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Journal of Global Health Aug 2023Vitamin A deficiency (VAD) is widely recognised as a major public health concern in low- and middle-income countries (LMICs). Despite various interventions implemented...
BACKGROUND
Vitamin A deficiency (VAD) is widely recognised as a major public health concern in low- and middle-income countries (LMICs). Despite various interventions implemented in many countries, a lack of reliable data is hindering progress. We aimed to consolidate available data and quantify estimates of the prevalence of VAD among children ≤18 years in LMICs.
METHODS
We searched PubMed, Medline and Embase for studies reported the prevalence of VAD or marginal (m)VAD among children. A multilevel mixed-effects meta-regression approach was applied to establish the regression models for VAD and mVAD prevalence. The total numbers of children affected by VAD and mVAD in LMICs in 2019 were separately calculated from the estimated age- and socio-demographic index (SDI)-specific prevalence with their corresponding United Nations Population Division populations projections. We estimated areas of significant public health concern in 165 LMICs using the lower confidence interval (CI) of VAD prevalence.
RESULTS
A total of 116 articles from 40 LMICs were retained. In 2019, VAD and mVAD affected 333.95 million (95% CI = 253.00-433.74) and 556.13 million (95% CI = 388.83-767.94) children and adolescents in 165 LMICs, respectively, corresponding to a prevalence of 14.73% (95% CI = 11.16-19.14) and 24.54% (95% CI = 17.15-33.88). The prevalence of both VAD and mVAD was the highest in children aged 0-5 years at 19.53% (95% CI = 15.03-24.91) and 28.22% (95% CI = 20.00-38.24), respectively, with both steadily decreasing to 10.09% (95% CI = 7.44-13.50) and 20.76% (95% CI = 14.16-29.50) in adolescents aged 13-18 years. The prevalence of VAD was significantly higher in the low SDI region at 29.67% (95% CI = 22.67-37.53) compared to 5.17% (95% CI = 3.14-8.43) estimated in the high-middle SDI region. 68 of the 165 LMICs (41.21%) were classified as areas of moderate to severe VAD public health significance.
CONCLUSIONS
VAD continues to pose a significant public health concern in many low-income settings. Development in LMICs is a crucial factor for VAD, with a disproportionately higher burden in low SDI regions.
REGISTRATION
This study protocol was registered with PROSPERO, CRD42020220654.
Topics: Adolescent; Child; Humans; Vitamin A Deficiency; Developing Countries; Prevalence; Public Health; Poverty
PubMed: 37565390
DOI: 10.7189/jogh.13.04084 -
The Cochrane Database of Systematic... Aug 2016Vitamin A is necessary for normal lung growth and the integrity of respiratory tract epithelial cells. Preterm infants have low vitamin A status at birth and this has... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Vitamin A is necessary for normal lung growth and the integrity of respiratory tract epithelial cells. Preterm infants have low vitamin A status at birth and this has been associated with an increased risk of developing chronic lung disease.
OBJECTIVES
To evaluate supplementation with vitamin A on the incidence of death or neonatal chronic lung disease and long-term neurodevelopmental disability in very low birth weight (VLBW) infants compared with a control (placebo or no supplementation), and to consider the effect of the supplementation route, dose, and timing.
SEARCH METHODS
For the original review and subsequent updates, we searched the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library), MEDLINE, Science Citation Index, and the Oxford Database of Perinatal Trials. The reference lists of relevant trials, paediatric and nutrition journals, and conference abstracts and proceedings were handsearched up to 2010.For the 2016 update, we used the standard search strategy of the Cochrane Neonatal Review group to search the Cochrane Central Register of Controlled Trials (CENTRAL 2016, Issue 4), MEDLINE via PubMed (1 May 2016), EMBASE (1 May 2016), and CINAHL (1 May 2016). We also searched clinical trials' databases, conference proceedings, and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials.
SELECTION CRITERIA
Randomised controlled trials comparing vitamin A supplementation with a control (placebo or no supplementation) or other dosage regimens in VLBW infants (birth weight ≤ 1500 grams or less than 32 weeks' gestation).
DATA COLLECTION AND ANALYSIS
Two review authors screened the search results, extracted data, and assessed the trials for risk of bias. Results were reported as risk ratios (RR), risk differences (RD), and number needed to treat to benefit (NNTB), all with 95% confidence intervals (CI). Trialists were contacted for additional data.
MAIN RESULTS
Eleven trials met the inclusion criteria. Ten trials (1460 infants) compared vitamin A supplementation with a control and one (120 infants) compared different regimens of vitamin A supplementation. Compared to the control group, vitamin A appeared to have a small benefit in reducing the risk of death or oxygen requirement at one month of age (typical RR 0.93, 95% CI 0.88 to 0.99; typical RD -0.05, 95% CI -0.10 to -0.01; NNTB 20, 95% CI 10 to 100; 6 studies, 1165 infants) and the risk of chronic lung disease (oxygen requirement) at 36 weeks' postmenstrual age (typical RR 0.87, 95% CI 0.77 to 0.99; typical RD -0.07, 95% CI -0.13 to -0.01; NNTB 11, 95% CI 6 to 100; 5 studies, 986 infants) (moderate-quality evidence). There was a marginal reduction of the combined outcome of death or chronic lung disease (typical RR 0.92, 95% CI 0.84 to 1.01; typical RD -0.05, 95% CI -0.11 to 0.01; 4 studies, 1089 infants). Neurodevelopmental assessment of 88% of the surviving infants in the largest trial showed no difference between the groups at 18 to 22 months of age, corrected for prematurity (low-quality evidence). There is no evidence to support different vitamin A dosing regimens. No adverse effects of vitamin A supplementation were reported, but it was noted that intramuscular injections of vitamin A were painful.
AUTHORS' CONCLUSIONS
Whether clinicians decide to utilise repeat intramuscular doses of vitamin A to prevent chronic lung disease may depend upon the local incidence of this outcome and the value attached to achieving a modest reduction in the outcome balanced against the lack of other proven benefits and the acceptability of the treatment. Information on long-term neurodevelopmental status suggests no evidence of either benefit or harm from the intervention.
Topics: Humans; Infant, Newborn; Infant, Premature; Infant, Premature, Diseases; Infant, Very Low Birth Weight; Lung Diseases; Randomized Controlled Trials as Topic; Vitamin A; Vitamins
PubMed: 27552058
DOI: 10.1002/14651858.CD000501.pub4 -
Journal of the Academy of Nutrition and... Jan 2017Carotid intima media thickness (IMT) is a noninvasive marker of the extent and severity of subclinical atherosclerosis. Micronutrient intake may affect atherosclerosis... (Review)
Review
BACKGROUND
Carotid intima media thickness (IMT) is a noninvasive marker of the extent and severity of subclinical atherosclerosis. Micronutrient intake may affect atherosclerosis and play a major role in the development of cardiovascular diseases (CVDs).
OBJECTIVE
The primary aim of this review was to synthesize the evidence regarding the association between carotid IMT and selected micronutrients.
METHOD
The authors searched PubMed, Cochrane, and EMBASE databases from inception to June 2016 for selected micronutrients, CVD, carotid IMT, and antioxidants. Thirty-five original studies met the inclusion criteria and were reviewed following preferred reporting items for systematic review and meta-analysis guidelines.
RESULTS
Although not all studies found consistent results, the weight of the evidence suggests that high intakes and/or circulatory levels of magnesium, as well as vitamin D and the vitamin B group, may be associated with lower carotid IMT or reduced progression of carotid IMT. The majority of studies did not find any significant association between vitamin E and C and carotid IMT. Less evidence was available for associations of retinol, zinc, and iron with carotid IMT.
CONCLUSIONS
In general, the current evidence concerning micronutrient intake and carotid IMT is largely inconclusive. Pragmatic clinical trials are required to determine whether dietary or supplemental intake of specific micronutrients alters carotid IMT, which is a surrogate measure of cardiovascular risk.
Topics: Antioxidants; Ascorbic Acid; Biomarkers; Cardiovascular Diseases; Carotid Intima-Media Thickness; Databases, Factual; Disease Progression; Humans; Iron; Magnesium; Micronutrients; Nutritional Status; Randomized Controlled Trials as Topic; Risk Factors; Vitamin A; Vitamin B Complex; Vitamin D; Vitamin E; Zinc
PubMed: 27863993
DOI: 10.1016/j.jand.2016.09.031 -
Nutrients Oct 2023Cataract, defined as the opacification of the lens that prevents clear vision, is a leading cause of vision loss and impairment worldwide. Elderly people comprise the... (Review)
Review
Cataract, defined as the opacification of the lens that prevents clear vision, is a leading cause of vision loss and impairment worldwide. Elderly people comprise the highest proportion of those suffering from this eye disease. According to the National Institute of Health (NIH), the risk of developing aged-related cataract (ARC) increases with every decade of life, starting from the age of 40. Despite progress in surgical treatment methods, life-style modifications may be beneficial in prevention or slowing down the progression of ARC. This systematic review aims to summarize studies on the significance of specific nutritional patterns, dietary products, vitamins, minerals, and carotenoids intake in the onset or progression of ARC. In this context, the presented paper thoroughly analyzes 24 articles, following the PRISMA guidelines. The results indicate significant protective effects of various dietary patterns, including the Korean balanced diet, vegetarian diet, "dairy products and vegetables", "traditional", "antioxidant", and "omega-3" patterns. Additionally, the consumption of fruits, vegetables, legumes, nuts, skimmed yoghurt, fish, coffee, and vitamins has shown positive effects on cataract incidence. Therefore, further research seems to be essential to gain a better understanding of these associations and to create uniform dietary recommendations for both the vulnerable population and ARC patients.
Topics: Aged; Animals; Humans; Vitamins; Diet; Cataract; Antioxidants; Vitamin A; Vegetables; Vitamin K
PubMed: 37960238
DOI: 10.3390/nu15214585 -
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 -
Allergy Jan 2024Acute respiratory infections are a major cause of morbidity and mortality in children worldwide. Dietary and nutritional interventions, including minerals and vitamin...
Acute respiratory infections are a major cause of morbidity and mortality in children worldwide. Dietary and nutritional interventions, including minerals and vitamin supplementation, have been explored as potential treatments for these infections. However, the evidence on their efficacy is limited and inconclusive. This systematic review and meta-analysis aim to provide a comprehensive summary of the available evidence on the effectiveness of dietary and nutritional interventions for treating acute respiratory tract infections in children. A systematic review was conducted according to the PRISMA 2020 guidelines in April 2022 and updated in April 2023. Clinical trials focusing on dietary or nutritional interventions, including supplementations, in children with acute respiratory tract infections were included. The selection of interventions and outcomes was based on biological plausibility. Data were extracted using a standardized form, and the risk of bias was assessed using the Cochrane Risk of Bias Tool. Meta-analysis was performed using random-effect models. A total of 50 studies were included in the review. Four trials were conducted in low, 32 in lower-middle, 12 in upper-middle, and only two in high-income countries. The studies evaluated various dietary interventions, including zinc, vitamin A, vitamin E, vitamin D, and probiotics. The results of individual studies on the efficacy of these interventions were mixed, with some showing positive effects on clinical outcomes such as duration of symptoms, while others showed no significant impact. Meta-analysis was conducted for zinc supplementation in children with pneumonia, and the pooled results suggested a potential limited benefit in terms of reduced hospital length of stay but not time to recovery. Meta-analyses on vitamin D did not show any effect in children with pneumonia. This systematic review fills a critical gap in the literature by synthesizing the available evidence on the efficacy and safety of nutritional or dietary interventions for acute respiratory tract infections in children. The findings indicate no dietary or nutritional intervention can currently be recommended for the routine treatment of respiratory tract infections in children based on single supplement studies. The metanalysis suggests that zinc supplementation might have a beneficial effect on length of hospitalization in children with pneumonia. New studies are needed to establish more conclusive evidence for pediatric acute respiratory diseases especially for children living in a context of high-income countries.
PubMed: 38174413
DOI: 10.1111/all.15997 -
International Journal For Vitamin and... Apr 2023Sexual dysfunction can adversely affect the quality of life, self-confidence, and interpersonal relationships. Some studies reported a relationship between vitamin... (Review)
Review
Sexual dysfunction can adversely affect the quality of life, self-confidence, and interpersonal relationships. Some studies reported a relationship between vitamin supplementation and sexual health. This systematic review aimed to evaluate the effect of vitamins on female and male sexual function. All relevant English and Persian articles published in English databases (Medline, Scopus, Cochrane Library, Web of Sciences, Psycho-Info, and Proquest) and Farsi databases (SID and Magiran) until July 2020 were searched. The Cochrane Handbook for Systematic Reviews of Interventions was used for assessing the risks of bias. A total of 11 randomized controlled trials (RCTs) on 337 women, 472 men, and 35 couples were included. One study reported that vitamin D 300000 IU supplement administrated twice through intramuscular injection (at the beginning and after four weeks) had a significant effect on female sexual function (p<0.05), whereas another study showed that vitamin D 2000 IU supplement for six months did not have any significant effect on female sexual function (p>0.05). A study reported the significant effect of niacin (vitamin B3) 1500 mg daily for 12 weeks on erectile function (p=0.004). The results showed that vitamins A, C, and E had no significant effect on male and female sexual function. The conduction of trials with long-term interventions is recommended to reach a more definitive conclusion about the effect of vitamins on sexual function.
Topics: Female; Humans; Male; Dietary Supplements; Vitamin A; Vitamin D; Vitamin K; Vitamins
PubMed: 33779240
DOI: 10.1024/0300-9831/a000703 -
Pancreatology : Official Journal of the... 2016Chronic pancreatitis (CP) patients are at risk for fat-soluble vitamins (A, D, E, K) deficiency, but available studies are small and heterogeneous. We conducted a... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND AND AIMS
Chronic pancreatitis (CP) patients are at risk for fat-soluble vitamins (A, D, E, K) deficiency, but available studies are small and heterogeneous. We conducted a systematic review and meta-analysis to determine the prevalence of fat-soluble vitamins deficiency in CP patients.
METHODS
Medline was searched up to January 2016 for case series and case-control studies reporting prevalence of fat-soluble vitamin deficiency in CP patients. The prevalent deficiency rate was pooled for included studies, and deficiency rate between CP and controls, with relative odds ratio (OR) and 95% confidence interval (CI) calculated for case-control studies.
RESULTS
Twelve studies including 548 patients included. With a random-effect model, the pooled prevalence rate of vitamin A, D and E deficiency were 16.8% (95%CI 6.9-35.7), 57.6% (95%CI 43.9-70.4) and 29.2% (95%CI 8.6-64.5) respectively, with considerable heterogeneity (I = 75%, 87.1% and 92%). Only one study evaluated vitamin K deficiency. The pooled OR for vitamin D deficiency in CP cases compared with controls was 1.17 (95% CI 0.77-1.78). Sensitivity analyses showed lower prevalence of vitamin A and E, and higher prevalence of vitamin D deficiency in high-quality studies. The rate of pancreatic exocrine insufficiency did not seem affect the deficiency rates, while the use of different cut-offs influences results and heterogeneity for vitamin E, but not A.
CONCLUSIONS
Fat-soluble vitamins deficiency is frequent in CP patients, with considerable heterogeneity. There is, however, no apparent increased risk of vitamin D deficiency in CP compared to controls. Larger, high-quality studies are necessary to better estimate the prevalence of fat-soluble vitamins deficiency, including vitamin K.
Topics: Avitaminosis; Humans; Pancreatitis, Chronic; Prevalence; Vitamin A Deficiency; Vitamin D Deficiency; Vitamin E Deficiency; Vitamin K Deficiency
PubMed: 27681502
DOI: 10.1016/j.pan.2016.09.008 -
International Journal of MCH and AIDS 2015In high-prevalence populations, HIV-related maternal mortality is high with increased mortality found among HIV-infected pregnant and postpartum women compared to their... (Review)
Review
BACKGROUND
In high-prevalence populations, HIV-related maternal mortality is high with increased mortality found among HIV-infected pregnant and postpartum women compared to their uninfected peers. The scale-up of HIV-related treatment options and broader reach of programming for HIV-infected pregnant and postpartum women is likely to have decreased maternal mortality. This systematic review synthesized evidence on interventions that have directly reduced mortality among this population.
METHODS
Studies published between January 1, 2003 and November 30, 2014 were searched using PubMed. Of the 1,373 records screened, 19 were included in the analysis.
RESULTS
Interventions identified through the review include antiretroviral therapy (ART), micronutrients (multivitamins, vitamin A, and selenium), and antibiotics. ART during pregnancy was shown to reduce mortality. Timing of ART initiation, duration of treatment, HIV disease status, and ART discontinuation after pregnancy influence mortality reduction. Incident pregnancy in women already on ART for their health appears not to have adverse consequences for the mother. Multivitamin use was shown to reduce disease progression while other micronutrients and antibiotics had no beneficial effect on maternal mortality.
CONCLUSIONS
ART was the only intervention identified that decreased death in HIV-infected pregnant and postpartum women. The findings support global trends in encouraging initiation of lifelong ART for all HIV-infected pregnant and breastfeeding women (Option B+), regardless of their CD4+ count, as an important step in ensuring appropriate care and treatment.
GLOBAL HEALTH IMPLICATIONS
Maternal mortality is a rare event that highlights challenges in measuring the impact of interventions on mortality. Developing effective patient-centered interventions to reduce maternal morbidity and mortality, as well as corresponding evaluation measures of their impact, requires further attention by policy makers, program managers, and researchers.
PubMed: 27622004
DOI: No ID Found -
The Cochrane Database of Systematic... Aug 2018People with cystic fibrosis (CF) and pancreatic insufficiency are at risk of a deficiency in fat-soluble vitamins, including vitamin A. Vitamin A deficiency...
BACKGROUND
People with cystic fibrosis (CF) and pancreatic insufficiency are at risk of a deficiency in fat-soluble vitamins, including vitamin A. Vitamin A deficiency predominantly causes eye and skin problems, while excessive levels of vitamin A can harm the respiratory and skeletal systems in children and interfere with the metabolism of other fat-soluble vitamins. Most CF centres administer vitamin A as supplements to reduce the frequency of vitamin A deficiency in people with CF and to improve clinical outcomes such as growth, although the recommended dose varies between different guidelines. Thus, a systematic review on vitamin A and vitamin A-like supplementation (carotenes or other retinoids) in people with CF would help guide clinical practice. This is an update of an earlier Cochrane Review.
OBJECTIVES
To determine if supplementation with vitamin A, carotenes or other retinoid supplements in children and adults with CF reduces the frequency of vitamin A deficiency disorders, improves general and respiratory health and affects the frequency of vitamin A toxicity.
SEARCH METHODS
We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Cystic Fibrosis Trials Register compiled from electronic database searches and handsearching of journals and conference abstract books. Additionally we searched several ongoing trials registries, including ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform and the International Standard Randomised Controlled Trial Number Registry.Most recent database searches: 01 June 2018.
SELECTION CRITERIA
All randomised or quasi-randomised controlled studies comparing all preparations of oral vitamin A, carotenes or retinoids (or in combination), used as a supplement compared to placebo at any dose, for at least three months, in people with CF (diagnosed by sweat tests or genetic testing) with and without pancreatic insufficiency.
DATA COLLECTION AND ANALYSIS
Two authors individually assessed study quality and extracted data on outcome measures. The authors assessed the quality of the evidence using the GRADE system. Investigators were contacted to retrieve missing quantitative data.
MAIN RESULTS
No studies of vitamin A or other retinoid supplementation were eligible for inclusion. However, one randomised study of beta (β)-carotene supplementation involving 24 people with CF who were receiving pancreatic enzyme substitution was included. The study compared successive β-carotene supplementation periods (high dose followed by low dose) compared to placebo. The results for the low-dose supplementation period should be interpreted with caution, due to the lack of a wash-out period after the high-dose supplementation.The included study did not report on two of the review's primary outcomes (vitamin A deficiency disorders and mortality); results for our third primary outcome of growth and nutritional status (reported as z score for height) showed no difference between supplementation and placebo, mean difference (MD) -0.23 (95% confidence interval (CI) -0.89 to 0.43) (low-quality evidence). With regards to secondary outcomes, supplementation with high-dose β-carotene for three months led to significantly fewer days of systemic antibiotics required to treat pulmonary exacerbations, compared to controls, MD -15 days (95% CI -27.60 to -2.40); however, this was not maintained in the second three-month section of the study when the level of β-carotene supplementation was reduced, MD -8 days (95% CI -18.80 to 2.80) (low-quality evidence). There were no statistically significant effects between groups in lung function (low-quality evidence) and no adverse events were observed (low-quality evidence). Supplementation affected levels of β-carotene in plasma, but not vitamin A levels. The study did not report on quality of life or toxicity.
AUTHORS' CONCLUSIONS
Since no randomised or quasi-randomised controlled studies on retinoid supplementation were identified, no conclusion on the supplementation of vitamin A in people with CF can be drawn. Additionally, due to methodological limitations in the included study, also reflected in the low-quality evidence judged following the specific evidence grading system (GRADE), no clear conclusions on β-carotene supplementation can be drawn. Until further data are available, country- or region-specific guidelines regarding these practices should be followed.
Topics: Cystic Fibrosis; Humans; Provitamins; Randomized Controlled Trials as Topic; Vitamin A; Vitamin A Deficiency; Vitamins; beta Carotene
PubMed: 30091146
DOI: 10.1002/14651858.CD006751.pub5