Oral vitamin A supplements to prevent acute upper respiratory tract infections in children up to seven years of age.

BACKGROUND: According to global prevalence analysis studies, acute upper respiratory tract infections (URTIs) are the most common acute infectious disease in children, especially in preschool children. Acute URTIs lead to an economic burden on families and society. Vitamin A refers to the fat-soluble compound all-trans-retinol and also represents retinol and its active metabolites. Vitamin A interacts with both the innate immune system and the adaptive immune system and improves the host's defences against infections. Correlation studies show that serum retinol deficiency was associated with a higher risk of respiratory tract infections. Therefore, vitamin A supplementation may be important in preventing acute URTIs. OBJECTIVES: To assess the effectiveness and safety of vitamin A supplements for preventing acute upper respiratory tract infections in children up to seven years of age. SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, the Chinese Biomedical Literature Database, and two trial registration platforms to 8 June 2023. We also checked the reference lists of all primary studies and reviewed relevant systematic reviews and trials for additional references. We imposed no language or publication restrictions. SELECTION CRITERIA: We included randomised controlled trials (RCTs), which evaluated the role of vitamin A supplementation in the prevention of acute URTIs in children up to seven years of age. DATA COLLECTION AND ANALYSIS: We used the standard methodological procedures expected by Cochrane. MAIN RESULTS: We included six studies (27,351 participants). Four studies were RCTs and two were cluster-RCTs. The included studies were all conducted in lower-middle-income countries (two in India, two in South Africa, one in Ecuador, and one in Haiti). Three studies included healthy children who had no vitamin A deficiency, one study included children born to HIV-infected women, one study included low-birthweight neonates, and one study included children in areas with a high local prevalence of malnutrition and xerophthalmia. In two studies, vitamin E was a co-treatment administered in addition to vitamin A. We judged the included studies to be at either a high or unclear risk of bias for random sequence generation, incomplete outcome data, and blinding. Primary outcomes Six studies reported the incidence of acute URTIs during the study period. Five studies reported the number of acute URTIs over a period of time, but there was population heterogeneity and the results were presented in different forms, therefore only three studies were meta-analysed. We are uncertain of the effect of vitamin A supplementation on the number of acute URTIs over two weeks (risk ratio (RR) 1.00, 95% confidence interval (CI) 0.92 to 1.09; I2 = 44%; 3 studies, 22,668 participants; low-certainty evidence). Two studies reported the proportion of participants with an acute URTI. We are uncertain of the effect of vitamin A supplementation on the proportion of participants with an acute URTI (2 studies, 15,535 participants; low-certainty evidence). Only one study (116 participants) reported adverse events. No infant in either the placebo or vitamin A group was found to have feeding difficulties (failure to feed or vomiting), a bulging fontanelle, or neurological signs before or after vitamin A administration (very low-certainty evidence). Secondary outcomes Two studies (296 participants) reported the severity of subjective symptoms, presented by the mean duration of acute URTI. Vitamin A may have little to no effect on the mean duration of acute URTI (very low-certainty evidence). AUTHORS' CONCLUSIONS: The evidence for the use of vitamin A supplementation to prevent acute URTI is uncertain, because population, dose and duration of interventions, and outcomes vary between studies. From generally very low- to low-certainty evidence, we found that there may be no benefit in the use of vitamin A supplementation to prevent acute URTI in children up to seven years of age. More RCTs are needed to strengthen the current evidence. Future research should report over longer time frames using validated tools and consistent reporting, and ensure adequate power calculations, to allow for easier synthesis of data. Finally, it is important to assess vitamin A supplementation for preschool children with vitamin A deficiency.

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.

Vitamins in Gynecologic Malignancies.

The combination of vitamin A and D derivatives with classical chemotherapeutic treatments results in more satisfactory outcomes. The use of drug combinations, such as 9cUAB130 with carboplatin and cisplatin with TAC-101, shows enhanced cytotoxic effects and reductions in ovarian tumor volume compared to single-drug treatments. Combining cisplatin with calcitriol and progesterone increases VDR expression, potentially enhancing the effectiveness of anticancer therapy in ovarian cancer. The effectiveness of vitamin derivatives in anticancer treatment may vary depending on the characteristics of the tumor and the cell line from which it originated. An increase in thiamine intake of one unit is associated with an 18% decrease in HPV infection. Higher intake of vitamin C by 50 mg/day is linked to a lower risk of cervical neoplasia. Beta-carotene, vitamin C, and vitamin E are associated with risk reductions of 12%, 15%, and 9% in endometrial cancer, respectively. A balanced daily intake of vitamins is important, as both deficiency and excess can influence cancer development. It has been observed that there is a U-shaped relationship between group B vitamins and metabolic markers and clinical outcomes.

Vitamin A - discovery, metabolism, receptor signaling and effects on bone mass and fracture susceptibility.

The first evidence of the existence of vitamin A was the observation 1881 that a substance present in small amounts in milk was necessary for normal development and life. It was not until more than 100 years later that it was understood that vitamin A acts as a hormone through nuclear receptors. Unlike classical hormones, vitamin A cannot be synthesized by the body but needs to be supplied by the food as retinyl esters in animal products and ß-carotene in vegetables and fruits. Globally, vitamin A deficiency is a huge health problem, but in the industrialized world excess of vitamin A has been suggested to be a risk factor for secondary osteoporosis and enhanced susceptibility to fractures. Preclinical studies unequivocally have shown that increased amounts of vitamin A cause decreased cortical bone mass and weaker bones due to enhanced periosteal bone resorption. Initial clinical studies demonstrated a negative association between intake of vitamin A, as well as serum levels of vitamin A, and bone mass and fracture susceptibility. In some studies, these observations have been confirmed, but in other studies no such associations have been observed. One meta-analysis found that both low and high serum levels of vitamin A were associated with increased relative risk of hip fractures. Another meta-analysis also found that low levels of serum vitamin A increased the risk for hip fracture but could not find any association with high serum levels of vitamin A and hip fracture. It is apparent that more clinical studies, including large numbers of incident fractures, are needed to determine which levels of vitamin A that are harmful or beneficial for bone mass and fracture. It is the aim of the present review to describe how vitamin A was discovered and how vitamin A is absorbed, metabolized and is acting as a ligand for nuclear receptors. The effects by vitamin A in preclinical studies are summarized and the clinical investigations studying the effect by vitamin A on bone mass and fracture susceptibility are discussed in detail.

Uncommon opsin's retinal isomer is involved in mammalian sperm thermotaxis.

In recent years it became apparent that, in mammals, rhodopsin and other opsins, known to act as photosensors in the visual system, are also present in spermatozoa, where they function as highly sensitive thermosensors for thermotaxis. The intriguing question how a well-conserved protein functions as a photosensor in one type of cells and as a thermosensor in another type of cells is unresolved. Since the moiety that confers photosensitivity on opsins is the chromophore retinal, we examined whether retinal is substituted in spermatozoa with a thermosensitive molecule. We found by both functional assays and mass spectrometry that retinal is present in spermatozoa and required for thermotaxis. Thus, starvation of mice for vitamin A (a precursor of retinal) resulted in loss of sperm thermotaxis, without affecting motility and the physiological state of the spermatozoa. Thermotaxis was restored after replenishment of vitamin A. Using reversed-phase ultra-performance liquid chromatography mass spectrometry, we detected the presence of retinal in extracts of mouse and human spermatozoa. By employing UltraPerformance convergence chromatography, we identified a unique retinal isomer in the sperm extracts-tri-cis retinal, different from the photosensitive 11-cis isomer in the visual system. The facts (a) that opsins are thermosensors for sperm thermotaxis, (b) that retinal is essential for thermotaxis, and (c) that tri-cis retinal isomer uniquely resides in spermatozoa and is relatively thermally unstable, suggest that tri-cis retinal is involved in the thermosensing activity of spermatozoa.

Modulatory effects of rutin and vitamin A on hyperglycemia induced glycation, oxidative stress and inflammation in high-fat-fructose diet animal model.

In the current study we investigated the impact of combination of rutin and vitamin A on glycated products, the glyoxalase system, oxidative markers, and inflammation in animals fed a high-fat high-fructose (HFFD) diet. Thirty rats were randomly divided into six groups (n = 5). The treatments, metformin (120 mg/kg), rutin (100 mg/kg), vitamin A (43 IU/kg), and a combination of rutin (100 mg/kg) and vitamin A (43 IU/kg) were given to relevant groups of rats along with high-fructose high-fat diet for 42 days. HbA1c, D-lactate, Glyoxylase-1, Hexokinase 2, malondialdehyde (MDA), glutathione peroxidase (GPx), catalase (CAT), nuclear transcription factor-B (NF-κB), interleukin-6 (IL-6), interleukin-8 (IL-8) and histological examinations were performed after 42 days. The docking simulations were conducted using Auto Dock package. The combined effects of rutin and vitamin A in treated rats significantly (p < 0.001) reduced HbA1c, hexokinase 2, and D-lactate levels while preventing cellular damage. The combination dramatically (p < 0.001) decreased MDA, CAT, and GPx in treated rats and decreased the expression of inflammatory cytokines such as IL-6 andIL-8, as well as the transcription factor NF-κB. The molecular docking investigations revealed that rutin had a strong affinity for several important biomolecules, including as NF-κB, Catalase, MDA, IL-6, hexokinase 2, and GPx. The results propose beneficial impact of rutin and vitamin A as a convincing treatment strategy to treat AGE-related disorders, such as diabetes, autism, alzheimer's, atherosclerosis.

Protective effect of provitamin A dietary carotenoid intake on overweight/obesity and their relation to inflammatory and oxidative stress biomarkers - a case-control study.

This investigation assessed associations between dietary carotenoid intake and the odds of overweight/obesity, as well as inflammatory/oxidative stress biomarkers, in 851 participants with overweight/obesity (BMI ≥25 kg m-2) and 754 normal-weight controls. A 124-item food-frequency-questionnaire (FFQ) and food composition databases were employed to estimate carotenoid intake. Binary logistic regressions assessed the association of carotenoid intake with the odds of overweight/obesity, adjusting for several potential confounders. Multiple linear regression models revealed associations between carotenoid intake and biomarkers (anthropometrics, blood lipids, inflammation, antioxidant status). Logistic regression models adjusted for various confounders and fruits and vegetables showed protective associations for provitamin A carotenoids (i.e., ß-carotene + α-carotene + ß-cryptoxanthin; odds ratio (OR): 0.655, p = 0.041) and astaxanthin (OR: 0.859, p = 0.017). Similarly adjusted multiple linear regressions revealed significant associations between several carotenoids and lower levels of interleukin (IL)-6, IL-1ß, and TNF-α and increased IL-10 and total antioxidant capacity. Further analysis revealed that lycopene was significantly associated with increased odds of overweight/obesity (OR: 1.595, p = 0.032) in a model adjusted for various confounders and vegetables (i.e., unadjusted for fruits). A protective association between the sum of provitamin A carotenoid and astaxanthin dietary intake and the odds of having overweight/obesity was found. The findings that carotenoids other than lycopene were not or inversely associated with the odds of overweight/obesity may point toward differentiating effects of various carotenoids or their associations with different food groups. Provitamin A rich food items including fruits and vegetables appear to be a prudent strategy to reduce inflammation and the odds of having overweight/obesity.

Gene expression profiles in COVID-19-associated tracheal stenosis indicate persistent anti-viral response and dysregulated retinol metabolism.

INTRODUCTION: Coronavirus disease 2019 (COVID-19)-associated tracheal stenosis (COATS) may occur as a result of prolonged intubation during COVID-19 infection. We aimed to investigate patterns of gene expression in the tracheal granulation tissue of patients with COATS, leverage gene expression data to identify dysregulated cellular pathways and processes, and discuss potential therapeutic options based on the identified gene expression profiles. METHODS: Adult patients (age ≥ 18 years) presenting to clinics for management of severe, recalcitrant COATS were included in this study. RNA sequencing and differential gene expression analysis was performed with transcriptomic data for normal tracheal tissue being used as a control. The top ten most highly upregulated and downregulated genes were identified. For each of these pathologically dysregulated genes, we identified key cellular pathways and processes they are involved in using Gene Ontology (GO) and KEGG (Kyoto Encyclopedia of Genes and Genomes) applied via Database for Annotation, Visualization, and Integrated Discovery (DAVID). RESULTS: Two women, aged 36 years and 37 years, were included. The profile of dysregulated genes indicated a cellular response consistent with viral infection (CXCL11, PI15, CCL8, DEFB103A, IFI6, ACOD1, and DEFB4A) and hyperproliferation/hypergranulation (MMP3, CASP14 and HAS1), while downregulated pathways included retinol metabolism (ALDH1A2, RBP1, RBP4, CRABP1 and CRABP2). CONCLUSION: Gene expression changes consistent with persistent viral infection and dysregulated retinol metabolism may promote tracheal hypergranulation and hyperproliferation leading to COATS. Given the presence of existing literature highlighting retinoic acid's ability to favorably regulate these genes, improve cell-cell adhesion, and decrease overall disease severity in COVID-19, future studies must evaluate its utility for adjunctive management of COATS in animal models and clinical settings.

Association between serum vitamin A and body mass index in adolescents from NHANES 1999 to 2006.

Vitamin A plays a pivotal role in health, particularly in regulating fat metabolism. Despite its significance, research into the direct relationship between vitamin A levels and obesity, especially among adolescents, is sparse. This study aims to explore this association within the adolescent population in the United States. This cross-sectional study analyzed the National Health and Nutrition Examination Survey (NHANES) data from 1999 to 2006, with 8218 participants. The levels of vitamin A in the serum were determined based on utilizing high-performance liquid chromatography with photodiode array detection. The relationship between serum vitamin A concentrations and body mass index (BMI) was evaluated using weighted multiple linear regression models, incorporating subgroup analyses by sex and race/ethnicity to provide nuanced insights. A positive correlation was observed between serum vitamin A levels and BMI, with BMI increasing progressively across vitamin A quartiles (P < 0.001). Using the lowest quartile of serum vitamin A as a reference, the BMI of the highest quartile of serum vitamin A was 1.236 times higher (95% CI 0.888, 1.585). Subgroup analyses revealed that this positive association persisted across different genders and racial/ethnic groups (P < 0.001). Notably, smooth curve fitting and saturation threshold analysis unveiled an inverted U-shaped relationship between serum vitamin A and BMI among female adolescents, non-Hispanic Whites, Mexican Americans, and other races/ethnicities groups. Our study substantiates the association between serum vitamin A levels and the risk of obesity/overweight status in adolescents. The findings suggest the potential serum vitamin A is an early biomarker for identifying obesity risk, although further studies are needed to determine to clarify its role as a contributing factor to obesity. This study contributes to the understanding of nutritional influences on adolescent obesity, highlighting the need for targeted interventions based on serum biomarkers.

Exploring the complex dynamics of BMI, age, and physiological indicators in early adolescents.

BACKGROUND AND OBJECTIVES: To investigate the relationship between body mass index (BMI) and blood biochemical indicators in early adolescence, and to provide ideas for early prevention of diseases and explore possible disease-related predictors. METHODS: 3125 participants aged 10 ∼ 14 years were selected from China from the survey of "China Nutrition and Health Surveillance ( 2016 ∼ 2017 ) ". Employing advanced statistical methods, including generalized linear models, heatmaps, hierarchical clustering, and generalized additive models, the study delved into the associations between BMI and various biochemical indicators. RESULTS: In early adolescence, indicators including systolic pressure, diastolic pressure, weight, height, BMI, hemoglobin, blood uric acid, serum creatinine, albumin, vitamin A presented increasing trends with the increase of age ( P < 0.05 ), whereas LDL-C, vitamin D, and ferritin showed decreasing trends with the increase of age ( P < 0.05 ). The increase in hemoglobin and blood uric acid levels with age was more pronounced in males compared to females ( P < 0.05 ). BMI was positively correlated with blood glucose, hemoglobin, triglyceride, LDL-C, blood uric acid, serum creatinine, ferritin, transferrin receptor, hs-CRP, total protein, vitamin A ( P < 0.05 ). There was a significant BMI × age interaction in the correlation analysis with LDL-C, transferrin receptor, serum creatinine, and hs-CRP ( P < 0.05 ). BMI was a risk factor for hypertension, hypertriglyceridemia, low high density lipoprotein cholesterolemia, and metabolic syndrome in all age groups ( OR > 1, P < 0.05 ). CONCLUSIONS: High BMI was a risk factor for hypertension, hypertriglyceridemia, low high density lipoprotein cholesterolemia, and MetS in early adolescents. With the focus on energy intake beginning in early adolescence, the maintenance of a healthy weight warrants greater attention.

Efficacy and Tolerability of Topical 0.1% Stabilized Bioactive Retinol for Photoaging: A Vehicle-Controlled Integrated Analysis.

INTRODUCTION: Chronic exposure to ultraviolet light photoages skin. Retinol, a precursor molecule to retinoic acid that causes less irritation, is available as a nonprescription, cosmetic retinoid and improves collagen production, skin elasticity, and signs of photoaging. Advances in formulation science have allowed the production of stabilized bioactive retinol formulations. This integrated analysis aims to build on previous studies and further examine the comprehensive efficacy and tolerability of topical 0.1% stabilized bioactive retinol. METHODS: This analysis included 6 vehicle-controlled studies of 0.1% stabilized bioactive retinol in women with mild-to-moderate signs of photodamage. Across all studies, the same dermatologist investigator assessed overall photodamage; wrinkles on the forehead, cheeks, and undereye area; crow’s feet wrinkles and fine lines; lack of even skin tone; and brown spots at baseline and weeks 4, 8, and 12 on a numerical scale. Tolerability was also assessed. RESULTS: Participants (retinol, N=237; vehicle, N=234) had a mean (SD) age of 47.4 (6.6) years. Retinol induced greater improvements from baseline in all signs of photoaging vs vehicle as early as week 4 and through 12 weeks of application. Few participants experienced irritation; all events were mild to moderate and transient. The most common signs of irritation were erythema (n=2) and skin scaling/peeling (n=5). CONCLUSIONS: This pooled analysis of 6 vehicle-controlled clinical studies provides new evidence for the efficacy of 0.1% stabilized bioactive retinol in improving signs of photoaging without causing major irritation. Topical 0.1% stabilized bioactive retinol was well tolerated with only a few reported cases of skin irritation. J Drugs Dermatol. 2024;23(4):     doi:10.36849/JDD.8124.

Recent Advances in the Nutrition and Metabolism of Dogs and Cats.

Domestic dogs (facultative carnivores) and cats (obligate carnivores) have been human companions for at least 12,000 and 9000 years, respectively. These animal species have a relatively short digestive tract but a large stomach volume and share many common features of physiological processes, intestinal microbes, and nutrient metabolism. The taste buds of the canine and feline tongues can distinguish sour, umami, bitter, and salty substances. Dogs, but not cats, possess sweet receptors. α-Amylase activity is either absent or very low in canine and feline saliva, and is present at low or substantial levels in the pancreatic secretions of cats or dogs, respectively. Thus, unlike cats, dogs have adapted to high-starch rations while also consuming animal-sourced foods. At metabolic levels, both dogs and cats synthesize de novo vitamin C and many amino acids (AAs, such as Ala, Asn, Asp, Glu, Gln, Gly, Pro, and Ser) but have a very limited ability to form vitamin D3. Compared with dogs, cats have higher requirements for AAs, some B-complex vitamins, and choline; greater rates of gluconeogenesis; a higher capacity to tolerate AA imbalances and antagonism; a more limited ability to synthesize arginine and taurine from glutamine/proline and cysteine, respectively; and a very limited ability to generate polyunsaturated fatty acids (PUFAs) from respective substrates. Unlike dogs, cats cannot convert either ß-carotene into vitamin A or tryptophan into niacin. Dogs can thrive on one large meal daily and select high-fat over low-fat diets, whereas cats eat more frequently during light and dark periods and select high-protein over low-protein diets. There are increasing concerns over the health of skin, hair, bone, and joints (specialized connective tissues containing large amounts of collagen and/or keratin); sarcopenia (age-related losses of skeletal-muscle mass and function); and cognitive function in dogs and cats. Sufficient intakes of proteinogenic AAs and taurine along with vitamins, minerals, and PUFAs are crucial for the normal structures of the skin, hair, bone, and joints, while mitigating sarcopenia and cognitive dysfunction. Although pet owners may have different perceptions about the feeding and management practice of their dogs and cats, the health and well-being of the companion animals critically depend on safe, balanced, and nutritive foods. The new knowledge covered in this volume of Adv Exp Med Biol is essential to guide the formulation of pet foods to improve the growth, development, brain function, reproduction, lactation, and health of the companion animals.

Characteristics of Nutrition and Metabolism in Dogs and Cats.

Domestic dogs and cats have evolved differentially in some aspects of nutrition, metabolism, chemical sensing, and feeding behavior. The dogs have adapted to omnivorous diets containing taurine-abundant meat and starch-rich plant ingredients. By contrast, domestic cats must consume animal-sourced foods for survival, growth, and development. Both dogs and cats synthesize vitamin C and many amino acids (AAs, such as alanine, asparagine, aspartate, glutamate, glutamine, glycine, proline, and serine), but have a limited ability to form de novo arginine and vitamin D3. Compared with dogs, cats have greater endogenous nitrogen losses and higher dietary requirements for AAs (particularly arginine, taurine, and tyrosine), B-complex vitamins (niacin, thiamin, folate, and biotin), and choline; exhibit greater rates of gluconeogenesis; are less sensitive to AA imbalances and antagonism; are more capable of concentrating urine through renal reabsorption of water; and cannot tolerate high levels of dietary starch due to limited pancreatic α-amylase activity. In addition, dogs can form sufficient taurine from cysteine (for most breeds); arachidonic acid from linoleic acid; eicosapentaenoic acid and docosahexaenoic acid from α-linolenic acid; all-trans-retinol from ß-carotene; and niacin from tryptophan. These synthetic pathways, however, are either absent or limited in all cats due to (a) no or low activities of key enzymes (including pyrroline-5-carboxylate synthase, cysteine dioxygenase, ∆6-desaturase, ß-carotene dioxygenase, and quinolinate phosphoribosyltransferase) and (b) diversion of intermediates to other metabolic pathways. Dogs can thrive on one large meal daily, select high-fat over low-fat diets, and consume sweet substances. By contrast, cats eat more frequently during light and dark periods, select high-protein over low-protein diets, refuse dry food, enjoy a consistent diet, and cannot taste sweetness. This knowledge guides the feeding and care of dogs and cats, as well as the manufacturing of their foods. As abundant sources of essential nutrients, animal-derived foodstuffs play important roles in optimizing the growth, development, and health of the companion animals.

[Distribution of usual vitamin intake and prevalence of inadequate intake among Chinese adults in 2015].

OBJECTIVE: To estimate the usual vitamin intake and the prevalence of inadequate intakes among Chinese adults in 2015, and to provide a scientific basis for developing nutrition intervention strategies and measures for target populations. METHODS: Data was drawn from the Chinese Nutrition and Health Surveillance 2015-2017, a nationally representative cross-sectional study. The multistage stratified whole-group random sampling method was used to draw participants from 298 surveillance sites in 31 provinces(autonomous regions and municipalities). Participants with no available information or abnormal energy intake were excluded, and finally, a total of 72 231 participants aged 18 years and older were included in the current study. The dietary data of the participants were collected by the 24-hour dietary recall method combined with the condiment weighing method for three consecutive days. The National Cancer Institute method was used to estimate the distribution of the usual intake of vitamin B_1(thiamine), vitamin B_2(riboflavin), niacin, vitamin C(ascorbic acid), and vitamin E(tocopherol), and the prevalence of inadequate intake was evaluated based on estimated average requirement or adequate intake from the Chinese Dietary Reference Intakes 2023. RESULTS: The usual intake of vitamin E, vitamin C, vitamin B_1, vitamin B_2 and niacin were 27.93 mg/d, 77.67 mg/d, 0.78 mg/d, 0.62 mg/d and 13.15 mg/d, respectively. The prevalence of inadequate intake was, in descending order, vitamin B_2(95.98%), vitamin B_1(86.73%), vitamin C(63.70%), niacin(39.81%), and vitamin E(21.17%). The prevalence of inadequate vitamin E, vitamin C, vitamin B_1 and niacin intake among females was higher than among males(P<0.01). Overall, the prevalence of inadequate vitamin intake increased with age. Rural residents had a higher prevalence of inadequate intake of vitamin C, vitamin B_2 and niacin than urban residents(P<0.01). Except for vitamin E, the prevalence of inadequate intake of vitamins decreased with increasing education levels. The prevalence of inadequate intake of these five vitamins was higher among participants with lower income levels than those with middle or high income(P<0.01). Participants with normal weight had a higher prevalence of inadequate intake of vitamin E than those with overweight or obesity and had a higher prevalence of inadequate intake of vitamin C than those with obesity. However, participants with normal weight had a higher prevalence of inadequate intake of vitamin E than those with overweight or obesity, with the differences being statistically significant(P<0.01). Except for vitamin E, the prevalence of inadequate intake of vitamins decreased with increasing physical activity intensity. CONCLUSION: In 2015, the usual intake of dietary vitamins of Chinese adults was low. There are differences in usual intakes of vitamins and prevalence of inadequate vitamin intake for adults aged 18 years and above in males and females, different age groups, urban and rural areas, education levels, household income levels, body mass index and physical activity intensity.

Metabolic Pathway Coupled with Fermentation Process Optimization for High-Level Production of Retinol in Yarrowia lipolytica.

Retinol is a lipid-soluble form of vitamin A that is crucial for human visual and immune functions. The production of retinol through microbial fermentation has been the focus of recent exploration. However, the obtained titer remains limited and the product is often a mixture of retinal, retinol, and retinoic acid, necessitating purification. To achieve efficient biosynthesis of retinol in Yarrowia lipolytica, we improved the metabolic flux of ß-carotene to provide sufficient precursors for retinol in this study. Coupled with the optimization of the expression level of ß-carotene 15,15'-dioxygenase, de novo production of retinol was achieved. Furthermore, Tween 80 was used as an extractant and butylated hydroxytoluene as an antioxidant to extract intracellular retinol and prevent retinol oxidation, respectively. This strategy significantly increased the level of retinol production. By optimizing the enzymes converting retinal to retinol, the proportion of extracellular retinol in the produced retinoids reached 100%, totaling 1042.3 mg/L. Finally, total retinol production reached 5.4 g/L through fed-batch fermentation in a 5 L bioreactor, comprising 4.2 g/L extracellular retinol and 1.2 g/L intracellular retinol. This achievement represents the highest reported titer so far and advances the industrial production of retinol.

Epidermal retinol dehydrogenases cyclically regulate stem cell markers and clock genes and influence hair composition.

The hair follicle (HF) is a self-renewing adult miniorgan that undergoes drastic metabolic and morphological changes during precisely timed cyclic organogenesis. The HF cycle is known to be regulated by steroid hormones, growth factors and circadian clock genes. Recent data also suggest a role for a vitamin A derivative, all-trans-retinoic acid (ATRA), the activating ligand of transcription factors, retinoic acid receptors, in the regulation of the HF cycle. Here we demonstrate that ATRA signaling cycles during HF regeneration and this pattern is disrupted by genetic deletion of epidermal retinol dehydrogenases 2 (RDHE2, SDR16C5) and RDHE2-similar (RDHE2S, SDR16C6) that catalyze the rate-limiting step in ATRA biosynthesis. Deletion of RDHEs results in accelerated anagen to catagen and telogen to anagen transitions, altered HF composition, reduced levels of HF stem cell markers, and dysregulated circadian clock gene expression, suggesting a broad role of RDHEs in coordinating multiple signaling pathways.

Overnutrition is a risk factor for iron, but not for zinc or vitamin A deficiency in children and young people: a systematic review and meta-analysis.

INTRODUCTION: Traditionally associated with undernutrition, increasing evidence suggests micronutrient deficiencies can coexist with overnutrition. Therefore, this work aimed to systematically review the associations between iron, zinc and vitamin A (VA) status and weight status (both underweight and overweight) in children and young people. METHODS: Ovid Medline, Ovid Embase, Scopus and Cochrane databases were systematically searched for observational studies assessing micronutrient status (blood, serum or plasma levels of iron, zinc or VA biomarkers) and weight status (body mass index or other anthropometric measurement) in humans under 25 years of any ethnicity and gender. Risk of bias assessment was conducted using the American Dietetic Association Quality Criteria Checklist. Where possible, random effects restricted maximum likelihood meta-analyses were performed. RESULTS: After screening, 83 observational studies involving 190 443 participants from 44 countries were identified, with many studies having reported on more than one micronutrient and/or weight status indicator. Iron was the most investigated micronutrient, with 46, 28 and 27 studies reporting data for iron, zinc and VA status, respectively. Synthesising 16 records of OR from seven eligible studies, overnutrition (overweight and obesity) increased odds of iron deficiency (ID) (OR (95% CI): 1.51 (1.20 to 1.82), p<0.0001, I2=40.7%). Odds appeared to be higher for children living with obesity (1.88 (1.33 to 2.43), p<0.0001, I2=20.6%) in comparison to those with overweight (1.31 (0.98 to 1.64), p<0.0001, I2=40.5%), although between group differences were not significant (p=0.08). CONCLUSIONS: Overnutrition is associated with increased risk of ID, but not zinc or VA deficiencies, with an inverted U-shaped relationship observed between iron status and bodyweight. Our results highlight significant heterogeneity in the reporting of micronutrient biomarkers and how deficiencies were defined. Inflammation status was rarely adequately accounted for, and the burden of ID may well be under-recognised, particularly in children and young people living with overnutrition. PROSPERO REGISTRATION NUMBER: CRD42020221523.

Retinol and retinol binding protein 4 levels and COVID-19: a Mendelian randomization study.

BACKGROUND: The Corona Virus Disease 2019 (COVID-19) pandemic has struck globally. Whether the related proteins of retinoic acid (RA) signaling pathway are causally associated with the risk of COVID-19 remains unestablished. We conducted a two-sample Mendelian randomization (MR) study to assess the associations of retinol, retinol binding protein 4 (RBP4), retinol dehydrogenase 16 (RDH16) and cellular retinoic acid binding protein 1 (CRABP1) with COVID-19 in European population. METHODS: The outcome utilized the summary statistics of COVID-19 from the COVID-19 Host Genetics Initiative. The exposure data were obtained from public genome wide association study (GWAS) database. We extracted SNPs from exposure data and outcome data. The inverse variance weighted (IVW), MR-Egger and Wald ratio methods were employed to assess the causal relationship between exposure and outcome. Sensitivity analyses were performed to ensure the validity of the results. RESULTS: The MR estimates showed that retinol was associated with lower COVID-19 susceptibility using IVW (OR: 0.69, 95% CI: 0.53-0.90, P: 0.0065), whereas the associations between retinol and COVID-19 hospitalization or severity were not significant. RBP4 was associated with lower COVID-19 susceptibility using the Wald ratio (OR: 0.83, 95% CI: 0.72-0.95, P: 0.0072). IVW analysis showed RDH16 was associated with increased COVID-19 hospitalization (OR: 1.10, 95% CI: 1.01-1.18, P: 0.0199). CRABP1 was association with lower COVID-19 susceptibility (OR: 0.95, 95% CI: 0.91-0.99, P: 0.0290) using the IVW. CONCLUSIONS: We found evidence of possible causal association of retinol, RBP4, RDH16 and CRABP1 with the susceptibility, hospitalization and severity of COVID-19. Our study defines that retinol is significantly associated with lower COVID-19 susceptibility, which provides a reference for the prevention of COVID-19 with vitamin A supplementation.

Ferulic acid in synergy with retinol alleviates oxidative injury of HaCaT cells during UVB-induced photoaging.

Application of retinol (Vitamin A, VA) in skincare is limited for instability, poor water solubility, and skin intolerance that combats skin aging. We employed computer-aided virtual screening and cell experiments with transcriptomics, thereby unveiling the comprehensive gene expression and regulation pathway of photoaging HaCaT cell treated with ferulic acid (FA) in synergizing with VA. Through network pharmacology analysis, the combined use of VA and FA exhibited highly correlated cross-targets with skin aging acting on EGFR, PTPN1, ESR2, GSK3B, BACE1, PYGL, PTGS2 and APP. The indicators of oxidative stress, such as SOD, GSH, MDA, CAT and ROS in HaCaT cells after co-administration, were significantly improved from those in photoaging group (p<0.0001). 155 differential expressed genes (DEGs) were specific between groups, while reducing the expression of PTGS2 was identified as an important regulatory factor in photoaging HaCaT cells by VA and FA. Those DEGs of co-administration group focused on oxidative-reduction enzyme activity, skin growth, keratinization, and steroid biosynthesis. Apparently, the co-administration of VA and FA effectively mitigated the process of UVB-induced photoaging by reducing oxidative stress injury, inflammation responses, and regulating cell growth. This synergistic approach significantly slowed down the photoaging progression and improved the applied performance of VA in HaCaT cells.

Iodine Nutrition, Thyroid-stimulating Hormone, and Related Factors of Postpartum Women from three Different Areas in China: A Cross-sectional Survey.

Objective: Studies on the relationship between iodine, vitamin A (VA), and vitamin D (VD) and thyroid function are limited. This study aimed to analyze iodine and thyroid-stimulating hormone (TSH) status and their possible relationships with VA, VD, and other factors in postpartum women. Methods: A total of 1,311 mothers (896 lactating and 415 non-lactating) from Hebei, Zhejiang, and Guangxi provinces were included in this study. The urinary iodine concentration (UIC), TSH, VA, and VD were measured. Results: The median UIC of total and lactating participants were 142.00 µg/L and 139.95 µg/L, respectively. The median TSH, VA, and VD levels in all the participants were 1.89 mIU/L, 0.44 µg/mL, and 24.04 ng/mL, respectively. No differences in the UIC were found between lactating and non-lactating mothers. UIC and TSH levels were significantly different among the three provinces. The rural UIC was higher than the urban UIC. Obese mothers had a higher UIC and a higher prevalence of excessive TSH. Higher UICs and TSHs levels were observed in both the VD deficiency and insufficiency groups than in the VD-sufficient group. After adjustment, no linear correlation was observed between UIC and VA/VD. No interaction was found between vitamins A/D and UIC on TSH levels. Conclusion: The mothers in the present study had no iodine deficiency. Region, area type, BMI, and VD may be related to the iodine status or TSH levels.