• Journal of Community Nutrition
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• v.6 no.2
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• pp.97-102
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• 2004

A cross-sectional epidemiologic study was conducted to evaluate vitamin C nutritional status by assessing dietary intake and blood vitamin C level and to identify the relationships between dietary vitamin C intake, serum vitamin C level and blood lead level in Korean lead workers. The study population was 118 lead workers from two battery manufacturing factories and 63 non-lead-exposed controls. A food consumption survey was conducted by the 24-hr recall method to determine the dietary vitamin C intake level. The anthropometric measurements, blood collection, and survey were performed between September and November, 2000. Blood lead levels and serum vitamin C levels were measured using an atomic absorption spectrometer and high performance liquid chromatography, respectively. Vitamin C nutritional status of Korean lead workers was lower than that of the control group, in terms of both dietary intake and the biochemical index: the mean daily dietary intake level of vitamin C of lead workers was 65.9mg (94% RDA), while that of controls was 132.6mg(189% RDA) ; and the serum vitamin C status of lead workers (0.10mg/dl) was significantly lower than that of controls (1.08mg/dl ; p<0.001). Both dietary vitamin C intake and serum vitamin C levels showed a significant negative correlation with blood lead level (p<0.001), which indicates that strategies of dietary management to promote the health of Korean lead workers should focus on promoting the vitamin C intakes of individuals.

• Nutrition Research and Practice
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• v.17 no.5
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• pp.997-1006
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• 2023

BACKGROUND/OBJECTIVES: Asthma and allergic rhinitis (AR) are closely related and considered as allergic respiratory diseases (ARD), and their prevalence has recently increased. Data on the association of dietary antioxidant vitamin intake with asthma and AR in adults are limited. The present study aimed to investigate the associations of vitamin A and C intake with asthma, AR, and all cases of both diseases in young adults who participated in a cross-sectional national survey, with the use of high-sensitivity C-reactive protein (hs-CRP) level as an effect modifier. SUBJECTS/METHODS: This study included 6,293 male and female adults aged 20-49 years from the Korea National Health and Nutrition Examination Survey (KNHANES) conducted between 2016 and 2018. The questionnaire-based reports on asthma and AR diagnosis were used to determine outcome variables. Further, 24-h recall data on dietary vitamin A and C, carotene, and retinol intake were acquired. Logistic regression analysis was performed to calculate odds ratios (ORs) and 95% confidence interval (CI). RESULTS: Dietary vitamin C intake was inversely associated with asthma prevalence among participants with hs-CRP levels (≥ 1 mg/L); the OR of asthma prevalence was 0.27 (95% CI, 0.08-0.84) for participants with vitamin C consumption ≥ 75 mg/day compared with those consuming < 20 mg/day. Similar association analyses limiting to non-users of dietary supplements were performed to rule out the potential effects of supplement intake on the outcomes; results showed a stronger association. However, the association between vitamin C and asthma was not significant in participants with hs-CRP levels < 1 mg/L; the OR of asthma was 1.44 (95% CI, 0.66-3.16) for participants with vitamin C consumption ≥ 75 mg/day compared with those consuming < 20 mg/day. Vitamin C intake was not associated with AR. Moreover, there was no association between vitamin A intake and neither asthma nor AR. CONCLUSIONS: These findings suggest that higher vitamin C intake may play a potential role in reducing asthma prevalence. Nevertheless, further studies should be conducted to evaluate whether this association is causal.

• Journal of the Korean Society of Food Culture
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• v.35 no.5
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• pp.493-502
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• 2020

The objective of this study was to investigate the effects of dietary vitamin B intake on biomarkers related to lipid metabolism, inflammation and blood glucose control, that are important in the development of type 2 diabetes and its complications. Seventy-six adults (42 males, 34 females) were recruited from a group of diabetes patients who had visited the medical center for treatment. Data on anthropometric characteristics and dietary intake of thiamine, riboflavin, niacin, vitamin B₆ and folate were collected using 24-hour diet recall and the CAN Pro 4.0 program. Also, data on clinical indices such as serum lipids, blood pressure, high-sensitivity C-reactive protein (hs-CRP), hemoglobin A1c (HbA1c) and homeostasis model assessment 2-insulin resistance (HOMA2-IR) were collected and analyzed for correlation with dietary vitamin B intake. Results from the dietary intake survey showed that riboflavin and folate intake (in males) and folate intake (in females) were below the Dietary Reference Intake for Koreans. Statistical analysis revealed a negative correlation between hs-CRP and dietary intake of B vitamins. Riboflavin intake was inversely associated with systolic blood pressure after adjustments for age, BMI, smoking, alcohol consumption, exercise, ingestion of diabetes mellitus medication and energy intake (p<0.05). Our results suggest that dietary vitamin B may influence inflammation and consequently may help in better management of type 2 diabetes.

• Journal of the Korean Society of Food Culture
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• v.36 no.6
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• pp.571-582
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• 2021

This study investigates the relationship between vitamin C intake and obesity prevalence among Korean adults. Based on data of the Korean National Health and Nutrition Examination Survey (2016-2017), a total of 1,356 participants were included in this analysis. Increasing the dietary vitamin C intake resulted in a significantly decreased occurrence of BMI obesity prevalence (p for trend=0.0194) and WC obesity prevalence (p for trend=0.0452). Moreover, increasing the dietary vitamin C intake of Korean adults having a high frequency of eating breakfast resulted in significantly decreased BMI obesity prevalence (p for trend=0.0406) and WC obesity prevalence (p for trend=0.0432). Among the Korean adults who ate out frequently, decreased BMI obesity prevalence was determined with increased intakes of dietary vitamin C (p for trend=0.0193) and total vitamin C (food and dietary supplements) (p for trend=0.0429), whereas significant decrease in WC obesity prevalence was observed with increased dietary vitamin C intake (p for trend=0.0484). Our results provide conclusive evidence that consumption of dietary vitamin C is associated with obesity prevalence in Korean adults, according to their habits of eating breakfast and frequency of eating out.

• Preventive Nutrition and Food Science
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• v.20 no.3
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• pp.198-203
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• 2015

The present study was conducted to assess the status of vitamin C among healthy young adults in relation to serum antioxidant parameters [glutathione (GSH), thiols, and total antioxidant capacity, (TAC)], and oxidative stress markers [malondialdehyde (MDA), and nitrites plus nitrates (NN)]. A prospective study included 200 young adults, and their dietary intake was assessed by using food diaries. Fasting plasma vitamin C, serum levels of GSH, thiols, TAC, MDA, and NN were measured using biochemical assays. It was observed that 38% of the enrolled subjects, n=76, had an adequate dietary intake of vitamin C (ADI group). Meanwhile, 62%, n=124, had a low dietary intake of vitamin C (LDI group) as compared to the recommended dietary allowances. The fasting plasma level of vitamin C was significantly higher in the ADI group as compared to the LDI group. Oxidative stress in the sera of the LDI group was evidenced by depletion of GSH, low thiols levels, impairment of TAC, an elevation of MDA, and increased NN. In the ADI group, positive correlations were found between plasma vitamin C and serum antioxidant parameters (GSH, thiols, and TAC). Meanwhile, the plasma vitamin C was negatively correlated with serum MDA and NN levels. This study reveals a significant increase of oxidative stress status and reduced antioxidant capacity in sera from healthy young adults with low intake of the dietary antioxidant, vitamin C.

• Nutrition Research and Practice
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• v.6 no.5
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• pp.429-435
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• 2012

Atopic dermatitis (AD) has become a serious epidemic in Korean children. We aimed to investigate the association between vitamin C, E and other nutrients, and serum total IgE/specific IgE levels in children with AD. A total of 119 children (0-24 mo) diagnosed with AD were recruited for this cross-sectional study from a medical center in Seoul. A 24 h recall was used to assess dietary intakes. Serum total and six food-allergen specific IgE levels were measured by CAP-FEIA. Serum vitamin E was also measured but only in 25 out of the total 119 participants. Multiple linear regression analysis was performed to estimate the coefficients between serum IgE levels and dietary intake as well as serum vitamin E. Serum vitamin E levels showed a significantly inverse association with serum total IgE and all specific IgE levels (P < 0.05). Fat intake was inversely related with specific-IgEs for egg whites, milk, buck wheat, soy, and peanuts (P < 0.05). Positive associations were found between carbohydrate (CHO) intake and total IgE and specific IgEs to egg whites, milk, soy, and peanuts (P < 0.05). Vitamin C, E and n-3/n-6 fatty acids were not related with serum total IgE and specific IgE levels except for the association between buck wheat and vitamin E. In addition, there were no significant differences between males and females in dietary intake and serum IgE levels by student's t-test. Although dietary vitamin E showed no association with serum IgE levels, serum vitamin E drew a significant inverse relationship with serum IgE levels. The evidence seems to suggest that vitamin E may possibly lower total and specific-IgEs in children with AD, and that it is important to maintain a relatively high serum vitamin E level in children with AD.

• The Korean Journal of Community Living Science
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• v.22 no.4
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• pp.509-518
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• 2011

This study was intended to investigate dietary behavior, health related behavior and the effects of nutrient intake of female college students. Dietary behavior, health related behavior and the perception of the body conditions were surveyed with anonymous questionnaires, and 24hrs recall method for nutrient intake was obtained from 161 female college students in Chungbuk area. The mean height and weight of the subjects were $161.4{\pm}5.0$cm and $53.8{\pm}7.4 $kg, respectively. The dietary behavior of female college students was generally inadequate. More specifically, irregularity of meals, indifference of dietary balance, and skipping breakfast, showing $4.77{\pm}2.20$for dietary behavior score, $11.76{\pm}3.89$ for DVS and $3.58{\pm}0.82$ for DDS, respectively. It was found that almost 63% of subjects did not anything for health care and the frequency of exercise of subjects was low. The perception of body conditions of the subjects seemed to be generally positive. However, satisfaction levels on body shape was very negative showing that only 12.4% of subjects answered as 'very satisfied' and 'satisfied'. When nutrient intake of the female college students was compared with Dietary Reference Intake for Korean, folate(45%), potassium(55%), vitamin C(59%), Ca(72%), fiber(72%), Fe(79%) and energy(80%) were found to be insufficient. But protein(138%), P(122%) and Na(179%) were found to be oversupplied. The nutrient intake of fiber, plant Ca, vitamin A, ${\beta}$-carotene, vitamin B6, vitamin C, folate and vitamin E were significantly higher, and those of Fe, Zn and protein were a little high in the high score group of dietary behavior. Also Food group intake, DDS and DVS were higher in the high score group of dietary behavior.

• Journal of Nutrition and Health
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• v.29 no.1
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• pp.122-133
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• 1996

As ciarette smoking adversely affects vitamin C metabolism in humans, smokers need substantially more vitamin C intake than do non-smokers to achieve similar serum vitamin C concentration. To provide the basic information currently available for the determination of vitamin C requirement for Korean smokers, we investigated the differences the serum vitamin C values between smokers(n=53) and non-smokers(n=62) in relation to their intake of the vitamin through diet in 115 male college students, who had not been using vitamin C supplements. Dietary intakes of vitamin C were determined by a 24-hour recall, and serum vitamin C was determined using the 2, 4-dinitrophenylhydrazine method. The mean vitamin C intakes of smokers and non-smokers were consuming less than 75% of the Koeran RDA for vitamin c in their diet. Smokers consumed yellow and green leafy vegetables more often (P=0.02) and fresh fruits less often(P=0.006) than non-smokers. The mean serum vitamin C concentration of smokers consuming the same amounts of vitamine C as non-smokers, 64.3 umol/1, were 20% lower than for non-smokers, 80.1 umol/l(P<0.05). The risk of low serum vitamin C concentration (LoC) among smokers were 3.8% compared with 1.6% in non-smokers, and the odd ratio for LoC risk was 2.43. There were no correlations between dietary and serum vitamin C for smokers and non-smokers. It was concluded that smokers might require at least 20% more vitamin C to reach the same concentration comparable to non-smokers.

• Korean Journal of Community Nutrition
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• v.10 no.1
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• pp.12-21
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• 2005

The aim of this study was to assess dietary fiber intake and the relationship between dietary fiber intake and nutrient intakes of elementary school students. Food consumption of 200 elementary school students (100 boys, 100 girls) in the 6th grade in Gimhae was assessed by 2-day estimated food records. Nutrient intakes were calculated using CAN-pro and total dietary fiber (TDF) intake using the TDF tables of the common Korean foods. The mean height and weight of the boys were 147.7 cm and 42.1 kg. The mean height and weight of the girls were 149.1 cm and 41.1 kg. The mean body mass index (BMI) of the boys (19.3 $kg/m^2$) was significantly higher than that of the girls (18.4 $kg/m^2$, p < 0.05). Average daily intake of energy of the boys and girls was 1733 and 1778 kcal, respectively. Intakes of protein, P, and niacin of the boys and girls exceeded $110\%$ of current RDA. Intakes of Fe, vitamin $B_1$ and vitamin $B_2$ of the boys were similar to RDA. Intake of vitamin $B_1$ exceeded $110\%$ of current RDA and intakes of Fe and vitamin A were similar to RDA among the girls. Ca intake of the boys and girls was $74.2\%$ and $60.1\%$ of RDA, respectively. Vitamin C intake of the boys and girls were $63.6\%$ and $71.7\%$ of RDA, respectively. Intakes of fat, Ca, P, and vitamin $B_2$ of the boys were significantly higher than the girls. Intakes of Fe and vitamin A of the boys were significantly lower than the girls. Average daily intakes of TDF of the boys and girls were 11.2 g and 11.1 g, respectively. TDF intake of the children at the 6th grade of elementary school was about $70\%$ of 'age (yr) + 5 g', a recommended level for American children. Major food groups to supply dietary fiber were vegetables, grains, and seasonings among the boys and girls. Major sources of dietary fiber were Kimchi, rice, and red pepper powder which supplied $17.85\%$. $15.71\%$, and $5.18\%$ of TDF among the boys and $18.02\%$, $16.22\%$, and $6.58\%$ among the girls. Daily fiber intake showed significant positive correlations with intakes of grains, vegetables, fruits, legumes, and seasonings among the boys and girls. Daily fiber intake showed significant positive correlations with intakes of energy, carbohydrates, protein, lipids, Ca, P, vitamin A, vitamin $B_1$ vitamin $B_2$, niacin, and vitamin C among both the boys and girls. From the results of this study we could conclude that it is recommended to increase dietary fiber intake in elementary school students at upper level.

• Nutritional Sciences
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• v.5 no.4
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• pp.211-220
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• 2002

Vitamin C is an essential nutrient involved in many functions. Humans are unable to synthesize vitamin C de novo, because they lack the last enzyme in the biosynthetic pathway. Previous Recommended Dietary Allowances (RDAs) for vitamin C were based on prevention of deficiency with a margin of safety. However preventing deficiency may not be equivalent to ideal nutrient intake. Recommendation should be based on vitamin function in relation to concentration. For this goal, data set of the relationship between wide-range of vitamin C dose and resulting concentrations in plasma and tissues and characterization of functional outcomes in relation to these concentrations should be acquired. This article reviews the current knowledge in these areas and suggest how this knowledge may contribute toward establishing dietary guideline for ideal vitamin C intake.