• Nutrition Research and Practice
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• v.10 no.3
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• pp.328-335
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• 2016

BACKGROUND/OBJECTIVES: Vitamin D plays an important role in the etiology of gestational diabetes mellitus (GDM). This study evaluated the effect of vitamin D supplementation on metabolic indices and hs-C-reactive protein (CRP) levels in GDM patients. SUBJECTS/METHODS: The study was a randomized, placebo-controlled, double-blinded clinical trial. Seventy-six pregnant women with GDM and gestational age between 24-28 weeks were assigned to receive four oral treatments consisting of 50,000 IU of vitamin $D_3$ (n = 38) or placebo (n = 38) once every 2 weeks for 2 months. Fasting blood glucose (FG), insulin, HbA1c, 25-hydroxyvitamin D, lipid profile, hs-CRP, and homeostasis model assessment-insulin resistance (HOMA-IR) were measured before and after treatment. Independent and paired t-tests were used to determine intra- and intergroup differences, respectively. ANCOVA was used to assess the effects of vitamin D supplementation on biochemical parameters. RESULTS: Compared with the placebo group, in the vitamin D group, the serum level of 25-hydroxyvitamin D increased (19.15 vs. -0.40 ng/ml; P < 0.01) and that of FG (-4.72 vs. 5.27 mg/dl; P = 0.01) as well as HbA1c (-0.18% vs. 0.17%; P = 0.02) decreased. Improvements in the lipid profiles were observed in the vitamin D group, but without statistical significance. Significant increases in concentrations of hs-CRP, FG, HbA1c, total cholesterol, and LDL cholesterol were observed in the placebo group. No significant change in fasting insulin and HOMA-IR was observed in either group. CONCLUSIONS: In GDM patients, vitamin D supplementation improved FG and HbA1c but had no significant effects on lipid profile or hs-CRP.

• The Korean Journal of Rehabilitation Nursing
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• v.5 no.2
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• pp.99-112
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• 2002

The purpose of this study is to determine the effect of oral vitamin C supplements on blood sugar and serum lipid level(total cholesterol, triglyceride, high density lipoprotein, low density lipoprotein) in non-insulin independent diabetes mellitus. The study design was a non equivalent control group pre-test post-test design. Data for the study were collected from June 24 to August 31, 2001. The ninty-five research subject were assigned to experimental group(51) and control group(44). Vitamin C(3g/day) was given to 51 subjects for 4 weeks. Following a 12h overnight fasting, blood sample was obstaind at baseline and at the end of 4week - supplementation. Blood samples were taken for plasma vitamin C concentration, fasting blood sugar, HbA1c and serum lipid level. The pre-equivalent test was used by Chi-squre, t-test and two group's pre and post experimental differences were analyzed by t-tset to compare with each other. The results of this study were as follows ; 1. The difference between the two groups in plasma vitamin C concentration was significant(t=-12.950, p=.000). 2. The difference between the two groups in fasting blood sugar was significant(t=5.293, p=.000). 3. The difference between the two groups in HbA1c was not significant(t=1.758, p=.082). 4. The difference between the two groups in total cholesterol, HDL, LDL was significant(t=3.786, p=.000 ; t=-5.515, p=.000 ; t= 4.169, p = .000). These results suggest that megadose vitamin C supplementation be effective in lowering fasting blood sugar, serum lipids and increasing plasma vitamin C. Thus dietary measures to increase plasma vitamin C may be on important health strategy for reducing the compliance of diabetic patients.

• Journal of Nutrition and Health
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• v.40 no.8
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• pp.708-718
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• 2007

The purpose of this project was to evaluate whether vitamin E supplementation could improve the antioxidant status and lymphocyte DNA damage in Korean postmenopausal women. This was double blinded, placebo-controlled trial. Thirty-five subject were randomized to receive either placebo 400 mg/capsule or natural $\alpha$-tocopherol 400 IU/capsule, 2 times a day for 6 weeks. We measured plasma vitamin C, $\alpha$-tocopherol, $\gamma$-tocopherol, $\alpha$-carotenoid, $\beta$-carotenoid, lycopene concentration and tail length, %DNA in tail, tail moment in lymphocyte DNA damage index. Vitamin E supplementation group had significantly increased plasma vitamin C(p<0.05), $\alpha$-tocopherol(p<0.000), whereas $\gamma$-tocopherol(p<0.000) and tail length(p<0.05) were significantly decreased. However, placebo supplementation group also had significantly increased plasma vitamin C(p<0.05). In conclusion, our study shows that vitamin E supplementation to Korean postmenopausal women may partially improve antioxidant status and lymphocyte DNA damage.

• Journal of the Korean Home Economics Association
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• v.24 no.2
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• pp.51-62
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• 1986

This study was designed to observe the effects of nutritional supplementation of general Korean diet on protein metabolism in growing rats. Seventy weanling Sprague-Dawely male rats weighing 76.8$\pm$1.45g were blocked into ten groups and fed ten different experimental diets for eight weeks. The rats in cereal-vegetable group were fed ad libitum for all the experimental period and those in other experimental groups were pairfed following the feed intake of rats in C-V gp. Control group was given 72% cornstarch-29% casein diet : C-V gp was fed cerealvegetable diet composed of rice, barley, soybean and Chinese cabbage : the other eight groups were fed C-V diets supplemented with casein, vitamin B\sub 2\ calcium, vitamin A, vitamin B\sub 2\ and vitamin A, vitamin A and calcium, vitamin B\sub 2\ and calcium, vitamin A and vitamin B\sub 2\ and calcium, respectively, on the basis of each nutrients content of standard diet.

• Journal of Nutrition and Health
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• v.38 no.3
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• pp.211-218
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• 2005

Elevated homocysteine concentration is known to be related to placental abruption, spontaneous abortion, and many adverse pregnancy outcomes. The purpose of this study was to investigate the effects of folic acid supplementation ($1000{\cal}ug$ per day) and 5, 10 methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism genotype on serum homocysteine and B vitamin levels in 50 infertile women ($31.2{\pm}3.2\;years$). Blood sampling was performed at baseline and at the end of folic acid supplementation period. In infertile women, serum folate and vitamin $B_{12}$ concentrations were significantly higher in post-supplementation than those in pre-supplementation. Serum homocysteine concentration was significantly lower in post-supplementation than that in pre-supplementation. However, serum homocysteine levels were still higher in the T/T genotype than those in the C/C or C/T even after folic acid supplementation. Serum homo-cysteine was inversely related to serum folate in T/T homozygotes at baseline and at the end of folic acid supplementation. These results suggest that folic acid supplementation is needed for infertile women to improve their vitamin status and also to reduce the risk of hyperhomocysteinemia. These effects were different according to their MTHFR C677T genotypes. Therefore, further studies are necessary to determine the optimal level of supplementation of folic acid by MTHFR genotypes.

• 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.

• Nutritional Sciences
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• v.1 no.1
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• pp.22-28
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• 1998

Plasma concentrations of Vitamins E and A were measured in 15 non-insulin dependent Korean female subjects and 15 age-matched normal subjects using reversed-phase high-performance liquid chromatography. No differences were found in plasma Vitamin E concentrations between the 2 groups. Plasma Vitamin A concentrations were higher in subjects with non-insulin dependent diabetes melitus (NIDDM). The effects were evaluated of 4 weeks of daily supplementation of 400 mg Vitamin E on plasma levels of these two vitamins. In addition, the effects were observed for Vitamin E supplementation on oxidative stress and immune-related compound productions in non-insulin dependent diabetic patients and control subjects. After treatment with Vitamin E, plasma Vitamin E concentrations were significantly elevated in both groups. Basal plasma thiobarbituric acid reactive substances (TBABS) were identical, and a decreased level of TBARS caused by Vitamin E was observed only in the diabetic group (0.02739$\pm$0.0024 versus 0.01814$\pm$0.0008 nmols malondialdehyde equivalents/dl plasma ; p<0.05). The basal and after-treatment levels of immunoglobulins A, G, M were identical in control and diabetic groups, indicating that Vitamin E did not appear to alter gross humoral responses in this study. However, elevation of Complement 3 ($C_3$) was noticed due to Vitamin E supplementation, revealing a possible effect of vitamin E on one aspect of humoral immunity, Furthermore, an increase in prostaglandin E_2 ($PGE_2$) levels in diabetic patients was normalized by Vitamin E supplementation. This suggests indirectly that the depressed cell-mediated response due to elevated $PGE_2$ could be normalized. For the definitive antioxidant intake recommendations for prevention and treatment of adverse effects of non-insulin dependent diabetes, evidence from intervention trials like this study should be collected. The present data suggests that Vitamin E may oxen some protective effects against oxidative damage and might have beneficial effects of partial immune-stimulation.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.8
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• pp.1179-1189
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• 2006

This experiment was designed to examine the effects of supplemental vitamin D on laying performance, metabolic profile and egg quality of hens fed diets containing different fat sources and levels. Lohman strains (n = 480) were assigned to one of 10 diets: basal diet (BD), BD plus 2.5 and 5.0% sunflower oil (SO) or tallow (T) at vitamin D provided $1{\times}$ and $3{\times}$ of the current recommendation. The experiment lasted from week 30 to 44 of age. Each diet was tested in 12 replicate cages of 4 hens. Production, metabolism, and egg quality data were subjected to three-way ANOVA. Both fats decreased feed intake (FI) as compared to BD. Increasing SO and T levels linearly decreased and quadratically increased FI, respectively. The dietary factors did not affect egg production (EP) and egg weight. Vitamin D supplementation increased and decreased EP when diets contained SO and T, respectively. Feed conversion efficiency (FCE) for hens fed SO was lower than for hens fed T. However, increasing T level improved FCE, whereas increasing SO level worsened FCR. Vitamin D supplementation increased serum vitamin D and glucose concentrations. Vitamin D supplementation also caused a decrease and an increase in serum vitamin D concentration when diets contained SO and T, respectively. Serum glucose concentration for hens fed SO was lower than hens fed T. Increasing fat level linearly increased serum triglyceride and VLDL concentrations, regardless of the fat type. Increasing SO level linearly decreased serum cholesterol concentration. Vitamin D supplementation did not alter lipid metabolites. The dietary factors did not affect serum total protein, Ca, and P concentrations. As compared with BD, feeding SO decreased dry tibia and ash weights more than feeding T. Vitamin D supplementation tended to increase dry tibia weight and decrease tibia ash weight. Eggshell strength and thickness, yolk and albumen indexes, and Haugh unit were not responsive to the dietary factors. Eggshell strength quadratically increased with increasing T level. Yolk color for hens fed SO was lower than for hens fed T. The dietary factors did not affect most of yolk fatty acids. Increasing SO level quadratically decreased yolk $C_{18:2}$ concentration. Vitamin D supplementation increased and decreased yolk $C_{18:2}$ concentration when diets contained SO and T, respectively. In conclusion, increasing fat level improved laying performance without altering metabolic profile and egg quality. Vitamin D supplementation had minor alteration effects on laying performance, metabolic profile, and egg quality in response to fat feeding.

• Biomedical Science Letters
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• v.24 no.4
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• pp.311-318
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• 2018

Vitamin C (ascorbic acid) supplementation has been suggested to negatively correlate with obesity in humans and other animals. Previous studies, including ours, have demonstrated that a high-fat diet (HFD) induces obesity and related diseases such as hyperlipidemia, hyperglycemia, insulin resistance, and nonalcoholic fatty liver disease. Here, we investigated the effects of vitamin C on visceral adipocyte hypertrophy and glucose intolerance in C57BL/6J mice. Mice received a low-fat diet (LFD, 10% kcal fat), HFD (45% kcal fat), or the same HFD supplemented with vitamin C (HFD-VC, 1% w/w) for 15 weeks. Visceral adiposity and glucose intolerance were examined using metabolic measurements, histology, and gene expression analyses. Mice in the HFD-VC supplementation group had reduced body weight, mesenteric fat mass, and mesenteric adipocyte size compared with HFD-fed mice. Vitamin C intake in obese mice also decreased the mRNA levels of lipogenesis-related genes (i.e., stearoyl-CoA desaturase 1 and sterol regulatory element-binding protein 1c) in mesenteric adipose tissues, inhibited hyperglycemia, and improved glucose tolerance. In addition, vitamin C attenuated the HFD-induced increase in the size of pancreatic islets. These results suggest that vitamin C suppresses HFD-induced visceral adipocyte hypertrophy and glucose intolerance in part by decreasing the visceral adipose expression of genes involved in lipogenesis.

• Journal of Nutrition and Health
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• v.22 no.3
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• pp.209-217
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• 1989

The present study examined the effects of dietary PUFA and vitamin E supplementation(2,000 I.U./Kg diet) on vitamin E levels of serum, liver and brain in chicks aged one week (younger chick) and four weeks(older chick). 1) Younger chicks showed more sensitive response to vitamin E supplementation in the diet than older chicks in their serum levels, but not in liver levels. 2) Chicks fed excess vitamin E showed significantly higher levels of vitamin E in both serum and liver than unsupplemented groups. 3) PUFA diet lowered serum and liver vitamin E levels especially for vitamin E supplemented groups except for older chick liver at 3 weeks of the experimental period. 4) Vitamin E levels of brain were relatively lower than those of serum and liver and showed little change according either to the dietary PUFA or to vitamin E supplementation.