• 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 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 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.

• 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.

• The Korean Journal of Community Living Science
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• v.26 no.4
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• pp.661-673
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• 2015

This study examines the effects of a low-calorie raw juice diet on the level of serum ferritin in adults and analyzes nutrient intake from the diet. There were significant differences between juices; the highest calorie was provided by pear juice, highest crude protein, vitamin A, and vitamin B2 levels were from green Juice 1; and highest vitamin C and vitamin B1 levels were from fruit juices. The ratio of estimated energy requirements (EER) for the participants was 56.2% from the raw juice diet. The percentages of recommended intake (RI) from the raw juice diet of protein (57.9%), dietary fiber (19.1%), niacin (6.2%), calcium (0.1%), and magnesium (0.2%) were lower than 75%. However, those of RI of vitamin A, vitamin B1, vitamin B2, vitamin B6, and vitamin C were 1796.5%, 7481.7%, 1915.5%, 30858.7%, and 7500%, respectively, exceeding the tolerable upper intake level (UL) for vitamin A, vitamin B6, and vitamin C. There were significant decreases in weight, the body mass index (BMI), body fat mass, and skeletal muscle mass in males and females. After the diet program, serum iron and SOD (superoxide dismutase) showed significant decreases, whereas RBC, hemoglobin, hematocrit, and serum ferritin showed significant increases. There were negative correlations between serum ferritin and weight and between serum ferritin and skeletal muscle mass for all participants. There were negative correlations between serum ferritin and skeletal muscle mass for males and between serum ferritin and body fat mass for females. These results suggest that a raw juice diet can supplement a regular diet to prevent excess or deficient nutrient intake.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.5
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• pp.914-919
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• 1997

We investigated the effects of vitamin E supplementation on the protein glycosylation in vivo. Weaned KK-mice were fed high fat diet containing 20% corn oil(wt/wt), and sacrificed at 4, 6, and 0 months of age. High vitamin E diet was the high fat diet supplemented with an excess amount of 이-$\alpha$-tocopheryl acetate(2080IU/kg diet). We measured $HbA_{1C}$ as a glycosylation early product, and collagen-linked fluorescence (CLF) of skin as a glycosylation and product. We found that diabetic group had increased levels of $HbA_{1C}$ within 2 months after onset of diabetes and during the experiments. The skin CLF increased dramatically 5 months after onset of diabetics. Treatment with vitamin E did not modify the level of blood glucose. However, we observed a significant lowering in CLF and $HbA_{1C}$ in diabetic mice.

• Journal of Nutrition and Health
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• v.30 no.6
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• pp.639-647
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• 1997

The effect of excess L-ascorbic acid(AsA) in blood, liver lipid levels and peroxidation status were investigate . Ten Sprague-Dawley male rats weighing 150-200g were fed 300mg AsA/100g body weight/day, mixed into ground chow diet, for 4 weeks. And another set of then rats were fed only chow diet as the control. Average body weight gain was slightly lowered by AsA feeding without food intake change. The AsA group showed higher AsA levels in plasma and liver than the control group. In addition, the AsA group showed a higher plasma TBARS value. Liver TBARS seemed to be elevated in the AsA, but not significantly. The hemolysis of red cells tended to increase with excess AsA, accompanied by a raised GSH-Px activity and lowered total GSH levels. Plasma HDL-Chol level was increased while the levels of total Chol, LDL-plus VLDL-Chol , and triglyceride were unchanged . Atherogenic index decreased. Hepatic TG levels were also decreased, but the total amount of Chol increased slightly . Platelet TXA$_2$ production was inhibited by excess AsA feeding. Above results indicafe that oral feeding of excess AsA may be beneficial in reducing the risk of atherosclerosis ; however such practice may be detrimental for tissue lipid peroxidation and weight gain.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.9
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• pp.1290-1295
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• 2000

The present study was conducted to evaluate effects of the increased dietary vitamin A supplementation on the vitamin A, vitamin E and ascorbic acid concentrations in the plasma and liver and activities of some enzymes in the liver of the growing chicken. One hundred and twenty female chickens at 4 weeks of age were divided in 6 equal groups in accordance with their body weight. They were housed in cages and fed on standard wheat-barley-based broiler diet balanced in the major nutrients. Vitamin A was supplemented in the form of retinyl acetate. Control diet was supplemented with 10 IU/g and experimental feeds were supplemented with 50, 100, 500, 1000 and 2000 IU/g. At days 42 and 56 of the development 8 chickens from each group were killed, plasma and liver were collected for vitamin and enzyme analyses. The increased vitamin A supplementation was associated with its increased accumulation in the liver and with a reduction of ${\alpha}-tocopherol$ concentrations in the plasma and liver. The blood plasma was more resistant to vitamin A concentration changes and the retinol level was elevated only when the vitamin A dose exceeded 100 IU/g feed. Ascorbic acid concentration in the liver was elevated when moderately high vitamin A supplementation was used but significantly decreased at the highest vitamin A dose. Similar changes were observed with glycogen concentration in the liver. Activities of hexokinase, glucose-6-phosphatase and lactate dehydrogenase in the chicken liver were also dependent on vitamin A supplementation, decreasing with highest vitamin A doses. Therefore the observations showed that the vitamin A excess compromises antioxidant system of the growing chickens suggesting that prooxidant activity may be responsible for at least part of the toxicity of vitamin A.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.2
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• pp.239-245
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• 2011

This study was conducted to determine the effects of excess vitamin A on alkaline phosphatase (ALP) activity, contents of calcium-binding protein (CaBP), bone gla-protein (BGP) in culture medium and CaBP mRNA expression in chicken osteoblasts in vitro. Osteoblastic cells in the tibia from 1-day-old Arbor Acre broiler chickens were isolated using enzyme digestion. The subconfluenced cells were divided into eight treatments with six replicates in each treatment and cultured in a medium containing either vehicle or different levels of vitamin A (0, 0.2, 0.6, 1.0, 2.0, 5.0, 10.0 and $20.0\;{\mu}g$/ml), and the control received an equivalent volume of ethanol. The incubation lasted 48 h. The results showed that vitamin A down-regulated ALP activity in the culture medium as well as CaBP mRNA expression of osteoblasts in a linear dose-dependent manner (p = 0.124 and p<0.10, respectively), and suppressed the contents of BGP and CaBP in the culture medium in a quadratic dose-dependent manner (p<0.05 and p<0.10, respectively) with increasing addition of vitamin A. The addition of 0-$0.2\;{\mu}g$/ml vitamin A to the culture medium increased ALP activity, BGP and CaBP contents as well as CaBP mRNA expression compared with other groups, but positive effects of vitamin A tended to be suppressed when vitamin A was increased to $1.0\;{\mu}g$/ml, and adverse effects occurred when vitamin A was increased to 10.0-$20.0\;{\mu}g$/ml. These results implied that there was a threshold level of vitamin A inclusion beyond which inhibitory effects occurred, and the mechanism by which overdose of vitamin A reduced bone growth in chickens was probably reduced osteoblastic cell activity, and inhibited expression of CaBP mRNA and CaBP secretion.