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Molecular Psychiatry Oct 2023Adolescence represents a critical period for brain and behavioural health and characterised by the onset of mood, psychotic and anxiety disorders. In rodents,...
Adolescence represents a critical period for brain and behavioural health and characterised by the onset of mood, psychotic and anxiety disorders. In rodents, neurogenesis is very active during adolescence, when is particularly vulnerable to stress. Whether stress-related neurogenesis changes influence adolescence onset of psychiatric symptoms remains largely unknown. A systematic review was conducted on studies investigating changes in hippocampal neurogenesis and neuroplasticity, hippocampal-dependent cognitive functions, and behaviour, occurring after adolescence stress exposure in mice both acutely (at post-natal days 21-65) and in adulthood. A total of 37 studies were identified in the literature. Seven studies showed reduced hippocampal cell proliferation, and out of those two reported increased depressive-like behaviours, in adolescent rodents exposed to stress. Three studies reported a reduction in the number of new-born neurons, which however were not associated with changes in cognition or behaviour. Sixteen studies showed acutely reduced hippocampal neuroplasticity, including pre- and post-synaptic plasticity markers, dendritic spine length and density, and long-term potentiation after stress exposure. Cognitive impairments and depressive-like behaviours were reported by 11 of the 16 studies. Among studies who looked at adolescence stress exposure effects into adulthood, seven showed that the negative effects of stress observed during adolescence on either cell proliferation or hippocampal neuroplasticity, cognitive deficits and depressive-like behaviour, had variable impact in adulthood. Treating adolescent mice with antidepressants, glutamate receptor inhibitors, glucocorticoid antagonists, or healthy diet enriched in omega-3 fatty acids and vitamin A, prevented or reversed those detrimental changes. Future research should investigate the translational value of these preclinical findings. Developing novel tools for measuring hippocampal neurogenesis in live humans, would allow assessing neurogenic changes following stress exposure, investigating relationships with psychiatric symptom onset, and identifying effects of therapeutic interventions.
Topics: Animals; Mice; Brain; Cognition; Hippocampus; Neurogenesis; Rodentia; Stress, Psychological
PubMed: 37612364
DOI: 10.1038/s41380-023-02229-2 -
The Cochrane Database of Systematic... Jun 2020Retinitis pigmentosa (RP) comprises a group of hereditary eye diseases characterized by progressive degeneration of retinal photoreceptors. It results in severe visual... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Retinitis pigmentosa (RP) comprises a group of hereditary eye diseases characterized by progressive degeneration of retinal photoreceptors. It results in severe visual loss that may lead to blindness. Symptoms may become manifest during childhood or adulthood which include poor night vision (nyctalopia) and constriction of peripheral vision (visual field loss). Visual field loss is progressive and affects central vision later in the disease course. The worldwide prevalence of RP is approximately 1 in 4000, with 100,000 individuals affected in the USA. At this time, there is no proven therapy for RP.
OBJECTIVES
The objective of this review was to synthesize the best available evidence regarding the effectiveness and safety of vitamin A and fish oils (docosahexaenoic acid (DHA)) in preventing the progression of RP.
SEARCH METHODS
We searched the Cochrane Central Register of Controlled Trials (CENTRAL), which contains the Cochrane Eyes and Vision Trials Register (2020, Issue 2); Ovid MEDLINE; Embase.com; PubMed; Latin American and Caribbean Health Sciences Literature Database (LILACS); ClinicalTrials.gov; the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP); and OpenGrey. We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 7 February 2020.
SELECTION CRITERIA
We included randomized controlled trials that enrolled participants of any age diagnosed with any degree of severity or type of RP, and evaluated the effectiveness of vitamin A, fish oils (DHA), or both compared to placebo, vitamins (other than vitamin A), or no therapy, as a treatment for RP. We excluded cluster-randomized trials and cross-over trials.
DATA COLLECTION AND ANALYSIS
We prespecified the following outcomes: mean change from baseline visual field, mean change from baseline electroretinogram (ERG) amplitudes, and anatomic changes as measured by optical coherence tomography (OCT), at one-year follow-up, and mean change in visual acuity, at five-year follow-up. Two review authors independently extracted data and evaluated risk of bias for all included trials. We also contacted study investigators for further information when necessary.
MAIN RESULTS
In addition to three trials from the previous version of this review, we included a total of four trials with 944 participants aged 4 to 55 years. Two trials included only participants with X-linked RP and the other two included participants with RP of all forms of genetic predisposition. Two trials evaluated the effect of DHA alone; one trial evaluated vitamin A alone; and one trial evaluated DHA and vitamin A versus vitamin A alone. Two trials recruited participants from the USA, and the other two recruited from the USA and Canada. All trials were at low risk of bias for most domains. We did not perform meta-analysis due to clinical heterogeneity. Four trials assessed visual field sensitivity. Investigators found no evidence of a difference in mean values between the groups. However, one trial found that the annual rate of change of visual field sensitivity over four years favored the DHA group in foveal (-0.02 ± 0.55 (standard error (SE)) dB versus -0.47 ± 0.03 dB, P = 0.039), macular (-0.42 ± 0.05 dB versus -0.85 ± 0.03 dB, P = 0.031), peripheral (-0.39 ± 0.02 versus -0.86 ± 0.02 dB, P < 0.001), and total visual field sensitivity (-0.39 ± 0.02 versus -0.86 ± 0.02 dB, P < 0.001). The certainty of the evidence was very low. The four trials evaluated visual acuity (LogMAR scale) at a follow-up of four to six years. In one trial (208 participants), investigators found no evidence of a difference between the two groups, as both groups lost 0.7 letters of the Early Treatment Diabetic Retinopathy Study (ETDRS) visual acuity per year. In another trial (41 participants), DHA showed no evidence of effect on visual acuity (mean difference -0.01 logMAR units (95% confidence interval -0.14 to 0.12; one letter difference between the two groups; very low-certainty evidence). In the third trial (60 participants), annual change in mean number of letters correct was -0.8 (DHA) and 1.4 letters (placebo), with no evidence of between-group difference. In the fourth trial (572 participants), which evaluated (vitamin A + vitamin E trace) compared with (vitamin A trace + vitamin E trace), decline in ETDRS visual acuity was 1.1 versus 0.9 letters per year, respectively. All four trials reported electroretinography (ERG). Investigators of two trials found no evidence of a difference between the DHA and placebo group in yearly rates of change in 31 Hz cone ERG amplitude (mean ± SE) (-0.028 ± 0.001 log μV versus -0.022 ± 0.002 log μV; P = 0.30); rod ERG amplitude (mean ± SE) (-0.010 ± 0.001 log μV versus -0.023 ± 0.001 log μV; P = 0.27); and maximal ERG amplitude (mean ± SE) (-0.042 ± 0.001 log μV versus -0.036 ± 0.001 log μV; P = 0.65). In another trial, a slight difference (6.1% versus 7.1%) in decline of ERG per year favored vitamin A (P = 0.01). The certainty of the evidence was very low. One trial (51 participants) that assessed optical coherence tomography found no evidence of a difference in ellipsoid zone constriction (P = 0.87) over two years, with very low-certainty evidence. The other three trials did not report this outcome. Only one trial reported adverse events, which found that 27/60 participants experienced 42 treatment-related emergent adverse events (22 in DHA group, 20 in placebo group). The certainty of evidence was very low. The rest of the trials reported no adverse events, and no study reported any evidence of benefit of vitamin supplementation on the progression of visual acuity loss.
AUTHORS' CONCLUSIONS
Based on the results of four studies, it is uncertain if there is a benefit of treatment with vitamin A or DHA, or both for people with RP. Future trials should also take into account the changes observed in ERG amplitudes and other outcome measures from trials included in this review.
Topics: Adolescent; Adult; Child; Child, Preschool; Combined Modality Therapy; Disease Progression; Docosahexaenoic Acids; Electroretinography; Female; Fish Oils; Humans; Male; Middle Aged; Randomized Controlled Trials as Topic; Retinitis Pigmentosa; Visual Acuity; Visual Fields; Vitamin A; Vitamins; Young Adult
PubMed: 32573764
DOI: 10.1002/14651858.CD008428.pub3 -
Advances in Nutrition (Bethesda, Md.) Jun 2021Vitamin A (VA) is an essential nutrient often lacking in the diets of people in developing countries. Accurate biomarkers of VA status are vital to inform public health... (Meta-Analysis)
Meta-Analysis
Vitamin A (VA) is an essential nutrient often lacking in the diets of people in developing countries. Accurate biomarkers of VA status are vital to inform public health policy and monitor interventions. The relative dose-response (RDR) and modified-RDR (MRDR) tests are semi-quantitative screening tests for VA deficiency that have been used in Demographic and Health Surveys and VA intervention studies. A systematic review and meta-analysis of sensitivity and specificity were conducted to summarize the physiological evidence to support the RDR tests as methods to assess VA status and investigate the impact of different pathological and physiological states on the tests. A total of 190 studies were screened for inclusion, with 21 studies comparing the RDR tests with the gold-standard biomarker, liver VA concentration (68% and 80% sensitivity and 85% and 69% specificity for the RDR and MRDR, respectively). Nearly all studies with VA interventions in VA-deficient populations demonstrated a response of the tests to VA intake that would be expected to improve VA status. The impacts of chronic liver disease, protein malnutrition, age, pregnancy and lactation, infection and inflammation, and various other conditions were examined in 51 studies. The RDR and MRDR tests were reported to have been used in 39 observational studies, and the MRDR has been used in at least 6 national micronutrient surveys. The RDR and MRDR are sensitive tests for determining population VA status and assessing VA interventions. Although they are robust to most physiological and pathological states, caution may be warranted when using the tests in neonates, individuals with chronic liver disease, and those with protein or iron malnutrition. Research on further improvements to the tests to increase accessibility, such as sampling breast milk instead of blood or using intramuscular doses in subjects with malabsorption, will allow wider adoption. This review was registered with PROSPERO as CRD42019124180.
Topics: Breast Feeding; Dose-Response Relationship, Drug; Female; Humans; Infant, Newborn; Lactation; Milk, Human; Nutritional Status; Vitamin A; Vitamin A Deficiency
PubMed: 33130884
DOI: 10.1093/advances/nmaa136 -
The British Journal of Nutrition May 2023Vitamin A is an essential micronutrient, especially during pregnancy. We aimed to assess the prevalence of vitamin A deficiency in Brazilian women of childbearing age.... (Meta-Analysis)
Meta-Analysis Review
Vitamin A is an essential micronutrient, especially during pregnancy. We aimed to assess the prevalence of vitamin A deficiency in Brazilian women of childbearing age. We conducted a systematic review with meta-analysis of studies that assessed vitamin A deficiency in women of childbearing age following the registered protocol (CRD42020171856). Independent peer researchers selected the studies retrieved from MEDLINE, Embase, Scopus and other sources. Data from the eligible studies were extracted in pairs and assessed for methodological quality. The prevalence of vitamin A deficiency (< 0·70 µmol/l or <0·20 µg/dl) and 95 % CI was combined by meta-analysis, and heterogeneity was estimated by . Out of 3610 screened records, thirty-two studies were included, which assessed 12 577 women from 1965 to 2017, mostly in maternity hospitals. Main limitations of the studies were in sample frame (30/32) and sampling method (29/32). Deficiency occurred in 13 % (95 % CI 9·4, 17·2 %; = 97 %) of all women and was higher in pregnant women (16·1 %; 95 % CI 5·6, 30·6 %; = 98 %) than non-pregnant women (12·3 %; 95 % CI 8·4, 16·8 %; = 96 %). The prevalence increased according to the decade, from 9·5 % (95 % CI 1·9–21·6 %; = 98 %) up to 1990, 10·8 % (95 % CI 7·9, 14·2 %; = 86 %) in the 2000s and 17·8 % (95 % CI 8·7, 29·0 %; = 98 %) in the 2010s. Over 10 % of Brazilian women in childbearing age were deficient in vitamin A. Higher prevalence was observed in pregnant women, and deficiency seemed to be increasing over the decades. Low representativeness of the studies, mainly based on convenience sampling that included pregnant, postpartum, lactating and non-pregnant women, as well as high heterogeneity, limits the findings.
Topics: Humans; Female; Pregnancy; Vitamin A Deficiency; Brazil; Vitamin A; Lactation; Prevalence
PubMed: 35670044
DOI: 10.1017/S0007114522001714 -
Nutrients Apr 2024This review aims to evaluate the efficacy of any vitamin administration(s) in preventing and managing COVID-19 and/or long-COVID. Databases were searched up to May 2023... (Meta-Analysis)
Meta-Analysis Review
The Efficacy of Multivitamin, Vitamin A, Vitamin B, Vitamin C, and Vitamin D Supplements in the Prevention and Management of COVID-19 and Long-COVID: An Updated Systematic Review and Meta-Analysis of Randomized Clinical Trials.
This review aims to evaluate the efficacy of any vitamin administration(s) in preventing and managing COVID-19 and/or long-COVID. Databases were searched up to May 2023 to identify randomized clinical trials comparing data on the effects of vitamin supplementation(s) versus placebo or standard of care on the two conditions of interest. Inverse-variance random-effects meta-analyses were conducted to estimate pooled risk ratios (RRs) and 95% confidence intervals (CIs) for all-cause mortality between supplemented and non-supplemented individuals. Overall, 37 articles were included: two regarded COVID-19 and long-COVID prevention and 35 records the COVID-19 management. The effects of vitamin D in preventing COVID-19 and long-COVID were contrasting. Similarly, no conclusion could be drawn on the efficacy of multivitamins, vitamin A, and vitamin B in COVID-19 management. A few positive findings were reported in some vitamin C trials but results were inconsistent in most outcomes, excluding all-cause mortality (RR = 0.84; 95% CI: 0.72-0.97). Vitamin D results were mixed in most aspects, including mortality, in which benefits were observed in regular administrations only (RR = 0.67; 95% CI: 0.49-0.91). Despite some benefits, results were mostly contradictory. Variety in recruitment and treatment protocols might explain this heterogeneity. Better-designed studies are needed to clarify these vitamins' potential effects against SARS-CoV-2.
Topics: Humans; Dietary Supplements; COVID-19; Vitamins; Vitamin D; Randomized Controlled Trials as Topic; Ascorbic Acid; SARS-CoV-2; Vitamin A; COVID-19 Drug Treatment; Vitamin B Complex
PubMed: 38732592
DOI: 10.3390/nu16091345 -
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 -
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 -
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 -
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 -
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