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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 -
Nutrients Dec 2023This systematic review aims to assess whether edible vegetable oils and fats fortified with vitamin A and/or D are effective and safe in improving vitamin intake and... (Meta-Analysis)
Meta-Analysis Review
Benefits and Harms of Edible Vegetable Oils and Fats Fortified with Vitamins A and D as a Public Health Intervention in the General Population: A Systematic Review of Interventions.
This systematic review aims to assess whether edible vegetable oils and fats fortified with vitamin A and/or D are effective and safe in improving vitamin intake and ameliorating deficiency states in the general population. In November 2022, we systematically searched MEDLINE, Cochrane CENTRAL, Scopus, Global Index Medicus, ClinicalTrials.gov, and WHO ICTRP (International Clinical Trials Registry Platform) for randomized controlled trials (RCT) and non-randomized studies of interventions (NRSI) investigating the fortification of edible vegetable oils and fats with either vitamin A or vitamin D or both as compared to the same vegetable oils and/or fats without vitamin A and D fortification or no interventions, in the general population, without age restriction. We assessed the methodological quality of included RCTs using Cochrane's risk of bias tool 2.0 and of NRSIs using ROBINS-I tool. We performed random-effects meta-analysis and assessed certainty of evidence using GRADE. We included eight studies. Available evidence showed no significant effect of fortification with vitamin A on serum retinol levels (RCTs: MD 0.35 µmol/L, 95% CI -0.43 to 1.12; two trials; 514 participants; low-certainty evidence; CCTs: MD 0.31 µmol/L, 95% CI -0.18 to 0.80; two trials; 205 participants; very low-certainty evidence) and on subclinical vitamin A deficiency. Low-certainty evidence showed no effect of vitamin D fortification on serum 25-hydroxy vitamin D concentration (MD 6.59 nmol/L, 95% CI -6.89 to 20.07; one trial; 62 participants). In conclusion, vitamin A-fortified vegetable oils and fats may result in little to no difference in serum retinol levels in general populations. The dose of vitamin A used in the trials may be safe but may not be sufficient to reduce subclinical vitamin A deficiency. Further, the evidence suggests that vitamin D fortification results in little to no difference in serum 25-hydroxy vitamin D concentration. Several aspects of providing fortified oils and fats to the general population as a public health intervention should be further investigated, including optimal fortification dose, effects on vitamin D deficiency and its clinical symptoms and potential adverse effects.
Topics: Humans; Vitamins; Vitamin A; Vitamin A Deficiency; Vegetables; Public Health; Plant Oils; Food, Fortified; Vitamin K; Vitamin D
PubMed: 38140394
DOI: 10.3390/nu15245135 -
The Cochrane Database of Systematic... Sep 2016Vitamin A deficiency is a significant public health problem in low- and middle-income countries. Vitamin A supplementation provided to infants less than six months of... (Review)
Review
BACKGROUND
Vitamin A deficiency is a significant public health problem in low- and middle-income countries. Vitamin A supplementation provided to infants less than six months of age is one of the strategies to improve the nutrition of infants at high risk of vitamin A deficiency and thus potentially reduce their mortality and morbidity.
OBJECTIVES
To evaluate the effect of synthetic vitamin A supplementation in infants one to six months of age in low- and middle-income countries, irrespective of maternal antenatal or postnatal vitamin A supplementation status, on mortality, morbidity and adverse effects.
SEARCH METHODS
We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL 2016, Issue 2), MEDLINE via PubMed (1966 to 5 March 2016), Embase (1980 to 5 March 2016) and CINAHL (1982 to 5 March 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 or quasi-randomised, individually or cluster randomised trials involving synthetic vitamin A supplementation compared to placebo or no intervention provided to infants one to six months of age were eligible.
DATA COLLECTION AND ANALYSIS
Two review authors assessed the studies for eligibility and assessed their risk of bias and collected data on outcomes.
MAIN RESULTS
The review included 12 studies (reported in 22 publications). The included studies assigned 24,846 participants aged one to six months to vitamin A supplementation or control group. There was no effect of vitamin A supplementation for the primary outcome of all-cause mortality based on seven studies that included 21,339 (85%) participants (risk ratio (RR) 1.05, 95% confidence interval (CI) 0.89 to 1.25; I = 0%; test for heterogeneity: P = 0.79; quality of evidence: moderate). Also, there was no effect of vitamin A supplementation on mortality or morbidity due to diarrhoea and respiratory tract infection. There was an increased risk of bulging fontanelle within 24 to 72 hours of supplementation in the vitamin A group compared to control (RR 3.10, 95% CI 1.89 to 5.09; I = 9%, test for heterogeneity: P = 0.36; quality of evidence: high). There was no reported subsequent increased risk of death, convulsions or irritability in infants who developed bulging fontanelle after vitamin A supplementation, and it resolved in most cases within 72 hours. There was no increased risk of other adverse effects such as vomiting, irritability, diarrhoea, fever and convulsions in the vitamin A supplementation group compared to control. Vitamin A supplementation did not have any statistically significant effect on vitamin A deficiency (RR 0.86, 95% CI 0.70 to 1.06; I = 27%; test for heterogeneity: P = 0.25; quality of evidence: moderate).
AUTHORS' CONCLUSIONS
There is no convincing evidence that vitamin A supplementation for infants one to six months of age results in a reduction in infant mortality or morbidity in low- and middle-income countries. There is an increased risk of bulging fontanelle with vitamin A supplementation in this age group; however, there were no reported subsequent complications because of this adverse effect.
PubMed: 27681486
DOI: 10.1002/14651858.CD007480.pub3 -
The American Journal of Clinical... Dec 2021A previous systematic review showed that intramuscular vitamin A supplementation reduced the risk of bronchopulmonary dysplasia (BPD) in very-low-birth-weight (VLBW)... (Meta-Analysis)
Meta-Analysis
BACKGROUND
A previous systematic review showed that intramuscular vitamin A supplementation reduced the risk of bronchopulmonary dysplasia (BPD) in very-low-birth-weight (VLBW) infants. However, more recent studies have questioned this finding.
OBJECTIVES
Our objective was to synthesize current evidence on vitamin A supplementation in very-preterm (<32 wk gestational age) or VLBW infants and investigate the factors that may modify its efficacy.
METHODS
A systematic review was conducted using the Cochrane systematic review methodology. We included randomized controlled trials investigating vitamin A supplementation for reducing morbidity and mortality in very-preterm or VLBW infants. Certainty of evidence was assessed using Grading of Recommendations, Assessment, Development and Evaluation (GRADE) recommendations. Prespecified subgroup analyses assessed factors that may modify the effects of vitamin A supplementation.
RESULTS
We included 17 studies (n = 2471) in the qualitative and 15 studies (n = 2248) in the quantitative synthesis. Moderate-certainty evidence suggested a beneficial effect of vitamin A for decreasing the risk of BPD at 36 wk postmenstrual age (RR: 0.83; 95% CI: 0.74, 0.93; numbers needed to treat for an additional beneficial outcome: 16; 95% CI: 9, 53; 9 studies, n = 1752; P = 0.002). Subgroup analysis suggested that the beneficial effect was limited to infants with baseline vitamin A intake <1500 IU · kg-1 · d-1. Both enteral and parenteral routes were effective. Vitamin A supplementation did not have adverse effects and did not alter mortality before discharge (12 studies, n = 1917) or neurodevelopmental outcomes at 18-22 mo (1 study, n = 538).
CONCLUSIONS
The benefit of vitamin A supplementation for reducing BPD is likely to be limited to infants with baseline vitamin A intake <1500 IU · kg-1 · d-1 and is not affected by the route of administration.
Topics: Bronchopulmonary Dysplasia; Dietary Supplements; Humans; Infant; Infant, Newborn; Infant, Premature; Infant, Very Low Birth Weight; Morbidity; Randomized Controlled Trials as Topic; Vitamin A
PubMed: 34582542
DOI: 10.1093/ajcn/nqab294 -
Brain Sciences Oct 2023β-carotene is a powerful antioxidant and dietary precursor of vitamin A whose role in maintaining mental health and cognitive performance, either alone or in... (Review)
Review
β-carotene is a powerful antioxidant and dietary precursor of vitamin A whose role in maintaining mental health and cognitive performance, either alone or in combination with other dietary compounds, has been a topic of recent research. However, its effectiveness is still unclear. This systematic review, conducted according to the PRISMA guideline and assisted by the MySLR platform, addressed this issue. A total of 16 eligible original research articles were identified. Dietary intake or β-carotene serum levels were associated with improved measures of cognitive function in 7 out of 10 epidemiological studies included. In intervention studies, β-carotene consumption alone did not promote better cognitive function in the short term, but only in a long-term intervention with a mean duration of 18 years. However, all but one intervention study suggested the beneficial effects of β-carotene supplementation at doses ranging from 6 mg to 50 mg per day in combination with a multicomplex such as vitamin E, vitamin C, zinc, or selenium for a period of 16 weeks to 20 years. Despite the current limitations, the available evidence suggests a potential association between β-carotene dietary/supplementary intake and the maintenance of cognitive function. The β-carotene most probably does not act alone but in synergy with other micronutrients.
PubMed: 37891835
DOI: 10.3390/brainsci13101468 -
Advances in Nutrition (Bethesda, Md.) Nov 2023Accumulation of deoxyribonucleic acid (DNA) damage diminishes cellular health, increases risk of developmental and degenerative diseases, and accelerates aging.... (Review)
Review
Protective Effects of Micronutrient Supplements, Phytochemicals and Phytochemical-Rich Beverages and Foods Against DNA Damage in Humans: A Systematic Review of Randomized Controlled Trials and Prospective Studies.
Accumulation of deoxyribonucleic acid (DNA) damage diminishes cellular health, increases risk of developmental and degenerative diseases, and accelerates aging. Optimizing nutrient intake can minimize accrual of DNA damage. The objectives of this review are to: 1) assemble and systematically analyze high-level evidence for the effect of supplementation with micronutrients and phytochemicals on baseline levels of DNA damage in humans, and 2) use this knowledge to identify which of these essential micronutrients or nonessential phytochemicals promote DNA integrity in vivo in humans. We conducted systematic literature searches of the PubMed database to identify interventional, prospective, cross-sectional, or in vitro studies that explored the association between nutrients and established biomarkers of DNA damage associated with developmental and degenerative disease risk. Biomarkers included lymphocyte chromosome aberrations, lymphocyte and buccal cell micronuclei, DNA methylation, lymphocyte/leukocyte DNA strand breaks, DNA oxidation, telomere length, telomerase activity, and mitochondrial DNA mutations. Only randomized, controlled interventions and uncontrolled longitudinal intervention studies conducted in humans were selected for evaluation and data extraction. These studies were ranked for the quality of their study design. In all, 96 of the 124 articles identified reported studies that achieved a quality assessment score ≥ 5 (from a maximum score of 7) and were included in the final review. Based on these studies, nutrients associated with protective effects included vitamin A and its precursor β-carotene, vitamins C, E, B1, B12, folate, minerals selenium and zinc, and phytochemicals such as curcumin (with piperine), lycopene, and proanthocyanidins. These findings highlight the importance of nutrients involved in (i) DNA metabolism and repair (folate, vitamin B, and zinc) and (ii) prevention of oxidative stress and inflammation (vitamins A, C, E, lycopene, curcumin, proanthocyanidins, selenium, and zinc). Supplementation with certain micronutrients and their combinations may reduce DNA damage and promote cellular health by improving the maintenance of genome integrity.
Topics: Humans; Prospective Studies; Selenium; Lycopene; Cross-Sectional Studies; Curcumin; Proanthocyanidins; Randomized Controlled Trials as Topic; Vitamins; Vitamin A; Micronutrients; Folic Acid; Zinc; Beverages; Phytochemicals; DNA; DNA Damage; Biomarkers; Dietary Supplements
PubMed: 37573943
DOI: 10.1016/j.advnut.2023.08.004 -
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 -
Journal of Epidemiology and Global... Dec 2018Animal studies have shown that vitamin A plays a role in immunity and protection against infectious diseases. Its role reducing incidence of diarrhea and measles, and... (Meta-Analysis)
Meta-Analysis
Animal studies have shown that vitamin A plays a role in immunity and protection against infectious diseases. Its role reducing incidence of diarrhea and measles, and childhood mortality is known, but its role in relation to malaria is unclear. Thus, a comprehensive, systematic literature search was conducted on PubMed and Cochrane Library to identify randomized controlled trials (RCTs) on the role of vitamin A during pregnancy and childhood for prevention and treatment of malaria. A total of 107 titles/abstracts were identified, of which 15 articles (11 studies) were selected for final inclusion. Based on the meta-analysis, vitamin A supplementation during pregnancy had no benefit for placental infection (relative risk = 1.09; 95% confidence interval (CI), 0.95-1.25; fixed effects, = 0; 2 RCTs). Similarly, there was no effect on peripheral parasitemia or episodes of new clinical malaria. Preventive vitamin A supplementation in children younger than 5 years did not reduce the incidence of peripheral parasitemia or malaria mortality (latter rate ratio = 0.49; 95% CI, 0.07-3.26; random effects, = 72%, 2 RCTs). Vitamin A as an adjunct treatment for cerebral or severe malaria in children did not have benefit on survival, fever resolution time, parasite clearance time, or incidence of neurological or other complications. Vitamin A has no benefit for malarial infection either as prevention or treatment in pregnancy or childhood based on RCT evidence.
Topics: Adolescent; Child; Developing Countries; Dietary Supplements; Female; Humans; Incidence; Malaria; Male; Pakistan; Pregnancy; Pregnancy Complications, Infectious; Primary Prevention; Randomized Controlled Trials as Topic; Risk Assessment; Vitamin A
PubMed: 30859783
DOI: 10.2991/j.jegh.2018.04.104 -
Nutrients Mar 2020Suboptimal nutritional status of a newborn is a risk factor for short- and long-term morbidity and mortality. The objectives of this review were to assess the efficacy... (Meta-Analysis)
Meta-Analysis
Effect of Synthetic Vitamin A and Probiotics Supplementation for Prevention of Morbidity and Mortality during the Neonatal Period. A Systematic Review and Meta-Analysis of Studies from Low- and Middle-Income Countries.
Suboptimal nutritional status of a newborn is a risk factor for short- and long-term morbidity and mortality. The objectives of this review were to assess the efficacy and effectiveness of neonatal synthetic vitamin A supplementation, dextrose gel and probiotic supplementation for prevention of morbidity and mortality during infancy in low and middle-income countries. We included randomized trials. Primary outcome was all-cause mortality. We conducted electronic searches on multiple databases. Data were meta-analyzed to obtain relative risk (RR) and 95% confidence interval (CI). Studies for vitamin A and Probiotics were analyzed separately. No studies were found for dextrose gel supplementation during neonatal period. The overall rating of evidence was determined by Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. Sixteen studies assessed the effect of vitamin A supplementation during the neonatal period. Based on pooled data from community-based studies only, there was no significant effect of vitamin A on all-cause mortality at age 1 month (RR 0.99, 95% CI 0.90, 1.08), 6 months (RR 0.98; 95% CI 0.89-1.08) and 12 months (RR 1.04, 95% CI 0.94, 1.14) but increased risk of bulging fontanelle (RR 1.53, 95% CI 1.12, 2.09). The overall quality of evidence was high for the above outcomes. Thirty-three studies assessed the effect of probiotic supplementation during the neonatal period and were mostly conducted in the hospital setting. Probiotics reduced the risk of all-cause mortality (RR 0.80, 95% CI 0.66, 0.96), necrotizing enterocolitis (RR 0.46, 95% CI 0.35, 0.59) and neonatal sepsis (RR 0.78, 95% CI 0.70, 0.86). The grade ratings for the above three outcomes were high. Vitamin A supplementation during the neonatal period does not reduce all-cause neonatal or infant mortality in low and middle-income countries in the community setting. Probiotic supplementation during the neonatal period seems to reduce all-cause mortality, NEC, and sepsis in babies born low birth weight and/or preterm in the hospital setting.
Topics: Developing Countries; Enterocolitis, Necrotizing; Humans; Infant; Infant Mortality; Infant, Newborn; Nutritional Status; Probiotics; Randomized Controlled Trials as Topic; Sepsis; Vitamin A
PubMed: 32192165
DOI: 10.3390/nu12030791 -
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