The role of vitamin A and related retinoids in immune function

Exploring the Effects of Vitamin D and Vitamin A Levels on the Response to COVID-19 Vaccine

COVID-19 vaccines were developed at an unprecedented speed in history. The factors affecting the response to COVID-19 vaccines are not clear. Herein, the effects of vitamin D and vitamin A (retinol) levels on the response to the BNT162b2 vaccine were explored. A total of 124 vaccine recipients were recruited from the general population attending vaccination centers in Irbid, Jordan. Blood samples were collected immediately before receiving the first vaccine dose (D0) and three weeks later (D21). Baseline (D0) levels of 25-hydroxyvitamin D [25(OH)D], retinol, and SARS-CoV-2 S1 IgG antibodies were measured with ELISA. The response to the BNT162b2 vaccine was tested by measuring the levels and avidity of SARS-CoV-2 S1 IgG antibodies on D21. The participants were divided into two groups, unexposed and exposed, based on the D0 SARS-CoV-2 antibody results. No significant correlation was found between the levels of 25(OH)D or retinol and the levels, avidity, or fold increase of antibodies in both groups. Similarly, no significant difference in antibody response was found between 25(OH)D status groups, retinol status groups, or combined status groups. These findings show that the baseline vitamin D or vitamin A levels have no effect on the short-term response to a single dose of BNT162b2 vaccine.

The Possible Role of Selected Vitamins and Minerals in the Therapeutic Outcomes of Leishmaniasis

Leishmaniasis is a protozoal disease declared as an endemic in areas suffering from severe malnutrition and poverty. The factors associated with poverty like low income, ecological factors, and malnutrition cause disruption in immunity and host defense increasing risk of infection. Altered resistance to infection and host susceptibility are associated with low micronutrient levels in undernourished patients. Malnutrition has been recognized as a poor predictive marker for leishmaniasis, in particular the deficiency of trace elements like zinc, iron, and vitamin A, B, C, D which has a prominent function in the regulation of innate and adaptive immunity, cell proliferation, human physiology, etc. Malnourishment can exacerbate host sensitivity and pathophysiologic intensity to infection in variety of ways, whereas infection can enhance underlying poor nutrition or enhance host vulnerability and sandfly's urge to attack specific hosts. The intensity of leishmaniasis can be influenced by body mass and micronutrient availability in the blood. Vitamin D, C, zinc, and iron are proved effective in inhibiting the growth of leishmaniasis in both amastigote or promastigote forms, either directly or by acting as precursor for a pathway which inhibits the parasite growth. This article elucidates a new perception to the crucial role of micronutrients and their probable role in the therapeutic outcomes of leishmaniasis. Since there is requirement of novel drugs to fight drug resistance and relapse of leishmaniasis, this article may pave way to understand the importance of micronutrients and their role in therapeutic outcomes of leishmaniasis.

Nutritional supplements for the control of avian coccidiosis

Coccidiosis is acclaimed as the most prevalent enteric parasitic ailment of poultry. It is caused by an apicomplexan protozoon of the genus Eimeria, which resides in chicken intestinal epithelium leading to intestinal damage. As a result, bloody droppings are there, feed efficiency is reduced, the growth rate is impaired, and egg production is temporarily decreased. Treatment and prevention of coccidiosis are primarily accomplished by inoculating live vaccines and administering anticoccidial drugs. Due to anticoccidials’ continuous and excessive use, the mounting issue is drug resistant Eimeria strains. The poultry industry has managed resistance-related issues by suggesting shuttle and rotation schemes. Furthermore, new drugs have also been developed and introduced, but it takes a long time and causes cost inflation in the poultry industry. Moreover, government disallows growth promoters and drugs at sub-therapeutic doses in poultry due to increased concerns about the drug residues in poultry products. These constraints have motivated scientists to work on alternative ways to control coccidiosis effectively, safely, and sustainably. Using nutritional supplements is a novel way to solve the constraints mentioned above. The intriguing aspects of using dietary supplements against coccidiosis are that they reduce the risk of drug-resistant pathogen strains, ensure healthy, nutritious poultry products, have less reliance on synthetic drugs, and are typically considered environmentally safe. Furthermore, they improve productivity, enhance nonspecific immunity, preventing oxidation of fats (acting as antioxidants) and inflammation (acting as an anti-inflammatory). The present manuscript focuses on the efficacy, possible mechanism of action, applications, and different facets of nutrition supplements (such as organic acids, minerals, vitamins, probiotics, essential oils, amino acids, dietary nucleotides, feed enzymes, and yeast derivatives) as feed additive for treating poultry coccidiosis.

Immune Impairment Associated with Vitamin A Deficiency: Insights from Clinical Studies and Animal Model Research

Vitamin A (VA) is critical for many biological processes, including embryonic development, hormone production and function, the maintenance and modulation of immunity, and the homeostasis of epithelium and mucosa. Specifically, VA affects cell integrity, cytokine production, innate immune cell activation, antigen presentation, and lymphocyte trafficking to mucosal surfaces. VA also has been reported to influence the gut microbiota composition and diversity. Consequently, VA deficiency (VAD) results in the imbalanced production of inflammatory and immunomodulatory cytokines, intestinal inflammation, weakened mucosal barrier functions, reduced reactive oxygen species (ROS) and disruption of the gut microbiome. Although VAD is primarily known to cause xerophthalmia, its role in the impairment of anti-infectious defense mechanisms is less defined. Infectious diseases lead to temporary anorexia and lower dietary intake; furthermore, they adversely affect VA status by interfering with VA absorption, utilization and excretion. Thus, there is a tri-directional relationship between VAD, immune response and infections, as VAD affects immune response and predisposes the host to infection, and infection decreases the intestinal absorption of the VA, thereby contributing to secondary VAD development. This has been demonstrated using nutritional and clinical studies, radiotracer studies and knockout animal models. An in-depth understanding of the relationship between VAD, immune response, gut microbiota and infections is critical for optimizing vaccine efficacy and the development of effective immunization programs for countries with high prevalence of VAD. Therefore, in this review, we have comprehensively summarized the existing knowledge regarding VAD impacts on immune responses to infections and post vaccination. We have detailed pathological conditions associated with clinical and subclinical VAD, gut microbiome adaptation to VAD and VAD effects on the immune responses to infection and vaccines.

Effect of food and key micronutrients on Covid-19: A review

Humanity has faced different pandemics in history. The Covid-19 pandemic has made a new course in the world caused by SARS-CoV-2 that can be transmitted to humans. Finding alternative methods to prevent and control the disease through food and some micronutrients is important. This review summarizes effect of food and key micronutrients on Covid-19. There are currently no reports of the feasibility of transmission through the food sector. However, malnutrition and deficiency of some nutrients can lead to disorders of immune system. Coronavirus may be transferred through raw and uncooked foods; more safety and preventive measures are needed. Furthermore, sufficient intake of omega-3 fatty acids, minerals and vitamins are required for proper immune system function. Therefore, a healthy diet is required for prevent Covid-19. Personal hygiene and employee awareness is the two most important features in the prevention of Covid-19. Further studies are needed to confirm these results.

Major dietary patterns in relation to disease severity, symptoms, and inflammatory markers in patients recovered from COVID-19

Background

COVID-19 is a highly transmissible viral infection with high morbidity. Few studies have been done about dietary intakes in patients with COVID-19. This study aimed to evaluate the association between major dietary patterns before COVID-19 diagnosis in recovered patients and the risk of disease severity and symptoms after the disease begins.

Methods

Overall, 250 recovered cases with both genders completed study questionnaires providing data on demographic characteristics, self-reported web-based 168-item food frequency questionnaire (FFQ), and COVID-19 outcomes in Shahid Beheshti Hospital, Kashan. PCR was used to determine a positive diagnosis of COVID-19. We used multivariable logistic regression models to assess the association between major dietary patterns and study outcomes. All statistical analyses were done by SPSS version 16.

Results

We identified three major dietary patterns—unhealthy, traditional, and healthy dietary patterns. Serum levels of C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) were significantly higher in patients with unhealthy and traditional dietary patterns and lower in those with healthy dietary patterns. There was a significant direct relationship between unhealthy and traditional patterns with risk of severe COVID-19 and hospitalization duration and a significant direct association between an unhealthy pattern and the odds ratio (OR) of convalescence duration. A significant inverse relationship was found between healthy pattern and risk of severe COVID-19 and OR of convalescence duration. We found a significant direct association between unhealthy pattern and OR of cough, fever, chilling, weakness, myalgia, nausea and vomiting, and sore throat and between traditional pattern and OR of cough, fever, and chilling. In contrast, a significant inverse association was seen between healthy pattern and OR of dyspnea, weakness, and sore throat.

Conclusion

This study showed that high adherence to an healthy pattern was associated with lower CRP and ESR levels and lower risk of severe COVID-19, hospitalization, and convalescence duration in patients who recovered from COVID-19. More adherence to unhealthy or traditional dietary patterns was associated with higher CRP and ESR levels and a higher risk of severe COVID-19 and hospitalization duration. A direct association was found between unhealthy and traditional patterns and the risk of some COVID-19 symptoms, while an inverse association was found for a healthy dietary pattern.

Recurrent respiratory infections and vitamin A levels: a link? It is cross-sectional

Respiratory tract infections are common illnesses in children, causing significant morbidity and negatively affecting their health. Vitamin A protects against infections and maintains epithelial integrity. The goal of this study was to determine the correlation between vitamin A deficiency and recurrent respiratory tract infections (RRTIs). Participants in this cross-sectional study were divided into 3 groups: RRTIs (including patients with history of RRTIs presenting with respiratory tract infection symptoms), RTI (including patients without history of RRTIs presenting with respiratory tract infection symptoms), and control (including children who came for a routine health checkup without a history of RRTIs or respiratory tract infection symptoms). The vitamin A assay was performed using high-performance liquid chromatography. The study included 550 children aged 6.64 ± 2.61 years. The RRTIs group included 150 children (27.3%), the RTI group included 300 children (54.5%), and the control group included 100 children (18.2%). Subclinical vitamin A deficiency and vitamin A deficiency affected 3.1% and 1.3% of subjects, respectively. Subclinical vitamin A deficiency and vitamin A deficiency were higher in children with RRTIs than in those with RTI (8% vs 1.3%, P = .001 and 4% vs 0.3%, P = .006). Additionally, children with RRTIs had significantly higher rates of subclinical vitamin A deficiency and vitamin A deficiency than those in the control group, which had 1% subclinical vitamin A deficiency (P = .017) and no cases of vitamin A deficiency (P = .043). The RRTIs group had higher rates of otitis media (27.3%), sinusitis (20%), and pneumonia (4.7%) than the RTI group (P = .002). Vitamin A insufficiency was associated with RRTIs in children.

Multiple Micronutrient Supplementation: As a Supportive Therapy in the Treatment of COVID-19

During the infection and treatment of the SARS-CoV-2 viral infection, age and comorbidities play a major role in the successful management of COVID-19. The nutritional status changes which occur in the body vary with the age and underlying conditions and has a vital role in the functioning of the immune system and cellular membrane integrity, thus minimizing the vulnerability to the infection. Considering the data already published by eminent researchers, a few micronutrients have shown outstanding results as supportive therapies in the treatment of viral infections. Micronutrient like zinc improves the membrane barrier integrity, has anti-inflammatory activity, and is involved in antibody production. Vitamin A supports the phagocytic activity of macrophages, while vitamin C reduces the worsening of respiratory tract infections by restoring the dysfunctional epithelial barrier of the lungs. Vitamin D, vitamin E, selenium, and omega-3 fatty acid metabolites play a major role in immunomodulation and in the inhibition of proinflammatory cytokine production. Magnesium is involved in the synthesis of antibodies, while copper, vitamin B12, and folate have significant effects on immune cells. A few researchers suggest that iron supplementation has reduced the risk of acquiring respiratory tract infections in children. As the age of the patient increases, the need for micronutrients increases, thus leading to an imbalanced nutritional status which in turn increases the risk and fatality of the infections. The use of micronutrients in modulating the inflammatory, immune responses, and the epithelial barrier integrity is explored during the treatment of viral infections for faster recovery.

The role of micronutrients in the management of COIVD-19 and optimizing vaccine efficacy

Since COVID-19 was declared as a pandemic, a race between researchers has begun to deeply examine the mechanism of the virus and how to combat it. Few clinical investigations and studies have paid attention to the role of micronutrients in the disease's course and how it may affect the disease outcomes. Micronutrients have a noticeable effect on the host immune system regulation, as well as micronutrients insufficiencies where they can affect the host immune response against SARS-CoV-2 by, for example, altering the production and the function of the inflammatory cytokines such as IFN-γ, IFN-α, TNF and interleukins. Recent studies have shown that low levels of vitamin D, vitamin C, vitamin A, zinc, selenium, copper and magnesium have a great clinical impact on COVID-19 patients, where, they are linked to prolong hospital stay, increase the mortality rate and raise the complications rate related not only to the respiratory system but also to the other systems. Optimizing the need for these micronutrients will act as a productive factor by decreasing the incidence of COVID-19 infection, lowering the rate of complications, and improving the disease prognosis and outcomes. Optimal micro-nutrition supports and contributes to the efficiency of COVID-19 vaccine. The aim of this review is to highlight the role of different micronutrients in the management of COVID-19 and optimizing vaccines, and to revile the clinical effects of micronutrients deficiencies on patients with COVID-19.

Priming with Retinoic Acid, an Active Metabolite of Vitamin A, Increases Vitamin A Uptake in the Small Intestine of Neonatal Rats

Given that combined vitamin A (VA) and retinoic acid (RA) supplementation stimulated the intestinal uptake of plasma retinyl esters in neonatal rats, we administrated an RA dose as a pretreatment before VA supplementation to investigate the distinct effect of RA on intestinal VA kinetics. On postnatal days (P) 2 and 3, half of the pups received an oral dose of RA (RA group), while the remaining received canola oil as the control (CN). On P4, after receiving an oral dose of ³H-labeled VA, pups were euthanized at selected times (n = 4–6/treatment/time) and intestine was collected. In both CN and RA groups, intestinal VA mass increased dramatically after VA supplementation; however, RA-pretreated pups had relatively higher VA levels from 10 h and accumulated 30% more VA over the 30-h study. Labeled VA rapidly peaked in the intestine of CN pups and then declined from 13 h, while a continuous increase was observed in the RA group, with a second peak at 10 h and nearly twice the accumulation of ³H-labeled VA compared to CN. Our findings indicate that RA pretreatment may stimulate the influx of supplemental VA into the intestine, and the increased VA accumulation suggests a potential VA storage capacity in neonatal intestine.

Effect of organophosphorus pesticide exposure on the immune cell phenotypes among farm women and their children

Epidemiological studies suggest suppression of the lymphocytes function through cholinergic stimulation due to organophosphorus pesticide exposure. The study aimed to assess the alteration in the levels of immune cell phenotypes among farm women (FW) and farm children (FC) who were occupationally exposed to pesticides and age/gender-matched control subjects belonging to Rangareddy district (Telangana, India). A total of 129 FW, 129 FC and 268 age/gender-matched controls were recruited. Blood samples were collected from the selected subjects to estimate the levels of nine organophosphorus pesticide residues and CD (CD3+, CD4+, CD8+, CD16+ and CD19+) cell markers using LC-MS/MS and flow cytometry, respectively. Independent t-test analysis was conducted to compare the immune cell phenotypes between exposed and control groups. Spearman's rank correlation test was further carried out to identify any possible correlation between the pesticide residues and CD markers. The mean percentage for CD4+, CD8+ and CD16+ was found to be significantly low, while for CD19 + itwas significantly high in the FW as compared to the CW group (p < 0.01). Further, the residues of chlorpyrifos and monocrotophos among FW were found to be significantly correlating with the mean percentages of CD19+ and CD8+ markers, respectively. The cell marker subsets of CD4+ and CD8+ were significantly low in FC children 9-12 years and 13-15 years age groups, respectively (p < 0.05). Also, these levels were significantly correlating with the residues of malathion and monocrotophos. The present study could indicate an alteration in the lymphocytes' subpopulations, which may thereby infer the toxicity in the first phase assessment of immunotoxicity. Therefore, further studies may be conducted to understand the suspected pesticides' mechanism along with various other factors in causing immune suppression coupled with nutritional and other related disorders.

Western Dietary Pattern Antioxidant Intakes and Oxidative Stress: Importance During the SARS-CoV-2/COVID-19 Pandemic

The importance of balanced dietary habits, which include appropriate amounts of antioxidants to maintain the immune system, has become increasingly relevant during the current SARS-CoV-2/COVID-19 pandemic, because viral infections are characterized by high oxidative stress. Furthermore, the measures taken by governments to control the pandemic have led to increased anxiety, stress, and depression, which affect physical and mental health, all of which are influenced by nutritional status, diet, and lifestyle. The Mediterranean diet (MD), Atlantic diet (AD), and the Dietary Guidelines for Americans all provide the essential vitamins, minerals, and phenolic compounds needed to activate enzymatic and nonenzymatic antioxidant responses. However, viral pandemics such as the current COVID-19 crisis entail high oxidative damage caused by both the infection and the resultant social stresses within populations, which increases the probability and severity of infection. Balanced dietary patterns such as the MD and the AD are characterized by the consumption of fruit, vegetables, legumes, olive oil, and whole grains with low intakes of processed foods and red meat. For a healthy lifestyle in young adults, the MD in particular provides the required amount of antioxidants per day for vitamins D (0.3-3.8 μg), E (17.0 mg), C (137.2-269.8 mg), A (1273.3 μg), B-12 (1.5-2.0 μg), and folate (455.1-561.3 μg), the minerals Se (120.0 μg), Zn (11.0 mg), Fe (15.0-18.8 mg), and Mn (5.2-12.5 mg), and polyphenols (1171.00 mg) needed to maintain an active immune response. However, all of these diets are deficient in the recommended amount of vitamin D (20 μg/d). Therefore, vulnerable populations such as elders and obese individuals could benefit from antioxidant supplementation to improve their antioxidant response. Although evidence remains scarce, there is some indication that a healthy diet, along with supplemental antioxidant intake, is beneficial to COVID-19 patients.

Association Between Serum Vitamin A Levels and Recurrent Respiratory Tract Infections in Children

To evaluate the association between serum vitamin A levels and the prevalence of recurrent respiratory tract infections (RRTIs) in children and adolescents and to provide evidence that would help decrease the prevalence of respiratory tract infections (RTIs) in children. This cross-sectional study included 8034 children and adolescents in Beijing aged 6 months to 17 years. RRTI and RTI symptoms were diagnosed according to the Clinical Concept and Management of Recurrent Respiratory Tract Infections in Children. Multivariate logistic regression models were used to evaluate the association between serum vitamin A levels and RRTIs after adjusting for potential confounders. Among the included children, 721 (8.97%) were diagnosed with vitamin A deficiency, whereas 3,073 (38.25%) were diagnosed with subclinical vitamin A deficiency. Only 28.8% (208/721) of children with vitamin A deficiency and 53.1% (1,631/3,073) of children with subclinical vitamin A deficiency had no RRTI and RTI symptoms, respectively. Compared with children with normal vitamin A levels, those with vitamin A deficiency and subclinical vitamin A deficiency had a greater risk for RRTIs, with an odds ratio (OR) of 6.924 [95% confidence interval (CI): 5.433-8.824] and 2.140 (95% CI: 1.825-2.510), respectively]. Vitamin A levels were also positively associated with RTI symptoms, with those having vitamin A deficiency and subclinical vitamin A deficiency showing an OR of 1.126 (95% CI: 0.773-1.640) and 1.216 (95% CI: 1.036-1.427), respectively. The present cross-sectional study found that low serum vitamin A levels were significantly associated with RRTI or RTI prevalence in children and adolescents.

COVID-19: Is there a role for immunonutrition in obese patient?

On December 12, 2019 a new coronavirus (SARS-CoV-2) emerged in Wuhan, China, triggering a pandemic of severe acute respiratory syndrome in humans (COVID-19). Today, the scientific community is investing all the resources available to find any therapy and prevention strategies to defeat COVID-19. In this context, immunonutrition can play a pivotal role in improving immune responses against viral infections. Immunonutrition has been based on the concept that malnutrition impairs immune function. Therefore, immunonutrition involves feeding enriched with various pharmaconutrients (Omega 3 Fatty Acids, Vitamin C, Arginine, Glutamine, Selenium, Zinc, Vitamin, E and Vitamin D) to modulate inflammatory responses, acquired immune response and to improve patient outcomes. In literature, significant evidences indicate that obesity, a malnutrition state, negatively impacts on immune system functionality and on host defense, impairing protection from infections. Immunonutrients can promote patient recovery by inhibiting inflammatory responses and regulating immune function. Immune system dysfunction is considered to increase the risk of viral infections, such as SARS-CoV-2, and was observed in different pathological situations. Obese patients develop severe COVID-19 sequelae, due to the high concentrations of TNF-α, MCP-1 and IL-6 produced in the meantime by visceral and subcutaneous adipose tissue and by innate immunity. Moreover, leptin, released by adipose tissue, helps to increase inflammatory milieu with a dysregulation of the immune response. Additionally, gut microbiota plays a crucial role in the maturation, development and functions of both innate and adaptive immune system, as well as contributing to develop obese phenotype. The gut microbiota has been shown to affect lung health through a vital crosstalk between gut microbiota and lungs, called the "gut-lung axis". This axis communicates through a bi-directional pathway in which endotoxins, or microbial metabolites, may affect the lung through the blood and when inflammation occurs in the lung, this in turn can affect the gut microbiota. Therefore, the modulation of gut microbiota in obese COVID-19 patients can play a key role in immunonutrition therapeutic strategy. This umbrella review seeks to answer the question of whether a nutritional approach can be used to enhance the immune system's response to obesity in obese patients affected by COVID-19.

Dietary micronutrients in the wake of COVID-19: an appraisal of evidence with a focus on high-risk groups and preventative healthcare

Existing micronutrient deficiencies, even if only a single micronutrient, can impair immune function and increase susceptibility to infectious disease. Certain population groups are more likely to have micronutrient deficiencies, while certain disease pathologies and treatment practices also exacerbate risk, meaning these groups tend to suffer increased morbidity and mortality from infectious diseases. Optimisation of overall nutritional status, including micronutrients, can be effective in reducing incidence of infectious disease. Micronutrient deficiencies are rarely recognised but are prevalent in the UK, as well as much more widely, particularly in high-risk groups susceptible to COVID-19. Practitioners should be aware of this fact and should make it a consideration for the screening process in COVID-19, or when screening may be difficult or impractical, to ensure blanket treatment as per the best practice guidelines. Correction of established micronutrient deficiencies, or in some cases assumed suboptimal status, has the potential to help support immune function and mitigate risk of infection. The effects of and immune response to COVID-19 share common characteristics with more well-characterised severe acute respiratory infections. Correction of micronutrient deficiencies has proven effective in several infectious diseases and has been shown to promote favourable clinical outcomes. Micronutrients appear to play key roles in mediating the inflammatory response and such effects may be enhanced through correction of deficiencies. Many of those at highest risk during the COVID-19 pandemic are also populations at highest risk of micronutrient deficiencies and poorer overall nutrition. Correction of micronutrient deficiencies in established COVID-19 infection may contribute to supporting immune response to infection in those at highest risk. There is a need for further research to establish optimal public health practice and clinical intervention regimens.

Association Between Serum Retinol and α-Tocopherol Levels and Metabolic Syndrome in Korean General Population: Analysis of Population-based Nationally Representative Data

This study aimed to evaluate the association between serum retinol and α-tocopherol levels and metabolic syndrome (MetS) using data from the Korea National Health and Nutrition Examination Survey. Of the 24,269 individuals, 5885 adults (2672 men and 3213 women) were included. The prevalence of MetS and its components according to quartiles of serum retinol and α-tocopherol levels was calculated. Multivariate linear regression model was used to calculate the number of metabolic components according to serum vitamin levels. The association between serum vitamin levels and MetS with its components was assessed using multivariate logistic regression model. The prevalence of MetS was highest in Q4 and lowest in Q1 for both vitamins, regardless of sex. A dose-dependent association between serum retinol and α-tocopherol levels and MetS was observed. After adjustment for covariates, the odds ratio (OR) for MetS in Q4 compared to Q1 was 2.351 (95% CI: 1.748-3.163, Ptrend < 0.001) in the retinol group and 2.559 (95% CI: 1.953-3.353, Ptrend < 0.001) in α-tocopherol group. Among metabolic components, hypertriglyceridemia, high fasting glucose, and high blood pressure was positively associated with serum retinol and α-tocopherol levels. In conclusion, high serum retinol and α-tocopherol levels were associated with increased risk of MetS.

Marker discovery and associations with β-carotene content in Indian dairy cattle and buffalo breeds

Vitamin A is essential for human health, but current intake levels in many developing countries such as India are too low due to malnutrition. According to the World Health Organization, an estimated 250 million preschool children are vitamin A deficient globally. This number excludes pregnant women and nursing mothers, who are particularly vulnerable. Efforts to improve access to vitamin A are key because supplementation can reduce mortality rates in young children in developing countries by around 23%. Three key genes, BCMO1, BCO2, and SCARB1, have been shown to be associated with the amount of β-carotene (BC) in milk. Whole-genome sequencing reads from the coordinates of these 3 genes in 202 non-Indian cattle (141 Bos taurus, 61 Bos indicus) and 35 non-Indian buffalo (Bubalus bubalis) animals from several breeds were collected from data repositories. The number of SNP detected in the coding regions of these 3 genes ranged from 16 to 26 in the 3 species, with 5 overlapping SNP between B. taurus and B. indicus. All these SNP together with 2 SNP in the upstream part of the gene but already present in dbSNP (https://www.ncbi.nlm.nih.gov/projects/SNP/) were used to build a custom Sequenom array. Blood for DNA and milk samples for BC were obtained from 2,291 Indian cows of 5 different breeds (Gir, Holstein cross, Jersey Cross, Tharparkar, and Sahiwal) and 2,242 Indian buffaloes (Jafarabadi, Murrah, Pandharpuri, and Surti breeds). The DNA was extracted and genotyped with the Sequenom array. For each individual breed and the combined breeds, SNP with an association that had a P-value <0.3 in the first round of linear analysis were included in a second step of regression analyses to determine allele substitution effects to increase the content of BC in milk. Additionally, an F-test for all SNP within gene was performed with the objective of determining if overall the gene had a significant effect on the content of BC in milk. The analyses were repeated using a Bayesian approach to compare and validate the previous frequentist results. Multiple significant SNP were found using both methodologies with allele substitution effects ranging from 6.21 (3.13) to 9.10 (5.43) μg of BC per 100 mL of milk. Total gene effects exceeded the mean BC value for all breeds with both analysis approaches. The custom panel designed for genes related to BC production demonstrated applicability in genotyping of cattle and buffalo in India and may be used for cattle or buffalo from other developing countries. Moreover, the recommendation of selection for significant specific alleles of some gene markers provides a route to effectively increase the BC content in milk in the Indian cattle and buffalo populations.

Starch quality traits of improved provitamin A cassava (Manihot esculenta Crantz)

Provitamin A cassava clones were analysed for starch yield and critical starch quality attributes, to understand possible applications in the food industry. Total carotenoids content in the test clones ranged from 0.03-11.94 μg g^-1 of fresh root. Starch yield ranged from 8.4-33.2 % and correlated negatively (r = -0.588, P < 0.001) with carotenoids content. Amylose content (16.4–22.1%) didn't differ significantly (P ≤ 0.05) among the cassava clones. Meanwhile, total carotenoid content had significant negative correlations (P ≤ 0.05) with starch pasting temperature, peak time, setback viscosities and peak area. The reduced peak time and pasting temperatures in high-carotenoid cassava signifies reduction in energy requirements in yellow-fleshed roots when compared to white-fleshed cassava. This attribute is desirable for the food industry as it would reduce the overall cost of processing the cassava. Furthermore, final viscosities of starch from carotenoid-rich cassava were lower than those of white-fleshed roots, making provitamin A cassava suitable for soft food processing.

Vitamin A Deficiency Disorders in Children and Women

Vitamin A deficiency is an endemic nutrition problem throughout much of the developing world, especially affecting the health and survival of infants, young children, and pregnant and lactating women. These age and life-stage groups represent periods when both nutrition stress is high and diet likely to be chronically deficient in vitamin A. Approximately 127 million preschool-aged children and 7 million pregnant women are vitamin A deficient. Health consequences of vitamin A deficiency include mild to severe systemic effects on innate and acquired mechanisms of host resistance to infection and growth, increased burden of infectious morbidity, mild to severe (blinding) stages of xerophthalmia, and increased risk of mortality. These consequences are defined as vitamin A deficiency disorders (VADD). Globally, 4.4 million preschool children have xerophthalmia and 6 million mothers suffer night blindness during pregnancy. Both conditions are associated with increased risk of morbidity and mortality. While reductions of child mortality of 19–54% following vitamin A treatment have been widely reported, more recent work suggests that dosing newborns with vitamin A may, in some settings, lower infant mortality. Among women, one large trial has so far reported a ≥ 40% reduction in mortality related to pregnancy with weekly, low-dose vitamin A supplementation. Epidemiologic data on vitamin A deficiency disorders can be useful in planning, designing, and targeting interventions.

Feedlot performance and immune function analysis of implanted and non-implanted steers selected for alcohol dehydrogenase 1 C (ADH1C) genotype and fed a low vitamin A diet

Previous studies have shown that the interaction between limiting vitamin A (VA) and an alcohol dehydrogenase 1 C (ADH1C) variant in beef cattle results in increased intramuscular fat in the longissimus thoracis muscle in one genotype when fed low dietary VA. Although quality grade is important for increased profitability and improving taste characteristics of beef products, limiting VA too drastically can impair animal welfare. The objectives of this study were to determine if this marker-assisted management strategy would be effective, and whether any impairment in immune function would occur in a feedlot setting. Mixed breed beef steers (n=2000) were sorted into 40 feedlot pens so that all combinations of ADH1C genotype (TT or CT), VA level (50% or 100% of recommended) and hormonal implant status (implanted (IMP) or non-implanted (NI)) were equally represented within the population. The VA×ADH1C interaction was not observed. An implant status × ADH1C interaction was observed with average daily gain (ADG; P=0.03). Steers that were IMP and CT had higher ADG than IMP TT (CT=1.69 and TT=1.62 kg/day), whereas both genotypes in the NI steers were lower (CT=1.29 and TT=1.32 kg/day). Implant status was shown to affect dry matter intake (DMI; IMP=8.55 and NI=7.87 kg; P&lt;0.01), total days-on-feed (IMP=164.4 and NI 210.5 days; P&lt;0.01), USDA yield grade (YIELD; IMP=2.40 and NI=2.77; P&lt;0.01), marbling score (MARB; IMP=392 and NI=455; P&lt;0.01), longissimus thoracis area (LTA; IMP=85.0 and NI=80.7 cm2; P=0.01) and backfat thickness (FAT; IMP=8.0 and NI 10.0 mm; P&lt;0.01). Overall, IMP animals finished on fewer total days-on-feed with higher ADG, DMI, larger LTA, and lower YIELD, MARB and FAT. To investigate immune function parameters, crossbred steers (n=18) were selected from a prior feeding trial so that all combinations of ADH1C (TT, CT and CC) and VA (25% or 75%) were equally represented. Blood cell count analysis and peripheral blood mononuclear cell proliferation and stimulation assays were conducted. None of these immune parameters were affected by VA level. Treatment and mortality records were examined in the 2000 steer population, where no correlations with ADH1C, implant status or VA level were observed. Due to no VA × ADH1C interaction, this nutrigenetic marker-assisted management strategy is not effective at this time in commercial beef cattle feedlots, however, supplementing VA at a level as low as 25% of recommended in finishing rations would likely not result in signs of immune dysfunction.

Vitamin B5 Reduces Bacterial Growth via Regulating Innate Immunity and Adaptive Immunity in Mice Infected with Mycobacterium tuberculosis

The mechanisms by which vitamins regulate immunity and their effect as an adjuvant treatment for tuberculosis have gradually become very important research topics. Studies have found that vitamin B5 (VB5) can promote epithelial cells to express inflammatory cytokines. We aimed to examine the proinflammatory and antibacterial effect of VB5 in macrophages infected with Mycobacterium tuberculosis (MTB) strain H37Rv and the therapeutic potential of VB5 in vivo with tuberculosis. We investigated the activation of inflammatory signal molecules (NF-κB, AKT, JNK, ERK, and p38), the expression of two primary inflammatory cytokines (tumor necrosis factor and interleukin-6) and the bacterial burdens in H37Rv-infected macrophages stimulated with VB5 to explore the effect of VB5 on the inflammatory and antibacterial responses of macrophages. We further treated the H37Rv-infected mice with VB5 to explore VB5's promotion of the clearance of H37Rv in the lungs and the effect of VB5 on regulating the percentage of inflammatory cells. Our data showed that VB5 enhanced the phagocytosis and inflammatory response in macrophages infected with H37Rv. Oral administration of VB5 decreased the number of colony-forming units of H37Rv in lungs of mice at 1, 2, and 4 weeks after infection. In addition, VB5 regulated the percentage of macrophages and promoted CD4+ T cells to express interferon-γ and interleukin-17; however, it had no effect on the percentage of polymorphonuclear neutrophils, CD4+ and CD8+ T cells. In conclusion, VB5 significantly inhibits the growth of MTB by regulating innate immunity and adaptive immunity.

Vitamin A supplements for reducing mother-to-child HIV transmission

BACKGROUND

Strategies to reduce the risk of mother-to-child transmission of the human immunodeficiency virus (HIV) include lifelong antiretroviral therapy (ART) for HIV-positive women, exclusive breastfeeding from birth for six weeks plus nevirapine or replacement feeding plus nevirapine from birth for four to six weeks, elective Caesarean section delivery, and avoiding giving children chewed food. In some settings, these interventions may not be practical, feasible, or affordable. Simple, inexpensive, and effective interventions (that could potentially be implemented even in the absence of prenatal HIV testing programmes) would be valuable. Vitamin A, which plays a role in immune function, is one low-cost intervention that has been suggested in such settings.

OBJECTIVES

To summarize the effects of giving vitamin A supplements to HIV-positive women during pregnancy and after delivery.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, Embase, and the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) up to 25 August 2017, and checked the reference lists of relevant articles for eligible studies.

SELECTION CRITERIA

We included randomized controlled trials conducted in any setting that compared vitamin A supplements to placebo or no intervention among HIV-positive women during pregnancy or after delivery, or both.

DATA COLLECTION AND ANALYSIS

At least two review authors independently assessed study eligibility and extracted data. We expressed study results as risk ratios (RR) or mean differences (MD) as appropriate, with their 95% confidence intervals (CI), and conducted random-effects meta-analyses. This is an update of a review last published in 2011.

MAIN RESULTS

Five trials met the inclusion criteria. These were conducted in Malawi, South Africa, Tanzania, and Zimbabwe between 1995 and 2005 and none of the participants received ART. Women allocated to intervention arms received vitamin A supplements at a variety of doses (daily during pregnancy; a single dose immediately after delivery, or daily doses during pregnancy plus a single dose after delivery). Women allocated to comparison arms received identical placebo (6601 women, 4 trials) or no intervention (697 women, 1 trial). Four trials (with 6995 women) had low risk of bias and one trial (with 303 women) had high risk of attrition bias.The trials show that giving vitamin A supplements to HIV-positive women during pregnancy, the immediate postpartum period, or both, probably has little or no effect on mother-to-child transmission of HIV (RR 1.07, 95% CI 0.91 to 1.26; 4428 women, 5 trials, moderate certainty evidence) and may have little or no effect on child death by two years of age (RR 1.06, 95% CI 0.92 to 1.22; 3883 women, 3 trials, low certainty evidence). However, giving vitamin A supplements during pregnancy may increase the mean birthweight (MD 34.12 g, 95% CI -12.79 to 81.02; 2181 women, 3 trials, low certainty evidence) and probably reduces the incidence of low birthweight (RR 0.78, 95% CI 0.63 to 0.97; 1819 women, 3 trials, moderate certainty evidence); but we do not know whether vitamin A supplements affect the risk of preterm delivery (1577 women, 2 trials), stillbirth (2335 women, 3 trials), or maternal death (1267 women, 2 trials).

AUTHORS' CONCLUSIONS

Antepartum or postpartum vitamin A supplementation, or both, probably has little or no effect on mother-to-child transmission of HIV in women living with HIV infection and not on antiretroviral drugs. The intervention has largely been superseded by ART which is widely available and effective in preventing vertical transmission.

Retinoic acid receptor gamma impacts cellular adhesion, Alpha5Beta1 integrin expression and proliferation in K562 cells

The interplay between cellular adhesion and proliferation is complex; however, integrins, particularly the α5β1 subset, play a pivotal role in orchestrating critical cellular signals that culminate in cellular adhesion and growth. Retinoids modify the expression of a variety of adhesive/proliferative signaling proteins including α5β1 integrins; however, the role of specific retinoic acid receptors involved in these processes has not been elucidated. In this study, the effect of all-trans-retinoic acid receptor (RAR) agonists on K562 cellular adhesion, proliferation, and α5β1 integrin cell surface expression was investigated. RARγ agonist exposure increased K562 cellular adhesion to RGD containing extracellular matrix proteins fibronectin and FN-120 in a time- and concentration dependent manner, while RARα or RARβ agonist treatment had no effect on cellular adhesion. Due to the novel RARγ- dependent cellular adhesion response exhibited by K562 cells, we examined α5 and β1 integrin subunit expression when K562 cells were exposed to retinoid agonists or vehicle for 24, 48, 72 or 96 hours. Our data demonstrates no differences in K562 cell surface expression of the α5 integrin subunit when cells were exposed to RARα, RARβ, or RARγ agonists for all time points tested. In contrast, RARγ agonist exposure resulted in an increase in cell surface β1 integrin subunit expression within 48 hours that was sustained at 72 and 96 hours. Finally, we demonstrate that while exposure to RARα or RARβ agonists have no effect on K562 cellular proliferation, the RARγ agonist significantly dampens K562 cellular proliferation levels in a time- and concentration- dependent manner. Our study is the first to report that treatment with a RARγ specific agonist augments cellular adhesion to α5β1 integrin substrates, increases cell surface levels of the β1 integrin subunit, and dampens cellular proliferation in a time and concentration dependent manner in a human erythroleukemia cell line.

Single High-Dose Vitamin A Supplementation to Neonatal Piglets Results in a Transient Dose Response in Extrahepatic Organs and Sustained Increases in Liver Stores

Background: Neonatal vitamin A (VA) supplementation is being evaluated as a public health policy for preventing infant mortality, but inconsistencies in mortality trials demand mechanistic work to determine biological plausibility.Objectives: We investigated the absorption, distribution, and storage of single large oral VA doses administered shortly after birth.Methods: Fifty pregnant sows (Sus scrofas domesticas) were fed a VA-free diet. Male and female newborn piglets (n = 313) were orally administered 0, 25,000, 50,000, or 200,000 IU VA in oil within 12 h of birth when mean ± SD weight was 1.56 ± 0.25 kg. Blood was drawn to determine absorption and storage 0.5-240 h after administration. Metabolic and postnatal dose-timing substudies were performed. Liver, lung, kidney, spleen, and adrenal VA concentrations were determined 7-240 h after administration.Results: Serum retinol and retinyl ester concentrations responded to treatment (P < 0.0001); however, differences between groups disappeared by 96 h. Liver VA concentrations responded to treatment (P < 0.0001), which persisted for 240 h. Liver VA for control piglets at 10 d (mean ± SD: 0.05 ± 0.02 μmol/g) was ≤0.1 μmol/g (deficiency), whereas groups that received VA maintained concentrations >0.1 μmol/g. Extrahepatic tissue VA concentrations displayed treatment effects (P ≤ 0.0077); groups that received treatments had higher VA concentrations than controls at early time points. Lung, kidney, and spleen VA did not differ between groups by 96 h, whereas adrenal glands did not differ by 240 h. Body weight was affected by treatment (P = 0.0002); VA-deficient piglets weighed 23-29% more than all treated groups 240 h after administration.Conclusions: A high dose of VA administered to newborn piglets was well absorbed, appeared in serum primarily as retinyl esters, and was taken up dose-dependently in all tissues studied; however, enhancement did not persist in sera, lungs, kidneys, spleens, or adrenal glands. Short-term impacts of retinoid signaling on weight gain remain to be elucidated, and longer follow-up studies are needed.

Vitamin A and Carotenoid Toxicity

Large differences in time and dose needed to induce hypervitaminosis A have been observed. High doses of vitamin A in food and oily solutions are well tolerated, whereas emulsified preparations have higher toxicity. Chronic hypervitaminosis seems to be induced following daily doses of 300,000 to 600,000 IU of vitamin A (90–180 mg of retinol) in oily preparations for many months or years, whereas teratogenicity may be induced by daily doses as low as 40,000 IU of vitamin A (12 mg of retinol) in oil during the first trimester. for the provitamin A, β-carotene, serious adverse effects have been reported in large-scale prospective randomized trials: four years of supplementation with 20 to 30 mg β-carotene per day was associated with increased risk of lung cancer and cardiovascular disease among smokers and workers exposed to asbestos. These results strongly suggest that high doses of β-carotene should not be recommended for any group until the safety of such doses can be established.

The Relationship between Vitamin A Deficiency and Hiv Infection: Review of Scientific Studies

Review of the literature shows that in adults there are variations in the association of hyporetinemia with disease progression as well as variations in the response to supplementation. Populations that are likely to be deficient in vitamin A show the biggest responses. Additional vitamin A supplementation may not be necessary, and may even be harmful, in adults who already have a good dietary intake of vitamin A and who take many other vitamin supplements. Vitamin A supplementation does not appear to have any impact on mother-to-child transmission of HIV; nevertheless, vitamin A supplementation of pregnant women in the third trimester may be useful to reduce the incidence of low-birthweight and premature infants. the impact of vitamin A on mother-to-child transmission of HIV in preterm infants is awaiting further investigation. Vitamin A supplementation of HIV-infected children appears to be beneficial to reduce the incidence and severity of diarrhea in particular. Randomized, placebo-controlled trials in pregnant women and adults have shown that the association between vitamin A and HIV is probably an association of reverse causality.

Obesity, Inflammation, and Periodontal Disease

The prevalence of obesity has increased substantially over the past decades in most industrialized countries. Obesity is a systemic disease that predisposes to a variety of co-morbidities and complications that affect overall health. Cross-sectional studies suggest that obesity is also associated with oral diseases, particularly periodontal disease, and prospective studies suggest that periodontitis may be related to cardiovascular disease. The possible causal relationship between obesity and periodontitis and potential underlying biological mechanisms remain to be established; however, the adipose tissue actively secretes a variety of cytokines and hormones that are involved in inflammatory processes, pointing toward similar pathways involved in the pathophysiology of obesity, periodontitis, and related inflammatory diseases. We provide an overview of the definition and assessment of obesity and of related chronic diseases and complications that may be important in the periodontist’s office. Studies that have examined the association between obesity and periodontitis are reviewed, and adipose-tissue-derived hormones and cytokines that are involved in inflammatory processes and their relationship to periodontitis are discussed. Our aim is to raise the periodontist’s awareness when treating obese individuals.

Saponin-Based Nanoemulsification Improves the Antioxidant Properties of Vitamin A and E in AML-12 Cells

Our work aimed to investigate the protective effects of saponin-based nanoemulsions of vitamin A and E against oxidative stress-induced cellular damage in AML-12 cells. Saponin nanoemulsions of vitamin A (SAN) and vitamin E (SEN) were prepared by high-pressure homogenization and characterized in terms of size, zeta potential, and polydispersity index. SEN and SAN protect AML-12 cells against oxidative stress-induced cellular damage more efficiently via scavenging reactive oxygen species (ROS), and reducing DNA damage, protein carbonylation, and lipid peroxidation. These results provide valuable information for the development of nanoemulsion-based delivery systems that would improve the antioxidant properties of vitamin A and E.

Levels of retinyl palmitate and retinol in stratum corneum, epidermis and dermis of SKH-1 mice

Vitamin A (retinol) regulates many biological functions, including epidermal cell growth. Retinyl palmitate (RP) is the major esterified form of retinol and the predominant component of retinoids in the skin; however, how endogenous levels of RP and retinol in the skin are affected by the age of the animal remains unknown. Furthermore, the levels of retinol and RP in the various skin layers- the stratum corneum, epidermis and dermis of skin- have not been reported. In this paper, we report the development of a convenient method for separation of the skin from SKH-1 female mice into the stratum corneum, epidermis, and dermis and the determination of the levels of RP and retinol in the three fractions by HPLC analysis. The total quantities of RP and retinol from the stratum corneum, epidermis, and dermis are comparable to those extracted from the same amount of intact skin from the same mouse. There was an age-related effect on the levels of RP and retinol in the skin and liver of female mice. An age-related effect was also observed in the stratum corneum, epidermis, and dermis. The levels of RP and retinol were highest in the epidermis of 20-week-old mice, and decreased when the age increased to 60- and 68-weeks. The total amount of RP at 20 weeks of age was found to be 1.52 ng/mg skin, and decreased about 4-fold at 60- and 68-weeks of age. A similar trend was found for the effects of age on the levels of retinol.

Nutritional supplements for people being treated for active tuberculosis

BACKGROUND

Tuberculosis and malnutrition are linked in a complex relationship. Tuberculosis may cause undernutrition through increased metabolic demands and decreased intake, and nutritional deficiencies may worsen the disease, or delay recovery by depressing important immune functions. At present, there is no evidence-based nutritional guidance for adults and children being treated for tuberculosis.

OBJECTIVES

To assess the effects of oral nutritional supplements in people being treated with antituberculous drug therapy for active tuberculosis.

SEARCH METHODS

We searched the Cochrane Infectious Disease Group Specialized Register, Cochrane Central Register of Controlled Trials (CENTRAL; Issue 1, 2016), MEDLINE (from 1946 to 4 February 2016), EMBASE (from 1980 to 4 February 2016), LILACS (from 1982 to 4 February 2016), the metaRegister of Controlled Trials (mRCT), the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP), and the Indian Journal of Tuberculosis up to 4 February 2016, and checked the reference lists of all included studies.

SELECTION CRITERIA

Randomized controlled trials that compared any oral nutritional supplement given for at least four weeks with no nutritional intervention, placebo, or dietary advice only for people being treated for active tuberculosis. The primary outcomes of interest were all-cause death, and cure at six and 12 months.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion, and extracted data and assessed the risk of bias in the included trials. We presented the results as risk ratios (RR) for dichotomous variables, and mean differences (MD) for continuous variables, with 95% confidence intervals (CIs). Where appropriate, we pooled data from trials with similar interventions and outcomes. We assessed the quality of the evidence using the Grading of Recommendation Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

Thirty-five trials, including 8283 participants, met the inclusion criteria of this review. Macronutrient supplementationSix trials assessed the provision of free food, or high-energy supplements. Only two trials measured total dietary intake, and in both trials the intervention increased calorie consumption compared to controls.The available trials were too small to reliably prove or exclude clinically important benefits on mortality (RR 0.34, 95% CI 0.10 to 1.20; four trials, 567 participants, very low quality evidence), cure (RR 0.91, 95% CI 0.59 to 1.41; one trial, 102 participants, very low quality evidence), or treatment completion (data not pooled; two trials, 365 participants, very low quality evidence).Supplementation probably produces a modest increase in weight gain during treatment for active tuberculosis, although this was not seen consistently across all trials (data not pooled; five trials, 883 participants, moderate quality evidence). Two small studies provide some evidence that quality of life may also be improved but the trials were too small to have much confidence in the result (data not pooled; two trials, 134 participants, low quality evidence). Micronutrient supplementationSix trials assessed multi-micronutrient supplementation in doses up to 10 times the dietary reference intake, and 18 trials assessed single or dual micronutrient supplementation.Routine multi-micronutrient supplementation may have little or no effect on mortality in HIV-negative people with tuberculosis (RR 0.86, 95% CI 0.46 to 1.6; four trials, 1219 participants, low quality evidence), or HIV-positive people who are not taking antiretroviral therapy (RR 0.92, 95% CI 0.69 to 1.23; three trials, 1429 participants, moderate quality evidence). There is insufficient evidence to know if supplementation improves cure (no trials), treatment completion (RR 0.99, 95% CI 0.95 to 1.04; one trial, 302 participants, very low quality evidence), or the proportion of people who remain sputum positive during the first eight weeks (RR 0.92, 95% CI 0.63 to 1.35; two trials, 1020 participants, very low quality evidence). However, supplementation may have little or no effect on weight gain during treatment (data not pooled; five trials, 2940 participants, low quality evidence), and no studies have assessed the effect on quality of life.Plasma levels of vitamin A appear to increase following initiation of tuberculosis treatment regardless of supplementation. In contrast, supplementation probably does improve plasma levels of zinc, vitamin D, vitamin E, and selenium, but this has not been shown to have clinically important benefits. Of note, despite multiple studies of vitamin D supplementation in different doses, statistically significant benefits on sputum conversion have not been demonstrated.

AUTHORS' CONCLUSIONS

There is currently insufficient research to know whether routinely providing free food, or energy supplements improves tuberculosis treatment outcomes, but it probably improves weight gain in some settings.Although blood levels of some vitamins may be low in people starting treatment for active tuberculosis, there is currently no reliable evidence that routinely supplementing above recommended daily amounts has clinical benefits.

Fat Soluble Vitamins and Immune System: An Overview

The immune system guards against invasion by foreign microrganisms and molecules. In this way, it protects from fatal illnesses and communicable diseases. Its proper functioning is fundamental for survival.

Research has demonstrated that proper nutrition plays a crucial role in the prevention of chronic disease. Protein-energy malnutrition is associated with a significant impairment of cell-mediated immunity, phagocyte function, the complement system, secretory immunoglobulin A antibody concentrations, and cytokine production. Deficiency of single nutrients also results in altered immune responses; this is observed even when the deficiency state is relatively mild. Of the micronutrients, zinc, selenium, iron, copper, vitamins A,C,E and B, and folic acid have important influences on the immune response.

It is now apparent that vitamin E and β-carotene have more subtle roles and that deficient dietary intake of these vitamins increases susceptibility to certain cancers and cardiovascular disease. This reflects, in part, the antioxidant properties of the vitamins and their ability to reduce free radical-mediated damage to DNA, proteins and lipid membranes. These findings have considerable practical and public health significance. The aim of this review is to give an up-to date account of the roles of selected fat-soluble vitamins in health and disease.

Vitamin A degradation in triglycerides varying by their saturation levels

Vitamin A deficiency has a widespread occurrence globally and is considered as one of the world's most serious health risk factors. Potential solutions to address this deficiency include dietary diversification or supplementation, but food fortification is generally accepted as the most cost-effective solution. The main issue with food fortification of this vitamin is related to its high instability in food matrices. Dilution of vitamin A in triglycerides is a natural and appropriate way to stabilize this compound. We show here that vitamin A palmitate stability increases with increasing concentration of triglycerides. Moreover, we found that vitamin A palmitate displays improved stability in more saturated oils. Using various temperatures, and Arrhenius plots of experiments performed at storage temperatures between 30°C and 60°C for oils varying by their saturation and crystallinity, we demonstrate that crystallization is not responsible for this phenomenon. Additionally, we show by centrifugation that vitamin A is preferably solubilized in the liquid phase compared to the crystalline phase, explaining that triglyceride crystallization does not stabilize vitamin A palmitate. It is proposed that unsaturated fats generate more oxidation products such as radicals and peroxides, leading to a quicker degradation of vitamin A.

Significance of nutrition in pulmonary tuberculosis

Malnutrition and tuberculosis are both problems mostly of the developing countries. Tuberculosis can lead to malnutrition and malnutrition may predispose to tuberculosis. Poor nutrition leads to protein-energy malnutrition and micronutrients deficiencies which lead to immunodeficiency. This secondary immunodeficiency increases the host's susceptibility to infection and hence increase the risk for developing tuberculosis. Tuberculosis itself leads to reduction in appetite, nutrient malabsorption, micronutrient malabsorption, and altered metabolism leading to wasting and poor nutritional status. Nutritional status and dietary intake and hence nutritional status of patients get improved during antituberculosis treatment.

Retinoic acid-induced IgG production in TLR-activated human primary B cells involves ULK1-mediated autophagy

In the present study we have established a vital role of autophagy in retinoic acid (RA)-induced differentiation of toll-like receptor (TLR)-stimulated human B cells into Ig-secreting cells. Thus, RA enhanced autophagy in TLR9- and CD180-stimulated peripheral blood B cells, as revealed by increased levels of the autophagosomal marker LC3B-II, enhanced colocalization between LC3B and the lysosomal marker Lyso-ID, by a larger percentage of cells with more than 5 characteristic LC3B puncta, and by the concomitant reduction in the level of SQSTM1/p62. Furthermore, RA induced expression of the autophagy-inducing protein ULK1 at the transcriptional level, in a process that required the retinoic acid receptor RAR. By inhibiting autophagy with specific inhibitors or by knocking down ULK1 by siRNA, the RA-stimulated IgG production in TLR9- and CD180-mediated cells was markedly reduced. We propose that the identified prominent role of autophagy in RA-mediated IgG-production in normal human B cells provides a novel mechanism whereby vitamin A exerts its important functions in the immune system.

Lipid-Based Nutrient Supplements Providing Approximately the Recommended Daily Intake of Vitamin A Do Not Increase Breast Milk Retinol Concentrations among Ghanaian Women

BACKGROUND

Vitamin A deficiency remains a global public health problem. Daily supplementation with a lipid-based nutrient supplement (LNS) has potential for increasing milk vitamin A concentrations.

OBJECTIVE

The objective of this study was to determine whether daily supplementation with approximately the recommended daily intake of vitamin A in an LNS or a multiple-micronutrient supplement (MMN) during pregnancy and the first 6 mo postpartum has an effect on breast milk retinol concentration at 6 mo postpartum.

METHODS

Women ≤20 wk pregnant (n = 1320) were randomly assigned to receive either the MMN providing 18 micronutrients, including 800 μg retinol equivalents of vitamin A, or the LNS with the same nutrients as the MMN group, plus 4 minerals and macronutrients, until 6 mo postpartum; a control group received iron and folic acid during pregnancy and a placebo (calcium tablet) during the first 6 mo postpartum. Breast milk samples collected at 6 mo postpartum were analyzed for retinol and fat concentrations by HPLC and creamatocrit, respectively, in a subsample of 756 women.

RESULTS

The breast milk retinol concentration was (mean ± SD) 56.3 ± 2.1 nmol/g fat, with no significant differences between groups [iron and folic acid (n = 243): 59.1 ± 2.8; MMN (n = 260): 55.4 ± 2.5; LNS (n = 253): 54.7 ± 2.5 nmol/g fat; P = 0.45], regardless of whether the woman had or had not received a high-dose vitamin A supplement (200,000 IU) soon after childbirth. Around 17% of participants had low milk retinol (≤28 nmol/g fat). We estimated that 41% of infants were potentially receiving vitamin A at amounts above the Tolerable Upper Intake Level (600 μg retinol activity equivalents/d), with no group differences in percentages with low or high milk retinol concentration.

CONCLUSION

Daily consumption of approximately the recommended intake of vitamin A did not increase breast milk retinol concentrations in this sample of Ghanaian women. This trial was registered at clinicaltrials.gov as NCT00970866.

Retinoic Acid Induces Embryonic Stem Cell Differentiation by Altering Both Encoding RNA and microRNA Expression

Retinoic acid (RA) is a vitamin A metabolite that is essential for early embryonic development and promotes stem cell neural lineage specification; however, little is known regarding the impact of RA on mRNA transcription and microRNA levels on embryonic stem cell differentiation. Here, we present mRNA microarray and microRNA high-output sequencing to clarify how RA regulates gene expression. Using mRNA microarray analysis, we showed that RA repressed pluripotency-associated genes while activating ectoderm markers in mouse embryonic stem cells (mESCs). Moreover, RA modulated the DNA methylation of mESCs by altering the expression of epigenetic-associated genes such as Dnmt3b and Dnmt3l. Furthermore, H3K4me2, a pluripotent histone modification, was repressed by RA stimulation. From microRNA sequence data, we identified two downregulated microRNAs, namely, miR-200b and miR-200c, which regulated the pluripotency of stem cells. We found that miR-200b or miR-200c deficiency suppressed the expression of pluripotent genes, including Oct4 and Nanog, and activated the expression of the ectodermal marker gene Nestin. These results demonstrate that retinoid induces mESCs to differentiate by regulating miR-200b/200c. Our findings provide the landscapes of mRNA and microRNA gene networks and indicate the crucial role of miR-200b/200c in the RA-induced differentiation of mESCs.

Treatment with 4-methylpyrazole modulated stellate cells and natural killer cells and ameliorated liver fibrosis in mice

Background & Aims

Accumulating evidence suggests that retinol and its metabolites are closely associated with liver fibrogenesis. Recently, we demonstrated that genetic ablation of alcohol dehydrogenase 3 (ADH3), a retinol metabolizing gene that is expressed in hepatic stellate cells (HSCs) and natural killer (NK) cells, attenuated liver fibrosis in mice. In the current study, we investigated whether pharmacological ablation of ADH3 has therapeutic effects on experimentally induced liver fibrosis in mice.

Methods

Liver fibrosis was induced by intraperitoneal injections of carbon tetrachloride (CCl₄) or bile duct ligation (BDL) for two weeks. To inhibit ADH3-mediated retinol metabolism, 10 μg 4-methylpyrazole (4-MP)/g of body weight was administered to mice treated with CCl₄ or subjected to BDL. The mice were sacrificed at week 2 to evaluate the regression of liver fibrosis. Liver sections were stained for collagen and α-smooth muscle actin (α-SMA). In addition, HSCs and NK cells were isolated from control and treated mice livers for molecular and immunological studies.

Results

Treatment with 4-MP attenuated CCl₄- and BDL-induced liver fibrosis in mice, without any adverse effects. HSCs from 4-MP treated mice depicted decreased levels of retinoic acids and increased retinol content than HSCs from control mice. In addition, the expression of α-SMA, transforming growth factor-β1 (TGF-β1), and type I collagen α1 was significantly reduced in the HSCs of 4-MP treated mice compared to the HSCs from control mice. Furthermore, inhibition of retinol metabolism by 4-MP increased interferon-γ production in NK cells, resulting in increased apoptosis of activated HSCs.

Conclusions

Based on our data, we conclude that inhibition of retinol metabolism by 4-MP ameliorates liver fibrosis in mice through activation of NK cells and suppression of HSCs. Therefore, retinol and its metabolizing enzyme, ADH3, might be potential targets for therapeutic intervention of liver fibrosis.

Alcohol dehydrogenase III exacerbates liver fibrosis by enhancing stellate cell activation and suppressing natural killer cells in mice

The important roles of retinols and their metabolites have recently been emphasized in the interactions between hepatic stellate cells (HSCs) and natural killer (NK) cells. Nevertheless, the expression and role of retinol metabolizing enzyme in both cell types have yet to be clarified. Thus, we investigated the expression of retinol metabolizing enzyme and its role in liver fibrosis. Among several retinol metabolizing enzymes, only alcohol dehydrogenase (ADH) 3 expression was detected in isolated HSCs and NK cells, whereas hepatocytes express all of them. In vitro treatment with 4-methylpyrazole (4-MP), a broad ADH inhibitor, or depletion of the ADH3 gene down-regulated collagen and transforming growth factor-β1 (TGF-β1) gene expression, but did not affect α-smooth muscle actin gene expression in cultured HSCs. Additionally, in vitro, treatments with retinol suppressed NK cell activities, whereas inhibition of ADH3 enhanced interferon-γ (IFN-γ) production and cytotoxicity of NK cells against HSCs. In vivo, genetic depletion of the ADH3 gene ameliorated bile duct ligation- and carbon tetrachloride-induced liver fibrosis, in which a higher number of apoptotic HSCs and an enhanced activation of NK cells were detected. Freshly isolated HSCs from ADH3-deficient mice showed reduced expression of collagen and TGF-β1, but enhanced expression of IFN-γ was detected in NK cells from these mice compared with those of control mice. Using reciprocal bone marrow transplantation of wild-type and ADH3-deficient mice, we demonstrated that ADH3 deficiency in both HSCs and NK cells contributed to the suppressed liver fibrosis.

CONCLUSION

ADH3 plays important roles in promoting liver fibrosis by enhancing HSC activation and inhibiting NK cell activity, and could be used as a potential therapeutic target for the treatment of liver fibrosis.

Does vitamin A supplementation protect schoolchildren from acquiring soil-transmitted helminthiasis? A randomized controlled trial

Background

Despite the intensive global efforts to control intestinal parasitic infections, the prevalence of soil-transmitted helminth (STH) infections is still very high in many developing countries particularly among children in rural areas.

Methods

A randomized, double-blind, placebo-controlled trial was conducted on 250 Aboriginal schoolchildren in Malaysia to investigate the effects of a single high-dose of vitamin A supplementation (200 000 IU) on STH reinfection. The effect of the supplement was assessed at 3 and 6 months after receiving interventions; after a complete 3-day deworming course of 400 mg/daily of albendazole tablets.

Results

Almost all children (98.6%) were infected with at least one STH species. The overall prevalence of ascariasis, trichuriasis and hookworm infection was 67.8%, 95.5% and 13.4%, respectively. Reinfection rates of Ascaris, Trichuris and hookworm were high; at 6 months, assessment reached 80% of the prevalence reported before treatment. There were no significant differences in the reinfection rates and intensities of STH between vitamin A supplemented-children and those who received placebo at 3 and 6 months (p > 0.05).

Conclusions

Vitamin A supplementation showed no protective effect against STH reinfection and this could be due to the high endemicity of STH in this community. Long-term interventions to reduce poverty will help significantly in reducing this continuing problem and there is no doubt that reducing intestinal parasitic infection would have a positive impact on the health, nutrition and education of these children.

Trial registration

This trial was registered at clinicaltrials.gov as NCT00936091.

Oral doses of α-retinyl ester track chylomicron uptake and distribution of vitamin A in a male piglet model for newborn infants

α-Retinol has utility in determining chylomicron trafficking of vitamin A to tissues given that it will not be recirculated in blood on retinol binding protein (RBP). In this study, α-retinol was used as a chylomicron tag to investigate short-term uptake from high-dose supplements given to piglets as a model for neonates. The distribution of orally administered α-retinol doses in liver and extrahepatic tissues was assessed at varying times after dosing. Male piglets (n = 24 per group) from vitamin A-depleted sows were orally given 26.2 or 52.4 μmol of α-retinyl acetate, the molar equivalent of 25,000 and 50,000 IU of vitamin A, respectively. Tissues were collected and analyzed by HPLC. Lung (6.46 ± 2.94 nmol/g), spleen (22.1 ± 11.3 nmol/g), and adrenal gland (17.0 ± 11.2 nmol/g) α-retinol concentrations peaked at 7 h after dosing, and, by 7 d, α-retinol was essentially cleared from these tissues (≤0.25 ± 0.12 nmol/g). This demonstrates that the lung, spleen, and adrenal gland receive substantial vitamin A from chylomicra to maintain concentrations. Conversely, storage of α-retinol in the liver reached a plateau at 24 h (1.72 ± 0.58 μmol/liver) and was retained through 7 d (2.10 ± 0.38 μmol/liver) (P > 0.05). This indicates that α-retinol was not substantially utilized locally in the liver nor transported out from the liver via RBP. In serum, the majority of α-retinol was in the ester form, which confirms that α-retinol does not bind to RBP but does circulate. α-Retinyl esters were detectable at 7 d in the serum but were not different from baseline. Collectively, these data suggest that crucial immune organs need constant dietary intake to maintain vitamin A concentrations because α-retinol was quickly taken up by tissues and decreased to baseline in all tissues except long-term storage in the liver.

The cross talk between microbiota and the immune system: metabolites take center stage

The human meta-organism consists of more than 90% of microbial cells. The gastrointestinal tract harbors trillions of commensal microorganisms that influence the development and homeostasis of the host. Alterations in composition and function of the microbiota, termed dysbiosis, have been implicated in a multitude of metabolic and inflammatory diseases in humans. Thus, understanding the molecular underpinnings the cross talk between commensal bacteria and their host during homeostasis and dysbiosis may hold the key to understanding many idiopathic diseases. While most attention has focused on the innate recognition of immune-stimulatory bacterial molecules, such as cell wall components and nucleic acids, we emphasize here the impact of diet-dependent microbial metabolites on the development and function of the immune system.

Nutritional supplementation increases rifampin exposure among tuberculosis patients coinfected with HIV

Nutritional supplementation to tuberculosis (TB) patients has been associated with increased weight and reduced mortality, but its effect on the pharmacokinetics of first-line anti-TB drugs is unknown. A cohort of 100 TB patients (58 men; median age, 35 [interquartile range {IQR}, 29 to 40] years, and median body mass index [BMI], 18.8 [17.3 to 19.9] kg/m(2)) were randomized to receive nutritional supplementation during the intensive phase of TB treatment. Rifampin plasma concentrations were determined after 1 week and 2 months of treatment. The effects of nutritional supplementation, HIV, time on treatment, body weight, and SLCO1B1 rs4149032 genotype were examined using a population pharmacokinetic model. The model adjusted for body size via allometric scaling, accounted for clearance autoinduction, and detected an increase in bioavailability (+14%) for the patients in the continuation phase. HIV coinfection in patients not receiving the supplementation was found to decrease bioavailability by 21.8%, with a median maximum concentration of drug in serum (Cmax) and area under the concentration-time curve from 0 to 24 h (AUC0-24) of 5.6 μg/ml and 28.6 μg · h/ml, respectively. HIV-coinfected patients on nutritional supplementation achieved higher Cmax and AUC0-24 values of 6.4 μg/ml and 31.6 μg · h/ml, respectively, and only 13.3% bioavailability reduction. No effect of the SLCO1B1 rs4149032 genotype was observed. In conclusion, nutritional supplementation during the first 2 months of TB treatment reduces the decrease in rifampin exposure observed in HIV-coinfected patients but does not affect exposure in HIV-uninfected patients. If confirmed in other studies, the use of defined nutritional supplementation in HIV-coinfected TB patients should be considered in TB control programs. (This study has the controlled trial registration number ISRCTN 16552219.).

9-cis-retinoic Acid and troglitazone impacts cellular adhesion, proliferation, and integrin expression in K562 cells

Retinoids are established pleiotropic regulators of both adaptive and innate immune responses. Recently, troglitazone, a PPAR gamma agonist, has been demonstrated to have anti-inflammatory effects. Separately, retinoids and troglitazone are implicated in immune related processes; however, their combinatory role in cellular adhesion and proliferation has not been well established. In this study, the effect of 9-cis-retinoic acid (9-cis-RA) and troglitazone on K562 cellular adhesion and proliferation was investigated. Troglitazone exposure decreased K562 cellular adhesion to RGD containing extracellular matrix proteins fibronectin, FN-120, and vitronectin in a concentration and time-dependent manner. In the presence of troglitazone, 9-cis-retinoic acid restores cellular adhesion to levels comparable to vehicle treatment alone on fibronectin, FN-120, and vitronectin substrates within 72 hours. Due to the prominent role of integrins in attachment to extracellular matrix proteins, we evaluated the level of integrin α5 subunit expression. Troglitazone treatment results in decrease in α5 subunit expression on the cell surface. In the presence of both agonists, cell surface α5 subunit expression was restored to levels comparable to vehicle treatment alone. Additionally, troglitazone and 9-cis-RA mediated cell adhesion was decreased in the presence of a function blocking integrin alpha 5 inhibitor. Further, through retinoid metabolic profiling and HPLC analysis, our study demonstrates that troglitazone augments retinoid availability in K562 cells. Finally, we demonstrate that troglitazone and 9-cis-retinoic acid synergistically dampen cellular proliferation in K562 cells. Our study is the first to report that the combination of troglitazone and 9-cis-retinoic acid restores cellular adhesion, alters retinoid availability, impacts integrin expression, and dampens cellular proliferation in K562 cells.