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Hormone Molecular Biology and Clinical... Sep 2020The increasing prevalence of metabolic syndrome (MS) especially in female population, has become a major problem in health care systems. In this regards, it is necessary... (Meta-Analysis)
Meta-Analysis
BACKGROUND
The increasing prevalence of metabolic syndrome (MS) especially in female population, has become a major problem in health care systems. In this regards, it is necessary to identify the risk factors. Vitamin D deficiency is now proposed as one of the possible risk factors for metabolic syndrome, we investigated the relationship between vitamin D status and MS in female.
METHODS
We searched observational studies with keywords Vitamin D, metabolic syndrome, metabolic syndrome X, insulin-resistance syndrome, metabolic cardiovascular syndrome and Reaven Syndrome X and female in pubmed, scopus, science direct, cochrane, web of science, google scholar and SID databases, regardless of publication time. Two hundred ninety five studies were found, and finally only 12 articles were selected according to exclusion and inclusion criteria.
RESULTS
In nine studies that reported the prevalence of MS, the prevalence of MS among women with vitamin D deficiency was higher than female with normal vitamin D (34.5 vs. 30.2%). The prevalence of abdominal obesity, high blood pressure, high TG and HDL deficiency is higher in women with vitamin D deficiency. Also, the mean waist circumference, blood pressure, fast blood sugar (FBS), TG and BMI were higher. The most incident factor was high blood pressure (61.4 vs. 56.5%) and the lowest prevalence is associated with high FBS (32.2 vs. 33.5% in the other group).
CONCLUSION
The prevalence of MS is significantly associated with vitamin D deficiency, and among related factors, HDL, TG and blood pressure are statistically associated with vitamin D status.
Topics: Biomarkers; Disease Susceptibility; Female; Humans; Metabolic Syndrome; Population Surveillance; Prevalence; Sex Factors; Vitamin D Deficiency
PubMed: 32986612
DOI: 10.1515/hmbci-2020-0033 -
Nutrients May 2022Vitamin E deficiency (VED) is associated with clinical repercussions in preterm newborns (PTN), but low levels are also found in full-term newborns (TN). As this... (Review)
Review
Vitamin E deficiency (VED) is associated with clinical repercussions in preterm newborns (PTN), but low levels are also found in full-term newborns (TN). As this inadequacy can compromise neurogenesis in childhood, studies are needed to assess whether there is a difference in vitamin E status among newborns according to gestational age to provide support for neonatal monitoring protocols. This systematic review presents a synthesis of the available information on the vitamin E status among PTN and TN. The review was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Observational studies that evaluated alpha-tocopherol levels were searched in the databases reported in the protocol registered in PROSPERO (CRD42021165152). The Newcastle-Ottawa Scale was used to assess the methodological quality. Overall, 1809 articles were retrieved; 10 were included in the systematic review. In the PTN, the alpha-tocopherol levels ranged from 3.9 to 8.5 mmol/L, while in TN, they were 4.9 to 14.9 mmol/L, and VED ranged from 19% to 100% in newborns. Despite substantial heterogeneity in research methodology and VED classification, the results suggest that the alpha-tocopherol levels among preterm and full-term newborns is below the recommended levels. Our findings demonstrate that further investigations are needed to standardize this classification and to monitor vitamin E status in birth and postnatal with adequate bias control.
Topics: Gestational Age; Humans; Infant; Infant, Newborn; Vitamin E; Vitamin E Deficiency; alpha-Tocopherol
PubMed: 35684057
DOI: 10.3390/nu14112257 -
Allergy and Asthma Proceedings May 2017Vitamin D insufficiency has been associated with immune dysfunction and linked to the epidemic of atopic diseases in the Western hemisphere, yet there are studies with... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Vitamin D insufficiency has been associated with immune dysfunction and linked to the epidemic of atopic diseases in the Western hemisphere, yet there are studies with conflicting results, and the risk has not been quantified uniformly across studies.
OBJECTIVE
To perform a systematic review and meta-analysis to evaluate and quantify if vitamin D deficiency is associated with the presence and persistence of food allergy.
METHODS
A systematic review was undertaken to assess for the association between food allergy and vitamin D status in children.
RESULTS
A total of 368 citations relevant to this systematic review were identified. In the whole review, 5105 children were included. We did not find a significant association between 25 hydroxy vitamin D (25(OH)D) status and risk of food allergy in children (odds ratio [OR] 1.35 [95% confidence interval {CI}, 0.79-2.29]; p = 0.27, I2 = 58.3%). We conducted subgroup analyses based on different cutoffs of the 25(OH)D status (20 versus 30 ng/mL). Only one study used 30 ng/mL and found that children with <30 ng/mL were more likely to report food allergy than children with a 25(OH)D status of ≥30 ng/mL (OR 2.04 [95% CI, 1.02-4.04]; p = 0.04). Four studies compared children with a 25(OH)D status of <20 ng/mL to children with a 25(OH)D status of ≥20 ng/mL and found no significant differences (OR 1.18 [95% CI, 0.62-2.27]; p = 0.62, I2 = 62.7%).
CONCLUSION
Based on the studies analyzed, this systematic review did not identify a significant association between vitamin D status and food allergy. Interpretation of the included studies was limited by a lack of a standard definition for vitamin D deficiency and insufficient knowledge regarding the optimal vitamin D status needed to impact immune function. Longitudinal studies are warranted to assess if vitamin D might contribute to the development of food allergy.
Topics: Child; Food Hypersensitivity; Humans; Odds Ratio; Vitamin D; Vitamin D Deficiency
PubMed: 28441981
DOI: 10.2500/aap.2017.38.4043 -
Maturitas May 2014Vitamin D has multiple functions in the nervous system. Our objective was to systematically review and quantitatively synthesize evidence on the location and nature of... (Meta-Analysis)
Meta-Analysis Review
Vitamin D has multiple functions in the nervous system. Our objective was to systematically review and quantitatively synthesize evidence on the location and nature of brain morphometric changes linked to vitamin D depletion or repletion. A Medline search was conducted in February 2014, without limit of date and language restriction, using the MeSH terms "Vitamin D" OR "Ergocalciferols" combined with "Brain Mapping" OR "Magnetic Resonance Imaging" OR "Tomography, X-ray Computed" OR "Tomography, Emission-Computed, Single-Photon" OR "Positron-Emission Tomography" OR "Nuclear Medicine" OR "Radionucleide Imaging". Of the 376 selected studies, nine observational studies - two animal and seven human studies - met the selection criteria. The number of participants ranged from 20 to 333 (40-79% female). Three studies were eligible for fixed-effects meta-analysis of bias-corrected effect size of the difference in lateral ventricle volume between cases with vitamin D depletion and controls. Results showed that vitamin D depletion was associated with lower brain volume, specifically larger lateral ventricles. The pooled effect size was 1.01 [95% CI: 0.62; 1.41], a 'large' effect size indicating that the ventricle volume was 1.01 SD higher with vitamin D depletion. Results on brain subvolumes were mixed, and indicated that brain atrophy with vitamin D depletion could be explained not by temporal lobe atrophy but rather by loss of matter at the cranial vertex, possibly in the precuneus cortex. In conclusion, despite increasing evidence arguing for an action of vitamin D in the brain, data is sparse regarding brain morphological changes related to vitamin D depletion. The retrieved association between vitamin D depletion and brain atrophy provides a scientific base for vitamin D replacement trials.
Topics: Atrophy; Brain; Female; Humans; Lateral Ventricles; Male; Vitamin D; Vitamin D Deficiency
PubMed: 24674855
DOI: 10.1016/j.maturitas.2014.02.013 -
BioMed Research International 2020Vitamin A deficiency is a major nutritional concern in lower-income countries. The aim of this systematic review and meta-analysis was to show the magnitude of vitamin A... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Vitamin A deficiency is a major nutritional concern in lower-income countries. The aim of this systematic review and meta-analysis was to show the magnitude of vitamin A deficiency among preschoolers in Ethiopia.
OBJECTIVE
The present study was aimed at synthesizing qualitatively and quantitatively the existing literature on the prevalence of VAD in preschool children in Ethiopia.
METHODS
Studies were searched through the search engine of Google Scholar, Hinari, MEDLINE/PubMed, Cochrane Library, and Africa-Wide Information. Searching was made using the keywords/MeSH of vitamin A deficiency, xerophthalmia, night blindness, Bitot's spot, retinol, children, and Ethiopia. Data were analyzed and compared with the WHO threshold criteria to declare a public health problem. Heterogeneity among studies was assessed using a Cochran test and statistics. A random-effects model with 95% confidence interval was used for prevalence estimations.
RESULTS
Of the 13 studies included in clinical analysis, 12 of them reported the prevalence of night blindness and/or Bitot's spot among preschool children in Ethiopia which was above WHO cutoff point for the public health problem 1% and 0.5%, respectively. The prevalence of night blindness significantly decreased from moderate public health problem 4.2% (95% CI: 2.8%-5.7%) in a period from 1990 to 2004 to mild public health problem 0.8% (95% CI: 0.6%-1.0%) in a period from 2005 to 2019. Furthermore, statistically insignificant reduction was observed in the prevalence of Bitot's spot in a period from 1990 to 2004, 2.2% (95% CI: 1.3%-3.2%) to 1.8% (95% CI: 1.2%-2.3%) in a period from 2005 to 2019. Among 8 studies on subclinical vitamin A deficiency, 7 of them indicated a severe public health problem (>20%). The prevalence of subclinical vitamin A deficiency decreased from 55.7% (95% CI: 39.8%-71.6%) in a period from 1990 to 2004 to 28.3% (95% CI: 9.8%-46.7%) in a period from 2005 to 2019, but not statistically significant.
CONCLUSIONS
Despite the reduced proportion of night blindness and Bitot's spot, still both clinical and subclinical vitamin A deficiencies remain a public health problem in Ethiopia requiring strengthen intervention through the newly initiated health extension program.
Topics: Child, Preschool; Ethiopia; Female; Humans; Infant; Infant, Newborn; Male; Models, Biological; Prevalence; Vitamin A Deficiency
PubMed: 32258145
DOI: 10.1155/2020/8032894 -
Clinical Nutrition (Edinburgh, Scotland) Feb 2016Vitamin D inadequacy is now an internationally recognized health problem and pediatric cancer patients may be at even higher risk than healthy children. We aimed to... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND AND AIMS
Vitamin D inadequacy is now an internationally recognized health problem and pediatric cancer patients may be at even higher risk than healthy children. We aimed to evaluate primary research to establish the prevalence of vitamin D inadequacy and to explore its possible causes in pediatric cancer patients.
METHODS
Electronic databases were searched (no restriction-Aug 2013) with no language restrictions and keywords related to cancer and vitamin D. We included studies of patients aged <18 years, diagnosed with and treated for cancer and reporting plasma vitamin D status. Evidence was critically appraised employing the CASP tool. Meta-analysis was performed when appropriate.
RESULTS
We included 19 studies, which were mainly of moderate-quality and heterogeneous in the definitions of vitamin D deficiency and insufficiency. The median (range) prevalence of vitamin D deficiency was 14% (0-61.5%) and insufficiency 23% (0-83%). Finally, a significant effect of younger age with vitamin D inadequacy was shown (effect size: -0.132; 95%CI -0.203, -0.060).
CONCLUSION
There is a possibility of a high prevalence of vitamin D inadequacy in pediatric cancer patients, especially older children, urging the need for high-quality population-based longitudinal studies using standard definitions.
Topics: Adolescent; Child; Databases, Factual; Dietary Supplements; Humans; Neoplasms; Parathyroid Hormone; Prevalence; Vitamin D; Vitamin D Deficiency
PubMed: 25638403
DOI: 10.1016/j.clnu.2014.12.023 -
International Journal of Environmental... Jul 2022Vitamin D deficiency and insufficiency are highly prevalent conditions worldwide due to several factors, including poor sun exposure. Shift workers may be exposed to the... (Meta-Analysis)
Meta-Analysis Review
Vitamin D deficiency and insufficiency are highly prevalent conditions worldwide due to several factors, including poor sun exposure. Shift workers may be exposed to the risk of hypovitaminosis D due to fewer opportunities for sunlight exposure compared to day workers. A systematic review of the PubMed, SCOPUS, and EMBASE databases was conducted according to the Preferred Reporting Items for Systemic Reviews and Meta-Analyses (PRISMA) statement to investigate the effect of shift work on vitamin D levels. Mean differences (MD) and 95% confidence intervals (CI) of serum 25-OH-D levels in shift workers and non-shift workers were calculated. A total of 13 cross-sectional studies were included in the meta-analysis. We found significantly lower levels of serum 25-OH-D in shift workers compared with non-shift workers (MD: −1.85, 95% CI [−2.49 to −1.21]). Heterogeneity among included studies was high (I2 = 89%, p < 0.0001), and neither subgroup analysis nor meta-regression were able to identify specific sources of the heterogeneity that may be related to the different characteristics of shift work among studies. The monitoring of serum vitamin D levels and prompt correction of any deficiencies should be considered in shift workers. Notably, since a large part of the observations are derived from Koreans, larger epidemiological studies are needed in other populations.
Topics: Cross-Sectional Studies; Humans; Rickets; Vitamin D; Vitamin D Deficiency; Vitamins
PubMed: 35897284
DOI: 10.3390/ijerph19158919 -
Osteoporosis International : a Journal... Jun 2021Thalassemia is a chronic congenital disease characterized by a combination of endocrine and metabolic disorders. Bone disease is a very common complication related to... (Review)
Review
Thalassemia is a chronic congenital disease characterized by a combination of endocrine and metabolic disorders. Bone disease is a very common complication related to the poor absorption of calcium, the secondary chronic renal disease with low vitamin D, as well as multiple endocrine risk factors. The aim of this systematic review was to estimate the prevalence of vitamin D deficiency in thalassemia, as well as its association with osteoporosis/low bone mass. A systematic review was carried out using PubMed/Medline, Cochrane, and EBSCO databases. The methodological quality of the included studies was assessed with the validated Newcastle-Ottawa Quality Assessment Scale adapted for cross-sectional studies and cohort studies respectfully and the Cochrane Collaboration for clinical trials. After application of predetermined exclusion criteria compatible with the PICOS process, a total of 12 suitable articles were identified. The prevalence of vitamin D deficiency varied considerably. Only five of the reviewed studies examined the correlation between vitamin D levels and BMD of which just three showed a statistically significant positive association of mild/moderate grade. Vitamin D deficiency is a common comorbidity in patients with thalassemia. However, both its prevalence and its severity vary considerably in different populations, and existing evidence is insufficient to conclude whether vitamin D supplementation is also associated with BMD improvement in this special population group.
Topics: Bone Density; Cross-Sectional Studies; Health Status; Humans; Vitamin D; Vitamin D Deficiency; Vitamins; beta-Thalassemia
PubMed: 33423084
DOI: 10.1007/s00198-021-05821-w -
Epidemiology and Health 2021Although vaccination has started, coronavirus disease 2019 (COVID-19) poses a continuing threat to public health. Therefore, in addition to vaccination, the use of... (Meta-Analysis)
Meta-Analysis
OBJECTIVES
Although vaccination has started, coronavirus disease 2019 (COVID-19) poses a continuing threat to public health. Therefore, in addition to vaccination, the use of supplements to support the immune system may be important. The purpose of this study was to synthesize evidence on the possible effect of low serum vitamin D levels (25[OH]D<20 ng/mL or 50 nmol/L) on COVID-19 infection and outcomes.
METHODS
We searched Google Scholar, PubMed, Scopus, Web of Science, and ScienceDirect without any language restrictions for articles published between January 1 and December 15, 2020. We performed 3 meta-analyses (called vitamin D and COVID-19 infection meta-analysis [D-CIMA], vitamin D and COVID-19 severity meta-analysis [D-CSMA], and vitamin D and COV ID-19 mortality meta-analysis [D-CMMA] for COVID-19 infection, severity, and mortality, respectively) to combine odds ratio values according to laboratory measurement units for vitamin D and the measured serum 25(OH)D level.
RESULTS
Twenty-one eligible studies were found to be relevant to the relationship between vitamin D and COVID-19 infection/outcomes (n=205,869). The D-CIMA meta-analysis showed that individuals with low serum vitamin D levels were 1.64 times (95% confidence interval [CI], 1.32 to 2.04; p<0.001) more likely to contract COVID-19. The D-CSMA meta-analysis showed that people with serum 25(OH)D levels below 20 ng/mL or 50 nmol/L were 2.42 times (95% CI, 1.13 to 5.18; p=0.022) more likely to have severe COVID-19. The D-CMMA meta-analysis showed that low vitamin D levels had no effect on COVID-19 mortality (OR, 1.64; 95% CI, 0.53 to 5.06, p=0.390).
CONCLUSIONS
According to our results, vitamin D deficiency may increase the risk of COVID-19 infection and the likelihood of severe disease. Therefore, we recommend vitamin D supplementation to prevent COVID-19 and its negative outcomes.
Topics: COVID-19; Humans; SARS-CoV-2; Vitamin D; Vitamin D Deficiency; Vitamins
PubMed: 34607398
DOI: 10.4178/epih.e2021074 -
The Cochrane Database of Systematic... Mar 2022Vitamin A deficiency (VAD) is a major public health problem in low- and middle-income countries, affecting 190 million children under five years of age and leading to... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Vitamin A deficiency (VAD) is a major public health problem in low- and middle-income countries, affecting 190 million children under five years of age and leading to many adverse health consequences, including death. Based on prior evidence and a previous version of this review, the World Health Organization has continued to recommend vitamin A supplementation (VAS) for children aged 6 to 59 months. The last version of this review was published in 2017, and this is an updated version of that review.
OBJECTIVES
To assess the effects of vitamin A supplementation (VAS) for preventing morbidity and mortality in children aged six months to five years.
SEARCH METHODS
We searched CENTRAL, MEDLINE, Embase, six other databases, and two trials registers up to March 2021. We also checked reference lists and contacted relevant organisations and researchers to identify additional studies.
SELECTION CRITERIA
Randomised controlled trials (RCTs) and cluster-RCTs evaluating the effect of synthetic VAS in children aged six months to five years living in the community. We excluded studies involving children in hospital and children with disease or infection. We also excluded studies evaluating the effects of food fortification, consumption of vitamin A rich foods, or beta-carotene supplementation.
DATA COLLECTION AND ANALYSIS
For this update, two review authors independently assessed studies for inclusion resolving discrepancies by discussion. We performed meta-analyses for outcomes, including all-cause and cause-specific mortality, disease, vision, and side effects. We used the GRADE approach to assess the quality of the evidence.
MAIN RESULTS
The updated search identified no new RCTs. We identified 47 studies, involving approximately 1,223,856 children. Studies were set in 19 countries: 30 (63%) in Asia, 16 of these in India; 8 (17%) in Africa; 7 (15%) in Latin America, and 2 (4%) in Australia. About one-third of the studies were in urban/periurban settings, and half were in rural settings; the remaining studies did not clearly report settings. Most studies included equal numbers of girls and boys and lasted about one year. The mean age of the children was about 33 months. The included studies were at variable overall risk of bias; however, evidence for the primary outcome was at low risk of bias. A meta-analysis for all-cause mortality included 19 trials (1,202,382 children). At longest follow-up, there was a 12% observed reduction in the risk of all-cause mortality for VAS compared with control using a fixed-effect model (risk ratio (RR) 0.88, 95% confidence interval (CI) 0.83 to 0.93; high-certainty evidence). Nine trials reported mortality due to diarrhoea and showed a 12% overall reduction for VAS (RR 0.88, 95% CI 0.79 to 0.98; 1,098,538 children; high-certainty evidence). There was no evidence of a difference for VAS on mortality due to measles (RR 0.88, 95% CI 0.69 to 1.11; 6 studies, 1,088,261 children; low-certainty evidence), respiratory disease (RR 0.98, 95% CI 0.86 to 1.12; 9 studies, 1,098,538 children; low-certainty evidence), and meningitis. VAS reduced the incidence of diarrhoea (RR 0.85, 95% CI 0.82 to 0.87; 15 studies, 77,946 children; low-certainty evidence), measles (RR 0.50, 95% CI 0.37 to 0.67; 6 studies, 19,566 children; moderate-certainty evidence), Bitot's spots (RR 0.42, 95% CI 0.33 to 0.53; 5 studies, 1,063,278 children; moderate-certainty evidence), night blindness (RR 0.32, 95% CI 0.21 to 0.50; 2 studies, 22,972 children; moderate-certainty evidence), and VAD (RR 0.71, 95% CI 0.65 to 0.78; 4 studies, 2262 children, moderate-certainty evidence). However, there was no evidence of a difference on incidence of respiratory disease (RR 0.99, 95% CI 0.92 to 1.06; 11 studies, 27,540 children; low-certainty evidence) or hospitalisations due to diarrhoea or pneumonia. There was an increased risk of vomiting within the first 48 hours of VAS (RR 1.97, 95% CI 1.44 to 2.69; 4 studies, 10,541 children; moderate-certainty evidence).
AUTHORS' CONCLUSIONS
This update identified no new eligible studies and the conclusions remain the same. VAS is associated with a clinically meaningful reduction in morbidity and mortality in children. Further placebo-controlled trials of VAS in children between six months and five years of age would not change the conclusions of this review, although studies that compare different doses and delivery mechanisms are needed. In populations with documented VAD, it would be unethical to conduct placebo-controlled trials.
Topics: Child; Child, Preschool; Diarrhea; Dietary Supplements; Female; Humans; Male; Measles; Morbidity; Respiration Disorders; Vitamin A; Vitamin A Deficiency
PubMed: 35294044
DOI: 10.1002/14651858.CD008524.pub4