• Journal of Nutrition and Health
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• v.24 no.3
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• pp.189-198
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• 1991

This study was performed to examine the effect of excess vitamin A feeding on lipid profile and vitamin A content of rats. 12 male Sprague-Dawley rats. weighing 114.1$\pm$0.9g, were divided into control and excess vitamin A group, and fed experimental diet for 6 weeks. In the excess vitamin A group, the level of vitamin A was 400, 000 1.U./kg diet(100 times of standard level). It was observed that vitamin A excess group had higher levels of plasma total lipid, total cholesterol, and trighlyceride and lower HDL ratio, indicating a high risk to coronary heart disease. In the liver, total CHOL and TG content were also high, and fatty liver was produced by excess Vitamin A. Vitamin A contents of organs were higher when excess vitamin A was given. These results suggested that excess vitamin A could be a dietary factor increasing the lipid contents of plasma and liver. Therefore, it could be said that vitamin A megadose can be one of the risk factors to coronary heart disease.

• Journal of Nutrition and Health
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• v.25 no.6
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• pp.492-500
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• 1992

The rate of vitamin K-dependent carboxylation of endogenous liver microsomal proteins and an exogenous peptide substrate for carboxylase were measured to test the effects of excess vitamin A on vitamin K function in rats. In vitro vitamin A incubation in normal rat microsomes of vitamin K-sufficient ras did not influence the carboxylation rates of either endogenous prothrombin precursors or a peptide substrate added, Similarly vitamin A incubation in micro-somes from control and excess vitamin A-fed rats that were on vitamin K-free diet did not change the rate significantly within the respectively groups ; however the rates of endogenous protein carboxylation from excess vitamin A-fed rats tended to be increased by the in vitro vitamin A addition compared to that of control rats. Excess vitamin A-fed rats had 2- to 3- fold higher carboxylase activites of endogenous protein carboxylation either with or without the invitro vitamin A incubation than did control rats. In an in vivo study carboxyalase activites with an added exogenous peptide substrate were not influenced by excess intake of vitamin excess vitamin A-fed rats than for control rats. Carboxylase activites tended to be increased amounts of vitamin A on endogenous protein carboxylation appeareed as early as one week post-initiation of the diet. The results of this study indicate that excess vitamin A produces toxic effect rapidly and that excess dietary vitamin A increase the rate of carboxylation of endogenous protein mainly prothrombin precursors which is an indication of vitamin K defi-ciency.

• Journal of the Korean Home Economics Association
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• v.28 no.3
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• pp.25-32
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• 1990

This study was carried out to observe the effects of dietary sources of vitamin A and Zn levels on Zn and vitamin A distribution in rats fed excess vitamin A diet. In this study, 40 weanling male rats of the Sprague-Dawley strain, weighing 40-50g, were chosen and divided into for groups by dietary Zn levels and the sources of vitamin A. The two levels of dietary Zn were supplied: adequate Zn(30mg Zn/Kg diet), low Zn(3mg Zn/Kg diet). Excess vitamin A level was 100 times of RDA, retional and $\beta$-carotene were used as the sources of vitamin A. Vitamin A concentration of plasma and liver were significantly higher in rats fed retional than in rats fed $\beta$-carotene (p<0.05), but these were not affected by dietary Zn levels. Vitamin A accumulationin the liver appeared to be servere in rats fed retinol and low Zn diet. Zn levels of plasma and liver were not affected by the sources of vitamin A whereas Zn levels of kidney were slightly lower in retinol group, and Zn levels of tests were found to be significantly lower in rats fed retinol and low Zn diet. Fragility of erythrocytes in hypotonic saline soultion was greater in low Zn groups, whereas the lower fragility was found in adequate Zn groups in feeding excess vitamin A diet. Thus, these results suggest that an adequate Zn intake is preferable when excess vitamin A is taken, and $\beta$-carotene intake is more beneficial than retinol in order to diminish toxic effects of vitamin A.

• Journal of Nutrition and Health
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• v.26 no.5
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• pp.558-565
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• 1993

This study was carried out to observe the effects of dietary n-6, n-3 fatty acids and vitamin A levels on serum lipid contents and hepatic tissues in rats. Sixty eight male Sprague-Dawley rats were fed 6 different experimental diets for 6 weeks. The diets were composed of 10% of either corn oil or fish oil with three levels of vitamin A ; defient (1240IU/kg diet), adequate (4000IU/kg diet), excess(400,000IU/kg diet). It was observed that triglyceride content and lipoprotein ratio in serum were not affected by dietary fat types and vitamin A levels. However, total serum cholesterol contents were significantly lower in fish oil groups than in corn oil groups, which were not affected by vitamin A levels. Under light microscope, vitamin A excess groups showed pathological abnormalites, such as fatty change and inflammation of the hepatic tissues. There abnormalities were less severe in fish oil groups. These results suggested that fish oil could be a dietary factor lowering the serum lipid contents, and it seems to relieve the abnormal changes in liver induced by excess vitamin A.

• Journal of Nutrition and Health
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• v.25 no.6
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• pp.468-475
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• 1992

This study was carried out to observe the effects of dietaryn-6, n-3 fatty acids and vitamin A levels on humoral immunity in rat. Sixty eight male Sprague-Dawley rats were fed 6 different experimental diets for 6 weeks. The diets were composed of 10% of either corn oil or fish oil with various levels of vitamin A ; deficient(12450 IU/kg diet) adequate(4000IU/kg diet) and excess(400,000 IU/kg diet) The weight of spleen from the excess vitamin A-fish oil group showed the lowest value of all the groups when spleen weight was expressed/100g body weight. The number of PFC to SRBC was not affected by dietary at type and vitamin A levels. Hemagglutination titers were significantly lower in fish oil groups compared to corn oil groups and the values of vitamin A deficient groups were lower than the ones of adequate and excess vitamin A groups. IgM contents is serum were significantly lower in fish oil groups than in corn oil groups. IgG contents were higher in fish oil groups than in corn oil groups and the highest levels was recorded in excess vitamin A-fish oil group which showed the smallest speen size. Light microscopical examination showed that spleen tissues of fish oil groups were well developed than those of the corn oil groups and vitamin A deficient and excessive groups showed poor development than the adequate groups. Therefore it is suggested that adequate amounts of vitamin A consumption is necessary for healthy individuals and fish oil intake along with excess vitamin A should be avoided in order to maintain immune function properly.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.1
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• pp.1-6
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• 1994

The present study was conducted to evaluate the effect of dietary levels of vitamin A on the lipid composition in rats fed Zn-deficient diets. Fifty male Sprague-Dawley rats were fed 5 experimental diets for 7 weeks. Rats were fed Zn-and vitamin A-deficient diet or the same diets supplemented with various levels of vitamin. A liver total lipid, cholesterol and triglycerides contents tended to decrease in Zn-deficient rats, but the supplementation of excess vitamin A enhanced those contents. Plasma cholesterol content was significantly higher in feeding Zn-deficient and excess vitamin A diet. Plasma triglyceride and phospolipid contents were higher in Zn-deficient groups, but not influenced by dietary levels of vitamin. A . Plasma HDL-cholesterol content was not changed by Zn-deficient diets. Plasma alkaline phosphatase activity was significantly reduced in Zn-deficient groups. Zinc contents of plasma and liver were influenced by the dietary level of zinc, but not changed by supplementation of vitamin A.

• Journal of Nutrition and Health
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• v.33 no.2
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• pp.141-146
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• 2000

This study was conducted to investigate the effects of vitamin E supplementation renal lipid peroxidation in high fat diet and adriamycin (ADR) induced experimental nephrotic syndrome model rats. Treated rats were injected intraperitoneally with ADR (2mg/kgBW/wk) once a week for four weeks. control rats were injected with saline solution instead of ADR. The rats in each group were fed experimental diets of three levels of vitamin E for 10 weeks: Normal (501U/kg diet), high (5,000IU/kg diet), excess (7,500IU/kg diet). The high fat diet and ADR treatment was performed to induce the decrease of kidney functions. Serum total cholesterol was significantly decreased by the excess supplementation. But there was no effect of vitamin E supplementation on serum total lipid and triglyceride. Thiobarbituric acid reacting substances(TBARS) was significantly decreased at high and excess supplementation. Glutathione reductase (GR), glutathione peroxidase ({TEX}$GP_{x}${/TEX}) and catalase activities (CAT) were measured as antioxidative enzymes. The renalglutathione reductase (GR) and catalase activities (CAT) were inclined to elevate by vitamin E supplementation. Thus the vitamin E supplementation was found to have an antioxicant effect. These results suggested that vitamin E supplementation could alleviate the changes in renal lipid peroxidation.

• Journal of Nutrition and Health
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• v.18 no.2
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• pp.147-154
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• 1985

The present study was undertaken to investigate the effects of excess vitamin E supple-mentation (0.5%) and cholesterol (0.5%) on levels of serum and liver vitamin E and cholesterol in two categories of rats, group A and group B. Rats in group A(45-65g) were fed experimental diets for 3 weeks ( I-C, II-E, III-Ch, IV-ECh). On the other hand rats in group B(45g-65g) were first fed control diet for 3 weeks and then fed experimental diets when they were 100-l20g for the subsequent 3 weeks ( I'-C, II'-E, III'-Ch, & IV'-ECh). The levels of serum vitamin E were higher in vitamin supplemented groups as expected. Dietary cholesterol showed a tendency to lower serum vitamin E levels of vitamin E supplemented groups. Serum cholesterol levels tended to stay in a narrow range showing resistancy to dietary cholesterol and were not affected by vitamin E status. Whereas vitamin E supplementation seemed to lower the levels of hepatic cholesterol in both groups A & B( I-C, I'-C vs II-E, II'-E ), simultaneous supplementation of vitamin E with 0.5% cholesterol appeared to increase further the hepatic cholesterol levels which were already increased by cholesterol feeding ( IV-ECh, IV'-ECh, vs III- Ch, III'-Ch). Hepatic vitamin A levels decreased as rats grew older during the experimental period. Even though vitamin A levels did not differ from each other significantly, excess amount of vitamin E supplementation in group B seemed to show a tendency to decrease the vitamin A storage in liver.

• Journal of the East Asian Society of Dietary Life
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• v.9 no.4
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• pp.427-434
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• 1999

This study was conducted to investigate the effects of vitamin I supplementation on renal function in high fat diet and adriamycin (ADR) induced experimental nephrotic syndrome in model rats. The effects of vitamin E supplementation on renal function in high fat diet and ADR treated rats were as follows. Kidney weight was decreased by vitamin E supplementation. Serum total protein was increased by the excess supplementation. Blood urea nitrogen(BUN) was decreased by the high supplementation. However, serum albumin and creatinine showed no significant differences between groups. Urinary volume tended to increase by vitamin I supplementation. Urinary urea-N tended by vitamin I supplementation. Particularly glomerular filtration rate(GFR) was significantly decreased by vitamin E supplementation. These results suggested that vitamin E supplementation could alleviate the adverse effects caused in renal function by highfatdiet and ADR treatments.

• Korean Journal of Poultry Science
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• v.22 no.2
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• pp.85-95
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• 1995

This study was conducted to investigate the immune response of layers fed diets supplemented with excess micronutrients, i.e., vitamin A, methionine, Zn, Cu, and Fe to the inoculation of Newcastle disease vaccine(NDV) or infectious bronchitis vaccine(IBV). The antibody titer against the NDV increased immediately after the inoculation and stayed high during the next 6 wk. On the other hand, The antibody titer against the IBV increased after 4 wk of inoculation The IgM level increased rapidly after 1 wk of NDV inoculation, however, it decreased after 5 wk of inoculation. The IgA displayed similar pattern to that of IgM in response to NDV inoculation. The pattern of IgM change after IBV inoculation was similar to that when layers were treated with NDV. However, IgA level changed earlier than did IgM. The IgG response to the NDV and IBV was very weak compared to the other immune responses. The excess supplementation of micronutrients to the diets of layers inoculated with NDV elicited favorable antibody titer and immune response compared to the layers fed the control diet. The excess Zn, however, allowed the layers to have higher antibody titer for the 4-wk period after NDV injection: after that they showed no effect of extra-Zn. The immune responses of layers fed excess vitamin A, Cu, methionine, and Fe were markedly higher in IgA and IgG than the control layers. The excess Zn, however, did not bring about any favorable result. No difference was detected in IgG level between control and micronutrients-treated groups.