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Nutrients Jan 2020Micronutrient deficiencies continue to be widespread among children under-five in low- and middle-income countries (LMICs), despite the fact that several effective... (Meta-Analysis)
Meta-Analysis
Micronutrient Supplementation and Fortification Interventions on Health and Development Outcomes among Children Under-Five in Low- and Middle-Income Countries: A Systematic Review and Meta-Analysis.
Micronutrient deficiencies continue to be widespread among children under-five in low- and middle-income countries (LMICs), despite the fact that several effective strategies now exist to prevent them. This kind of malnutrition can have several immediate and long-term consequences, including stunted growth, a higher risk of acquiring infections, and poor development outcomes, all of which may lead to a child not achieving his or her full potential. This review systematically synthesizes the available evidence on the strategies used to prevent micronutrient malnutrition among children under-five in LMICs, including single and multiple micronutrient (MMN) supplementation, lipid-based nutrient supplementation (LNS), targeted and large-scale fortification, and point-of-use-fortification with micronutrient powders (MNPs). We searched relevant databases and grey literature, retrieving 35,924 papers. After application of eligibility criteria, we included 197 unique studies. Of note, we examined the efficacy and effectiveness of interventions. We found that certain outcomes, such as anemia, responded to several intervention types. The risk of anemia was reduced with iron alone, iron-folic acid, MMN supplementation, MNPs, targeted fortification, and large-scale fortification. Stunting and underweight, however, were improved only among children who were provided with LNS, though MMN supplementation also slightly increased length-for-age z-scores. Vitamin A supplementation likely reduced all-cause mortality, while zinc supplementation decreased the incidence of diarrhea. Importantly, many effects of LNS and MNPs held when pooling data from effectiveness studies. Taken together, this evidence further supports the importance of these strategies for reducing the burden of micronutrient malnutrition in children. Population and context should be considered when selecting one or more appropriate interventions for programming.
Topics: Anemia, Iron-Deficiency; Child Nutrition Disorders; Child, Preschool; Developing Countries; Dietary Supplements; Female; Folic Acid; Food, Fortified; Growth Disorders; Humans; Income; Iron; Iron Deficiencies; Male; Micronutrients; Thinness; Trace Elements
PubMed: 31973225
DOI: 10.3390/nu12020289 -
PloS One 2018Many interventions have shown effectiveness in reducing the duration of acute diarrhea and gastroenteritis (ADG) in children. Yet, there is lack of comparative efficacy... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Many interventions have shown effectiveness in reducing the duration of acute diarrhea and gastroenteritis (ADG) in children. Yet, there is lack of comparative efficacy of interventions that seem to be better than placebo among which, the clinicians must choose. Our aim was to determine the comparative effectiveness and safety of the pharmacological and nutritional interventions for reducing the duration of ADG in children.
METHODS
Data sources included Medline, Embase, CENTRAL, CINAHL, LILACS, and Global-Health up to May 2017. Eligible trials compared zinc (ZN), vitamin A, micronutrients (MN), probiotics, prebiotics, symbiotics, racecadotril, smectite(SM), loperamide, diluted milk, lactose-free formula(LCF), or their combinations, to placebo or standard treatment (STND), or among them. Two reviewers independently performed screening, review, study selection and extraction. The primary outcome was diarrhea duration. Secondary outcomes were stool frequency at day 2, diarrhea at day 3, vomiting and side effects. We performed a random effects Bayesian network meta-analysis to combine the direct and indirect evidence for each outcome. Mean differences and odds ratio with their credible intervals(CrI) were calculated. Coherence and transitivity assumptions were assessed. Meta-regression, subgroups and sensitivity analyses were conducted to explore the impact of effect modifiers. Summary under the cumulative curve (SUCRA) values with their CrI were calculated. We assessed the evidence quality and classified the best interventions using the Grading of Recommendations, Assessment, Development & Evaluation (GRADE) approach for each paired comparison.
RESULTS
A total of 174 studies (32,430 children) proved eligible. Studies were conducted in 42 countries of which most were low-and middle-income countries (LMIC). Interventions were grouped in 27 categories. Most interventions were better than STND. Reduction of diarrhea varied from 12.5 to 51.1 hours. The combinations Saccharomyces boulardii (SB)+ZN, and SM+ZN were considered the best interventions (i.e., GRADE quality of evidence: moderate to high, substantial superiority to STND, reduction in duration of 35 to 40 hours, and large SUCRA values), while symbiotics (combination of probiotics+prebiotics), ZN, loperamide and combinations ZN+MN and ZN+LCF were considered inferior to the best and better than STND [Quality: moderate to high, superior to STND, and reduction of 17 to 25 hours]. In subgroups analyses, effect of ZN was higher in LMIC and was not present in high-income countries (HIC). Vitamin A, MN, prebiotics, kaolin-pectin, and diluted milk were similar to STND [Quality: moderate to high]. The remainder of the interventions had low to very-low evidence quality. Loperamide was the only intervention with more side effects than STND [Quality: moderate].
DISCUSSION/CONCLUSION
Most interventions analyzed (except vitamin A, micronutrients, prebiotics, and kaolin-pectin) showed evidence of superiority to placebo in reducing the diarrhea. With moderate-to high-quality of evidence, SB+ZN and SM+ZN, demonstrated the best combination of evidence quality and magnitude of effect while symbiotics, loperamide and zinc proved being the best single interventions, and loperamide was the most unsafe. Nonetheless, the effect of zinc, SB+ZN and SM+ZN might only be applied to children in LMIC. Results suggest no further role for studies comparing interventions against no treatment or placebo, or studies testing loperamide, MN, kaolin-pectin, vitamin A, prebiotics and diluted milk.
PROSPERO REGISTRATION
CRD42015023778.
Topics: Antidiarrheals; Bayes Theorem; Child; Diarrhea; Gastroenteritis; Humans; Loperamide; Network Meta-Analysis; Prebiotics; Probiotics; Saccharomyces boulardii; Treatment Outcome; Zinc
PubMed: 30517196
DOI: 10.1371/journal.pone.0207701 -
Journal of Cosmetic Dermatology Dec 2022Bakuchiol (BAK), a meroterpene phenol abundant in the plant Psoralea corylifolia, is an emerging cosmeceutical agent with promising anti-aging, anti-inflammatory, and... (Review)
Review
BACKGROUND
Bakuchiol (BAK), a meroterpene phenol abundant in the plant Psoralea corylifolia, is an emerging cosmeceutical agent with promising anti-aging, anti-inflammatory, and antibacterial properties. The trend for "clean" skincare products and search for anti-aging retinoid alternatives have poised BAK as a "must-have" ingredient in skincare.
AIMS
Our aim was to review the data for the applications of BAK in dermatology.
METHODS
This is a systematic review of PubMed.
RESULTS
Thirty articles matched our search terms ["Bakuchiol" and "Dermatology"] or ["Bakuchiol" and "Skin"] of which one did not meet inclusion criteria, 16 were pre-clinical studies, seven clinical studies, three commentaries, two narrative reviews, and one report on adverse events. BAK has been mostly studied for its effects on photoaging, acne, and post-inflammatory hyperpigmentation (PIH), showing beneficial results comparable to those achieved by topical retinoids. While having no structural resemblance to retinoids, BAK can function as a retinol analog, through retinol-like regulation of gene expression. In in vivo studies, BAK was used alone or in combination with other products resulting in a significant reduction in photodamage, hyperpigmentation, wrinkle scores, and acne severity. Additionally, in vitro studies hinted at its anti-cancer properties by inhibiting epidermal growth factor induced neoplastic cell transformation. Also, demonstrated potential applications in psoriasis by normalizing keratinocyte activity and in pigmentary disorders through inhibition of melanogenesis. There was one adverse event case reported of contact dermatitis in the literature.
CONCLUSIONS
Bakuchiol is a retinol alternative with anti-aging, antibacterial, and anti-inflammatory properties. Additional studies are warranted to better understand its applications in dermatology.
Topics: Humans; Vitamin A; Retinoids; Phenols; Acne Vulgaris; Anti-Bacterial Agents
PubMed: 36176207
DOI: 10.1111/jocd.15420 -
Revista Brasileira de Epidemiologia =... 2015To assess the impact of vitamin A supplementation on adult pregnant and puerperal women in Brazil regarding the content of vitamin A and secretory immunoglobulin A on... (Review)
Review
OBJECTIVE
To assess the impact of vitamin A supplementation on adult pregnant and puerperal women in Brazil regarding the content of vitamin A and secretory immunoglobulin A on colostrum and breast milk, in child's health conditions, and in mother-child binomial vitamin A status.
METHODS
A research was conducted in Medline, Scopus, Web of Science, and Lilacs electronic databases for the studies published between January 2000 and January 2014. The methodological quality of the studies was assessed according to Jadad scale. The study search was conducted in January 2014, independently by two authors.
RESULTS
Seven studies were found concerning the effects of vitamin A supplementation in the puerperal period on breast milk and infant morbidity. No study regarding pregnant women supplementation was found. The supplementation in the puerperal period raised the retinol content on breast milk, thus increasing the offer of vitamin A for the child and the concentration of secretory immunoglobulin A on colostrum. There was no description of effects on infant morbidity.
CONCLUSION
It seems that the advantages of postpartum supplementation were not established in the Brazilian program, although the supplementation contributes to a better nutritional status of vitamin A for both the child and the puerperal woman and increases the offer of vitamin A for the newborn through the breast milk.
Topics: Brazil; Dietary Supplements; Female; Humans; Milk, Human; Postpartum Period; Pregnancy; Vitamin A; Vitamin A Deficiency
PubMed: 26982298
DOI: 10.1590/1980-5497201500040012 -
The Cochrane Database of Systematic... Sep 2021Anaemia is a prevalent health problem worldwide. Some types are preventable or controllable with iron supplementation (pills or drops), fortification (sprinkles or... (Review)
Review
BACKGROUND
Anaemia is a prevalent health problem worldwide. Some types are preventable or controllable with iron supplementation (pills or drops), fortification (sprinkles or powders containing iron added to food) or improvements to dietary diversity and quality (e.g. education or counselling).
OBJECTIVES
To summarise the evidence from systematic reviews regarding the benefits or harms of nutrition-specific interventions for preventing and controlling anaemia in anaemic or non-anaemic, apparently healthy populations throughout the life cycle.
METHODS
In August 2020, we searched MEDLINE, Embase and 10 other databases for systematic reviews of randomised controlled trials (RCTs) in anaemic or non-anaemic, apparently healthy populations. We followed standard Cochrane methodology, extracting GRADE ratings where provided. The primary outcomes were haemoglobin (Hb) concentration, anaemia, and iron deficiency anaemia (IDA); secondary outcomes were iron deficiency (ID), severe anaemia and adverse effects (e.g. diarrhoea, vomiting).
MAIN RESULTS
We included 75 systematic reviews, 33 of which provided GRADE assessments; these varied between high and very low. Infants (6 to 23 months; 13 reviews) Iron supplementation increased Hb levels and reduced the risk of anaemia and IDA in two reviews. Iron fortification of milk or cereals, multiple-micronutrient powder (MMNP), home fortification of complementary foods, and supplementary feeding increased Hb levels and reduced the risk of anaemia in six reviews. In one review, lipid-based nutrient supplementation (LNS) reduced the risk of anaemia. In another, caterpillar cereal increased Hb levels and IDA prevalence. Food-based strategies (red meat and fortified cow's milk, beef) showed no evidence of a difference (1 review). Preschool and school-aged children (2 to 10 years; 8 reviews) Daily or intermittent iron supplementation increased Hb levels and reduced the risk of anaemia and ID in two reviews. One review found no evidence of difference in Hb levels, but an increased risk of anaemia and ID for the intermittent regime. All suggested that zinc plus iron supplementation versus zinc alone, multiple-micronutrient (MMN)-fortified beverage versus control, and point-of-use fortification of food with iron-containing micronutrient powder (MNP) versus placebo or no intervention may increase Hb levels and reduce the risk of anaemia and ID. Fortified dairy products and cereal food showed no evidence of a difference on the incidence of anaemia (1 review). Adolescent children (11 to 18 years; 4 reviews) Compared with no supplementation or placebo, five types of iron supplementation may increase Hb levels and reduce the risk of anaemia (3 reviews). One review on prevention found no evidence of a difference in anaemia incidence on iron supplementation with or without folic acid, but Hb levels increased. Another suggested that nutritional supplementation and counselling reduced IDA. One review comparing MMN fortification with no fortification observed no evidence of a difference in Hb levels. Non-pregnant women of reproductive age (19 to 49 years; 5 reviews) Two reviews suggested that iron therapy (oral, intravenous (IV), intramuscular (IM)) increased Hb levels; one showed that iron folic acid supplementation reduced anaemia incidence; and another that daily iron supplementation with or without folic acid or vitamin C increased Hb levels and reduced the risk of anaemia and ID. No review reported interventions related to fortification or dietary diversity and quality. Pregnant women of reproductive age (15 to 49 years; 23 reviews) One review apiece suggested that: daily iron supplementation with or without folic acid increased Hb levels in the third trimester or at delivery and in the postpartum period, and reduced the risk of anaemia, IDA and ID in the third trimester or at delivery; intermittent iron supplementation had no effect on Hb levels and IDA, but increased the risk of anaemia at or near term and ID, and reduced the risk of side effects; vitamin A supplementation alone versus placebo, no intervention or other micronutrient might increase maternal Hb levels and reduce the risk of maternal anaemia; MMN with iron and folic acid versus placebo reduced the risk of anaemia; supplementation with oral bovine lactoferrin versus oral ferrous iron preparations increased Hb levels and reduced gastrointestinal side effects; MNP for point-of-use fortification of food versus iron and folic acid supplementation might decrease Hb levels at 32 weeks' gestation and increase the risk of anaemia; and LNS versus iron or folic acid and MMN increased the risk of anaemia. Mixed population (all ages; 22 reviews) Iron supplementation versus placebo or control increased Hb levels in healthy children, adults, and elderly people (4 reviews). Hb levels appeared to increase and risk of anaemia and ID decrease in two reviews investigating MMN fortification versus placebo or no treatment, iron fortified flour versus control, double fortified salt versus iodine only fortified salt, and rice fortification with iron alone or in combination with other micronutrients versus unfortified rice or no intervention. Each review suggested that fortified versus non-fortified condiments or noodles, fortified (sodium iron ethylenediaminetetraacetate; NaFeEDTA) versus non-fortified soy sauce, and double-fortified salt versus control salt may increase Hb concentration and reduce the risk of anaemia. One review indicated that Hb levels increased for children who were anaemic or had IDA and received iron supplementation, and decreased for those who received dietary interventions. Another assessed the effects of foods prepared in iron pots, and found higher Hb levels in children with low-risk malaria status in two trials, but no difference when comparing food prepared in non-cast iron pots in a high-risk malaria endemicity mixed population. There was no evidence of a difference for adverse effects. Anaemia and malaria prevalence were rarely reported. No review focused on women aged 50 to 65 years plus or men (19 to 65 years plus).
AUTHORS' CONCLUSIONS
Compared to no treatment, daily iron supplementation may increase Hb levels and reduce the risk of anaemia and IDA in infants, preschool and school-aged children and pregnant and non-pregnant women. Iron fortification of foods in infants and use of iron pots with children may have prophylactic benefits for malaria endemicity low-risk populations. In any age group, only a limited number of reviews assessed interventions to improve dietary diversity and quality. Future trials should assess the effects of these types of interventions, and consider the requirements of different populations.
Topics: Adolescent; Adult; Aged; Anemia; Anemia, Iron-Deficiency; Animals; Child; Dietary Supplements; Female; Food, Fortified; Humans; Iron; Life Cycle Stages; Male; Micronutrients; Middle Aged; Pregnancy; Systematic Reviews as Topic; Young Adult
PubMed: 34564844
DOI: 10.1002/14651858.CD013092.pub2 -
Journal of Family Medicine and Primary... Nov 2021Even though vitamin A (Vit A) is one of the essential vitamins required for bone growth and development, it is still uncertain whether its effect on bone mineral density...
BACKGROUND
Even though vitamin A (Vit A) is one of the essential vitamins required for bone growth and development, it is still uncertain whether its effect on bone mineral density (BMD) is beneficial or harmful.
AIM
To assess Vit A's effect and its derivatives on BMD and the risk of developing osteoporosis.
DATA SOURCES
PubMed, Cochrane Library, Science Direct, Embase, and Google Scholar were searched in February 2019 and updated in November 2020.
METHODS
Conducted following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines.
RESULTS
A total of 13 studies were included in this report out of 9,124 citations. Five of them were cross-sectional studies, and nine were cohort studies. Three out of five cross-sectional studies showed an increase in BMD, while two showed a decrease in BMD. Four out of eight cohort studies found an increase in BMD; two studies found no association between vitamin A level and BMD; one showed an inverse U-shape association of vitamin A with BMD, suggesting that both the increase or decrease levels of vitamin A affect BMD, while only one study showed a decrease in BMD.
CONCLUSION
Although most of the included studies showed a favorable effect of Vit A on BMD, Vit A's role or its derivatives on BMD change remains unclear.
PubMed: 35136772
DOI: 10.4103/jfmpc.jfmpc_663_21 -
Journal of Clinical Medicine Mar 2020Dietary patterns may play an important role in musculoskeletal well-being. However, the link between dietary patterns, the components of patients' diet, and chronic... (Review)
Review
Dietary patterns may play an important role in musculoskeletal well-being. However, the link between dietary patterns, the components of patients' diet, and chronic musculoskeletal pain remains unclear. Therefore, the purpose of this review was to systematically review the literature on the link between dietary patterns, the components of patients' diet and chronic musculoskeletal pain. This review was conducted following the "Preferred Reporting Items for Systematic reviews and Meta-Analyses" (PRISMA) guidelines and was registered in PROSPERO with the registration number CRD42018110782. PubMed, Web of Science, and Embase online databases were searched. After screening titles and abstracts of 20,316 articles and full texts of 347 articles, 12 eligible articles were included in this review, consisting of nine experimental and three observational studies. Seven out of nine experimental studies reported a pain-relieving effect of dietary changes. Additionally, protein, fat, and sugar intake were found to be associated with pain intensity and pain threshold. In conclusion, plant-based diets might have pain relieving effects on chronic musculoskeletal pain. Patients with chronic rheumatoid arthritis pain can show inadequate intake of calcium, folate, zinc, magnesium, and vitamin B6, whilst patients with fibromyalgia can show a lower intake of carbohydrates, proteins, lipids, vitamin A-E-K, folate, selenium, and zinc. Chronic pain severity also shows a positive relation with fat and sugar intake in osteoarthritis, and pain threshold shows a positive association with protein intake in fibromyalgia.
PubMed: 32150934
DOI: 10.3390/jcm9030702 -
International Health Nov 2023Vitamin A deficiency (VAD) during pregnancy is a public health challenge in low-income countries. There are inconsistent findings that can affect policy in planning... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Vitamin A deficiency (VAD) during pregnancy is a public health challenge in low-income countries. There are inconsistent findings that can affect policy in planning appropriate intervention. This systematic review and meta-analysis were conducted to summarize the evidence in order to identify existing gaps and propose strategies to reduce VAD during pregnancy in Ethiopia.
METHODS
This study included published and unpublished observational studies searched from different databases (PubMed, CINHAL [EBSCO], Embase, Google Scholar, Directory of Open Access Journals, Web of Sciences, MEDLINE, Cochrane Library, Scopus, Google Search and MedNar). Statistical analysis was conducted using Stata version 14 software. Heterogeneity and publication bias were assessed. Forest plots were used to present the pooled prevalence using the random effects model.
RESULTS
A total of 37 618 pregnant women from 15 studies were included. The overall pooled prevalence of VAD was 29% (95% confidence interval 21 to 36) with I2=99.67% and p<0.001. Socio-economic and sociodemographic factors were identified as affecting vitamin A deficiencies among pregnant women.
CONCLUSIONS
Nearly one-third of pregnant women in Ethiopia had VAD. Strengthening intervention modalities that aimed to increase the uptake of vitamin A-rich foods can avert VAD among pregnant women in Ethiopia.
Topics: Female; Pregnancy; Humans; Pregnant Women; Vitamin A Deficiency; Ethiopia; Vitamin A; Prevalence; Observational Studies as Topic
PubMed: 37264928
DOI: 10.1093/inthealth/ihad038 -
The Cochrane Database of Systematic... Dec 2018Vitamins and minerals play multiple functions within the central nervous system which may help to maintain brain health and optimal cognitive functioning.... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Vitamins and minerals play multiple functions within the central nervous system which may help to maintain brain health and optimal cognitive functioning. Supplementation of the diet with various vitamins and minerals has been suggested as a means of maintaining cognitive function, or even of preventing dementia, in later life.
OBJECTIVES
To evaluate the effects of vitamin and mineral supplementation on cognitive function in cognitively healthy people aged 40 years or more.
SEARCH METHODS
We searched ALOIS, the Cochrane Dementia and Cognitive Improvement Group's (CDCIG) specialised register, as well as MEDLINE, Embase, PsycINFO, CINAHL, ClinicalTrials.gov and the WHO Portal/ICTRP from inception to 26th January 2018.
SELECTION CRITERIA
We included randomised controlled trials that evaluated the cognitive effects on people aged 40 years or more of any vitamin or mineral supplements taken by mouth for at least three months.
DATA COLLECTION AND ANALYSIS
Study selection, data extraction, and quality assessments were done in duplicate. Vitamins were considered broadly in the categories of B vitamins, antioxidant vitamins, and combinations of both. Minerals were considered separately, where possible. If interventions and outcomes were considered sufficiently similar, then data were pooled. In order to separate short-term cognitive effects from possible longer-term effects on the trajectory of cognitive decline, data were pooled for various treatment durations from 3 months to 12 months and up to 10 years or more.
MAIN RESULTS
In total, we included 28 studies with more than 83,000 participants. There were some general limitations of the evidence. Most participants were enrolled in studies which were not designed primarily to assess cognition. These studies often had no baseline cognitive assessment and used only brief cognitive assessments at follow-up. Very few studies assessed the incidence of dementia. Most study reports did not mention adverse events or made only very general statements about them. Only 10 studies had a mean follow-up > 5 years. Only two studies had participants whose mean age was < 60 years at baseline. The risk of bias in the included studies was generally low, other than a risk of attrition bias for longer-term outcomes. We considered the certainty of the evidence behind almost all results to be moderate or low.We included 14 studies with 27,882 participants which compared folic acid, vitamin B12, vitamin B6, or a combination of these to placebo. The majority of participants were aged over 60 years and had a history of cardio- or cerebrovascular disease. We found that giving B vitamin supplements to cognitively healthy adults, mainly in their 60s and 70s, probably has little or no effect on global cognitive function at any time point up to 5 years (SMD values from -0.03 to 0.06) and may also have no effect at 5-10 years (SMD -0.01). There were very sparse data on adverse effects or on incidence of cognitive impairment or dementia.We included 8 studies with 47,840 participants in which the active intervention was one or more of the antioxidant vitamins: ß-carotene, vitamin C or vitamin E. Results were mixed. For overall cognitive function, there was low-certainty evidence of benefit associated with ß-carotene after a mean of 18 years of treatment (MD 0.18 TICS points, 95% CI 0.01 to 0.35) and of vitamin C after 5 years to 10 years (MD 0.46 TICS points, 95% CI 0.14 to 0.78), but not at earlier time points. From two studies which reported on dementia incidence, there was low-certainty evidence of no effect of an antioxidant vitamin combination or of vitamin E, either alone or combined with selenium. One of the included studies had been designed to look for effects on the incidence of prostate cancer; it found a statistically significant increase in prostate cancer diagnoses among men taking vitamin E.One trial with 4143 participants compared vitamin D3 (400 IU/day) and calcium supplements to placebo. We found low- to moderate-certainty evidence of no effect of vitamin D3 and calcium supplements at any time-point up to 10 years on overall cognitive function (MD after a mean of 7.8 years -0.1 MMSE points, 95% CI -0.81 to 0.61) or the incidence of dementia (HR 0.94, 95% CI 0.72 to 1.24). A pilot study with 60 participants used a higher dose of vitamin D3 (4000 IU on alternate days) and found preliminary evidence that this dose probably has no effect on cognitive function over six months.We included data from one trial of zinc and copper supplementation with 1072 participants. There was moderate-certainty evidence of little or no effect on overall cognitive function (MD 0.6 MMSE points, 95% CI -0.19 to 1.39) or on the incidence of cognitive impairment after 5 years to 10 years. A second smaller trial provided no usable data, but reported no cognitive effects of six months of supplementation with zinc gluconate.From one study with 3711 participants, there was low-certainty evidence of no effect of approximately five years of selenium supplementation on the incidence of dementia (HR 0.83, 95% CI 0.61 to 1.13).Finally, we included three trials of complex supplements (combinations of B vitamins, antioxidant vitamins, and minerals) with 6306 participants. From the one trial which assessed overall cognitive function, there was low-certainty evidence of little or no effect on the TICS (MD after a mean of 8.5 years 0.12, 95% CI -0.14 to 0.38).
AUTHORS' CONCLUSIONS
We did not find evidence that any vitamin or mineral supplementation strategy for cognitively healthy adults in mid or late life has a meaningful effect on cognitive decline or dementia, although the evidence does not permit definitive conclusions. There were very few data on supplementation starting in midlife (< 60 years); studies designed to assess cognitive outcomes tended to be too short to assess maintenance of cognitive function; longer studies often had other primary outcomes and used cognitive measures which may have lacked sensitivity. The only positive signals of effect came from studies of long-term supplementation with antioxidant vitamins. These may be the most promising for further research.
Topics: Adult; Aged; Antioxidants; Ascorbic Acid; Calcium; Cholecalciferol; Cognition; Cognitive Dysfunction; Copper; Dementia; Dietary Supplements; Folic Acid; Humans; Middle Aged; Minerals; Randomized Controlled Trials as Topic; Selenium; Vitamin A; Vitamin B 12; Vitamin B 6; Vitamin E; Vitamins; Zinc; beta Carotene
PubMed: 30556597
DOI: 10.1002/14651858.CD011906.pub2 -
Dementia & Neuropsychologia 2012Over the last 30 years, a variety of studies reporting the effects of vitamin A on memory have been published.
BACKGROUND
Over the last 30 years, a variety of studies reporting the effects of vitamin A on memory have been published.
OBJECTIVE
To perform a rigorous systematic review of the literature on vitamin A and memory in order to organize evidence-based data on the subject.
METHODS
Four authors carried out the systematic review in accordance with strict guidelines. The terms "vitamin A" OR "retinol" OR "retinoic acid" AND "memory" OR "cognition" OR "Alzheimer" were searched in virtually all medical research databases.
RESULTS
From 236 studies containing the key words, 44 were selected for this review, numbering 10 reviews and 34 original articles. Most studies used animal models for studying vitamin A and cognition. Birds, mice and rats were more frequently employed whereas human studies accounted for only two reports on brain tissue from autopsies and one on the role of isotretinoin in cognition among individuals taking this medication to treat acne.
CONCLUSION
Vitamin A may be an important and viable complement in the treatment and prevention of Alzheimer's disease. Clinical trials are imperative and, at present, there is no evidence-based data to recommend vitamin A supplementation for the prevention or treatment of Alzheimer's disease.
PubMed: 29213801
DOI: 10.1590/S1980-57642012DN06040005