Serum Vitamin D Level and Carotid Intima-Media Thickness: A Systematic Review and Meta-Analysis of Observational Studies and Randomized Control Trials

2020 ◽  
Vol 52 (05) ◽  
pp. 305-315
Author(s):  
Nasim Säidifard ◽  
Hadith Tangestani ◽  
Kurosh Djafarian ◽  
Sakineh Shab-Bidar

AbstractIt is reported that vitamin D deficiency is associated with carotid intima-media thickness (CIMT). In addition, several randomized clinical trials (RCTs) have studied the influence of vitamin D supplement on CIMT. However, results are inconclusive. This review aimed to systematically explore the potential link of the serum vitamin D level with CIMT pooling together observational studies and RCTs. PubMed and Scopus were searched for studies published until February 13, 2018. The Fisher’s z (SE) correlation coefficient, odds ratio (OR), and mean (SD) of changes in CIMT from baseline were used to perform meta-analysis in observational studies and RCTs, respectively. To pool data, both a fixed-effects model and a random-effects model (in case of heterogeneity) were used. Heterogeneity was assessed using Cochran’s Q and I2 tests. Nineteen observational studies and 3 RCTs met inclusion criteria. The pooled correlation coefficients of 17 observational studies showed [(Fisher’s z=− 0.41, 95% CI: –0.63 to –0.19, p<0.001), I2=96.9%, p < 0.001] a significant inverse association between serum vitamin D and risk of CIMT. Pooling three risk estimates of three studies [(OR = 1.69, 95% CI: 0.74 to 3.86, p=0.209); I2=085.1%, p<0.001)] indicated no significant association between serum vitamin D status and risk of CIMT. Combining data of RCTs showed vitamin D supplementation significantly reduced CIMT [(MD: –0.034, 95% CI: –0.62 to –0.05, p=0.012), I2=16.6%, p = 0.301]. Our findings show that serum vitamin D is inversely associated with CIMT and vitamin D supplementation may reduce CMIT.

2016 ◽  
Vol 116 (2) ◽  
pp. 286-293 ◽  
Author(s):  
Zatollah Asemi ◽  
Fariba Raygan ◽  
Fereshteh Bahmani ◽  
Zohreh Rezavandi ◽  
Hamid Reza Talari ◽  
...  

AbstractThis study was conducted to examine the effects of vitamin D, K and Ca co-supplementation on carotid intima-media thickness (CIMT) and metabolic status in overweight diabetic patients with CHD. This randomised, double-blind, placebo-controlled trial was conducted among sixty-six diabetic patients with CHD. Participants were randomly allocated into two groups to take either 5µg vitamin D, 90 µg vitamin K plus 500 mg Ca supplements (n 33) or placebo (n 33) twice a day for 12 weeks. Fasting blood samples were obtained at the beginning of the study and after the 12-week intervention period to determine related markers. Vitamin D, K and Ca co-supplementation resulted in a significant reduction in maximum levels of left CIMT (−0·04 (sd 0·22) v. +0·04 (sd 0·09) mm, P=0·02). Changes in serum vitamin D (+6·5 (sd 7·8) v. +0·4 (sd 2·2) ng/ml, P<0·001), Ca (+0·6 (sd 0·3) v. +0·1 (sd 0·1) mg/dl, P<0·001) and insulin concentrations (−0·9 (sd 3·1) v. +2·6 (sd 7·2) µIU/ml, P=0·01), homoeostasis model for assessment of estimated insulin resistance (−0·4 (sd 1·2) v. +0·7 (sd 2·3), P=0·01), β-cell function (−2·1 (sd 9·0) v. +8·9 (sd 23·7), P=0·01) and quantitative insulin sensitivity check index (+0·007 (sd 0·01) v. −0·006 (sd 0·02), P=0·01) in supplemented patients were significantly different from those in patients in the placebo group. Supplementation resulted in significant changes in HDL-cholesterol (+2·7 (sd 7·0) v. −2·5 (sd 5·7) mg/dl, P=0·002), high-sensitivity C-reactive protein (−1320·1 (sd 3758·3) v. +464·0 (sd 3053·3) ng/ml, P=0·03) and plasma malondialdehyde concentrations (−0·4 (sd 0·5) v. −1·0 (sd 1·1) µmol/l, P=0·007) compared with placebo. Overall, vitamin D, K and Ca co-supplementation for 12 weeks among diabetic patients with CHD had beneficial effects on maximum levels of left CIMT and metabolic status. The effect of vitamin D, K and Ca co-supplementation on maximum levels of left CIMT could be a chance finding.


Nutrients ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1182 ◽  
Author(s):  
Shamaila Rafiq ◽  
Per Jeppesen

The deficiency of vitamin D is prevalent all over the world. Studies have shown that vitamin D may play an important role in the development of obesity. The current study was conducted to quantitatively evaluate the association between serum 25-(OH) vitamin D levels and the risk of obesity in both diabetic and non-diabetic subjects. A systematic review and meta-analysis of observational studies was carried out for that purpose. We searched the Medline, PubMed, and Embase databases throughout all of March 2018. A total of fifty five observational studies for both diabetic and non-diabetic subjects were finally included in the meta-analysis. The data were analyzed by comprehensive meta-analysis software version 3 and the random effects model was used to analyze the data. The meta-analysis showed an overall inverse relationship between serum vitamin D status and body mass index (BMI) in studies of both diabetic (r = −0.173, 95% = −0.241 to −0.103, p = 0.000) and non-diabetic (r = −0.152, 95% = −0.187 to −0.116, p = 0.000) subjects. The evidence of publication bias was not found in this meta-analysis. In conclusion, the deficiency of vitamin D is associated with an increased level of BMI in the studies of both diabetic and non-diabetic subjects. Reliable evidence from well-designed future randomized controlled trials is required to confirm the findings from observational studies and to find out the potential regulatory effects of vitamin D supplementation to lower BMI.


2021 ◽  
Vol 9 ◽  
Author(s):  
Chunhua Song ◽  
Hongzhi Sun ◽  
Ben Wang ◽  
Chunli Song ◽  
Hongying Lu

Introduction: Undernutrition, defined as stunting, wasting, and underweight, still implicates millions of infants and children worldwide. Micronutrients have pivotal effects on growth rate. The outcomes of vitamin D deficiency on undernutrition indices have stayed controversial. The object of current study is to answer this question: is there any association between vitamin D status and undernutrition indices?Methods: The international databases were used for a systematic search to identify relevant observational studies in English up to January 2021. A random-effect model was applied to combine the results of included essays.Results: Among 3,400 citations, 7 observational studies (4 cohorts and 3 cross-sectional) were eligible to enter in meta-analysis. Analysis of the lowest 8,295 children indicated that low vs. high serum level of vitamin D is directly associated with a higher risk of wasting (Summary Risk Estimate: 1.30; 95% CI: 1.04, 1.62; I2 = 0%). However, there is no significant association between vitamin status and risk of stunting (Summary Risk Estimate: 1.10; 95% CI: 0.72, 1.70; I2 = 81.6%) and underweight (Summary Risk Estimate: 1.12; 95% CI: 0.81, 1.56; I2 = 49.2%).Conclusion: When comparing low and high serum vitamin D concentration categories, there is an inverse link between vitamin D status and wasting, but no relationship with stunting as well as underweight. However, further prospective and trial studies are required to deepen our understanding of these associations.


BMJ Open ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. e032626 ◽  
Author(s):  
Liza Bialy ◽  
Tanis Fenton ◽  
Jocelyn Shulhan-Kilroy ◽  
David W Johnson ◽  
Deborah A McNeil ◽  
...  

ObjectiveTo review the evidence to assess effectiveness of vitamin D supplementation during pregnancy and associations of serum vitamin D levels with perinatal outcomes.DesignOverview of systematic reviews (SRs).Data sourcesSearches conducted in January 2019: Ovid Medline (1946–), Cochrane Library databases.Eligibility criteria for selecting studiesTwo reviewers independently screened titles and abstracts, and full texts using predefined inclusion criteria: SRs evaluating vitamin D supplementation in pregnant women and/or examining the association between serum vitamin D levels reporting at least one predefined perinatal outcome. Only SRs with high AMSTAR scores were analysed.Data extraction and synthesisData were extracted independently by one reviewer and checked by a second. Results were assessed for quality independently by two reviewers using GRADE criteria.ResultsThirteen SRs were included, synthesising evidence from 204 unique primary studies. SRs of randomised controlled trials (RCTs) with the highest level of evidence showed no significant benefit from vitamin D in terms of preterm birth (RR 1.00 (95% CI 0.77, 1.30); high quality), pre-eclampsia (RR 0.91 (0.45, 1.86); low quality), gestational diabetes (RR 0.65 (0.39, 1.08); very low quality), stillbirth (RR 0.75 (0.50, 1.12); high quality), low birth weight (RR 0.74 (0.47, 1.16); low quality), caesarean section (RR 1.02 (0.93, 1.12); high quality). A significant difference was found for small for gestational age (RR 0.72 (0.52, 0.99); low quality). SRs of observational studies showed associations between vitamin D levels and preterm birth (RR 1.19 (1.08, 1.31); moderate quality), pre-eclampsia (RR 1.57 (1.21, 2.03) for 25-hydroxy vitamin D (25 (OH)D)<50 nmol/L subgroup; low quality), gestational diabetes (RR 1.12 (1.02, 1.22) for 25 (OH)D<50 nmol/L and RR 1.09 (1.03, 1.15)<75 nmol/L; moderate quality) and small for gestational age (RR 1.35 (1.18, 1.54)<50 nmol/L; low quality). SRs showed mixed results for associations between vitamin D and low birth weight (very low quality) and caesarean section (very low quality).ConclusionThere is some evidence from SRs of observational studies for associations between vitamin D serum levels and some outcomes; however SRs examining effectiveness from RCTs showed no effect of vitamin D supplementation in pregnancy with the exception of one predefined outcome, which had low quality evidence. Credibility of the evidence in this field is compromised by study limitations (in particular, the possibility of confounding among observational studies), inconsistency, imprecision and potential for reporting and publication biases.


Virulence ◽  
2017 ◽  
Vol 9 (1) ◽  
pp. 294-305 ◽  
Author(s):  
Allison Ross Eckard ◽  
Paolo Raggi ◽  
Mary Ann O'Riordan ◽  
Julia C. Rosebush ◽  
Danielle Labbato ◽  
...  

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