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BMJ Global Health Apr 2024Traditionally associated with undernutrition, increasing evidence suggests micronutrient deficiencies can coexist with overnutrition. Therefore, this work aimed to... (Meta-Analysis)
Meta-Analysis
INTRODUCTION
Traditionally associated with undernutrition, increasing evidence suggests micronutrient deficiencies can coexist with overnutrition. Therefore, this work aimed to systematically review the associations between iron, zinc and vitamin A (VA) status and weight status (both underweight and overweight) in children and young people.
METHODS
Ovid Medline, Ovid Embase, Scopus and Cochrane databases were systematically searched for observational studies assessing micronutrient status (blood, serum or plasma levels of iron, zinc or VA biomarkers) and weight status (body mass index or other anthropometric measurement) in humans under 25 years of any ethnicity and gender. Risk of bias assessment was conducted using the American Dietetic Association Quality Criteria Checklist. Where possible, random effects restricted maximum likelihood meta-analyses were performed.
RESULTS
After screening, 83 observational studies involving 190 443 participants from 44 countries were identified, with many studies having reported on more than one micronutrient and/or weight status indicator. Iron was the most investigated micronutrient, with 46, 28 and 27 studies reporting data for iron, zinc and VA status, respectively. Synthesising 16 records of OR from seven eligible studies, overnutrition (overweight and obesity) increased odds of iron deficiency (ID) (OR (95% CI): 1.51 (1.20 to 1.82), p<0.0001, I=40.7%). Odds appeared to be higher for children living with obesity (1.88 (1.33 to 2.43), p<0.0001, I=20.6%) in comparison to those with overweight (1.31 (0.98 to 1.64), p<0.0001, I=40.5%), although between group differences were not significant (p=0.08).
CONCLUSIONS
Overnutrition is associated with increased risk of ID, but not zinc or VA deficiencies, with an inverted U-shaped relationship observed between iron status and bodyweight. Our results highlight significant heterogeneity in the reporting of micronutrient biomarkers and how deficiencies were defined. Inflammation status was rarely adequately accounted for, and the burden of ID may well be under-recognised, particularly in children and young people living with overnutrition.
PROSPERO REGISTRATION NUMBER
CRD42020221523.
Topics: Child; Humans; Adolescent; Iron; Vitamin A Deficiency; Zinc; Overweight; Anemia, Iron-Deficiency; Micronutrients; Overnutrition; Vitamin A; Obesity; Risk Factors; Biomarkers
PubMed: 38599666
DOI: 10.1136/bmjgh-2024-015135 -
Nutrients Jul 2023Vitamin D has been shown to have multiple pleiotropic effects beyond bone and mineral metabolism, with purported roles in cardiovascular disease, cancer, and host... (Review)
Review
Vitamin D has been shown to have multiple pleiotropic effects beyond bone and mineral metabolism, with purported roles in cardiovascular disease, cancer, and host immunity. Vitamin D deficiency is common in patients with end-stage kidney disease (ESKD); however, current clinical practice has favored the use of the active hormone. Whether vitamin D deficiency should be corrected in patients with ESKD remains unclear, as few randomized trials have been conducted. In this systematic review, we summarize the current evidence examining whether vitamin D supplementation improves outcomes, beyond mineral metabolism, in patients with ESKD. Data from randomized controlled trials of adults with ESKD were obtained by searching Ovid MEDLINE, Embase, the Cochrane Central Register of Controlled Trials, and the Web of Science Core Collection from inception to February 2023. Twenty-three trials composed of 2489 participants were identified for inclusion. Data were synthesized by two independent reviewers and summarized in tables organized by outcome. Outcomes included measures of mortality, cardiovascular disease, inflammation, muscle strength/function, nutrition, patient well-being, and outcomes specific to ESKD including erythropoietin usage, pruritus, and dialysis access maturation. The Cochrane risk of Bias Tool (RoB 2, 2019) was used to assess study quality. Overall, our findings indicate a minimal and varied benefit of native vitamin D supplementation. From the largest studies included, we determine that vitamin D has no demonstrated effect on patient-reported measures of well-being or utilization of erythropoietin, nor does it change levels of the inflammation biomarker -reactive protein. Included trials were heterogeneous with regards to outcomes, and the majority studied small participant populations with a relatively short follow-up. We conclude that vitamin D supplementation corrects vitamin D deficiency and is safe and well-tolerated in humans with ESKD. However, it is not clear from clinical trials conducted to date that a causal pathway exists between 25(OH)D and pleiotropic effects that is responsive to vitamin D treatment.
Topics: Adult; Humans; Vitamin D; Cardiovascular Diseases; Renal Dialysis; Randomized Controlled Trials as Topic; Vitamins; Kidney Failure, Chronic; Vitamin D Deficiency; Dietary Supplements; Erythropoietin; Minerals
PubMed: 37447398
DOI: 10.3390/nu15133072 -
European Journal of Nutrition Apr 2024The objective of this systematic review was to determine a minimum serum 25-hydroxyvitamin D (25OHD) threshold based on the risk of having rickets in young children.... (Meta-Analysis)
Meta-Analysis Review
Serum 25-hydroxyvitamin D threshold and risk of rickets in young children: a systematic review and individual participant data meta-analysis to inform the development of dietary requirements for vitamin D.
PURPOSE
The objective of this systematic review was to determine a minimum serum 25-hydroxyvitamin D (25OHD) threshold based on the risk of having rickets in young children. This work was commissioned by the WHO and FAO within the framework of the update of the vitamin D requirements for children 0-3 years old.
METHODS
A systematic search of Embase was conducted to identify studies involving children below 4 years of age with serum 25OHD levels and radiologically confirmed rickets, without any restriction related to the geographical location or language. Study-level and individual participant data (IPD)-level random effects multi-level meta-analyses were conducted. The odds, sensitivity and specificity for rickets at different serum 25OHD thresholds were calculated for all children as well as for children with adequate calcium intakes only.
RESULTS
A total of 120 studies with 5412 participants were included. At the study-level, children with rickets had a mean serum 25OHD of 23 nmol/L (95% CI 19-27). At the IPD level, children with rickets had a median and mean serum 25OHD of 23 and 29 nmol/L, respectively. More than half (55%) of the children with rickets had serum 25OHD below 25 nmol/L, 62% below 30 nmol/L, and 79% below 40 nmol/L. Analysis of odds, sensitivities and specificities for nutritional rickets at different serum 25OHD thresholds suggested a minimal risk threshold of around 28 nmol/L for children with adequate calcium intakes and 40 nmol/L for children with low calcium intakes.
CONCLUSION
This systematic review and IPD meta-analysis suggests that from a public health perspective and to inform the development of dietary requirements for vitamin D, a minimum serum 25OHD threshold of around 28 nmol/L and above would represent a low risk of nutritional rickets for the majority of children with an adequate calcium intake.
Topics: Child; Humans; Child, Preschool; Infant, Newborn; Infant; Calcium; Vitamin D Deficiency; Vitamin D; Rickets; Vitamins; Calcifediol; Nutritional Requirements
PubMed: 38280944
DOI: 10.1007/s00394-023-03299-2 -
National Journal of Maxillofacial... 2023Bone metabolism is a key factor for successful osseointegration, and low vitamin D levels may negatively impact the process of osseointegration after implant placement.... (Review)
Review
Bone metabolism is a key factor for successful osseointegration, and low vitamin D levels may negatively impact the process of osseointegration after implant placement. The study was aimed at evaluating the relation of vitamin D levels with dental implant osseointegration and subsequently the success or failure of the implant. The focused questions were-What is the effect of vitamin D levels on successful dental implant osseointegration and what is the effect of vitamin D supplementation on successful implant osseointegration? A search was conducted on PubMed and Google Scholar using the terms "vitamin D," "cholecalciferol," "1,25(OH) D," "dental implant," "osseointegration," and "bone implant contact" for a period of 10 years from 2011 to 2020. Clinical trials, cross-sectional studies, case series, and case reports were included. A total of ten studies were included after the screening process. Five of these studies evaluated the effect of vitamin D supplementation on osseointegration, whereas five only evaluated the effect of vitamin D deficiency on dental implant osseointegration. Only five of these studies reported dental implant failure varying from 7% to 13% in vitamin D deficient/insufficient groups. Positive relationship exists between serum vitamin D levels and dental implant osseointegration; however, few studies failed to report any relation. More prospective clinical research studies as well as randomized controlled trials are needed to show a significant correlation between decreased serum levels of vitamin D and increased risk of dental implant failure in perspective of vitamin D supplementation which can promote the osseointegration of dental implants.
PubMed: 38273924
DOI: 10.4103/njms.njms_192_22 -
Frontiers in Nutrition 2023Since the association of vitamin D with atrial fibrillation (AF) risk is still unclear, we conducted this updated meta-analysis of prospective studies to identify the...
BACKGROUND
Since the association of vitamin D with atrial fibrillation (AF) risk is still unclear, we conducted this updated meta-analysis of prospective studies to identify the relationship between vitamin D or vitamin D supplementation and AF in the general population.
METHODS
We conducted a comprehensive search of multiple databases up to May 2023 for studies reporting vitamin D and AF. The hazard ratios (HRs) with 95% confidence intervals (CIs) were pooled by a random-effects model.
RESULTS
A total of seven studies were included in this meta-analysis. Vitamin D deficiency (<20 ng/ml) was associated with increased AF incidence (HR: 1.12, 95% CI: 1.005-1.25). The HR was not significant with vitamin D insufficiency (20-30 ng/ml; HR: 1.09, 95% CI: 0.98-1.21). Each 10 ng/ml increase in serum vitamin D was associated with a significantly decreased AF incidence (HR: 0.95, 95% CI: 0.93-0.97). Two studies reported the effect of vitamin D supplements on AF incidence but reached inconsistent results.
CONCLUSIONS
Vitamin D deficiency or insufficiency was associated with an increased risk of AF in the general population. The role of vitamin D supplementation in AF prevention needs further investigation.
PubMed: 37810914
DOI: 10.3389/fnut.2023.1246359 -
BMJ Open Apr 2024The objective of this study is to determine the relationship between serum vitamin D level and the risk of developing benign paroxysmal positional vertigo (BPPV)... (Meta-Analysis)
Meta-Analysis
OBJECTIVES
The objective of this study is to determine the relationship between serum vitamin D level and the risk of developing benign paroxysmal positional vertigo (BPPV) incidence and recurrence in countries in the Northern Hemisphere.
DESIGN
Systematic review and meta-analysis.
DATA SOURCES
PubMed, Scopus and Web of Science databases were searched for studies published between January 2000 and February 2023.
ELIGIBILITY CRITERIA FOR SELECTING STUDIES
Participants located in the Northern Hemisphere aged 18 or over with at least one episode of BPPV, serum 25-hydroxyvitamin D levels measured and reported, no comorbidities or history of vitamin D supplementation.
DATA EXTRACTION AND SYNTHESIS
Data extraction and synthesis were performed by a single reviewer and checked by a second reviewer. Inclusion and exclusion criteria and risk of bias were assessed by two independent reviewers using the Newcastle Ottawa Tool for Cohort studies and Risk of Bias Assessment Tool for Nonrandomised Studies checklist for case-control studies. Meta-analysis was conducted using random effects models. Standard mean difference with a 95% CI was used to measure the relationship between vitamin D level and BPPV.
RESULTS
The 35 articles identified by the literature search reported data of 9843 individuals. 19 studies (7387 individuals) were included in the BPPV incidence meta-analysis while 7 studies (622 individuals) were included in the BPPV recurrence meta-analysis. Lower serum vitamin D levels were found in BPPV incidence compared with controls, but the relationship between vitamin D levels in recurrent BPPV compared with non-recurrent disease remained uncertain.
CONCLUSION
Results of this systematic review and meta-analysis demonstrated a negative correlation between serum vitamin D and BPPV incidence, while any relationship between serum vitamin D and BPPV recurrence remained uncertain. Risk of bias analysis revealed evidence of variable quality. There were insufficient data available to evaluate seasonal relationships between serum vitamin D and BPPV. Given the potential for this as a confounding factor, future research should aim to investigate this further.
PROSPERO REGISTRATION NUMBER
CRD42021271840.
Topics: Humans; Benign Paroxysmal Positional Vertigo; Vitamin D Deficiency; Recurrence; Incidence; Vitamin D
PubMed: 38653514
DOI: 10.1136/bmjopen-2023-077986 -
Nutrients Jan 2024Older adults are prone to vitamin D3 (VD3) deficiency, which may impair their health. A high dose of VD3 (HDVD3 = 100,000 IU) could improve their 25-hydroxyvitamin D3... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Older adults are prone to vitamin D3 (VD3) deficiency, which may impair their health. A high dose of VD3 (HDVD3 = 100,000 IU) could improve their 25-hydroxyvitamin D3 [25(OH)D] level and health outcomes. However, evidence for such a beneficial effect of HDVD3 in older adults coming from clinical trials is mixed.
OBJECTIVE
To review the literature on the efficacy of a single dose of 100,000 IU of VD3 in older people.
METHODS
We searched PubMed/Medline, Science Direct, and NIH's clinical trials registry for clinical studies on the effect of a single high dose of VD3 on various health outcomes in older people. We also performed a meta-analysis using the standardized mean difference to assess the effect of VD3 on its blood level. Due to expected high heterogeneity, its amount (i.e., tau) was estimated using the DerSimonian-Laird estimator. To estimate tau, the Q-test for heterogeneity and the statistic were calculated.
RESULTS
Search results identify 13 studies that reported diverse health outcomes, such as lung and cardiovascular function, skin cancer progression, intensive care unit mortality, immune system response, and bone density. The meta-analysis showed a significant increase in 25(OH)D blood levels after treatment in 10 studies, with an average standardized mean difference of 2.60 ng/mL (95% CI: 2.07 to 3.13). Their results suggested that a single high dose of VD3 may benefit intensive care unit patients and skin cancer patients in remission. However, evidence for other beneficial health effects of HDVD3 was mixed due to high heterogeneity among studies.
CONCLUSIONS
A single high dose of VD3 may positively affect some health outcomes in older people, possibly due to its pleiotropic and immunomodulatory effects. However, the evidence needs to be more extensive and consistent, and more rigorous studies are required to confirm the benefits and safety of VD3 high doses in older patients.
Topics: Humans; Aged; Cholecalciferol; Skin Neoplasms; Bone Density; Calcifediol; Critical Care
PubMed: 38257146
DOI: 10.3390/nu16020252 -
Nutrients Mar 2024People are increasingly encouraged to reduce animal food consumption and shift towards plant-based diets; however, the implications for children's health are unclear. In... (Review)
Review
People are increasingly encouraged to reduce animal food consumption and shift towards plant-based diets; however, the implications for children's health are unclear. In this narrative review of research in high-income settings, we summarize evidence on the increasing consumption of plant-based diets in children and update an earlier systematic review regarding their associations with children's health outcomes. The evidence indicates that vegan, but not vegetarian, diets can restrict growth relative to omnivorous children and increase the risk of being stunted and underweight, although the percentage affected is relatively small. Bone mineral content is reduced in vegetarian and, in particular, vegan children, compared to omnivores. Both vegetarian and vegan children who do not use vitamin B12 supplements manifest with B12 deficiency; however, supplementation rectifies this problem. Both vegetarians and vegans have lower concentrations of 25(OH)D if unsupplemented, and lower body iron stores, but usually have normal iron metabolism markers. Both groups are at risk of iodine deficiency, and this might affect thyroid health. Children consuming a vegan diet have a more favorable lipid profile than omnivorous children; however, the results for a vegetarian diet are inconsistent and vary by outcome. Based on the same scientific evidence, national and international dietary recommendations are heterogeneous, with some countries supporting plant-based diets among infants, children, and adolescents, and others discouraging them. We offer a research roadmap, highlighting what is needed to provide adequate evidence to harmonize dietary recommendations for plant-based diets in children. A number of measures should urgently be introduced at international and national levels to improve the safety of their use in children.
Topics: Child; Infant; Adolescent; Animals; Humans; Diet, Plant-Based; Diet; Diet, Vegetarian; Vegetarians; Diet, Vegan; Iron; Outcome Assessment, Health Care
PubMed: 38474851
DOI: 10.3390/nu16050723 -
Nutrition & Diabetes May 2024Vitamin D deficiency has been linked with several adverse maternal and fetal outcomes.
BACKGROUND
Vitamin D deficiency has been linked with several adverse maternal and fetal outcomes.
OBJECTIVE
To summarize systematic reviews and meta-analyses evaluating the effects of vitamin D deficiency and of vitamin D supplementation in pregnancy on maternal and offspring health-related outcomes.
METHODS
Prior to conducting this umbrella review, we registered the protocol in PROSPERO (CRD42022368003). We conducted searches in PubMed, Embase, and Cochrane Library for systematic reviews and meta-analyses on vitamin D in pregnancy, from database inception to October 2, 2023. All outcomes related to vitamin D in pregnancy obtained from the systematic reviews and meta-analyses were extracted.
DATA EXTRACTION
Two reviewers independently chose studies and collected information on health outcomes. The quality of the included articles' methodology was assessed using AMSTAR 2 (A Measurement Tool to Assess Systematic Reviews-2).
RESULTS
We identified 16 eligible systematic reviews and meta-analyses, which included 250,569 women. Our results demonstrated that vitamin D deficiency in pregnancy is associated with increased risk of preterm birth, small-for gestational age/low birth weight infants, recurrent miscarriage, bacterial vaginosis and gestational diabetes mellitus. Vitamin D supplementation in pregnancy increases birth weight, and reduces the risk of maternal pre-eclampsia, miscarriage, and vitamin D deficiency, fetal or neonatal mortality, as well as attention-deficit hyperactivity disorder, and autism spectrum disorder in childhood. In women with gestational diabetes mellitus, vitamin D supplementation in pregnancy can reduce the risk of maternal hyperbilirubinemia, polyhydramnios, macrosomia, fetal distress, and neonatal hospitalization.
CONCLUSION
Due to the association with adverse maternal and offspring health outcomes, we recommend the vitamin D status in pregnancy should be monitored, particularly in women at high risk of vitamin D deficiency. It is suggested that pregnant women take a dose of >400 IU/day of vitamin D supplementation during pregnancy to prevent certain adverse outcomes.
Topics: Humans; Pregnancy; Female; Vitamin D Deficiency; Vitamin D; Pregnancy Complications; Dietary Supplements; Pregnancy Outcome; Systematic Reviews as Topic; Meta-Analysis as Topic; Infant, Newborn; Premature Birth
PubMed: 38816412
DOI: 10.1038/s41387-024-00296-0 -
Journal of Intensive Care Medicine Sep 2023This study aims to investigate the risk factors associated with severity and death from COVID-19 through a systematic review and meta-analysis of the published... (Meta-Analysis)
Meta-Analysis Review
This study aims to investigate the risk factors associated with severity and death from COVID-19 through a systematic review and meta-analysis of the published documents in Iran. A systematic search was performed based on all articles indexed in Scopus, Embase, Web of Science (WOS), PubMed, and Google Scholar in English and Scientific Information Database (SID) and Iranian Research Institute for Information Science and Technology (IRA)NDOC indexes in Persian. To assess quality, we used the Newcastle Ottawa Scale. Publication bias was assessed using Egger's tests. Forest plots were used for a graphical description of the results. We used HRs, and ORs reported for the association between risk factors and COVID-19 severity and death. Sixty-nine studies were included in the meta-analysis, of which 62 and 13 had assessed risk factors for death and severity, respectively. The results showed a significant association between death from COVID-19 and age, male gender, diabetes, hypertension, cardiovascular disease (CVD), cerebrovascular disease, chronic kidney disease (CKD), Headache, and Dyspnea. We observed a significant association between increased white blood cell (WBC), decreased Lymphocyte, increased blood urea nitrogen (BUN), increased creatinine, vitamin D deficiency, and death from COVID-19. There was only a significant relationship between CVD and disease severity. It is recommended that the predictive risk factors of COVID-19 severity and death mentioned in this study to be used for therapeutic and health interventions, to update clinical guidelines and determine patients' prognoses.
Topics: Humans; Male; COVID-19; Iran; Risk Factors; Cerebrovascular Disorders; Cardiovascular Diseases
PubMed: 36976873
DOI: 10.1177/08850666231166344