scholarly journals Interaction between Dietary Vitamin A and Single Oral Doses of 2,3,7,8-Tetrachlorodibenzo-p-Dioxin(TCDD) on the TCDD-Induced Toxicity and on the Vitamin A Status in the Rat.

1991 ◽  
Vol 37 (3) ◽  
pp. 239-255 ◽  
Author(s):  
Helen HÅKANSSON ◽  
Ellu MANZOOR ◽  
Ulf G. AHLBORG
Keyword(s):  
Vitamin A ◽  
Dietary Vitamin ◽  
Vitamin A Status ◽  
Tetrachlorodibenzo P Dioxin ◽  
Oral Doses

scholarly journals Evaluation of a two-generation rat model for vitamin A deficiency and the interrelationship with iron metabolism

1995 ◽  
Vol 74 (5) ◽  
pp. 689-700 ◽  
Author(s):  
Annet J. C. Roodenburg ◽  
Clive E. West ◽  
Robert Hovenier ◽  
Anton C. Beynen
Keyword(s):  
Vitamin A ◽  
Rat Model ◽  
Binding Capacity ◽  
Vitamin A Deficiency ◽  
Dietary Vitamin ◽  
Vitamin A Status ◽  
Normal Vitamin ◽  
Before And After ◽  
Pregnancy And Lactation ◽  
Plasma Retinol

In order to induce a range of vitamin A-deficient states in young growing rats and to study the effect of vitamin A deficiency on Fe status, we designed the following two-generation experiment. Dams were fed on diets with one of five vitamin A levels from 2 weeks before and throughout pregnancy and lactation. The pups received the same diets as their mothers both before and after weaning. The five dietary levels of vitamin A were 1200, 450, 150, 75 and 0 retinol equivalents/kg feed. Vitamin A intake did not affect reproduction outcome, nor were body and liver weights of the pups affected when they were 3·5 weeks old. Male pups with normal vitamin A status had higher plasma retinol levels than female pups. Vitamin A status of the offspring was affected from 3·5 weeks onwards. Body and liver weights were decreased in the male pups given the lowest dietary vitamin A levels from week 6·5 onwards but not in the female pups. Fe status was marginally affected. Haemoglobin levels were increased and total Fe-binding capacity was decreased in the groups given no dietary vitamin A at week 9·5. Splenic Fe was increased only in the male pups given the lowest levels of dietary vitamin A. However, as a whole, Fe status was only mildly affected and subject to considerable variation. We conclude that the two-generation rat model described here is not suitable for studying effects of vitamin A deficiency on Fe metabolism.

scholarly journals The effect of retinyl palmitate added to iron-fortified maize porridge on erythrocyte incorporation of iron in African children with vitamin A deficiency

2003 ◽  
Vol 90 (2) ◽  
pp. 337-343 ◽  
Author(s):  
Lena Davidsson ◽  
Pierre Adou ◽  
Christophe Zeder ◽  
Thomas Walczyk ◽  
Richard Hurrell
Keyword(s):  
Single Dose ◽  
Vitamin A ◽  
Test Meal ◽  
Vitamin A Deficiency ◽  
Geometric Mean ◽  
Retinyl Palmitate ◽  
Dietary Vitamin ◽  
Vitamin A Supplementation ◽  
Vitamin A Status ◽  
Before And After

Retinyl palmitate added to Fe-fortified maize bread has been reported to enhance Fe absorption in adult Venezuelan subjects but not in Western Europeans. It is not known to what extent these results were influenced by differences in vitamin A status of the study subjects. The objective of the present study was to evaluate the influence of retinyl palmitate added to Fe-fortified maize porridge on erythrocyte incorporation of Fe in children with vitamin A deficiency, before and after vitamin A supplementation. Erythrocyte incorporation of Fe-stable isotopes was measured 14 d after intake of maize porridge (2·0 mg Fe added as ferrous sulfate) with and without added retinyl palmitate (3·5 μmol; 3300 IU). The study was repeated 3 weeks after vitamin A supplementation (intake of a single dose of 210 μmol retinyl palmitate; ‘vitamin A capsule’). Vitamin A status was evaluated by the modified relative dose–response (MRDR) technique. Retinyl palmitate added to the test meal reduced the geometric mean erythrocyte incorporation of Fe at baseline from 4·0 to 2·6 % (P=0·008, n 13; paired t test). At 3 weeks after vitamin A supplementation, geometric mean erythrocyte incorporation was 1·9 and 2·3 % respectively from the test meal with and without added retinyl palmitate (P=0·283). Mean dehydroretinol:retinol molar ratios were 0·156 and 0·125 before and after intake of the single dose of 210 μmol retinyl palmitate; ‘vitamin A capsule’ (P=0·15). In conclusion, retinyl palmitate added to the labelled test meals significantly decreased erythrocyte incorporation of Fe in children with vitamin A deficiency at baseline but had no statistically significant effect 3 weeks after vitamin A supplementation. The difference in response to retinyl palmitate added to Fe-fortified maize porridge on erythrocyte incorporation of Fe before and after intake of the vitamin A capsule indicates, indirectly, changes in vitamin A status not measurable by the MRDR technique. The lack of conclusive data on the effect of retinyl palmitate on Fe absorption indicates the complexity of the interactions between vitamin A status, dietary vitamin A and Fe metabolism.

scholarly journals Vitamin A intake and infection are associated with plasma retinol among pre-school children in rural Zambia

2012 ◽  
Vol 15 (9) ◽  
pp. 1688-1696 ◽  
Author(s):  
Christine Hotz ◽  
Justin Chileshe ◽  
Ward Siamusantu ◽  
Uma Palaniappan ◽  
Emmanuel Kafwembe
Keyword(s):  
Vitamin A ◽  
Dose Response ◽  
Acute Phase Proteins ◽  
Vitamin A Deficiency ◽  
Dietary Vitamin ◽  
Response Test ◽  
Post Harvest ◽  
Vitamin A Status ◽  
Plasma Retinol ◽  
Modified Relative Dose Response

AbstractObjectiveTo determine the prevalence of vitamin A deficiency, infection and adequacy of vitamin A intakes among Zambian children, and the contribution of dietary vitamin A and infection to vitamin A status.DesignA cross-sectional survey of vitamin A intakes by the 24 h recall method, vitamin A status by plasma retinol and the modified relative dose-response test, and infection by acute-phase proteins.SettingRural communities in Central and Eastern Provinces of Zambia.SubjectsChildren 2–5 years of age.ResultsThe prevalence of vitamin A deficiency was 56 % by plasma retinol, 48 % with infection-adjusted plasma retinol and 22 % by the modified relative dose-response test. The majority of children (61 %) had a current infection. Vitamin A intakes were relatively high (331 to 585 μg retinol activity equivalents/d in the harvest/early post-harvest and late post-harvest seasons, respectively) and the prevalence of inadequate intakes was <1 % when compared with the Estimated Average Requirement (210 and 275 μg retinol activity equivalents/d for children aged 1–3 and 4–8 years, respectively). Elevated α-1-acid glycoprotein was negatively associated with plasma retinol (P< 0·0 0 1) and vitamin A intake was positively associated with plasma retinol (P< 0·05), but only when estimated assuming a 26:1 retinol equivalence for provitamin A from green and yellow vegetables.ConclusionsInfection and vitamin A intakes were significant determinants of plasma retinol. We cannot conclude which indicator more accurately represents the true vitamin A status of the population. Reasons for the persistent high prevalence of vitamin A deficiency in the presence of adequate vitamin A intakes are unclear, but the high rates of infection may play a role.

scholarly journals Interaction between dietary vitamin A, gut microbes, and host vitamin A status

2019 ◽  
Vol 33 (S1) ◽  
Author(s):  
Maryam Honarbakhsh ◽  
Kiana Malta ◽  
Aaron Erricson ◽  
Chengsheng Zhu ◽  
Yana Bromberg ◽  
...  
Keyword(s):  
Vitamin A ◽  
Dietary Vitamin ◽  
Gut Microbes ◽  
Vitamin A Status
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