scholarly journals Long-term vitamin A deficiency induces alteration of adult mouse spermatogenesis and spermatogonial differentiation: direct effect on spermatogonial gene expression and indirect effects via somatic cells

2013 ◽  
Vol 24 (6) ◽  
pp. 1123-1135 ◽  
Author(s):  
Catherine Boucheron-Houston ◽  
Lucile Canterel-Thouennon ◽  
Tin-Lap Lee ◽  
Vanessa Baxendale ◽  
Sohan Nagrani ◽  
...  
Keyword(s):  
Gene Expression ◽  
Vitamin A ◽  
Direct Effect ◽  
Indirect Effects ◽  
Adult Mouse ◽  
Vitamin A Deficiency ◽  
Somatic Cells

scholarly journals Role of Vitamin A in Mammary Gland Development and Lactation

Nutrients ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 80 ◽  
Author(s):  
M. Teresa Cabezuelo ◽  
Rosa Zaragozá ◽  
Teresa Barber ◽  
Juan R. Viña
Keyword(s):  
Retinoic Acid ◽  
Mammary Gland ◽  
Vitamin A ◽  
Vitamin A Deficiency ◽  
Retinoid Signaling ◽  
Nutritional Problem ◽  
Pregnancy And Lactation ◽  
Gland Development

Vitamin A (all-trans-retinol), its active derivatives retinal and retinoic acid, and their synthetic analogues constitute the group of retinoids. It is obtained from diet either as preformed vitamin A or as carotenoids. Retinal plays a biological role in vision, but most of the effects of vitamin A are exerted by retinoic acid, which binds to nuclear receptors and regulates gene transcription. Vitamin A deficiency is an important nutritional problem, particularly in the developing world. Retinol and carotenoids from diet during pregnancy and lactation influence their concentration in breast milk, which is important in the long term, not only for the offspring, but also for maternal health. In this study, we review the role of vitamin A in mammary gland metabolism, where retinoid signaling is required not only for morphogenesis and development of the gland and for adequate milk production, but also during the weaning process, when epithelial cell death is coupled with tissue remodeling.

scholarly journals Vitamin A deficiency in Bangladesh: a review and recommendations for improvement

1999 ◽  
Vol 2 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Faruk Ahmed
Keyword(s):  
Vitamin A ◽  
Nutrition Education ◽  
Night Blindness ◽  
Vitamin A Deficiency ◽  
School Age Children ◽  
Serum Retinol ◽  
Population Groups ◽  
Vitamin A Status ◽  
Subclinical Vitamin

AbstractObjective:This article provides a comprehensive review of the change in vitamin A status and the extent of vitamin A deficiency among different population groups in Bangladesh up to the present time. The result of experience with different strategies and interventions designed to improve vitamin A status are then reviewed, leading to a discussion of key options for action, as well as important areas for research and evaluation.Design and setting:All the available data have been examined in detail, including data from nationally representative samples and nationwide surveys, as well as small studies in different population groups. Reports on the effectiveness of different intervention programmes have been used.Results:Over the past three decades a number of studies, which include national nutrition surveys, have been carried out to investigate the prevalence of vitamin A deficiency among different population groups in Bangladesh, and they have demonstrated a significant public health problem. Studies have shown that the prevalence of severe deficiency, based on the prevalence of night blindness in preschool children, decreased from 3.6% in 1982–83 to 1.78% in 1989 and 0.6% in 1996. However, there is still a high prevalence of subclinical vitamin A deficiency, based on the biochemical assessment of serum retinol levels in preschool children, estimated mainly from hospital-based groups. Night blindness and Bitot's spot are also found to exist among school-age children and adolescents. Recent reports indicate that night blindness among rural mothers is as high as 1.4%. Only a limited number of studies, with small sample sizes, are available where serum retinol has been reported for school-age children, adolescents and pregnant women. Nevertheless, these studies confirm the presence of low levels of serum retinol and hence, the existence of subclinical vitamin A deficiency. Furthermore, the dietary intake of vitamin A in each population group has been found to be less than the Recommended Daily Allowance (RDA), indicating a significant risk of deficient intakes of vitamin A.To address the problem of vitamin A deficiency, the government of Bangladesh started the Nutritional Blindness Programme in 1973. The main activities of the programme include vitamin A capsule (VAC) supplementation to children of 6 months to 6 years old, nutrition education to increase the production and consumption of vitamin A rich foods, and training of primary health-care workers on the clinical diagnosis and treatment of vitamin A deficiency, VAC distribution and nutrition education. Since 1988, as a long-term strategy, Helen Keller International has been implementing community home gardening promotion projects. To date, the possibility that foods may be fortified with vitamin A, has not been explored as a possible approach in Bangladesh.Conclusion:Although short- to long-term prevention and control programmes are to some extent in place, to improve the situation of vitamin A deficiency, Bangladesh needs a more appropriate mix of interventions for the entire population. More operational research and evaluation are needed if a fully effective programme to alleviate the problem of vitamin A deficiency is to be developed. Finally, to achieve the goal of virtual elimination of vitamin A deficiency will require an integrated approach which brings together appropriate actions at every level, within and across the many sectors of society.

Effect of nutritional vitamin A deficiency on lipid metabolism in the rat heart: Its relation to PPAR gene expression

Nutrition ◽  
2009 ◽  
Vol 25 (7-8) ◽  
pp. 828-838 ◽  
Author(s):  
Verónica Analía Vega ◽  
Ana Cecilia Anzulovich ◽  
Silvia Mabel Varas ◽  
Mirtha Ruth Bonomi ◽  
María Sofía Giménez ◽  
...  
Keyword(s):  
Gene Expression ◽  
Lipid Metabolism ◽  
Vitamin A ◽  
Rat Heart ◽  
Vitamin A Deficiency ◽  
Nutritional Vitamin

Vitamin A Deficiency Decreases the Expression of RARβ and RXRβ/γ in Adult Mouse Brain: Effect of RA Administration

2000 ◽  
Vol 3 (3) ◽  
pp. 173-181 ◽  
Author(s):  
V. Enderlin ◽  
D. Higueret ◽  
S. Alfos ◽  
M. Husson ◽  
R. Jaffard ◽  
...  
Keyword(s):  
Vitamin A ◽  
Mouse Brain ◽  
Adult Mouse ◽  
Vitamin A Deficiency ◽  
Adult Mouse Brain

Biological evidence to define a vitamin A deficiency cutoff using total liver vitamin A reserves

2021 ◽  
pp. 153537022199273
Author(s):  
Sherry A Tanumihardjo
Keyword(s):  
Vitamin A ◽  
Vitamin A Deficiency ◽  
Biological Response ◽  
Population Based ◽  
Total Liver ◽  
Long Term Storage ◽  
Micronutrient Status ◽  
Term Storage ◽  
Liver Vitamin

Vitamin A is a fat-soluble vitamin involved in essential functions including growth, immunity, reproduction, and vision. The vitamin A Dietary Reference Intakes (DRIs) for North Americans suggested that a minimally acceptable total liver vitamin A reserve (TLR) is 0.07 µmol/g, which is not explicitly expressed as a vitamin A deficiency cutoff. The Biomarkers of Nutrition for Development panel set the TLR cutoff for vitamin A deficiency at 0.1 µmol/g based on changes in biological response of several physiological parameters at or above this cutoff. The criteria used to formulate the DRIs include clinical ophthalmic signs of vitamin A deficiency, circulating plasma retinol concentrations, excretion of vitamin A metabolites in the bile, and long-term storage of vitamin A as protection against vitamin A deficiency during times of low dietary intake. This review examines the biological responses that occur as TLRs are depleted. In consideration of all of the DRI criteria, the review concludes that induced biliary excretion and long-term vitamin A storage do not occur until TLRs are >0.10 µmol/g. If long-term storage is to continue to be part of the DRI criteria, vitamin A deficiency should be set at a minimum cutoff of 0.10 µmol/g and should be set higher during times of enhanced requirements where TLRs can be rapidly depleted, such as during lactation or in areas with high infection burden. In population-based surveys, cutoffs are important when using biomarkers of micronutrient status to define the prevalence of deficiency and sufficiency to inform public health interventions. Considering the increasing use of quantitative biomarkers of vitamin A status that indirectly assess TLRs, i.e. the modified-relative-dose response and retinol-isotope dilution tests, setting a TLR as a vitamin A deficiency cutoff is important for users of these techniques to estimate vitamin A deficiency prevalence. Future researchers and policymakers may suggest that DRIs should be set with regard to optimal health and not merely to prevent a micronutrient deficiency.

Differentiation-dependent regulation of retinal dehydrogenase gene expression in the trachea

1998 ◽  
Vol 76 (1) ◽  
pp. 59-62 ◽  
Author(s):  
Pangala V Bhat ◽  
Thomas Bader ◽  
Paul Nettesheim ◽  
Anton M Jetten
Keyword(s):  
Gene Expression ◽  
Retinoic Acid ◽  
Epithelial Cells ◽  
Vitamin A ◽  
Vitamin A Deficiency ◽  
Squamous Metaplasia ◽  
Tracheal Epithelium ◽  
Dehydrogenase Gene ◽  
Retinal Dehydrogenase ◽  
Mucociliary Differentiation

Retinoic acid (RA), a metabolite of vitamin A, is known to be a key signaling molecule in regulating epithelial cell differentiation. We recently characterized and cloned a retinal dehydrogenase (RALDH) that catalyzes the oxidation of retinal to RA. In this study, we investigated the effects of retinoids on the level of RALDH mRNA and protein as well as RALDH activity in the trachea and cultured tracheal epithelial cells. Vitamin A deficiency induced squamous metaplasia in the tracheal epithelium and down-regulated RALDH expression. Supplementation of retinol and retinoic acid to vitamin A deficient rats restored the normal mucociliary epithelium and up-regulated the RALDH expression. In rat epithelial cells cultured in vitro, RAinhibited squamous differentiation and promoted mucociliary differentiation. Squamous differentiated cultures (RA-) expressed very low levels of RALDH mRNA, whereas mucociliary differentiated cultures (RA+) expressed high levels of RALDH mRNA. Retinal and retinol were poor inducers of mucociliary differentiation as well as RALDH expression. The RALDH expression paralleled the expression of the mucin-1 gene in mucociliary cultures. These results suggest that the expression of RALDH is dependent on the differentiation state of the airway epithelium.Key words: retinoic acid, retinal dehydrogenase, gene expression, tracheal epithelium.

scholarly journals Iron and Vitamin A Deficiency in Long-Term African Refugees

2005 ◽  
Vol 135 (4) ◽  
pp. 808-813 ◽  
Author(s):  
Andrew J. Seal ◽  
Paul I. Creeke ◽  
Zahra Mirghani ◽  
Fathia Abdalla ◽  
Rory P. McBurney ◽  
...  
Keyword(s):  
Vitamin A ◽  
Vitamin A Deficiency ◽  
African Refugees
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