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Journal of Cancer Research and Clinical... May 2023Vitamin A and its derivatives positively influence the differentiation of epithelia and other tissues and prevent the proliferation of preneoplastic and neoplastic... (Review)
Review
PURPOSE
Vitamin A and its derivatives positively influence the differentiation of epithelia and other tissues and prevent the proliferation of preneoplastic and neoplastic cells. Vitamin A is therefore taken into account as a potential supporting factor in cancer therapy.
METHODS
In November 2020, a systematic search was conducted searching five electronic databases (EMBASE, Cochrane, PsycINFO, CINAHL and Medline) to find studies looking at the effects of using vitamin A as a complementary therapy for cancer patients. From all 12,823 search results, 9 publications referring to 9 studies with 4296 patients were included in this systematic review.
RESULTS
The patients treated with vitamin A were diagnosed with various cancers and stages. Outcome variables were overall survival of cancer, progression-free survival, occurrence of second primary tumours and recurrences, improvement of chronic radiation-induced proctopathy and side effects of vitamin A. For the most part, the studies had a limited methodological quality. In summary, it can be said that due to the methodological deficiencies of the studies, no concrete statement can be made regarding the prolongation of overall survival and progression-free survival. There is also no evidence of the benefit of vitamin A in the treatment of chronic radiation-induced proctopathy, which can be attributed to methodological deficiencies in the study, as well. In the studies that report on side effects, it becomes clear that side effects, such as mucocutaneous symptoms, temporary increase in liver enzymes and gastrointestinal side effects occur more frequently in the group with vitamin A intervention.
CONCLUSION
The limited interpretability of the results due to the methodological deficiencies of the included studies does not allow a final statement on the benefits of vitamin A as a complementary treatment for cancer patients.
Topics: Humans; Vitamin A; Neoplasms
PubMed: 35972692
DOI: 10.1007/s00432-022-04224-6 -
Nutrients Aug 2021Micronutrient deficiencies are a worldwide public health concern. Emerging evidence supports the ability of probiotics to enhance micronutrient status, which could aid... (Review)
Review
Micronutrient deficiencies are a worldwide public health concern. Emerging evidence supports the ability of probiotics to enhance micronutrient status, which could aid in the prevention of non-communicable disease-associated malnutrition. This systematic review evaluated evidence of the efficacy of probiotic supplementation to improve micronutrient status in healthy subjects. The authors searched for published English language peer-reviewed journal articles in PubMed, Scopus, Embase, and Google Scholar databases from inception to July 2020 using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The quality of eligible studies was assessed using the Revised Cochrane Risk-of-Bias tool (RoB)2 and Risk of Bias in Non-Randomized Studies of Interventions tool (ROBINS-I tool). Fourteen original studies out of 2790 met the inclusion criteria. The results indicated that, despite varying degrees of efficacy, the intake of certain probiotics in healthy subjects was associated with a positive impact on the status of certain micronutrients (vitamin B12, calcium, folate, iron and zinc). A limitation was that studies were widely heterogeneous in terms of participant age, probiotic strain, species, dosage, intervention duration, and form of administration. Additional clinical trials are warranted to determine the most effective strains of probiotics, doses and durations of interventions.
Topics: Bacteria; Gastrointestinal Microbiome; Healthy Volunteers; Humans; Malnutrition; Micronutrients; Minerals; Nutritional Status; Probiotics; Trace Elements; Vitamins
PubMed: 34578878
DOI: 10.3390/nu13093001 -
Clinica Chimica Acta; International... Nov 2020Hemolysis is one of the main pathophysiological characteristics of sickle cell disease (SCD) and might cause or could be the result of oxidative stress. Antioxidants are... (Review)
Review
Hemolysis is one of the main pathophysiological characteristics of sickle cell disease (SCD) and might cause or could be the result of oxidative stress. Antioxidants are studied in SCD due to their potential to ensure redox balance and minimize deleterious effects on erythrocyte membranes. The objective of this systematic review was to evaluate the efficacy of antioxidant nutrient supplementation on reducing hemolysis in SCD patients through randomized clinical trials. We conducted our study according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses and the Cochrane Handbook for Systematic Reviews of Interventions investigating whether antioxidants could improve the hemolytic status of SCD patients. This study included 587 articles published until April 2020. We reduced this pool to 12 articles by excluding duplicates, reviews, comments, and studies with non-human subjects. Omega-3 fatty acids, vitamin A, and zinc were the antioxidants that reportedly improved the indirect hemolysis parameters such as hemoglobin, hematocrit, mean corpuscular volume, or red blood cells. High-dose vitamin C and E supplementation worsened hemolysis, causing increased reticulocytes, lactate dehydrogenase, indirect bilirubin, and haptoglobin. More intervention studies especially high-quality controlled randomized clinical trials are needed to investigate the effects of antioxidant nutrients in reducing hemolysis in SCD.
Topics: Anemia, Sickle Cell; Antioxidants; Erythrocytes; Hemolysis; Humans; Nutrients
PubMed: 32673671
DOI: 10.1016/j.cca.2020.07.020 -
International Journal of Molecular... Nov 2023Diabetes is a serious chronic metabolic disease that causes complications over time, bringing serious public health challenges that affect different countries across the... (Review)
Review
Diabetes is a serious chronic metabolic disease that causes complications over time, bringing serious public health challenges that affect different countries across the world. The current clinical drugs for diabetes may lead to adverse effects such as hypoglycemia and liver and abdominal distension and pain, which prompt people to explore new treatments for diabetes without side effects. The research objective of this review article is to systematically review studies on vitamins and diabetes and to explain their possible mechanism of action, as well as to assess the role of vitamins as drugs for the prevention and treatment of diabetes. To achieve our objective, we searched scientific databases in PubMed Central, Medline databases and Web of Science for articles, using "vitamin" and "diabetes" as key words. The results of numerous scientific investigations revealed that vitamin levels were decreased in humans and animals with diabetes, and vitamins show promise for the prevention and/or control of diabetes through anti-inflammation, antioxidation and the regulation of lipid metabolism. However, a few studies showed that vitamins had no positive effect on the development of diabetes. Currently, studies on vitamins in the treatment of diabetes are still very limited, and there are no clinical data to clarify the dose-effect relationship between vitamins and diabetes; therefore, vitamins are not recommended as routine drugs for the treatment of diabetes. However, we still emphasize the great potential of vitamins in the prevention and treatment of diabetes, and higher quality studies are needed in the future to reveal the role of vitamins in the development of diabetes.
Topics: Humans; Vitamins; Dietary Supplements; Vitamin A; Vitamin K; Diabetes Mellitus
PubMed: 38003557
DOI: 10.3390/ijms242216371 -
Revista Panamericana de Salud Publica =... Nov 2014To examine dietary adequacy in the Andean area, including macro- and micronutrient intakes, with a particular focus on rural communities; to highlight nutrition... (Review)
Review
OBJECTIVE
To examine dietary adequacy in the Andean area, including macro- and micronutrient intakes, with a particular focus on rural communities; to highlight nutrition priorities in the Andes; and to identify opportunities for improvement.
METHODS
A comprehensive literature search was conducted, identifying published and grey literature in English and Spanish related to diet in the central Andean countries of Bolivia, Colombia, Ecuador, and Peru. Articles reporting data from dietary surveys or nutrition interventions were included. Thirty-four papers or reports published in 1969-2011 were included in the final review. The mean and variation in intakes by sex and age group of all presented nutrients were collated and the mean of means were calculated.
RESULTS
Thiamin, niacin, and vitamin C intakes were usually adequate. Intakes of most other micronutrients, including iron, zinc, vitamin A, riboflavin, vitamin B12, folate, and zinc were low, likely resulting in high levels of inadequacy. Energy intakes were lower than requirements, but it is unlikely to be a common problem, rather, this result was probably due to the known tendency of most dietary survey tools to underreport intake. However, energy from fat intakes was very low, usually less than 20% of the total, and in some settings, less than 10%.
CONCLUSIONS
The inadequate intake of some micronutrients is common in many developing countries, but the extremely low intake of dietary fat found in the central Andes is not. Increased consumption of animal-source foods would increase fat intakes, while addressing micronutrient deficiencies; however, the impact on the fragile ecosystem of the Andes needs considering. Indigenous crops, such as lupine bean, quinoa, and amaranth are also rich in fat or micronutrients.
Topics: Bolivia; Colombia; Diet; Dietary Fats; Ecuador; Energy Intake; Humans; Malnutrition; Micronutrients; Nutritional Requirements; Peru; Vitamins
PubMed: 25604101
DOI: No ID Found -
Birth Defects Research Oct 2022Congenital anomalies affect over 2% of pregnancies, with congenital heart disease (CHD) the most common. Understanding of causal factors is limited. Micronutrients are... (Review)
Review
BACKGROUND
Congenital anomalies affect over 2% of pregnancies, with congenital heart disease (CHD) the most common. Understanding of causal factors is limited. Micronutrients are essential trace elements with key roles in growth and development. We aimed to investigate whether maternal micronutrient deficiencies increase the risk of fetal CHD through systematic review of published literature.
METHOD
We performed a systematic review registered at PROSPERO as CRD42021276699. Ovid-MEDLINE, Ovid-EMBASE, and Cochrane Library were searched from their inception until September 7, 2021. Case control trials were included with a population of biological mothers of fetuses with and without CHD. The exposure was maternal micronutrient level measured in pregnancy or the postpartum period. Data extraction was performed by one author and checked by a second. Risk of bias assessment was performed according to the Scottish Intercollegiate Guidelines Network guidance. We performed a narrative synthesis for analysis.
RESULTS
726 articles were identified of which 8 met our inclusion criteria. Final analysis incorporated data from 2,427 pregnancies, 1,199 of which were complicated by fetal CHD assessing 8 maternal micronutrients: vitamin D, vitamin B12, folate, vitamin A, zinc, copper, selenium, and ferritin. Studies were heterogenous with limited sample sizes and differing methods and timing of maternal micronutrient sampling. Definitions of deficiency varied and differed from published literature. Published results were contradictory.
CONCLUSION
There is not enough evidence to confidently conclude if maternal micronutrient deficiencies increase the risk of fetal CHD. Further large-scale prospective study is required to answer this question.
Topics: Copper; Female; Ferritins; Folic Acid; Heart Defects, Congenital; Humans; Malnutrition; Maternal Nutritional Physiological Phenomena; Micronutrients; Observational Studies as Topic; Pregnancy; Selenium; Trace Elements; Vitamin A; Vitamin B 12; Vitamin D; Zinc
PubMed: 35979646
DOI: 10.1002/bdr2.2072 -
Advances in Nutrition (Bethesda, Md.) Nov 2023Vitamin A deficiency (VAD) increases risk for morbidity and mortality. Food-based approaches offer one strategy to improve vitamin A status. This systematic review... (Review)
Review
Vitamin A deficiency (VAD) increases risk for morbidity and mortality. Food-based approaches offer one strategy to improve vitamin A status. This systematic review assessed evidence of the effects of food-based approaches on the vitamin A status of women and children under 5 y. VAD was defined as clinical ocular symptoms, such as loss of vision, and/or retinol plasma or serum concentration <0.70 μmol/L. Searches on food-based approaches to improve vitamin A status were conducted for the period 2011-2022 on PubMed, CINHAL, Web of Science, and Google Scholar using PRISMA guidelines. English-language publications were included. Case studies, unpublished dissertations, and non-peer-reviewed studies were excluded. This review comprises 24 of 27,322 identified studies; 23 included studies focused on provitamin A carotenoids. There were 17,214 participants across the 24 studies with sample sizes ranging from 8 to 3571 individuals. Intervention studies spanned from 3 wk to 2 y. Fifteen (63%) studies were randomized control trials, 7 were cross-sectional, and 2 were longitudinal studies. Most studies (N = 21) used biochemical measurements, for example, serum retinol, to assess vitamin A status; other studies used clinical symptoms (for example, xerophtalmia) or dietary intake. Thirteen (54%) studies reported a statistically significant effect of food-based interventions (N = 8) or an association of diet (N = 5) on vitamin A status. This systematic review indicated that some food-based interventions improved vitamin A status, thus offering a safe and effective delivery mechanism for vitamin A. There appeared to be significant association between vitamin A status and consumption of foods with high concentrations of preformed vitamin A and provitamin A carotenoids. Differences across studies in regard to the period of evaluation, food approaches used, and statistical power may explain the lack of effectiveness of food-based approaches on vitamin A status in some studies.
Topics: Child; Humans; Female; Vitamin A; Provitamins; Vitamin A Deficiency; Diet; Carotenoids
PubMed: 37634852
DOI: 10.1016/j.advnut.2023.08.009 -
Frontiers in Veterinary Science 2023Vitamin A, a fat-soluble vitamin, is the basic substance required to maintain healthy vision and the main physiological functions of cattle. The results from previous...
Vitamin A, a fat-soluble vitamin, is the basic substance required to maintain healthy vision and the main physiological functions of cattle. The results from previous studies regarding the effect of vitamin A on intramuscular fat varied. This meta-analysis aimed to generate a more comprehensive understanding of the relationship between vitamin A and intramuscular fat content and to provide potential clues for future research and commercial practice. Electronic databases such as MEDLINE and Ovid were systematically searched, and studies investigating the relationship between vitamin A and intramuscular fat content were included. Standardized mean differences (SMDs) in intramuscular fat percentage and intramuscular fat score, with their respective 95% confidence intervals (CIs), were calculated. The heterogeneity and publication bias were evaluated. A total of 152 articles were identified through searches of databases. Seven articles were confirmed for inclusion in this meta-analysis. The SMD of IMF percentage derived from the analysis was-0.78 (-2.68, 1.12) (Q = 246.84, < 0.01). The SMD of the IMF score was 1.25 (-2.75, 5.25) (Q = 87.20, < 0.01). Our meta-analysis indicates that the addition of vitamin A could decrease intramuscular fat in cattle steers.
PubMed: 37008352
DOI: 10.3389/fvets.2023.1105754 -
Journal of Personalized Medicine Oct 2023Micronutrients are vital for general and oral health, and their potential anti-cancer properties are documented. We explore beneficial vitamins for oral potentially... (Review)
Review
BACKGROUND
Micronutrients are vital for general and oral health, and their potential anti-cancer properties are documented. We explore beneficial vitamins for oral potentially malignant disorders (OPMDs) and oral cancer (OC), assessing the therapeutic impacts of essential vitamin supplementation.
METHODS
We systematically review evidence on vitamin supplementation's therapeutic effects for OPMDs and OC. Relevant studies were identified through comprehensive searches of MEDLINE, Evidence-Based Medicine, and Web of Science until 16 May 2023. All studies underwent risk of bias using criteria modified from the Office of Health Assessment and Translation (OHAT) tool.
RESULTS
We analysed 80 papers. Vitamin K, studied in vitro, shows promising therapeutic potential. Vitamin C, investigated in vivo (animals and humans), demonstrated mixed animal results and generally positive human trial effects. Vitamin A's efficacy varied, with positive monotherapy or adjunct effects. Vitamins B and D showed therapeutic benefits. Oral cancer research was extensive, with a focus on oral lichen planus and oral leukoplakia among the 11 OPMDs. All bias levels were reported in 'selective reporting' and 'performance', except for "definitely high" in the 'selection', 'detection', and 'attrition/exclusion' domains.
CONCLUSIONS
Evidence of vitamin interventions for OPMDs and OC ranges from mixed to promising. Standardizing the study design and outcomes would enhance future research.
PubMed: 37888131
DOI: 10.3390/jpm13101520 -
European Journal of Clinical... Jun 2024Stroke represents a significant public health challenge, necessitating the exploration of preventive measures. This network meta-analysis aimed to assess the efficacy of... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND AND AIM
Stroke represents a significant public health challenge, necessitating the exploration of preventive measures. This network meta-analysis aimed to assess the efficacy of different vitamin treatments compared to a placebo in preventing stroke.
METHODS
A systematic electronic search in databases including PubMed, EmBASE, Web of Science, clinicaltrials.gov, and Google Scholar until 31 May 2023 was conducted, to identify published studies investigating the association between vitamin intake and the risk of stroke. Pooled risk ratio (RR) with 95% confidence intervals (CIs) was calculated using a frequentist network meta-analysis. Furthermore, we ranked vitamins based on p-scores, facilitating a comparative assessment of their effectiveness in preventing stroke.
RESULTS
A total of 56 studies, including 17 randomized controlled trials (RCTs) and 39 cohort studies were analyzed. Direct estimates obtained from network meta-analysis, we found that vitamin A (RR: .81 [.72-.91]), vitamin B-complex (RR: .85 [.74-.97]), vitamin B (RR: 79 [.68-.92]), folate (RR: .86 [.75-.97]), vitamin C (RR: .77 [.70-.85]) and vitamin D (RR: .73 [.64-.83]) were significantly associated with a decreased stroke risk. However, no significant association was observed for vitamin B, vitamin B, and vitamin E. Subsequent to network meta-analysis, vitamins were ranked in decreasing order of their efficacy in stroke prevention based on p-score, with vitamin D (p-score = .91), vitamin C (p-score = .79), vitamin B (p-score = .70), vitamin A (p-score = .65), vitamin B-complex (p-score = .53), folate (p-score = .49), vitamin B (p-score = .39), vitamin E (p-score = .28), vitamin B (.13) and placebo (.10).
CONCLUSION
Our study has established noteworthy connections between vitamin A, vitamin B-complex, vitamin B, folate, vitamin C, and vitamin D in the realm of stroke prevention. These findings add substantial weight to the accumulating evidence supporting the potential advantages of vitamin interventions in mitigating the risk of stroke. However, to solidify and validate these observations, additional research is imperative. Well-designed clinical trials or cohort studies are needed to further explore these associations and formulate clear guidelines for incorporating vitamin supplementation into effective stroke prevention strategies.
Topics: Humans; Vitamins; Stroke; Vitamin B Complex; Folic Acid; Network Meta-Analysis; Vitamin D; Vitamin E; Ascorbic Acid; Vitamin A; Vitamin B 6; Randomized Controlled Trials as Topic; Dietary Supplements
PubMed: 38291560
DOI: 10.1111/eci.14165