Kinetic Analysis Shows That Iron Deficiency Decreases Liver Vitamin A Mobilization in Rats

Jang, Jing Tsz; Green, Joanne Balmer; Beard, John L.; Green, Michael H.

doi:10.1093/jn/130.5.1291

Cited by 73 publications

(45 citation statements)

References 22 publications

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“…It has been suggested that low plasma retinol concentrations were in fact caused by iron deficiency rather than vitamin A deficiency (20). Deficiency and supplementation of iron have different effects on the complicated intrahepatic balance between cellular uptake and mobilization of vitamin A and, hence, RBP4 (31)(32)(33).…”

Section: Rbp4 Insulin Resistance and Iron Overloadmentioning

confidence: 99%

Circulating Retinol-Binding Protein-4 Concentration Might Reflect Insulin Resistance–Associated Iron Overload

2008

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OBJECTIVES-The mechanisms behind the association between retinol-binding protein-4 (RBP4) and insulin resistance are not well understood. An interaction between iron and vitamin A status, of which RBP4 is a surrogate, has long been recognized. We hypothesized that iron-associated insulin resistance could be behind the impaired insulin action caused by RBP4.RESEARCH DESIGN AND METHODS-Serum ferritin and RBP4 concentration and insulin resistance were evaluated in a sample of middle-aged men (n ϭ 132) and in a replication independent study. Serum RBP4 was also studied before and after iron depletion in patients with type 2 diabetes. Finally, the effect of iron on RBP4 release was evaluated in vitro in adipose tissue. RESULTS-A positive correlation between circulating RBP4and log serum ferritin (r ϭ 0.35 and r ϭ 0.61, respectively; P Ͻ 0.0001) was observed in both independent studies. Serum RBP4 concentration was higher in men than women in parallel to increased ferritin levels. On multiple regression analyses to predict serum RBP4, log serum ferritin contributed significantly to RBP4 variance after controlling for BMI, age, and homeostasis model assessment value. Serum RBP4 concentration decreased after iron depletion in type 2 diabetic patients (percent mean difference Ϫ13.7 [95% CI Ϫ25.4 to Ϫ2.04]; P ϭ 0.024). The iron donor lactoferrin led to increased dose-dependent adipose tissue release of RBP4 (2.4-fold, P ϭ 0.005) and increased RBP4 expression, while apotransferrin and deferoxamine led to decreased RBP4 release. CONCLUSIONS-The relationship between circulating RBP4and iron stores, both cross-sectional and after iron depletion, and in vitro findings suggest that iron could play a role in the RBP4 -insulin resistance relationship. Diabetes 57: [1918][1919][1920][1921][1922][1923][1924][1925] 2008 A dipose tissue is increasingly viewed as an endocrine organ that secretes many types of adipokines (such as leptin, tumor necrosis factor-␣, interleukin 6, and adiponectin) that modulate the action of insulin in other tissues. Retinol-binding protein-4 (RBP4), a new fat-derived adipokine that specifically binds to retinol, has recently been reported to provide a link between obesity and insulin resistance (1,2). Circulating RBP4 levels and adipose tissue RBP4 expression were raised in several different mouse models of obesity and insulin resistance. In these animal models, increasing the circulating levels of RBP4 leads to glucose intolerance, augmented hepatic gluconeogenesis, and attenuated insulin signaling in skeletal muscle, whereas knock-out of the RBP4 gene increases insulin sensitivity.In humans, different authors have reported increased serum RBP4 concentration in subjects with obesity, insulin resistance, or type 2 diabetes compared with lean subjects (2-6), although not all studies are concordant. At least two recent studies (7,8) did not observe a relationship between RBP4 and insulin resistance in women. Although some problems exist with serum RBP4 measurements (9), RBP4 mRNA was in fact downregulat...

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Section: Rbp4 Insulin Resistance and Iron Overloadmentioning

confidence: 99%

Circulating Retinol-Binding Protein-4 Concentration Might Reflect Insulin Resistance–Associated Iron Overload

2008

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“…b-Cryptoxanthin, which is the main pigment of many orange-fleshed fruits, such as peach, nectarine, orangefleshed papaya, persimmon and tomato, was absorbed very slowly compared to carotenes (33). We observed that, in absolute value, the rates of b-cryptoxanthin absorbed by the iron1zinc group was much higher than that of the iron group and zinc group supplemented with iron and zinc taken separately.…”

Section: Influence Of Iron Zinc and Iron1zinc On Chylomicron Intact mentioning

confidence: 69%

The Influence of Iron and Zinc Supplementation on the Bioavailability of Provitamin A Carotenoids from Papaya Following Consumption of a Vitamin A-Deficient Diet

Kana-Sop

Gouado

Achu

et al. 2015

J Nutr Sci Vitaminol

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Summary Iron deficiency anemia, zinc and vitamin A deficiencies are serious public health problems in Cameroon, as in many developing countries. Local vegetables which are sources of provitamin A carotenoids (PACs) can be used to improve vitamin A intakes. However, traditional meals are often unable to cover zinc and iron needs. The aim of this study was to determine the bioavailability of 3 PACs (a-carotene, b-carotene, and b-cryptoxanthin) in young men, who were fed with a vitamin A-free diet and received iron and zinc supplementation. Twelve healthy participants were divided into three groups and were supplemented with elemental iron (20 mg of iron fumarate), 20 mg of zinc sulfate or iron1zinc (20 mg of iron in the morning and 20 mg of zinc in the evening) for 11 d. They were given a vitamin A-and PAC-free diet from the 6th to the 11th day, followed by a test meal containing 0.55 kg of freshly peeled papaya as a source of PACs. Blood samples were collected four times successively on the 11th day (the test meal day), at T0 (just after the test meal), after 2 h (T2), after 4 h (T4) and after 7 h (T7). Ultracentrifugation was used to isolate serum chylomicrons. Retinol appearance and PAC postprandial concentrations were determined. The supplementation with zinc, iron and iron1zinc influenced the chylomicron appearance of retinol and PACs differently as reflected by retention times and maximum absorption peaks. Iron led to highest retinol levels in the chylomicron. Zinc and iron1zinc supplements were best for optimal intact appearance of a-carotene, b-carotene and b-cryptoxanthin respectively. Supplementation with iron led to the greatest bioavailability of PACs from papaya and its conversion to retinol.

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“…Suhamo et al (1993) demonstrated that there exists a correlation between vitamin A status and hemoglobin level. Jang et al (2000) suggested that iron deficiency inhibits mobilization of vitamin A stores and decreases the absorption and utilization of vitamin A. Furthermore, addition of retinyl palmitate to iron fortified maize-bread has been reported to enhance the absorption of iron (Davidson et al, 2003).…”

Section: Resultsmentioning

confidence: 99%

Effect of vitamin A supplementation on hematopoiesis in children with anemia

Garg¹,

Abrol²,

Tewari³

et al. 2005

Indian J Clin Biochem

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Fifty children (1-4 years age) presenting with micrecytic hypochromic anemia (hemoglobin less than 10g/dl) were studied in two groups of 25 each. Group I was supplemented with iron (ferrous sulphate 6 mg/kg/d) while group II in addition to iron was also supplemented with vitamin A (5000 IU/d). Hemoglobin concentration was found to be significantly increased after 4 weeks of iron supplementation. Rise in hemoglobin was comparatively more in-group II, as compared to group I, after 8 and 12 weeks. Serum iron was significantly higher after 4 weeks in both the groups. Packed cell volume (PCV) and retinol levels increased significantly in-group II only. The data suggests that supplementation of vitamin A improves hematopoiesis.

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Kinetic Analysis Shows That Iron Deficiency Decreases Liver Vitamin A Mobilization in Rats

Cited by 73 publications

References 22 publications

Circulating Retinol-Binding Protein-4 Concentration Might Reflect Insulin Resistance–Associated Iron Overload

Circulating Retinol-Binding Protein-4 Concentration Might Reflect Insulin Resistance–Associated Iron Overload

The Influence of Iron and Zinc Supplementation on the Bioavailability of Provitamin A Carotenoids from Papaya Following Consumption of a Vitamin A-Deficient Diet

Effect of vitamin A supplementation on hematopoiesis in children with anemia

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