Zinc

More than one year has passed since the first cases of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome (SARS)-CoV-2 coronavirus were reported in Wuhan (China), rapidly evolving into a global pandemic. This infectious disease has become a major public health challenge in the world. Unfortunately, to date, no specific antivirals have been proven to be effective against COVID-19, and although a few vaccines are available, the mortality rate is not decreasing but is still increasing. One therapeutic strategy has been focused on infection prevention and control measures. In this regard, the use of nutraceutical supports may play a role against some aspect of the infection, particularly the inflammatory state and the immune system function of patients, thus representing a strategy to control the worst outcomes of this pandemic. For this reason, we performed an overview including meta-analyses and systematic reviews to assess the association among melatonin, vitamin C, vitamin D, zinc supplementation and inflammatory markers using three databases, namely, MEDLINE, PubMed Central and the Cochrane Library of Systematic Reviews. According to the evidence available, an intake of 50,000 IU/month of vitamin D showed efficacy in CRP. An amount of 1 to 2 g per day of vitamin C demonstrated efficacy both in CRP and endothelial function, and a dosage of melatonin ranging from 5 to 25 mg /day showed good evidence of efficacy in CRP, TNF and IL6. A dose of 50 mg/day of elemental zinc supplementation showed positive results in CRP. Based on the data reported in this review, the public health system could consider whether it is possible to supplement the current limited preventive measures through targeted nutraceutical large-scale administration.

Molecular mechanisms from insulin-mimetic effect of vitamin D: treatment alternative in Type 2 diabetes mellitus

Diabetes mellitus is a complex and multifactorial disease with a global prevalence that exceeds 425 million people. Type 2 diabetes mellitus (T2DM) is characterized by a state of insulin resistance, which leads to metabolic alterations that aggravate the state of health of people. Vitamin D deficiency appears to play an important role in the triggering mechanisms of insulin resistance. In this review, an analysis is made of the biochemical mechanisms associated with the insulin-mimetic effect of vitamin D, its supplementation being a possible nutritional strategy for the T2DM treatment. The current scientific evidence is extensive regarding the dose of vitamin D used for an insulin-mimetic effect. However, clinical trials and systematic reviews show statistical differences on glucose, insulin, and glycated hemoglobin levels of patients with T2DM, associated with activation mechanisms of transcription factors related to genes of the glucide metabolism and the insulin receptor, and the regulation of intracellular Ca2+ insulin concentrations. Likewise, an indirect mechanism associated with antioxidant and anti-inflammatory effects has been shown that also leads to sensitivity to the insulin receptor. The use of a specific dose of vitamin D could be an effective alternative in the T2DM treatment, which would reduce the risk of complications derived from hyperglycemia.

Study of the Influence of Sociodemographic and Lifestyle Factors on Consumption of Dairy Products: Preliminary Study in Portugal and Brazil

Sociodemographic characteristics, including regional variations, have been associated with different food consumption patterns. Behavioral factors and lifestyle variables may also contribute to different food dietary trends. In this way, the present study intended to investigate the consumption habits of the most relevant types of dairy products around the world and relate them to sociodemographic factors, for example, age, sex, education and country as well as with some anthropometric and behavioral aspects, for example, body mass index, satisfaction with body weight and exercise or sedentary lifestyles. One other objective of the study was to categorize the lifestyles of the participants, according to measured variables linked with hours of inactivity or exercise, in order to use these as possible differentiating variables for the consumption of dairy products. The study involved a questionnaire survey undertaken on a non-probabilistic convenience sample of participants from Portugal (PT) and Brazil (BR), and participation was voluntary and anonymous. The data analysis involved different statistical techniques: basic statistics, chi-square tests, factor analysis, cluster analysis and tree classification analysis. The results showed that semi skimmed milk is never consumed by about half of the participants (47.4% for PT and 46.7 for BR), and those numbers increase for skimmed (64.8% for PT and 50.9% for BR), chocolate flavored milk (82.6% for PT and 65.6% for BR) and enriched milks (94.8% for PT and 85.3% for BR). Cheeses are also consumed in the two countries by small numbers of people. The number of participants consuming imported cheeses in both countries was particularly low (only 4.0% consume these more than once a week in both countries), suggesting national products may be preferred. It was further observed that those who consume cheese do it seldom (once a week) or sometimes (2–3 times per week). Butter is also consumed by only about half of the adult population (43.8% for PT and 49.5% for BR), but the percentage of those who never consume butter increases for skimmed butter (66.0% for PT and 82.6% for BR) and unsalted butter (70.2% for PT and 69.1% for BR). The consumption of yogurts also follows similar low consumption patterns. The most frequently consumed yogurt types in Portugal are liquid (30.5% consume regularly) and natural yogurts (34.8% consume regularly), while in Brazil the most frequent are creamy fruit pulp yogurt (14.4% consume regularly), liquid (13.7% consume regularly) and Greek type yogurt (10.2% consume regularly). A factor analysis and a cluster analysis established groups according to lifestyles, as follows: 1—Screeners, 2—Exercisers, 3—Travelers and 4—Others. These lifestyles were found to be influential in the consumption of dairy products for all classes of dairy tested: milk, cheese, yogurt and butter. For example, the screeners were found to consume more milk, more butter, more cheese and more yogurt. Additionally, other influential factors were age, sex, education, BMI and satisfaction with body weight. Nevertheless, country was not a meaningfully discriminant variable in relation to the other variables included in the classification analysis. The results concluded that, despite some small differences in the patterns of consumption of dairy products in both countries, the levels of consumption of dairy products are extremely low, for all classes studied (milk, cheese, yogurt or butter). Additionally, it was concluded that some factors are influential on the level of consumption of dairy products, and therefore decision makers can plan their interventions according to the characteristics of the targeted segments of the population, according to lifestyle, age, sex, education, BMI and satisfaction with body weight.

Calcium physiology, metabolism and supplementation: a glance at patients with ankylosing spondylitis

The aim of this review is to describe the metabolism of calcium in ankylosing spondylitis compared to physiologic conditions, and to present the current evidence on the benefits and disadvantages of calcium supplementation in these patients. A narrative review of the literature was conducted using the PubMed database and a total of 65 articles were selected. Calcium is involved in many physiopathological processes, including inflammation, bone loss and bone formation, all of which occur in ankylosing spondylitis. Many ankylosing spondylitis patients suffer from concomitant osteopenia or osteoporosis, which represent indications for calcium supplementation. Conversely, there are still concerns about the use of calcium salts for the prevention of bone fragility in non-osteoporotic or non-osteopenic patients. In these cases, biologic agents may indirectly normalize calcium dysmetabolism by rebalancing the cytokine milieu, in turn associated with bone remodeling. Calcium supplements may be disadvantageous for entheseal calcifications, but so far there are no clear data confirming that such an association exists.

The effect of vitamin E supplementation on selected inflammatory biomarkers in adults: a systematic review and meta-analysis of randomized clinical trials

The previous meta-analysis of clinical trials revealed a beneficial effect of vitamin E supplementation on serum C-reactive protein (CRP) concentrations; however, it is unknown whether this vitamin has the same influence on other inflammatory biomarkers. Also, several clinical trials have been published since the release of earlier meta-analysis. Therefore, we aimed to conduct a comprehensive meta-analysis to summarize current evidence on the effects of vitamin E supplementation on inflammatory biomarkers in adults. We searched the online databases using relevant keywords up to November 2019. Randomized clinical trials (RCTs) investigating the effect of vitamin E, compared with the placebo, on serum concentrations of inflammatory cytokines were included. Overall, we included 33 trials with a total sample size of 2102 individuals, aged from 20 to 70 years. Based on 36 effect sizes from 26 RCTs on serum concentrations of CRP, we found a significant reduction following supplementation with vitamin E (− 0.52, 95% CI − 0.80, − 0.23 mg/L, P < 0.001). Although the overall effect of vitamin E supplementation on serum concentrations of interleukin-6 (IL-6) was not significant, a significant reduction in this cytokine was seen in studies that used α-tocopherol and those trials that included patients with disorders related to insulin resistance. Moreover, we found a significant reducing effect of vitamin E supplementation on tumor necrosis factor-α (TNF-α) concentrations at high dosages of vitamin E; such that based on dose–response analysis, serum TNF-α concentrations were reduced significantly at the dosages of ≥ 700 mg/day vitamin E (P_{non-linearity} = 0.001). Considering different chemical forms of vitamin E, α-tocopherol, unlike other forms, had a reducing effect on serum levels of CRP and IL-6. In conclusion, our findings revealed a beneficial effect of vitamin E supplementation, particularly in the form of α-tocopherol, on subclinical inflammation in adults. Future high-quality RCTs should be conducted to translate this anti-inflammatory effect of vitamin E to the clinical setting.

The effect of green coffee extract supplementation on anthropometric measures in adults: A comprehensive systematic review and dose-response meta-analysis of randomized clinical trials

BACKGROUND AND AIM

Two meta-analyses summarized data on the effects of green coffee extract (GCE) supplementation on anthropometric measures. However, the accuracy of those meta-analyses is uncertain due to several methodological limitations. Therefore, we aimed to conduct a comprehensive systematic review and dose-response meta-analysis to summarize all available evidence on the effects of GCE supplementation on anthropometric measures by considering the main limitations in the previous meta-analyses.

METHODS

We searched available online databases for relevant publications up to January 2020, using relevant keywords. All randomized clinical trials (RCTs) investigating the effects of GCE supplementation, compared with a control group, on anthropometric measures [including body weight, body mass index (BMI), body fat percentage, waist circumference (WC) and waist-to-hip ratio (WHR)] were included.

RESULTS

After identifying 1871 studies from our initial search, 15 RCTs with a total sample size of 897 participants were included in the systematic review and meta-analysis. We found a significant reducing effect of GCE supplementation on body weight (weighted mean difference (WMD): -1.23, 95 % CI: -1.64, -0.82 kg,P < 0.001), BMI (WMD: -0.48, 95 % CI: -0.78, -0.18 kg/m², P = 0.001), and WC (WMD: -1.00, 95 % CI: -1.70, -0.29 cm, P = 0.006). No significant effect of GCE supplementation on body fat percentage and WHR was seen. In the dose-response analyses, there was no significant association between chlorogenic acid (CGA) dosage, as the main polyphenol in green coffee, and changes in anthropometric measures.

CONCLUSION

We found that GCE supplementation had a beneficial effect on body weight, BMI and WC. It provides a cost-effective and safe alternative for the treatment of obesity. Additional well-designed studies are required to further confirm our findings.