Uptake Of Vitamin Research Articles

Prevalence and factors associated with vitamin K prophylaxis utilization among neonates in rural Ethiopia in 2016

BackgroundNeonatal Mortality Ratio (NMR) could not be reversed sufficiently in Ethiopia in the last couple of years. Neonatal bleeding is one of the major causes of neonatal deaths. Administration of vitamin K prophylaxis at birth is the proven strategy to reduce neonatal death which can be caused by vitamin K deficiency bleeding. Although World Health Organization (WHO) recommends universal supplementation of vitamin K prophylaxis for all neonates at birth, many neonates could not get it in many resource poor countries. Despite its importance, information is scarce about uptake of vitamin K prophylaxis in Ethiopia in 2016. Therefore, this study aimed to identify prevalence and factors associated with vitamin K prophylaxis utilization among neonates in Ethiopia in 2016.MethodsSecondary data analysis of EDHS 2016 was done to assess prevalence and predictors of vitamin K prophylaxis among neonates in Ethiopia five years before EDHS 2016. Multi-stage cluster sampling was used in EDHS 2016. Sample weight and complex analysis were used to minimize bias. Bivariate and multivariable logistic regression analyses were carried out to identify factors associated with vitamin K prophylaxis. Finally, adjusted odds ratio with 95% confidence interval was calculated and P-value less than 0.05 taken as the cuff of point for declaration of the statistical significant association.ResultsPrevalence of vitamin K prophylaxis among neonates in Ethiopia in 2016 was found to be 4710(65.5%) in this study. Factors like: Institutional delivery (AOR = 2.2, 95%CI: 1.8, 2.7), neonates from richest family (AOR = 2.1, 95%CI: 1.6, 2.7), neonates from richer household (AOR = 1.4, 95%CI: 1.1, 1.8), starting of antenatal care from 3–6 months of gestational age (AOR = 2.9, 95%CI: 2.3, 3.6) were factors positively associated with vitamin K prophylaxis in Ethiopia.Conclusion and recommendationCompared with expected world health organization recommendation of universal supplementation vitamin K prophylaxis, vitamin K utilization is lower among neonates in this study. Hence, it is recommended that strengthen early antenatal care initiation and improving community awareness about vitamin K prophylaxis are the key interventions to improve its uptake. Furthermore, improving institutional delivery might increase uptake of vitamin K prophylaxis.

Mice Lacking the Systemic Vitamin A Receptor RBPR2 Show Decreased Ocular Retinoids and Loss of Visual Function

Simple SummaryThis work represents an initial evaluation of the second RBP4-vitamin A receptor RBPR2 in a mammalian model. We provide evidence that the membrane localized RBPR2 protein, under variable conditions of dietary vitamin A intake, plays an important role for dietary vitamin A transport to the eye for ocular retinoid homeostasis and visual function. These findings are of general interest, as disturbances in blood and ocular vitamin A homeostasis are linked to retinal degenerative diseases, which are blinding diseases. The animal model described here could also serve as an in vivo tool to study mechanisms related to retinal cell degeneration that are associated with vitamin A deficiency.The systemic transport of dietary vitamin A/all-trans retinol bound to RBP4 into peripheral tissues for storage is an essential physiological process that continuously provides visual chromophore precursors to the retina under fasting conditions. This mechanism is critical for phototransduction, photoreceptor cell maintenance and survival, and in the support of visual function. While the membrane receptor STRA6 facilitates the blood transport of lipophilic vitamin A into the eye, it is not expressed in most peripheral organs, which are proposed to express a second membrane receptor for the uptake of vitamin A from circulating RBP4. The discovery of a novel vitamin A receptor, RBPR2, which is expressed in the liver and intestine, but not in the eye, alluded to this long-sort non-ocular membrane receptor for systemic RBP4-ROL uptake and transport. We have previously shown in zebrafish that the retinol-binding protein receptor 2 (Rbpr2) plays an important role in the transport of yolk vitamin A to the eye. Mutant rbpr2 zebrafish lines manifested in decreased ocular retinoid concentrations and retinal phenotypes. To investigate a physiological role for the second vitamin A receptor, RBPR2, in mammals and to analyze the metabolic basis of systemic vitamin A transport for retinoid homeostasis, we established a whole-body Rbpr2 knockout mouse (Rbpr2−/−) model. These mice were viable on both vitamin A-sufficient and -deficient diets. Rbpr2−/− mice that were fed a vitamin A-sufficient diet displayed lower ocular retinoid levels, decreased opsins, and manifested in decrease visual function, as measured by electroretinography. Interestingly, when Rbpr2−/− mice were fed a vitamin A-deficient diet, they additionally showed shorter photoreceptor outer segment phenotypes, altogether manifesting in a significant loss of visual function. Thus, under conditions replicating vitamin A sufficiency and deficiency, our analyses revealed that RBPR2-mediated systemic vitamin A transport is a regulated process that is important for vitamin A delivery to the eye when RBP4-bound ROL is the only transport pathway in the fasting condition or under vitamin A deficiency conditions.

The combination of thymol and cinnamaldehyde reduces the survival and virulence of Listeria monocytogenes on autoclaved chicken breast.

To reveal the antibacterial mechanism of the combination of thymol and cinnamaldehyde to Listeria monocytogenes ATCC 19115 on autoclaved chicken breast. In this study, L. monocytogenes ATCC 19115 on autoclaved chicken breast was exposed to the stress of 125μg/ml thymol and 125μg/ml cinnamaldehyde, and transcriptome analysis was used to reveal the crucial antibacterial mechanism. According to the results, 1303 significantly differentially expressed genes (DEGs) were identified. Treated by thymol and cinnamaldehyde in combination, pyrimidine and branched-chain amino acid biosynthesis of L. monocytogenes were thwarted which impairs its nucleic acid biosynthesis and intracellular metabolism. The up-regulated DEGs involved in membrane composition and function contributed to membrane repair. Besides, pyruvate catabolism and TCA cycle were restrained which brought about the disturbance of amino acid metabolism. ABC transporters were also perturbed, for instance, the uptake of cysteine, D-methionine, and betaine was activated, while the uptake of vitamin, iron, and carnitine was repressed. Thus, L. monocytogenes tended to activate PTS, glycolysis, glycerol catabolism, and pentose phosphate pathways to obtain energy to adapt to the hostile condition. Noticeably, DEGs involved in virulence factors were totally down-regulated, including genes devoted to encoding flagella, chemotaxis, biofilm formation, internalin as well as virulence gene clusters. The combination of thymol and cinnamaldehyde is effective to reduce the survival and potential virulence of L. monocytogenes on autoclaved chicken breast. This work contributes to providing theoretical information for the application and optimization of thymol and cinnamaldehyde in ready-to-eat meat products to inhibit L. monocytogenes.

The prophylactic roles of dietary antioxidants for medical radiology workers: A mini-review

Antioxidants play a very crucial naturally role in our bodies. Still, unfortunately, that is not enough. We need to compensate for the shortage we face by increasing the dietary antioxidants as exogenous sources, especially when there is an exogenous factor-induced oxidative stress as with the medical radiology staff because how much ionizing radiation they are exposed to exceeds the primitive dose limit by the International Commission on Radiological Protection (ICRP). Thus, a suitable uptake of minerals, vitamins, and Combinations of dietary antioxidants through the daily diet and balanced it remains the promising approach without exceeding the uptakes doses that could reverse the positive effects of this approach. This review focuses on the present knowledge about dietary antioxidant sources, mechanisms, effects of the cell components. It critically investigates studies examining the effects of dietary antioxidant supplementation and its role among medical radiology workers.

Inhibition of NPC1L1 disrupts adaptive responses of drug‐tolerant persister cells to chemotherapy

Entering a drug‐tolerant persister (DTP) state of cancer cells is a transient self‐adaptive mechanism by which a residual cell subpopulation accelerates tumor progression. Here, we identified the acquisition of a DTP phenotype in multidrug‐resistant (MDR) cancer cells as a tolerance response to routine combination treatment. Characterization of MDR cancer cells with a DTP state by RNA‐seq revealed that these cells partially prevented chemotherapy‐triggered oxidative stress by promoting NPC1L1‐regulated uptake of vitamin E. Treatment with the NPC1L1 inhibitor ezetimibe further enhanced the therapeutic effect of combinatorial therapy by inducing methuosis. Mechanistically, we demonstrated that NRF2 was involved in transcriptional regulation of NPC1L1 by binding to the −205 to −215 bp site on its promoter. Decreased DNA methylation was also related partially to this process. Furthermore, we confirmed that a triple‐combination of chemotherapeutic agents, verapamil, and ezetimibe, had a significant anti‐tumor effect and prevented tumor recurrence in mice. Together, our study provides a novel insight into the role of DTP state and emphasizes the importance of disrupting redox homeostasis during cancer therapy.

Power Ultrasound-Assisted Impregnation of Apple Cubes with Vitamin B12

This work explores the use of ultrasound (US) as a means of intensifying the impregnation of apple cubes with vitamin B12 (cyanocobalamin). The effect of different US power densities (90 and 200 WL−1) and treatment times (5, 10, and 15 min) was evaluated, on vitamin load, vitamin stability, and physicochemical and microstructural properties of the fruit matrix. The US enhanced the impregnation producing high cyanocobalamin content products (0.12–0.19 mg vitamin/g db.). Vitamin losses in the sonication medium due to US application were not significant. Impregnated samples exhibited higher moisture and lower soluble solids with respect to the untreated fruit. Changes in chromatic coordinates were well correlated to vitamin uptake. Only at the highest treatment intensities (200 WL−1, 10, and 15 min) was a marked softening observed, which agreed with the microstructural changes observed in fruit tissues. Results permit US-assisted impregnation to be considered a promising technology in the preparation of vitamin B12 fortified apple cubes.

Factors Affecting Uptake of Vitamin D in Gastro-Intestinal Tract

Vitamin D deficiency affects about 50% of entire people. Vitamin D deficiency affects an estimated 100 million individuals worldwide, spanning all cultures and age groups. This catastrophic situation of vitamin D deficiency can mainly be attributed to lifestyle and the average impact that cuts down exposure to rays from the sun. It is required for the epithelium to produce vitamin D with the help of ultraviolet B (UVB). In comparison to fair-skinned people, dark-skinned people absorb a larger quantity of UVB in their epidermal melanin. Fairer folks require more solar exposition to get the same amount.
 The increased cases of vitamin D deficiency is a significant prevalent ailment caused by vitamin D deficiency. It is a self-governing, deadly cause of widespread mortality worldwide. New research supports hypovitaminosis D as a cause of neoplastic, cardiac, orthopedic, immunological, NIDDM, and mental disorders. Vitamin D doses are usually compounded to a minimum of 1000 IU by physicians. According to a 2007 study, a high vitamin D intake decreases mortality risk. We've focused on vitamin D research and abstracted the mechanisms that have been linked to vitamin D and its therapeutic implications.
 Vitamin D is unique in that it may be produced from the epidermis in reaction to UV radiation. AFTER IRRADIATING THE ERGOSTEROL TO UV LIGHT, Vitamin D2 is produced in sun-irradiated fungus. When UVB sunlight strikes the epidermis, vitamin D3 is produced. It's the most "natural" recipe possible. Humans produce vitamin D2. Vitamin D3 is produced mainly by oil-rich fish. Chylomicrons are generated when vitamin D is taken orally.

Association between a SLC23A2 Gene Variation, Plasma Vitamin C Levels, and Risk of Different Diseases

Background: Vitamin C is an important plasma water-soluble antioxidant that plays an essential role in the absorption of iron, detoxification of exogenous compounds, and remaking vitamin E for the protection of lipid membranes. In addition, vitamin C is essential in the synthesis of collagen. Vitamin C concentrations of plasma are determined by dietary intake and genetic factors. Ascorbic acid is the functional form of vitamin C, which is transported into the cell through sodium vitamin C transporters (SVCTs). There are two forms of SVCTs which are SVCT1 encoded by the SLC23A1 gene and SVCT2 encoded by the SLC23A2. The SLC23A2 gene locus on human chromosome 20P12. It expresses in most human tissues, except lung and skeletal muscle that it is important in regulating the intracellular concentration of ascorbic acid to protect the cell from oxidative stress and promote type 1 collagen maturation. Maintaining proper concentrations of plasma and cellular vitamin C concentration is important for the normal metabolic function of the body and preventing several diseases. In the contrast, a low concentration of vitamin C caused by SLC23A2 variation can cause several chronic diseases. Our systematic review discusses four diseases related to the variation of SLC23A2 gene and plasma vitamin C levels which are glaucoma, acute coronary syndrome among women, gastric cancer, and HPV16-associated head and neck cancer.
 Methods: By using NCBI databases, specifically GenBank to analyze DNA sequence and mRNA sequence of SLC23A2 gene. GenBank file format was helpful to extract an accession number of the gene, number of amino acids, number of exons and introns, and length of nucleotides. FASTA format was also useful to retrieve the nucleotide sequence and get the function of the protein. BLAST was used to compare the protein product of the SLC23A2 gene between humans and Macaca mulatta (Rhesus monkey).
 Results: the accession number of the SLC23A2 gene was NC_000020.11, the number of exons found was 18, and the gene was located in chromosome 20. This gene encodes one of the two required transporters, and the encoded protein accounts for tissue-specific uptake of vitamin C. This gene had an official symbol of SLC23A1. And they found a significant association between the single-nucleotide polymorphism (SNP) rs1279683 (A > G) in SLC23A2 and an increased risk of POAG in homozygous G allele (GG) carriers. Also, POAG patients with this SNP appear to have a significantly lower level of plasma vitamin C compared to other genotypes. Finally, many organisms have the same gene, such as dogs, mice, rats, and chickens.
 Conclusion: there is a significant association between SLC23A2 gene mutation, increased risk for vitamin C deficiency, and several diseases. SNP in the SLC23A2 gene was significantly associated with a higher risk of POAG in GG allele carriers as well as lower plasma vitamin C concentration.

Neutrophils Isolated from Septic Patients Exhibit Elevated Uptake of Vitamin C and Normal Intracellular Concentrations despite a Low Vitamin C Milieu.

Vitamin C (ascorbate) plays an important role in neutrophil function and is accumulated by the cells either directly via vitamin C transporters (SVCT) or indirectly following oxidation to dehydroascorbic acid. Septic patients are known to have significantly depleted plasma ascorbate status, but little is known about the ascorbate content of their circulating cells. Therefore, we assessed the ascorbate concentrations of plasma, leukocytes and erythrocytes from septic patients and compared these to healthy controls. Non-fasting blood samples were collected from healthy volunteers (n = 20) and critically ill patients with sepsis (n = 18). The ascorbate content of the plasma and isolated neutrophils and erythrocytes was measured using HPLC and plasma myeloperoxidase concentrations were determined using ELISA. Ex vivo uptake of ascorbate and dehydroascorbic acid by neutrophils from septic patients was also assessed. Neutrophils isolated from septic patients had comparable intracellular ascorbate content to healthy volunteers (0.33 vs. 0.35 nmol/106 cells, p > 0.05), despite significantly lower plasma concentrations than the healthy controls (14 vs. 88 µmol/L, p < 0.001). In contrast, erythrocytes from septic patients had significantly lower intracellular ascorbate content than healthy controls (30 vs. 69 µmol/L, p = 0.002), although this was 2.2-fold higher than the matched plasma concentrations in the patients (p = 0.008). Higher concentrations of myeloperoxidase, a source of reactive oxygen species, were observed in the septic patients relative to healthy controls (194 vs. 14 mg/mL, p < 0.0001). In contrast to neutrophils from healthy volunteers, the neutrophils from septic patients demonstrated elevated uptake of extracellular ascorbate. Overall, neutrophils from septic patients exhibited comparable intracellular ascorbate content to those from healthy controls, despite the patients presenting with hypovitaminosis C. The mechanisms involved are currently uncertain, but could include increased generation of dehydroascorbic acid in septic patients, enhanced basal activation of their neutrophils or upregulation of their vitamin C transporters.

Reduction of pulse “antinutritional” content by optimizing pulse canning process is insufficient to improve fat-soluble vitamin bioavailability

Some bioactive compounds found in pulses (phytates, saponins, tannins) display antinutritional properties and interfere with fat-soluble vitamin bioavailability (i.e., bioaccessibility and intestinal uptake). As canned chickpeas are consumed widely, our aim was to optimize the chickpea canning process and assess whether this optimization influences fat-soluble vitamin bioavailability. Different conditions during soaking and blanching were studied, as was a step involving prior germination. Proteins, lipids, fibers, vitamin E, lutein, 5-methyl-tetrahydro-folate, magnesium, iron, phytates, saponins and tannins were quantified. Bioaccessibility and intestinal uptake of vitamin D and K were assessed using in vitro digestion and Caco-2 cells, respectively. Significant reductions of phytate, saponin and tannin contents (−16 to −44%), but also of folate content (up to −97%) were observed under optimized canning conditions compared with the control. However, bioaccessibility and cellular uptake of vitamin D and K remained unaffected after in vitro digestion of test meals containing control or optimized canned chickpeas.

Revisiting food-sourced vitamins for consumer diet and health needs: a perspective review, from vitamin classification, metabolic functions, absorption, utilization, to balancing nutritional requirements.

The significant attention gained by food-sourced vitamins has provided insights into numerous current researches; for instance, the potential reversal of epigenetic age using a diet and lifestyle intervention, the balance between food and dietary supplements in the general population, the role of diet and food intake in age-related macular degeneration, and the association of dietary supplement use, nutrient intake and mortality among adults. As relevant literature about food-sourced vitamin increases, continuous synthesis is warranted. To supplement existing information, this perspective review discussed food-sourced vitamins for consumer diet and health needs, scoping from vitamin absorption, metabolic functions, utilization, to balancing nutritional requirements. Relevant literatures were identified through a search of databases like Google Scholar, Web of Science, the Interscience Online Library, ScienceDirect, and PubMed. We demonstrated that vitamins whether from plant- and animal-based sources are prerequisites for the metabolic functions of the human body. The fat- and water-soluble classification of vitamins remains consistent with their respective absorption and dissolution potentials, underpinned by numerous physiological functions. Vitamins, largely absorbed in the small intestine, have their bioavailability dependent on the food composition, its associated interactions, as well as alignment with their metabolic functions, which involves antioxidants, coenzymes, electron acceptor/donor, and hormones. Moreover, vitamin deficiencies, in every form, pose a serious threat to human health. Vitamin toxicities remain rare, but can still occur mainly from supplementation, although it appears much less in water-soluble vitamins of which some excesses get readily removed by the human body, different from the fat-soluble ones that are stored in tissues and organs. Besides discussions of absorption, transport, and cellular uptake of vitamins, this perspective review also included approaches to meeting vitamin requirements and therapeutic strategies against micronutrient deficiency and COVID-19. We have also attempted on how to strike the balance between food-sourced vitamins and dietary supplements.

Clickable Vitamins as a New Tool to Track Vitamin A and Retinoic Acid in Immune Cells

The vitamin A derivative, retinoid acid (RA) is key player in guiding adaptive mucosal immune responses. However, data on the uptake and metabolism of vitamin A within human immune cells has remained largely elusive because retinoids are small, lipophilic molecules which are difficult to detect. To overcome this problem and to be able to study the effect of vitamin A metabolism in human immune cell subsets, we have synthesized novel bio-orthogonal retinoid-based probes (clickable probes), which are structurally and functionally indistinguishable from vitamin A. The probes contain a functional group (an alkyne) to conjugate to a fluorogenic dye to monitor retinoid molecules in real-time in immune cells. We demonstrate, by using flow cytometry and microscopy, that multiple immune cells have the capacity to internalize retinoids to varying degrees, including human monocyte-derived dendritic cells (DCs) and naïve B lymphocytes. We observed that naïve B cells lack the enzymatic machinery to produce RA, but use exogenous retinoic acid to enhance CD38 expression. Furthermore, we showed that human DCs metabolize retinal into retinoic acid, which in co-culture with naïve B cells led to of the induction of CD38 expression. These data demonstrate that in humans, DCs can serve as an exogenous source of RA for naïve B cells. Taken together, through the use of clickable vitamins our data provide valuable insight in the mechanism of vitamin A metabolism and its importance for human adaptive immunity.

Elucidation of new vitamin K function aiming at application to cardiovascular disease prevention and treatment

Although Vitamin K is known to be required by the human body for blood clotting and bone metabolism, there remain many unknowns about this group of vitamins and there is a lack of biochemical research on vitamin K. Limitations in knowledge about vitamin k may mean that decisions about the vitamin's uptake and bone health may not be optimal. Professor Kimie Nakagawa Laboratory of Hygienic Sciences, Faculty of Pharmaceutical Sciences, Kobe Gakuin University, Japan, is performing detailed investigations on vitamin K to shed light on its specific functions in the human body and contribute to advancements in disease prevention and treatment, including cardiovascular disease. Her studies centre on UBIAD1 (UbiA prenyltransferase domain containing protein 1) and MK-4 (menaquinone-4). She is seeking to elucidate the role of MK-4 in the human body and reveal the unknown functions of UBIAD1. Nakagawa and the teams are doing so using UBIAD1 tissue-specific gene-deficient mice, which they are analysing in order to clarify the significance of biosynthesis of MK-4 in vivo and unravel the role of UBIAD1 and MK-4 in each tissue. Specific research goals for Nakagawa are to elucidate vitamin K conversion mechanisms, establish improved understanding of the physiological function of the vitamin, identify vitamin K converting enzymes and learn and explain more about the physiological function of this enzyme. The team made an important discovery in that UBIAD1 is the enzyme responsible for the conversion of vitamin k to MK-4 and the researchers will continue to build on this groundbreaking finding.

Low Plasma Ascorbate Levels in Type 2 Diabetic Patients With Adequate Dietary Vitamin C.

Background Dietary intake of antioxidative vitamin C plays a protective role in the prevention of oxidative damage in diabetics, demanding increased requirement of vitamin C. Hyperglycemia results in impaired uptake of vitamin C in the cell. The present study was conducted to compare the plasma ascorbate levels in type 2 diabetic patients and controls consuming adequate dietary vitamin C. Methodology Fifty consented type 2 diabetes mellitus (T2DM) patients who were on treatment with oral hypoglycemic drugs and consuming adequate vitamin C in diet were taken in the study and 50 healthy controls equitably matched for age, gender between 40 and 70 years, and dietary intake of vitamin C were compared. Dietary intake of vitamin C was estimated by a food frequency questionnaire. Subjects consuming more than 35 mg/d of vitamin C were included in the study. Fasting blood sugar was estimated by glucose oxidase and peroxidase method and estimation of ascorbic acid was done by using 2, 4 dinitro phenyl hydrazine method. Result The mean ± standard deviation levels of plasma ascorbate levels in diabetic subjects were 0.22 ± 0.12 mg/dL, which were significantly lower as compared with controls with plasma ascorbate level of 0.47 ± 0.15 mg/dL. In diabetic subjects, insignificant positive correlation was observed between these parameters with r -value 0.168 and p -value 0.245. Conclusion This study concludes that even with the recommended dietary intake of vitamin C low plasma ascorbate levels were found among T2DM patients, which necessitates increased demand and dietary advice to diabetic patients on consuming foods rich in vitamin C more than the recommended daily allowance.

Small and Large Intestine (I): Malabsorption of Nutrients.

Numerous disorders can alter the physiological mechanisms that guarantee proper digestion and absorption of nutrients (macro- and micronutrients), leading to a wide variety of symptoms and nutritional consequences. Malabsorption can be caused by many diseases of the small intestine, as well as by diseases of the pancreas, liver, biliary tract, and stomach. This article provides an overview of pathophysiologic mechanisms that lead to symptoms or complications of maldigestion (defined as the defective intraluminal hydrolysis of nutrients) or malabsorption (defined as defective mucosal absorption), as well as its clinical consequences, including both gastrointestinal symptoms and extraintestinal manifestations and/or laboratory abnormalities. The normal uptake of nutrients, vitamins, and minerals by the gastrointestinal tract (GI) requires several steps, each of which can be compromised in disease. This article will first describe the mechanisms that lead to poor assimilation of nutrients, and secondly discuss the symptoms and nutritional consequences of each specific disorder. The clinician must be aware that many malabsorptive disorders are manifested by subtle disorders, even without gastrointestinal symptoms (for example, anemia, osteoporosis, or infertility in celiac disease), so the index of suspicion must be high to recognize the underlying diseases in time.

Mechanisms of vitamin A metabolism and deficiency in the mammalian and fly visual system

Vitamin A deficiency can cause human pathologies that range from blindness to embryonic malformations. This diversity is due to the lack of two major vitamin A metabolites with very different functions: the chromophore 11-cis-retinal (vitamin A aldehyde) is a critical component of the visual pigment that mediates phototransduction, while the signaling molecule all-trans-retinoic acid regulates the development of various tissues and is required for the function of the immune system.Since animals cannot synthesize vitamin A de novo, they must obtain it either as preformed vitamin A from animal products or as carotenoid precursors from plant sources. Due to its essential role in the visual system, acute vitamin A deprivation impairs photoreceptor function and causes night blindness (poor vision under dim light conditions), while chronic deprivation results in retinal dystrophies and photoreceptor cell death. Chronic vitamin A deficiency is the leading cause of preventable childhood blindness according to the World Health Organization. Due to the requirement of vitamin A for retinoic acid signaling in development and in the immune system, vitamin A deficiency also causes increased mortality in children and pregnant women in developing countries.Drosophila melanogaster is an excellent model to study the effects of vitamin A deprivation on the eye because vitamin A is not essential for Drosophila development and chronic deficiency does not cause lethality. Moreover, genetic screens in Drosophila have identified evolutionarily conserved factors that mediate the production of vitamin A and its cellular uptake. Here, we review our current knowledge about the role of vitamin A in the visual system of mammals and Drosophila melanogaster. We compare the molecular mechanisms that mediate the uptake of dietary vitamin A precursors and the metabolism of vitamin A, as well as the consequences of vitamin A deficiency for the structure and function of the eye.

Association Between Homocysteine and Vitamin Levels in Demented Patients.

Although it is known that the nutritional status among elderly persons and, in particular, patients with dementia, is compromised, malnutrition that results in insufficient uptake of several vitamins is often not diagnosed. An elevated homocysteine level is a known strong risk factor for vascular dementia (VaD) and Alzheimer's disease (AD). Several B vitamins are involved in the metabolism of homocysteine. Therefore, we investigated the serum levels of vitamin B1, vitamin B6, folate, and vitamin B12 in 97 patients with mild cognitive impairment (MCI) or different forms of dementia and 54 elderly control persons without dementia. Compared to aged non-demented people, vitamins B1, B6, B12, and folate were decreased in serum of patients with AD, and patients with Lewy body dementia had reduced vitamin B12 level. Vitamin B6 was diminished in VaD. Patients with frontotemporal dementia showed no alterations in vitamin levels. Age was identified as an important factor contributing to the concentrations of vitamin B1 and B6 in serum, but not vitamin B12 and folate. Increased levels of total homocysteine were detected especially in MCI and AD. Homocysteine correlated negatively with levels of vitamins B6, B12, and folate and positively with Q Albumin. Our data suggest that despite increased homocysteine already present in MCI, vitamin levels are decreased only in dementia. We propose to determine the vitamin levels in patients with cognitive decline, but also elderly people in general, and recommend supplementing these nutrients if needed.

Assessing effects of diet alteration on selected parameters of chronically mentally ill residents of a 24-hour Nursing Home. Part I: Effects of diet modification on carbohydrate-lipid metabolism.

The study was aimed at finding out whether, and to what extent, it is possible to introduce and maintain proper nutrition habits in chronically mentally ill residents of a24-hour Nursing Home. The study involved 52 residents of a 24-hour Nursing Home (NH) for the chronically mentally ill. The study was carried out with a prospective method using questionnaires, nutrition-related interviews, anthropometric measurements, and analysis of selected blood biochemical indicators. Diet modification, accompanied by simultaneous health-promoting nutrition-related education, involved balancing the energy and nutrient contents, with adue consideration to gender and age as well as the major ailment and the accompanying disorders. Sources of the basic nutrients, i.e., proteins, carbohydrates and lipids, were replaced by recommended and/or health-promoting ones. Both female and male patients showed a statistically significant reduction in energy uptake, resulting primarily from a significant reduction in the uptake of lipids and simple carbohydrates. Changes in nutritional habits were reflected in statistically significant increase in the uptake of vitamins, minerals and liquids (in the form of water). Diet composition modifications translated into beneficial changes in concentrations of glucose, triacylglycerols, cholesterol (total as well as HDL and LDL fractions) in numerous patients examined. The study showed chronic mental patients to be capable of adopting, with full acceptance and cooperation, proper nutritional habits. Changes in those habits were reflected in improved body functions, including carbohydrate-lipid metabolism indicators, also in schizophrenia patients treated with antipsychotics.

Increasing the uptake of vitamin D supplement use in Australian residential aged care facilities: results from the vitamin D implementation (ViDAus) study

BackgroundAdequate (≥800 IU/day) vitamin D supplement use in Australian residential aged care facilities (RACFs) is variable and non-optimal. The vitamin D implementation (ViDAus) study aimed to employ a range of strategies to support the uptake of this best practice in participating facilities. The aim of this paper is to report on facility level prevalence outcomes and factors associated with vitamin D supplement use.MethodsThis trial followed a stepped wedge cluster, non-randomised design with 41 individual facilities serving as clusters pragmatically allocated into two wedges that commenced the intervention six months apart. This multifaceted, interdisciplinary knowledge translation intervention was led by a project officer, who worked with nominated champions at participating facilities to provide education and undertake quality improvement (QI) planning. Local barriers and responsive strategies were identified to engage stakeholders and promote widespread uptake of vitamin D supplement use.ResultsThis study found no significant difference in the change of vitamin D supplement use between the intervention (17 facilities with approx. 1500 residents) and control group (24 facilities with approx. 1900 residents) at six months (difference in prevalence change between groups was 1.10, 95% CI − 3.8 to 6.0, p = 0.6). The average overall facility change in adequate (≥800 IU/day) vitamin D supplement use over 12 months was 3.86% (95% CI 0.6 to 7.2, p = 0.02), which achieved a facility level average prevalence of 59.6%. The variation in uptake at 12 months ranged from 25 to 88% of residents at each facility. In terms of the types of strategies employed for implementation, there were no statistical differences between facilities that achieved a clinically meaningful improvement (≥10%) or a desired prevalence of vitamin D supplement use (80% of residents) compared to those that did not.ConclusionsThis work confirms the complex nature of implementation of best practice in the RACF setting and indicates that more needs to be done to ensure best practice is translated into action. Whilst some strategies appeared to be associated with better outcomes, the statistical insignificance of these findings and the overall limited impact of the intervention suggests that the role of broader organisational and governmental support for implementation should be investigated further.Trial registrationRetrospectively registered (ANZCTR ID: ACTRN12616000782437).

Differential effects of vitamin D3 vs vitamin D2 on cellular uptake, tissue distribution and activation of vitamin D in mice and cells

To combat vitamin D deficiency, vitamin D3 and vitamin D2 are commonly used as a supplement or to fortify food sources. Human data show that the response of 25-hydroxyvitamin D (25(OH)D) to supplementation with vitamin D3 is higher than to vitamin D2. To elucidate the metabolic route of both vitamers, we conducted a study with vitamin D-depleted mice, which were allotted into three groups (n = 12) and received equal doses of either deuterated vitamin D3, deuterated vitamin D2 or both for 4 weeks. To further investigate the hepatic uptake and hydroxylation of both D-vitamers to 25(OH)D, we conducted cell culture experiments with murine and human hepatoma cells (Hepa1-6 and HepG2). The vitamin D metabolite concentrations in serum, tissues and cells were analyzed by LC-MS/MS or ELISA.In mice, vitamin D2 resulted in lower serum and tissue concentrations of vitamin D (P < 0.001) than vitamin D3, while the group which received both D-vitamers showed values in between. Interestingly, vitamin D2 fed mice had 1.9-times and 2.9-times higher serum concentrations of total and free 25(OH)D (P < 0.001) than mice fed vitamin D3, while the concentration of 1,25-dihydroxyvitamin D (1,25(OH)2D) was 1.8-times lower (P < 0.001). The gene and protein expression of enzymes, involved in the hydroxylation and renal uptake of vitamin D remained largely unaffected by the D-vitamer. In contrast to the mice data, hepatoma cells preferred vitamin D3 for 25-hydroxylation over vitamin D2 (P < 0.001). In general, the formation of 25(OH)D was much more pronounced in human than in murine hepatoma cells (P < 0.001).To conclude, in contrast to humans, vitamin D2 was more efficient in increasing 25(OH)D than vitamin D3 in mice, although this difference was not caused by a preferential hydroxylation of vitamin D2 in the liver. The metabolic routes of D3 and D2 in mice differ, showing lower circulating 1,25(OH)2D and tissue vitamin D concentrations in D2- than in D3-fed mice.