Effect of vitamin D supplementation or fortification on bone turnover markers in women: a systematic review and meta-analysis.

Vitamin D is a vital indicator of musculoskeletal health, as it plays an important role through the regulation of bone and mineral metabolism. This meta-analysis was performed to investigate the effects of vitamin D supplementation/fortification on bone turnover markers in women. All human randomised clinical trials reported changes in bone resorption markers (serum C-terminal telopeptide of type-I collagen (sCTX) and urinary type I collagen cross-linked N-telopeptide (uNTX)) or bone formation factors (osteocalcin (OC), bone alkaline phosphatase (BALP) and procollagen type-1 intact N-terminal propeptide (P1NP)) following vitamin D administration in women (aged ≥ 18 years) were considered. Mean differences (MD) and their respective 95 % CI were calculated based on fixed or random effects models according to the heterogeneity status. Subgroup analyses, meta-regression models, sensitivity analysis, risk of bias, publication bias and the quality of the included studies were also evaluated. We found that vitamin D supplementation had considerable effect on sCTX (MD: -0·038, n 22) and OC (MD: -0·610, n 24) with high heterogeneity and uNTX (MD: -8·188, n 6) without heterogeneity. Our results showed that age, sample size, dose, duration, baseline vitamin D level, study region and quality of studies might be sources of heterogeneity in this meta-analysis. Subgroup analysis also revealed significant reductions in P1NP level in dose less than 600 µg/d and larger study sample size (>100 participants). Moreover, no significant change was found in BALP level. Vitamin D supplementation/fortification significantly reduced bone resorption markers in women. However, results were inconsistent for bone formation markers.

The effect of Royal jelly on liver enzymes and glycemic indices: A systematic review and meta-analysis of randomized clinical trials.

BACKGROUND: Royal jelly (RJ) may contribute to glycemic control and liver function through various mechanisms. The present study aimed to quantify the effect of RJ supplementation on these outcomes. METHODS: A literature search of Web of Science, Scopus, and PubMed/Medline, was conducted for RCTs investigating the efficacy of RJ on plasma liver enzymes and glycemic indices. Weighted mean differences (WMDs) and 95% confidence intervals (CIs) were calculated for net changes using a random-effects model. RESULTS: Ten RCTs were selected for inclusion in this meta-analysis. Combined estimate of effect sizes for the impact of RJ on neither the plasma liver enzymes nor the glycemic indices were statistically significant. Subgroup analysis showed a significant reduction of serum FPG in trials with intervention duration ≥ 8 weeks (WMD: -4.28 mg/dl, 95% CI -7.41 to -1.14 mg/dl, p = 0.007), and those conducted in non-healthy populations (WMD: -4.28 mg/dl, 95% CI -7.41 to -1.14, p = 0.007). CONCLUSION: RJ does not significantly affect liver function and glycemic profile of adult population. In trials with longer intervention and those conducted in non-healthy populations a significant reduction of serum FBG was observed. This meta-analysis should be repeated in the future, with more primary articles included, in order to provide conclusive results.

Whey Protein Supplementation with or without Vitamin D on Sarcopenia-Related Measures: A Systematic Review and Meta-Analysis.

The effects of supplementation with whey protein alone or with vitamin D on sarcopenia-related outcomes in older adults are unclear. We aimed to assess the effect of whey protein supplementation alone or with vitamin D on lean mass (LM), strength, and function in older adults with or without sarcopenia or frailty. We searched PubMed, Web of Science, and SCOPUS databases. Randomized controlled trials (RCT) that investigated the effect of whey protein supplementation with or without vitamin D on sarcopenia outcomes in healthy and sarcopenic or frail older adults were included. Standardized mean differences (SMDs) were calculated for LM, muscle strength, and physical function data. The analysis showed that whey protein supplementation had no effect on LM and muscle strength; nevertheless, a significant improvement was found in physical function (SMD = 0.561; 95% confidence interval [CIs]: 0.256, 0.865, n = 33), particularly gait speed (GS). On the contrary, whey protein supplementation significantly improved LM (SMD = 0.982; 95% CI: 0.228, 1.736; n = 11), appendicular lean mass and physical function (SMD = 1.211; 95% CI: 0.588, 1.834; n = 16), and GS in sarcopenic/frail older adults. By contrast, co-supplementation with vitamin D enhanced LM gains (SMD =0.993; 95% CI: 0.112, 1.874; n = 11), muscle strength (SMD =2.005; 95% CI: 0.975, 3.035; n = 11), and physical function (SMD = 3.038; 95% CI: 2.196, 3.879; n = 18) significantly. Muscle strength and physical function improvements after whey protein supplementation plus vitamin D were observed without resistance exercise (RE) and short study duration subgroups. Moreover, the combination of whey protein and vitamin D with RE did not enhance the effect of RE. Whey protein supplementation improved LM and function in sarcopenic/frail older adults but had no positive effect in healthy older persons. By contrast, our meta-analysis showed that co-supplementation with whey protein and vitamin D is effective, particularly in healthy older adults, which is likely owing, we propose, to the correction of vitamin D insufficiency or deficiency. The trial was registered at https://inplasy.com as INPLASY202240167.

Effect of omega-3 supplementation on lipid profile in children and adolescents: a systematic review and meta-analysis of randomized clinical trials.

PURPOSE: Dyslipidemia is considered as a known risk factor for cardiovascular disease. Yet various trials with wide ranges of doses and durations have reported contradictory results. We undertook this meta-analysis of randomized controlled trials (RCTs) to determine whether omega-3 supplementation can affect lipid profile in children and adolescents. METHODS: Cochrane Library, Embase, PubMed, and Scopus databases were searched up to March 2021. Meta-analysis was performed using random-effect method. Effect size was expressed as weighted mean difference (WMD) and 95% confidence interval (CI). Heterogeneity was assessed using the I2 index. In order to identification of potential sources of heterogeneity, predefined subgroup and meta-regression analysis was conducted. RESULTS: A total of 14 RCTs with 15 data sets were included. Based on the combination of effect sizes, there was a significant reduction in TG levels (WMD: -15.71 mg/dl, 95% CI: -25.76 to -5.65, P=0.002), with remarkable heterogeneity (I2=88.3%, P<0.001). However, subgroup analysis revealed that omega-3 supplementation significantly decreased TG only in studies conducted on participants ≤13 years old (WMD=-25.09, 95% CI: -43.29 to -6.90, P=0.007), (I2=84.6%, P<0.001) and those with hypertriglyceridemia (WMD=-28.26, 95% CI: -39.12 to -17.41, P<0.001), (I2=0.0%, P=0.934). Omega-3 supplementation had no significant effect on total cholesterol, HDL, and LDL levels. Also, results of nonlinear analysis showed significant effect of treatment duration on HDL status (Pnon-linearity=0.047). CONCLUSION: Omega-3 supplementation may significantly reduce TG levels in younger children and those with hypertriglyceridemia. Also, based on the HDL-related results, clinical trials with longer duration of intervention are recommended in this population.

The effect of Cornus mas fruit extract on vasomotor symptoms and sex hormones in postmenopausal women: a randomized, double-blind, clinical trial.

OBJECTIVES: Cornus mas fruit has various antioxidants and anti-inflammatory properties, so this study aims at assessing its effect on menopausal symptoms and sex hormones in postmenopausal women. METHODS: In the current randomized, double-blind clinical trial, 84 individuals (42 per group) were participated. C mas hydroalcoholic extract was prepared, and participants received 300 mg C mas extract or placebo three times a day (900 g in total) for 8 weeks. The demographic, dietary intake, and physical activity information were gathered. Anthropometric indices were measured by standard methods. Furthermore, menopause symptoms were assessed by Greene Climacteric Scale. Also, sex hormones were measured by enzyme-linked immunosorbent assay. RESULTS: Based on the results, there was a significant difference in total Greene score reduction between the intervention and placebo groups (-3.19 ± 0.54, -0.76 ± 0.32, and P < 0.001). In addition, vasomotor symptoms had a remarkable decrease in the C mas extract group (P < 0.001). Also, the intervention group demonstrated a decreasing trend in the number and duration of hot flushes. Moreover, follicle-stimulating hormone remarkably decreased and estradiol increased in the intervention group (P = 0.016 and P = 0.018). CONCLUSIONS: It has been found that the extract of C mas fruit has a favorable effect on vasomotor symptoms, sex hormones, and related complications in women experiencing menopausal symptoms.

The effect of synbiotic and vitamin D co-supplementation on body composition and quality of life in middle-aged overweight and obese women: A randomized controlled trial.

BACKGROUND & AIMS: Obesity is a worldwide problem which has involved large populations. Since some dietary factors might modify obesity through various signaling pathways, the aim of this study was to investigate the effect of synbiotic plus vitamin D co-supplementation on body composition parameters and quality of life, in middle-aged overweight and obese women. METHODS: A randomized, controlled, double-blinded trial was performed and 88 overweight and obese women were assigned to 4 groups (22 per group), receiving synbiotic plus vitamin D, synbiotic, vitamin D and placebo for 8 weeks. At the beginning and at the end of the trial, anthropometric indices, body composition indicators, physical activity level, dietary intake, and quality of life score were measured by trained nutritionists. Statistical analysis was performed with SPSS version 22. RESULTS: The results showed significant difference between 4 groups in waist circumference (WC), fat mass (FM), body fat percentage (BFP) and visceral fat area (VFA) values after 8 weeks of treatment (P = 0.005, P = 0.007, P = 0.003, and P = 0.009, respectively), with the greatest reduction in synbiotic plus vitamin D group compare to placebo. No significant results were demonstrated between groups in relation to other body composition variables. In addition, there were no significant differences between the 4 groups regarding physical, mental and total aspects of life quality over time. CONCLUSIONS: Our study demonstrated that synbiotic and vitamin D co-supplementation for 8 weeks, had favorable effect on various anthropometric indices and body composition indicators, but no desirable change in life quality score. CLINICAL TRIAL REGISTRY: IRCT (registration no. IRCT20090822002365N25).

The effects of synbiotic and/or vitamin D supplementation on gut-muscle axis in overweight and obese women: a study protocol for a double-blind, randomized, placebo-controlled trial.

BACKGROUND: Sarcopenia refers to an age-related loss of skeletal muscle content, strength, and function, leading to a decrease in mobility. Obesity may exacerbate age-related complications such as sarcopenia through inflammatory pathways. In addition, intestinal dysbiosis has been proposed as an emerging contributor to sarcopenia due to the stimulation of the immune system and elevated barrier permeability of the intestine. Targeting microbiome with synbiotic and vitamin D supplementation may modulate the microbiome followed by the enhancement of sarcopenia indices. Thus, the present study aims to evaluate the effect of synbiotic supplementation with or without vitamin D on the intestinal microbiome and its relationship with strength, muscle function, and body composition in middle-aged overweight and obese women. METHODS: This multi-factorial, double-blind, randomized controlled trial will be conducted on 88 participants in eight weeks. The participants will be allocated into four groups receiving vitamin D placebo (weekly) and synbiotic placebo (daily), vitamin D and synbiotic placebo, vitamin D placebo and symbiotic, and vitamin D and synbiotic. Intestinal microbiome assessment will be done by DNA isolation and real-time polymerase chain reaction (PCR). In addition, anthropometric indices, body composition, muscle strength, and physical performance will be evaluated by standard methods. All measurements will be made at the beginning and end of the study. DISCUSSION: The previous studies showed that probiotics were involved in reducing inflammation, insulin sensitivity, modulation of atrophy markers such as atherogen-1, and decreasing reactive oxygen indices. In addition, vitamin D was found to improve the intestinal microbiome and facilitate muscle anabolism. The present protocol is novel as it aims to investigate the impact of the co-supplementation of synbiotic and vitamin D on the gut microbiome and sarcopenia indices. TRIAL REGISTRATION: This trial has been registered in the Iranian Registry of Clinical Trials (IRCT20090822002365N25, date of registration: March 2021).

Effect of cardamom supplementation on a number of metabolic factors: A systematic review and meta-analysis.

BACKGROUND & AIMS: Cardamom known as "queen of spice" seems to be an anti-diabetic agent due to its poly phenolic content. Since, recent studies reported controversial results related to its effect on metabolic factors, present meta-analysis examined the effect of cardamom supplementation on glycemic indices and weight profile of randomized controlled clinical trials (RCTs). METHODS: A wide search was done on biomedical electronic databases including Scopus, PubMed, Cochrane, EMBASE and Iranian databases, for all relevant literature published up to May 2021. Our search strategy included: [HbA1C, Blood Sugar, glycemic index, glucose tolerance test, insulin, insulin resistance, insulin sensitivity, body weight, BMI, body composition, waist circumferences] added to searched queries based on scientific Mesh terms. The included papers required to be RCTs that reported the effect of cardamom on glycemic and weight indices. We excluded studies with: a) non-randomized or non-controlled trials, b) animal studies, c) not available full text articles d) duplicate citations and e) not available full text articles. The risk of bias was assessed based on the Cochrane Risk of Bias tool. The effects of cardamom supplementation were assessed using standardized mean difference (SMD) statistics. The SMD of metabolic risk factors were pooled together using random effect meta-analysis method. RESULTS: Totally, six publications enrolling 410 participants was included in present meta-analysis. Daily 3 g supplementation of cardamom from 8 weeks to 3 months showed no significant effect on BMI (WMD: 0.07; 95% CI: [-0.12, 0.27]; P:0.5), weight (WMD: 0.01; 95% CI: [-0.22, 0.21]; P:0.95) and WC (WMD: 0.09; 95% CI: [-0.34, 0.17]; P:0.63), FBS (WMD: 0.10; 95% CI: [ -0.32, 0.12]; P:0.37), insulin (WMD: 0.83; 95% CI: [-2.07, 0.40]; P:0.19) and QUICKI (WMD: 1.14; 95% CI: [-1.11, 3.39]; P:0.32). However, significant effect occurred on HOMA-IR (WMD: 0.40; 95% CI: [-0.65, -0.15]; P:0.00), and HbA1C (WMD: 0.48; 95% CI: [-0.80, -0.16]; P:0.00). CONCLUSION: Final findings suggest ameliorative effect of cardamom on metabolism of glucose.

Effect of whey protein consumption on IL-6 and TNF-α: A systematic review and meta-analysis of randomized controlled trials.

BACKGROUND AND AIMS: Due to inconsistent data about WP supplementation on inflammatory markers, present systematic review and meta-analysis was done to summarize its effect on TNF-α and IL-6. METHODS: Our search was done in Pubmed, Scopus, Embase, and Cochrane up to June 2021. Weighted mean difference (WMD) and 95% confidence intervals (CI) was used to indicate the effect sizes. Conceivable sources of heterogeneity were detected by subgroup analysis. RESULTS: Overall, 11 eligible RCTs were included. The pooled results showed that WP supplementation had no significant effect on TNF-α and IL-6 status compare to those receiving carbohydrate and other types of proteins as placebo. Results from subgroup analysis based on health status, study duration, WP dosage and sex, expressed no favorable effect of WP on TNF-α and IL-6 levels. CONCLUSION: It can be concluded that whey supplementation had no favorable effects on inflammatory biomarkers including TNF- α and IL-6.

Can vitamin E supplementation affect obesity indices? A systematic review and meta-analysis of twenty-four randomized controlled trials.

BACKGROUND: Several mechanisms have been proposed for the effect of vitamin E on weight loss. Yet various interventional studies with wide ranges of doses and durations have reported contradictory results. METHODS: Cochrane Library, PubMed, Scopus, and Embase databases were searched up to December 2020. Meta-analysis was performed using random-effect method. Effect size was presented as weighted mean difference (WMD) and 95% confidence interval (CI). Heterogeneity was evaluated using the I2 index. In order to identification of potential sources of heterogeneity, predefined subgroup and meta regression analyses was conducted. RESULTS: A total of 24 studies with 33 data sets were included. There was no significant effect of vitamin E on weight (WMD: 0.15, 95% CI: -1.35 to 1.65, P = 0.847), body mass index (BMI) (WMD = 0.04, 95% CI: -0.29 to 0.37, P = 0.815), and waist circumference (WC) (WMD = -0.19 kg, 95% CI: -2.06 to 1.68, P = 0.842), respectively. However, subgroup analysis revealed that vitamin E supplementation in studies conducted on participants with normal BMI (18.5-24.9) had increasing impact on BMI (P = 0.047). CONCLUSION: There was no significant effect of vitamin E supplementation on weight, BMI and WC. However, vitamin E supplementation might be associated with increasing BMI in people with normal BMI (18.5-24.9).

Wild pistachio (Pistacia atlantica mutica) oil improve metabolic syndrome features in rats with high fructose ingestion.

OBJECTIVES: Metabolic syndrome is a multiplex risk factor for diabetes and cardiovascular disease. Since some dietary fats such as mono-unsaturated fatty acids (MUFA) modify metabolic syndrome components the aim of the present study was to evaluate the preventive effects of mixture, kernel and hull oils of wild pistachio (WP) (Pistacia atlantica mutica) as good sources of MUFA on different features of this abnormality in rats under induction. MATERIALS AND METHODS: In this study rats were randomly assigned to six groups with 12 animals per group. Metabolic syndrome was induced by fructose solution in groups 2, 3, 4, 5, and 6. Group 3 received sunflower oil and groups 4, 5, and 6 received mixture, hull and kernel oils of WP (2 ml/kg/day), respectively, for 10 weeks. Then, lipid profiles, glycemic indices, oxidative stress and inflammatory parameters were measured using standard laboratory tests. RESULTS: Different forms of WP oil induced hypotriglyceridemia, but the hypocholesterolemia effect was seen only in the mixed and kernel oil groups. Kernel oil also significantly reduced LDL and HDL cholesterol (P<0.05). In addition, mixed and kernel oils notably decreased glycemic indices (fasting blood glucose and insulin resistance) compared with the fructose group. Serum insulin levels were significantly increased in the kernel oil group (P<0.05). All WP oils also significantly decreased inflammation (IL-6). CONCLUSION: The results showed that the consumption of WP kernel oil may have beneficial effects on preventing hyperglycemia, hypertriglyceridemia, hypercholesterolemia, inflammation and pancreatic secretory disorders.