-
Advances in Nutrition (Bethesda, Md.) Jun 2021A systematic review was conducted to summarize the absorption, transport, storage, and metabolism of oral neonatal vitamin A supplementation (NVAS). This review focused...
A systematic review was conducted to summarize the absorption, transport, storage, and metabolism of oral neonatal vitamin A supplementation (NVAS). This review focused specifically on the neonatal period (first 28 d of life for humans) to inform guidance by WHO on recommendations related to NVAS. A systematic search of international and regional databases was conducted. Inclusion criteria were human or animal studies that gave oral vitamin A as a single or limited number of doses to apparently healthy neonates. Studies evaluating fortification or food-based approaches, dosing with retinoic acid, or studies of neonatal models of disease were excluded. The search retrieved 8847 unique records. After screening by title and abstract, 88 were screened using the full text, and 35 records met inclusion criteria: 13 human and 22 animal studies. Studies indicate that high-dose NVAS is absorbed well by neonates, typically mirroring fat absorption. Doses were primarily stored in the liver and transiently increased in the lung, kidney, spleen, adrenal glands, brain, skin, and adipose tissue, generally with a dose-response. Serum retinol and retinyl esters also transiently increased following NVAS. Although minimal acute adverse effects are noted, there is a lack of data supporting NVAS for improving organ maturation or sustained delivery to target organs. Research gaps include the physiological effects of the short-term increase of vitamin A concentrations in extrahepatic tissues, or whether there are unknown adverse effects over time.
Topics: Animals; Dietary Supplements; Humans; Infant, Newborn; Liver; Retinyl Esters; Vitamin A; Vitamin A Deficiency
PubMed: 33216111
DOI: 10.1093/advances/nmaa137 -
Skin Appendage Disorders Oct 2018There are a number of toxic agents that can cause alopecia. In this review we summarize the known substances that cause alopecia as one of the clinical signs of overdose... (Review)
Review
IMPORTANCE/OBJECTIVE
There are a number of toxic agents that can cause alopecia. In this review we summarize the known substances that cause alopecia as one of the clinical signs of overdose or toxicity.
EVIDENCE REVIEW
A search was conducted using PubMed, EMBASE, and Cochrane for studies describing hair loss of any type as a result of exposure to or ingestion of a toxic agent. The search yielded 856 articles, with 47 studies included in this review.
FINDINGS
Agents with the strongest evidence of association to alopecia include thallium, mercury, selenium, and colchicine. Agents with described incidents include boric acid, arsenic, vitamin A, botulinum toxin, , and the synthetic opioid MT-45.
CONCLUSIONS AND RELEVANCE
Numerous toxic agents have been implicated in alopecia, and the strength of evidence behind each agent varies. Toxic levels of thallium and colchicine have long been established to cause alopecia, as compared to agents such as botulinum toxin A and synthetic recreational drugs which have less literature describing their links to alopecia and will need further investigation to characterize their relationships to hair loss. Knowledge of typical presentations of hair loss will aid in the development of a differential diagnosis for patients presenting with alopecia.
PubMed: 30410891
DOI: 10.1159/000485749 -
Nutrients Oct 2022Vitamin A (VA) deficiency is associated with increased host susceptibility to infections, but evidence on its role in the prevention and management of viral infections... (Review)
Review
Vitamin A (VA) deficiency is associated with increased host susceptibility to infections, but evidence on its role in the prevention and management of viral infections is still lacking. This review aimed at summarizing the effects of VA supplementation against viral infections to support clinicians in evaluating supplemental treatments. PubMed, Scopus, and Web of Science were searched. Randomized clinical trials comparing the direct effects of VA oral supplementation in any form vs. placebo or standard of care in the prevention and/or management of confirmed viral infections in people of any age were included. A narrative synthesis of the results was performed. The revised Cochrane Risk-Of-Bias tool was used to assess quality. Overall, 40 articles of heterogeneous quality were included. We found data on infections sustained by ( = 17), ( = 2), ( = 1), ( = 3), ( = 4), and ( = 13). Studies were published between 1987 and 2017 and mostly conducted in Africa. The findings were heterogeneous across and within viral families regarding virological, immunological, and biological response, and no meaningful results were found in the prevention of viral infections. For a few diseases, VA-supplemented individuals had a better prognosis and improved outcomes, including clearance of HPV lesions or reduction in some measles-related complications. The effects of VA oral supplementation seem encouraging in relation to the management of a few viral infections. Difference in populations considered, variety in recruitment and treatment protocols might explain the heterogeneity of the results. Further investigations are needed to better identify the benefits of VA administration.
Topics: Dietary Supplements; Humans; Randomized Controlled Trials as Topic; Virus Diseases; Vitamin A; Vitamin D
PubMed: 36235733
DOI: 10.3390/nu14194081 -
Medicine Jan 2021It is necessary to evaluate the effectiveness and safety of vitamin A supplementation on the bronchopulmonary dysplasia (BPD) in premature infants. (Meta-Analysis)
Meta-Analysis
BACKGROUND
It is necessary to evaluate the effectiveness and safety of vitamin A supplementation on the bronchopulmonary dysplasia (BPD) in premature infants.
METHODS
Randomized controlled trials (RCTs) on the role of supplemental vitamin A in preterm infants were searched. The Medline et al databases were manually searched from inception to April 30, 2020. Related outcomes including incidence of BPD, retinopathy of prematurity (ROP), necrotizing enterocolitis (NEC), intraventricular hemorrhage (IVH), sepsis and mortality were assessed with Review Manager 5.3 software, and Random-effect model was applied for all conditions.
RESULTS
A total of 9 RCTs with 1409 patients were included. The analyzed results showed that the incidence of BPD in vitamin A group was significantly less than that of control group (OR = 0.67, 95%CI [0.52-0.88]). There was no significant difference in the incidence of ROP (OR = 0.65, 95%CI [0.29-1.48]), NEC (OR = 0.88, 95%CI [0.59-1.30]), IVH (OR = 0.90, 95%CI [0.65-1.25]), sepsis (OR = 0.84, 95%CI [0.64-1.09]) and mortality (OR = 0.98, 95%CI [0.72-1.34]) among two groups.
CONCLUSION
Vitamin A supplementation is beneficial to the prophylaxis of BPD in premature infants, further studies on the administration approaches and dosages of vitamin A in premature infants are warranted.
Topics: Bronchopulmonary Dysplasia; Dietary Supplements; Female; Humans; Infant, Newborn; Infant, Premature; Male; Randomized Controlled Trials as Topic; Respiratory Distress Syndrome, Newborn; Vitamin A
PubMed: 33545924
DOI: 10.1097/MD.0000000000023101 -
Medicine Oct 2022To systematically review and meta-analyze the efficacy of vitamin A as an adjuvant therapy for pneumonia in children. (Meta-Analysis)
Meta-Analysis
BACKGROUND
To systematically review and meta-analyze the efficacy of vitamin A as an adjuvant therapy for pneumonia in children.
METHODS
We searched in PubMed, the Cochrane Library, Chinese National Knowledge Infrastructure, WanFang Database and Chongqing VIP information network from libraries building to March 2022, screening randomized controlled trials (RCT) about vitamin A combined with conventional therapy for pneumonia in children. Two researchers used the Cochrane risk of bias tool to assess the quality of included studies dependently. Data analysis was conducted in the RevMan 5.3.
RESULTS
15 trials involving 3496 patients (treated group: 1898; control group: 1598) were analyzed in this study. The Meta-analysis showed that vitamin A combined with conventional therapy improved clinical efficacy (P < .05), shortened the duration of fever and cough, negative time of chest X-ray, and the hospitalization, lung rale disappearance, choking milk disappearance, shortness of breath disappearance and perilabial cyanosis disappearance (P < .05). However, vitamin A combined with conventional therapy did not reduce the mortality of pneumonia in children (P > .05).
CONCLUSION
Vitamin A contributes to relieve the clinical symptoms and signs, and also shorten the hospitalization.
Topics: Child; Humans; COVID-19; Vitamin A; Pneumonia; Cough; Fever
PubMed: 36281101
DOI: 10.1097/MD.0000000000031289 -
International Journal of Molecular... Jun 2023Through a process termed , platelets cause thrombi to shrink and become more stable. After platelets are activated via inside-out signaling, glycoprotein αIIbβIII...
Through a process termed , platelets cause thrombi to shrink and become more stable. After platelets are activated via inside-out signaling, glycoprotein αIIbβIII binds to fibrinogen and initiates a cascade of intracellular signaling that ends in actin remodeling, which causes the platelet to change its shape. Clot retraction is also important for wound healing. Although the detailed molecular biology of clot retraction is only partially understood, various substances and physiological conditions modulate clot retraction. In this review, we describe some of the current literature pertaining to clot retraction modulators. In addition, we discuss compounds from , , and that diminish clot retraction and have numerous other health benefits. Caffeic acid and diindolylmethane, both common in plants and vegetables, likewise reduce clot retraction, as do all-trans retinoic acid (a vitamin A derivative), two MAP4K inhibitors, and the chemotherapeutic drug Dasatinib. Conversely, the endogenous anticoagulant Protein S (PS) and the matricellular protein secreted modular calcium-binding protein 1 (SMOC1) both enhance clot retraction. Most studies aiming to identify mechanisms of clot retraction modulators have focused on the increased phosphorylation of vasodilator-stimulated phosphoprotein and inositol 1,4,5-triphosphate receptor I and the decreased phosphorylation of various phospholipases (e.g., phospholipase A2 (PLA) and phosphatidylinositol-specific phospholipase Cγ2 (PLCγ), c-Jun N-terminal kinase, and (PI3Ks). One study focused on the decreased phosphorylation of Sarcoma Family Kinases (SFK), and others have focused on increased cAMP levels and the downregulation of inflammatory markers such as thromboxanes, including thromboxane A2 (TXA) and thromboxane B2 (TXB); prostaglandin A2 (PGE2); reactive oxygen species (ROS); and cyclooxygenase (COX) enzyme activity. Additionally, pregnancy, fibrinolysis, and the autoimmune condition systemic lupus erythematosus all seem to affect, or at least have some relation with, clot retraction. All the clot retraction modulators need in-depth study to explain these effects.
Topics: Blood Platelets; Clot Retraction; Phosphorylation; Platelet Aggregation; Signal Transduction
PubMed: 37445780
DOI: 10.3390/ijms241310602 -
PloS One 2022To determine the effects of oral vitamin A supplementation on clinical outcomes in preterm infants. (Meta-Analysis)
Meta-Analysis
OBJECTIVE
To determine the effects of oral vitamin A supplementation on clinical outcomes in preterm infants.
DESIGN
We conducted the meta-analysis by searching PubMed/Medline, Scopus, Embase, CINAHL, and the Cochrane Library databases from inception to 12 August 2021, including reference lists of retrieved articles. Only randomized controlled trials (RCTs) evaluating the effects of oral vitamin A on premature babies were included. We used a random-effects model to calculate risk ratios (RRs) and weighted mean differences (MDs) with 95% confidence intervals (CIs). We used the GRADE approach to grade evidence quality and assess how oral vitamin A supplementation affects clinical outcomes.
MAIN OUTCOMES MEASURES
The primary outcomes were respiratory outcomes, including the length of respiratory support, the need for oxygen at 36 weeks postmenstrual age (PMA), and moderate-to-severe bronchopulmonary dysplasia (BPD) at 36 weeks PMA. Secondary outcomes were hospitalization time, vitamin A status, mortality, other related outcomes, and potential adverse drug-related events.
RESULTS
We included four RCTs, with 800 patients total. In all trials, oral vitamin A treatment was compared to a placebo. Oral vitamin A supplementation did not significantly affect mechanical ventilation duration (MD, -1.07 days; 95% CI, -2.98 to 0.83 days), oxygen requirement at 36 weeks PMA (RR, 0.65; 95% CI, 0.33 to 1.31), or moderate-to-severe BPD at 36 weeks PMA (RR, 0.53; 95% CI, 0.07 to 4.17). However, oral vitamin A supplementation yielded a slightly shorter noninvasive ventilation duration (MD, -0.96 days; 95% CI, -1.59 to -0.33 days).
CONCLUSIONS
Administering oral vitamin A to preterm newborns did not alter the mechanical ventilation duration, oxygen needed at 36 weeks PMA, moderate-to-severe BPD at 36 weeks PMA, death, or short-term benefits. However, oral vitamin A supplementation may slightly affect the duration of noninvasive respiratory support without adverse drug-related events.
Topics: Bronchopulmonary Dysplasia; Dexamethasone; Dietary Supplements; Humans; Infant; Infant, Newborn; Infant, Premature; Oxygen; Vitamin A
PubMed: 35377893
DOI: 10.1371/journal.pone.0265876 -
Nutrition Reviews Jan 2019Modifiable factors that reduce the burden of the metabolic syndrome (MetS), particularly plant-derived biomarkers, have been a recent focus of rising interest. (Meta-Analysis)
Meta-Analysis
CONTEXT
Modifiable factors that reduce the burden of the metabolic syndrome (MetS), particularly plant-derived biomarkers, have been a recent focus of rising interest.
OBJECTIVE
This systematic review and meta-analysis, which follows PRISMA guidelines, evaluates evidence from a period of 20 years that links vitamin A and carotenoids with the occurrence of MetS and following the PRISMA guidelines.
DATA SOURCES
PubMed and Cochrane databases (January 1997 through March 2017) were systematically assessed for studies, including case-control, cross-sectional, and cohort studies, that evaluated the associations of MetS with carotenoids and retinyl esters and retinol (vitamin A).
DATA EXTRACTION
Key measures of associations were harmonized into odds ratios (ORs) and 95% confidence intervals (95%CI) of MetS per 1 standard deviation (SD) of exposure using forest plots and random effects models that pooled data points from 11 cross-sectional studies. Begg's funnel and harvest plots were constructed.
RESULTS
An inverse association between total carotenoids and MetS was found [ORpooled, 0.66; 95%CI, 0.56-0.78; 1 SD ∼ 0.82 µmol/L; n = 5 studies]. This association was the strongest for β-carotene, followed by α-carotene and β-crypotoxanthin. No association was detected between retinol and MetS (ORpooled, 1.00; 95%CI, 0.88-1.13; 1 SD ∼ 2.14 µmol/L; n = 6 studies). Publication bias was absent, and harvest plots indicated consistency upon replication for β-carotene and total carotenoid exposures.
CONCLUSIONS
This review and meta-analysis suggests that, unlike retinol, total and individual carotenoids were inversely related to MetS.
Topics: Carotenoids; Case-Control Studies; Cohort Studies; Cross-Sectional Studies; Humans; Metabolic Syndrome
PubMed: 30202882
DOI: 10.1093/nutrit/nuy044 -
BMJ (Clinical Research Ed.) Mar 2009To evaluate the effect of neonatal vitamin A supplementation on infant mortality, morbidity and early adverse effects. (Review)
Review
OBJECTIVE
To evaluate the effect of neonatal vitamin A supplementation on infant mortality, morbidity and early adverse effects.
DESIGN
Systematic review, meta-analysis, and meta-regression of randomised controlled trials.
DATA SOURCES
Electronic databases and hand search of reviews; abstracts and proceedings of conferences. Review methods Randomised or quasi-randomised or cluster randomised, placebo controlled trials evaluating the effect of prophylactic, neonatal (<1 month) supplementation with synthetic vitamin A on mortality or morbidity within infancy (<1 year), and early adverse effects (=7 days).
RESULTS
The six included trials were from developing countries. There was no convincing evidence of a reduced risk of mortality during infancy (relative risk 0.92, 95% confidence interval 0.75 to 1.12, P=0.393 random effect; I(2)=54.1%) or of an increase in early adverse effects including bulging fontanelle (1.16, 0.81 to 1.65, P=0.418; I(2)=65.3%). No variable emerged as a significant predictor of mortality, but data for important risk groups (high maternal night blindness prevalence and low birth weights) were restricted. Limited data (from one to four trials) did not indicate a reduced risk of mortality during the neonatal period (0.90, 0.75 to 1.08, P=0.270; I(2)=0%), cause specific mortality, common morbidities (diarrhoea and others), and admission to hospital. There was, however, evidence of an increased risk of acute respiratory infection and a reduced risk of clinic visits.
CONCLUSIONS
There is no convincing evidence of a reduced risk of mortality and possibly morbidity or of increased early adverse effects after neonatal supplementation with vitamin A. There is thus no justification for initiating such supplementation as a public health intervention in developing countries for reducing infant mortality and morbidity.
Topics: Child, Preschool; Dietary Supplements; Humans; Infant; Infant Mortality; Perinatal Care; Randomized Controlled Trials as Topic; Regression Analysis; Risk Factors; Treatment Outcome; Vitamin A; Vitamins
PubMed: 19329516
DOI: 10.1136/bmj.b919 -
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