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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 -
Surgery For Obesity and Related... Mar 2024Bariatric surgery has been associated with numerous micronutrient deficiencies. Several observational studies have found that these deficiencies are more common in...
BACKGROUND
Bariatric surgery has been associated with numerous micronutrient deficiencies. Several observational studies have found that these deficiencies are more common in racially/ethnically minoritized patients.
OBJECTIVES
To conduct a systematic review to investigate whether racially/ethnically minoritized patients experience worse nutritional outcomes after bariatric surgery.
SETTING
University of Wisconsin-Madison.
METHODS
PubMed, CINAHL, PsychINFO, and Cochrane databases were queried. We searched for manuscripts that reported micronutrient levels or conditions related to micronutrient deficiencies according to race/ethnicity (White, African American/Black, and Hispanic) after laparoscopic sleeve gastrectomy or Roux-en-Y gastric bypass between 2002 and 2022. Eleven micronutrients (vitamins A, B1 [thiamine], B12, D, E, K, calcium, copper, folate, iron, and zinc), and four conditions (anemia, bone loss, fractures, and hyperparathyroidism) were assessed.
RESULTS
Abstracts from 953 manuscripts were screened; 18 full-text manuscripts were reviewed for eligibility, and ten met the inclusion criteria. Compared to White patients, African Americans had a higher prevalence of thiamine, vitamin D, and vitamin A deficiencies. There were no differences in calcium and vitamin B12 deficiencies. The other six micronutrients were not assessed according to race/ethnicity. Hyperparathyroidism was more prevalent in African Americans than White patients in the three studies that evaluated it. The prevalence of fractures was mixed. Anemia and bone loss were not evaluated according to race/ethnicity.
CONCLUSIONS
Although the literature on micronutrient outcomes following bariatric surgery according to race/ethnicity is limited, African Americans appear to experience a higher prevalence of vitamin deficiencies and associated conditions. Qualitative and quantitative research to explore these disparities is warranted.
Topics: Humans; Obesity, Morbid; Calcium; Malnutrition; Bariatric Surgery; Gastric Bypass; Vitamins; Micronutrients; Thiamine; Anemia; Hyperparathyroidism
PubMed: 37891101
DOI: 10.1016/j.soard.2023.09.022 -
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 -
International Journal of Molecular... Oct 2023Bisphenols such as bisphenol A (BPA), S (BPS), C (BPC), F (BPF), AF (BPAF), tetrabromobisphenol, nonylphenol, and octylphenol are plasticizers used worldwide to... (Meta-Analysis)
Meta-Analysis Review
Bisphenols such as bisphenol A (BPA), S (BPS), C (BPC), F (BPF), AF (BPAF), tetrabromobisphenol, nonylphenol, and octylphenol are plasticizers used worldwide to manufacture daily-use articles. Exposure to these compounds is related to many pathologies of public health importance, such as infertility. Using a protector compound against the reproductive toxicological effects of bisphenols is of scientific interest. Melatonin and vitamins have been tested, but the results are not conclusive. To this end, this systematic review and meta-analysis compared the response of reproductive variables to melatonin and vitamin administration as protectors against damage caused by bisphenols. We search for controlled studies of male rats exposed to bisphenols to induce alterations in reproduction, with at least one intervention group receiving melatonin or vitamins (B, C, or E). Also, molecular docking simulations were performed between the androgen (AR) and estrogen receptors (ER), melatonin, and vitamins. About 1234 records were initially found; finally, 13 studies were qualified for review and meta-analysis. Melatonin plus bisphenol improves sperm concentration and viability of sperm and increases testosterone serum levels compared with control groups; however, groups receiving vitamins plus bisphenols had lower sperm concentration, total testis weight, and testosterone serum levels than the control. In the docking analysis, vitamin E had the highest negative MolDock score, representing the best binding affinity with AR and ER, compared with other vitamins and melatonin in the docking. Our findings suggest that vitamins could act as an endocrine disruptor, and melatonin is most effective in protecting against the toxic effects of bisphenols.
Topics: Male; Rats; Animals; Melatonin; Vitamins; Molecular Docking Simulation; Semen; Benzhydryl Compounds; Reproduction; Receptors, Estrogen; Vitamin A; Vitamin K; Testosterone; Endocrine Disruptors
PubMed: 37834378
DOI: 10.3390/ijms241914930 -
The Cochrane Database of Systematic... Oct 2023Undernutrition in the critical first 1000 days of life is the most common form of childhood malnutrition, and a significant problem in low- and middle-income countries... (Review)
Review
BACKGROUND
Undernutrition in the critical first 1000 days of life is the most common form of childhood malnutrition, and a significant problem in low- and middle-income countries (LMICs). The effects of undernutrition in children aged under five years are wide-ranging and include increased susceptibility to and severity of infections; impaired physical and cognitive development, which diminishes school and work performance later in life; and death. Growth monitoring and promotion (GMP) is a complex intervention that comprises regular measurement and charting of growth combined with promotion activities. Policymakers, particularly in international aid agencies, have differing and changeable interpretations and perceptions of the purpose of GMP. The effectiveness of GMP as an approach to preventing malnutrition remains a subject of debate, particularly regarding the added value of growth monitoring compared with promotion alone.
OBJECTIVES
To evaluate the effectiveness of child growth monitoring and promotion for identifying and addressing faltering growth, improving infant and child feeding practices, and promoting contact with and use of health services in children under five years of age in low- and middle-income countries.
SEARCH METHODS
We used standard, extensive Cochrane search methods. The latest search date was 3 November 2022.
SELECTION CRITERIA
We included randomised controlled trials (RCTs), cohort studies, and controlled before-after studies that compared GMP with standard care or nutrition education alone in non-hospitalised children aged under five years.
DATA COLLECTION AND ANALYSIS
We used standard Cochrane methods to conduct a narrative synthesis. Our primary outcomes were anthropometric indicators, infant and child feeding practices, and health service usage. Secondary outcomes were frequency and severity of childhood illnesses, and mortality. We used GRADE to assess the certainty of evidence for each primary outcome.
MAIN RESULTS
We included six studies reported in eight publications. We grouped the findings according to intervention. Community-based growth monitoring and promotion (without supplementary feeding) versus standard care We are unsure if GMP compared to standard care improves infant and child feeding practices, as measured at 24 months by the proportion of infants who have fluids other than breast milk introduced early (49.7% versus 70.5%; 1 study; 4296 observations; very low-certainty evidence). We are unsure if GMP improves health service usage, as measured at 24 months by the proportion of children who receive vitamin A (72.5% versus 62.9%; 1 study; 4296 observations; very low-certainty evidence) and the proportion of children who receive deworming (29.2% versus 14.6%; 1 study; 4296 observations; very low-certainty evidence). No studies reported selected anthropometric indicators (weight-for-age z-score or height-for-age z-score) at 12 or 24 months, infant and child feeding practices at 12 months, or health service usage at 12 months. Community-based growth monitoring and promotion (with supplementary feeding) versus standard care Two studies (with 569 participants) reported the mean weight-for-age z-score at 12 months, providing very low-certainty evidence: in one study, there was little or no difference between GMP and standard care (mean difference (MD) -0.07, 95% confidence interval (CI) -0.19 to 0.06); in the other study, mean weight-for-age z-score worsened in both groups, but we were unable to calculate a relative effect. GMP versus standard care may make little to no difference to the mean height-for-age z-score at 12 months (MD -0.15, 95% CI -0.34 to 0.04; 1 study, 337 participants; low-certainty evidence). Two studies (with 564 participants) reported a range of outcome measures related to infant and child feeding practices at 12 months, showing little or no difference between the groups (very low-certainty evidence). No studies reported health service usage at 12 or 24 months, feeding practices at 24 months, or selected anthropometric indicators at 24 months.
AUTHORS' CONCLUSIONS
There is limited uncertain evidence on the effectiveness of GMP for identifying and addressing faltering growth, improving infant and child feeding practices, and promoting contact with and use of health services in children aged under five years in LMICs. Future studies should explore the reasons for the apparent limited impact of GMP on key child health indicators. Reporting of GMP interventions and important outcomes must be transparent and consistent.
Topics: Infant; Female; Child; Humans; Child, Preschool; Developing Countries; Malnutrition; Milk, Human; Child Health; Nutrition Therapy
PubMed: 37823471
DOI: 10.1002/14651858.CD014785.pub2 -
Antioxidants (Basel, Switzerland) Aug 2023β-Carotene, which is a prominent carotenoid with notable antioxidant properties, may play a role in countering the oxidative stresses induced by malaria. The... (Review)
Review
BACKGROUND
β-Carotene, which is a prominent carotenoid with notable antioxidant properties, may play a role in countering the oxidative stresses induced by malaria. The association between β-carotene levels and malaria is not yet fully understood, prompting this systematic review and meta-analysis.
METHODS
A rigorous search of databases, including Nursing and Allied Health Premium, EMBASE, MEDLINE, Ovid, PubMed, Scopus, and Google Scholar, was undertaken to collate studies that focused on β-carotene levels in malaria patients. The selected studies underwent critical appraisal, followed by data extraction for a meta-analysis.
RESULTS
Of the 2498 records initially identified, 10 were deemed suitable for synthesis. A considerable number of these studies indicated a pronounced reduction in β-carotene levels among malaria patients in contrast with uninfected individuals. The meta-analysis, encompassing 421 malaria patients and 240 uninfected controls, revealed a significant correlation between reduced β-carotene levels and malaria ( < 0.01, Hedges's g: -1.26, 95% CI: -2.00-(-0.53), I: 93.86%, seven studies).
CONCLUSIONS
The conducted systematic review and meta-analysis corroborated the correlation between lower β-carotene levels and malaria. The intricate relationship between malaria and β-carotene merits deeper exploration. A comprehensive understanding of this association might pave the way for innovative therapeutic approaches leveraging the antioxidant attributes of β-carotene to combat malaria-induced oxidative stress.
PubMed: 37759990
DOI: 10.3390/antiox12091687 -
The Cochrane Database of Systematic... Sep 2023Age-related macular degeneration (AMD) is a degenerative condition of the back of the eye that occurs in people over the age of 50 years. Antioxidants may prevent... (Review)
Review
BACKGROUND
Age-related macular degeneration (AMD) is a degenerative condition of the back of the eye that occurs in people over the age of 50 years. Antioxidants may prevent cellular damage in the retina by reacting with free radicals that are produced in the process of light absorption. Higher dietary levels of antioxidant vitamins and minerals may reduce the risk of progression of AMD. This is the third update of the review.
OBJECTIVES
To assess the effects of antioxidant vitamin and mineral supplements on the progression of AMD in people with AMD.
SEARCH METHODS
We searched CENTRAL, MEDLINE, Embase, one other database, and three trials registers, most recently on 29 November 2022.
SELECTION CRITERIA
We included randomised controlled trials (RCTs) that compared antioxidant vitamin or mineral supplementation to placebo or no intervention, in people with AMD.
DATA COLLECTION AND ANALYSIS
We used standard methods expected by Cochrane.
MAIN RESULTS
We included 26 studies conducted in the USA, Europe, China, and Australia. These studies enroled 11,952 people aged 65 to 75 years and included slightly more women (on average 56% women). We judged the studies that contributed data to the review to be at low or unclear risk of bias. Thirteen studies compared multivitamins with control in people with early and intermediate AMD. Most evidence came from the Age-Related Eye Disease Study (AREDS) in the USA. People taking antioxidant vitamins were less likely to progress to late AMD (odds ratio (OR) 0.72, 95% confidence interval (CI) 0.58 to 0.90; 3 studies, 2445 participants; moderate-certainty evidence). In people with early AMD, who are at low risk of progression, this means there would be approximately four fewer cases of progression to late AMD for every 1000 people taking vitamins (one fewer to six fewer cases). In people with intermediate AMD at higher risk of progression, this corresponds to approximately 78 fewer cases of progression for every 1000 people taking vitamins (26 fewer to 126 fewer). AREDS also provided evidence of a lower risk of progression for both neovascular AMD (OR 0.62, 95% CI 0.47 to 0.82; moderate-certainty evidence) and geographic atrophy (OR 0.75, 95% CI 0.51 to 1.10; moderate-certainty evidence), and a lower risk of losing 3 or more lines of visual acuity (OR 0.77, 95% CI 0.62 to 0.96; moderate-certainty evidence). Low-certainty evidence from one study of 110 people suggested higher quality of life scores (measured with the Visual Function Questionnaire) in treated compared with non-treated people after 24 months (mean difference (MD) 12.30, 95% CI 4.24 to 20.36). In exploratory subgroup analyses in the follow-on study to AREDS (AREDS2), replacing beta-carotene with lutein/zeaxanthin gave hazard ratios (HR) of 0.82 (95% CI 0.69 to 0.96), 0.78 (95% CI 0.64 to 0.94), 0.94 (95% CI 0.70 to 1.26), and 0.88 (95% CI 0.75 to 1.03) for progression to late AMD, neovascular AMD, geographic atrophy, and vision loss, respectively. Six studies compared lutein (with or without zeaxanthin) with placebo and one study compared a multivitamin including lutein/zeaxanthin with multivitamin alone. The duration of supplementation and follow-up ranged from six months to five years. Most evidence came from the AREDS2 study in the USA; almost all participants in AREDS2 also took the original AREDS supplementation formula. People taking lutein/zeaxanthin may have similar or slightly reduced risk of progression to late AMD (RR 0.94, 95% CI 0.87 to 1.01), neovascular AMD (RR 0.92, 95% CI 0.84 to 1.02), and geographic atrophy (RR 0.92, 95% CI 0.80 to 1.05) compared with control (1 study, 4176 participants, 6891 eyes; low-certainty evidence). A similar risk of progression to visual loss of 15 or more letters was seen in the lutein/zeaxanthin and control groups (RR 0.98, 95% CI 0.91 to 1.05; 6656 eyes; low-certainty evidence). Quality of life (Visual Function Questionnaire) was similar between groups (MD 1.21, 95% CI -2.59 to 5.01; 2 studies, 308 participants; moderate-certainty evidence). One study in Australia randomised 1204 people to vitamin E or placebo with four years of follow-up; 19% of participants had AMD. The number of late AMD events was low (N = 7) and the estimate of effect was uncertain (RR 1.36, 95% CI 0.31 to 6.05; very low-certainty evidence). There was no evidence of any effect of treatment on visual loss (RR 1.04, 95% CI 0.74 to 1.47; low-certainty evidence). There were no data on neovascular AMD, geographic atrophy, or quality of life. Five studies compared zinc with placebo. Evidence largely drawn from the largest study (AREDS) found a lower progression to late AMD over six years (OR 0.83, 95% CI 0.70 to 0.98; 3 studies, 3790 participants; moderate-certainty evidence), neovascular AMD (OR 0.76, 95% CI 0.62 to 0.93; moderate-certainty evidence), geographic atrophy (OR 0.84, 95% CI 0.64 to 1.10; moderate-certainty evidence), or visual loss (OR 0.87, 95% CI 0.75 to 1.00; 2 studies, 3791 participants; moderate-certainty evidence). There were no data on quality of life. Gastrointestinal symptoms were the main reported adverse effect. In AREDS, zinc was associated with a higher risk of genitourinary problems in men, but no difference was seen between high- and low-dose zinc groups in AREDS2. Most studies were too small to detect rare adverse effects. Data from larger studies (AREDS/AREDS2) suggested there may be little or no effect on mortality with multivitamin (HR 0.87, 95% CI 0.60 to 1.25; low-certainty evidence) or lutein/zeaxanthin supplementation (HR 1.06, 95% CI 0.87 to 1.31; very low-certainty evidence), but confirmed the increased risk of lung cancer with beta-carotene, mostly in former smokers.
AUTHORS' CONCLUSIONS
Moderate-certainty evidence suggests that antioxidant vitamin and mineral supplementation (AREDS: vitamin C, E, beta-carotene, and zinc) probably slows down progression to late AMD. People with intermediate AMD have a higher chance of benefiting from antioxidant supplements because their risk of progression is higher than people with early AMD. Although low-certainty evidence suggested little effect with lutein/zeaxanthin alone compared with placebo, exploratory subgroup analyses from one large American study support the view that lutein/zeaxanthin may be a suitable replacement for the beta-carotene used in the original AREDS formula.
Topics: Male; Female; Humans; Antioxidants; Vitamins; Geographic Atrophy; beta Carotene; Lutein; Zeaxanthins; Minerals; Dietary Supplements; Macular Degeneration; Vitamin A; Vitamin K; Zinc; Malnutrition
PubMed: 37702300
DOI: 10.1002/14651858.CD000254.pub5 -
The American Surgeon Mar 2024Biliopancreatic diversion with duodenal switch (BPD-DS) is the most effective and durable metabolic and bariatric surgery to achieve a target weight loss. However, many... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Biliopancreatic diversion with duodenal switch (BPD-DS) is the most effective and durable metabolic and bariatric surgery to achieve a target weight loss. However, many surgeons are hesitant to adopt BPD-DS due to a lack of training, technical complexity, and long-term nutrition deficiencies. This meta-analysis aimed to investigate long-term nutrition outcomes after primary BPD-DS in the management of obesity.
METHODS
Cochrane, Embase, PubMed, Scopus, and Web of Science were searched for articles from their inception to February 2023 by 2 independent reviewers using the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) system. The review was registered prospectively with PROSPERO (CRD42023391316).
RESULTS
From 834 studies screened, 8 studies met the eligibility criteria, with a total of 3443 patients with obesity undergoing primary BPD-DS. At long-term follow-up (≥5 years), 25.4% of patients had vitamin A deficiency (95% CI: -.012, .520, I = 94%), and 57.3% had vitamin D deficiency (95% CI: .059, 1.086, I = 86%). Calcium deficiency was observed in 125 patients (22.2%, 95% CI: .061, .383, I = 97%), and 69.7% had an abnormal parathyroid hormone level (95% CI: .548, .847, I = 78%). Ferritin level was abnormal in 30 patients (29.0%, 95% CI: .099, .481, I = 79%).
CONCLUSIONS
Despite displaying comparable nutrition-related outcomes to mid-term follow-up, our study demonstrated that BPD-DS could result in a high level of long-term nutrition deficiency after BPD-DS for selected patients. However, further randomized controlled studies with standardized supplementation regimens and improvement in compliance are necessary to evaluate and prevent long-term nutritional deficiencies after BPD-DS.
Topics: Humans; Obesity, Morbid; Duodenum; Biliopancreatic Diversion; Malnutrition; Obesity; Retrospective Studies
PubMed: 37694730
DOI: 10.1177/00031348231201886 -
Reproductive Biology and Endocrinology... Aug 2023This study aimed to clarify the effect of antioxidant vitamins supplementation on endometriosis-related pain. (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
This study aimed to clarify the effect of antioxidant vitamins supplementation on endometriosis-related pain.
METHODS
A systematic search of PubMed, Web of Science, Cochrane Library, Scopus, and China National Knowledge Infrastructure (CNK) databases was conducted to identify relevant studies published in English and Chinese up to 16 March 2023. The search terms used were "endometriosis" OR "endometrioma" OR "endometrium" AND "antioxidant" OR "Vitamin C" OR "Vitamin E" OR "Vitamin D" OR "25-OHD" OR "25(OH)D" OR "25-hydroxyvitamin D". Eligible studies were randomized controlled trials (RCTs) that assessed pain scores using the Visual Analogue Scale (VAS). Mean differences or odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to evaluate the effect of antioxidant vitamins supplementation on endometriosis. The quality of the included studies was assessed using the Cochrane Risk of Bias Tool. The study was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines.
RESULTS
A total of 13 RCTs involving 589 patients were included in this meta-analysis. We identified 11 studies that evaluated the effect of antioxidant vitamins supplementation on endometriosis-related pain. The results indicated that the supplementation of antioxidant vitamins can effectively alleviate endometriosis-related pain. Subgroup analysis showed that the supplementation of vitamin E (with or without vitamin C) had a positive effect on improving clinical pelvic pain in patients with chronic pelvic pain. Conversely, supplementation of vitamin D was associated with a reduction in pelvic pain in endometriosis patients, but the difference was not statistically significant compared to the placebo. Additionally, we observed changes in oxidative stress markers following vitamin supplementation. Plasma malondialdehyde (MDA) concentration decreased in patients with endometriosis after antioxidant vitamin supplementation, and the plasma MDA level was inversely correlated with the time and dose of vitamin E and C supplementation. Furthermore, the inflammatory markers in peritoneal fluid, including RANTES, interleukin-6, and monocyte chemoattractant protein-1, significantly decreased after antioxidant therapy. These findings suggest that antioxidant vitamins may alleviate pain in endometriosis patients by reducing inflammation.
CONCLUSIONS
The included studies support the potential role of antioxidant vitamins in the management of endometriosis. Supplementation with antioxidant vitamins effectively reduced the severity of dysmenorrhea, improved dyspareunia and pelvic pain, and enhanced quality of life in these patients. Therefore, antioxidant vitamin therapy could be considered as an alternative treatment method, either alone or in combination with other approaches, for endometriosis-related pain.
TRIAL REGISTRATION
PROSPERO registration number: CRD42023415198.
Topics: Female; Humans; Antioxidants; Pelvic Pain; Vitamins; Endometriosis; Vitamin A; Ascorbic Acid; Vitamin K; Dietary Supplements
PubMed: 37644533
DOI: 10.1186/s12958-023-01126-1 -
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