• Journal of Nutrition and Health
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• v.55 no.5
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• pp.523-532
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• 2022

Vitamin C is an important physiological antioxidant which neutralizes reactive oxygen species (ROS) and reduces the oxidative stress in the body. Although it has been associated with various diseases, few studies have reported the dose-response relationship between vitamin C intake, storage and functions in the body, including its antioxidant function. The criteria to establish the Dietary Reference Intakes for Koreans (KDRIs) for vitamin C were based on the changes in plasma concentrations and saturation of leukocytes according to intake levels and the effects on antioxidant capacity and risk of metabolic diseases. When establishing the 2020 vitamin C KDRI, while there was no change in the criteria from those of 2015, the reference values were recalculated and revised to reflect changes such as the new standard weight by age. As the number of people consuming dietary supplements has increased over the last decade, only about 10% of adults consume less than the average total vitamin C, but the proportion of adolescents and elderly who consume less than the average is high. On the other hand, as the intake of vitamin C supplements increases, the proportion of people consuming excessive vitamin C is also increasing. There is a body of opinion that it is necessary to establish a vitamin C KDRI for smokers or people with chronic diseases such as the metabolic syndrome, but these standards have not been established due to the lack of supporting scientific evidence. As a result, studies to establish vitamin C KDRI for Korean smokers and patients with the metabolic syndrome, as well as studies on the excessive intake of vitamin C due to supplementation and interactions with other nutrients, are needed.

• Journal of Nutrition and Health
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• v.55 no.4
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• pp.430-440
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• 2022

Selenium is an important trace mineral that plays an essential role in maintaining the body's immunity with oxidative stress defense and antioxidant activity, immunity, thyroid hormone control, defense against drug or heavy metal harm, and reducing the risk of chronic diseases. A selenium deficiency increases the risk of various chronic diseases, such as cancer, cardiovascular disease, diabetes, neurological disease, osteoarthritis, muscle necrosis and weakness, thyroid disease, and inflammatory diseases. This paper explains the criteria for establishing and revising selenium in the 2020 Dietary Reference Intake for Koreans (KDRIs) and reviews the current status of the selenium database and suggestions for setting the 2025 KDRIs in the future. In the 2020 KDRIs, the selenium intake with the maximum plasma selenoprotein P level was used as the criteria. The weight and coefficient of the variation were applied to the Chinese' reported values. Compared to 2015 KDRIs, there were some revisions in the selenium dietary reference intakes by gender and age according to the change in reference weight. To improve and revise selenium dietary reference intakes in the future, a selenium intervention study is needed to determine the maximum level of plasma selenoprotein P in Koreans. In addition, a revision of the selenium database of the nutritional assessment program (CAN-Pro 5.0) is needed. An analysis of the selenium content of foods should be expanded to assess the selenium intake accurately. In addition, research on the relationship between selenium intake and the biological indicators in the body is required for healthy people and subjects of special environments, such as patients and athletes with various oxidative stress.

• Journal of Nutrition and Health
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• v.53 no.3
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• pp.271-287
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• 2020

Purpose: Variations in the iodine contents of foods is critical for estimating the iodine intake. This study aimed to update the iodine database of common Korean foods and evaluated the iodine intake in Korean adults. Methods: A list of 855 Korean foods was selected for the updated iodine database. The updated database was established with Version 1 and 2 by applying an average or minimum value for the imputed values. The iodine intake was estimated in 5,927 Korean adults using the data from the 2013-2015 Korea National Health and Nutrition Examination Survey. Results: The analytical values in the updated database were 166 (19.4%), followed in order by 318 (37.2%), 247 (28.9%), and 124 (14.5%) for the adapted, imputed, and missing values, respectively. The median of dietary iodine intake was 352.1 ㎍/day (± 2,166.1) and 343.4 ㎍/day (± 2,161.9) in Version 1 and 2 among the total population. The contribution rates of each food group to the iodine intake were 55.7% for seaweeds, which showed a similar trend in Version 2. When subjects were divided by consumption of seaweeds, the median iodine intake was 495.7 ㎍ in the consumer group, which was almost double (241.2 ㎍) that of the non-consumer group. The proportion of subjects who consumed below the Estimated Average Requirement of iodine was 11.0% in the non-consumer group. In contrast, 11.6% in the consumer group of seaweed consumed above the Upper Level of iodine. When the dietary iodine and urinary iodine were examined, the regression coefficient was 0.11718 in Version 1 and 0.11512 in Version 2 after adjusting for age and sex. Conclusion: This study presented the variation of iodine intake in Korean adults by applying different versions of the iodine database. As the iodine intake can vary due to the highly variable concentrations in the major food sources, an iodine database is necessary to be monitored, and caution should be taken when the database is used in research.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.2
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• pp.331-338
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• 2004

Folate nutrition in early pregnancy is crucial in order to prevent neural tube defects (NTDs) in the fetus and maternal folate deficiency in late pregnancy If the influencing factors on maternal folate status are identified we may be able to detect the women at most risk of folate deficiency. This study intends to determine folate intakes, assess the levels of serum folate, erythrocyte folate, and plasma homocysteine, and reveal theinfluencing factors on maternal folate status in early pregnancy. A total of 151 healthy women in their first trimester volunteered for this study. The average length of gestation period was 9.1$\pm$ 2.3 weeks and seventy subjects were primipara. They consumed 1599$\pm$589 ㎉/day of energy and 230.8$\pm$145.2 $\mu\textrm{g}$/day of folate. This represented 72.5％ and 46.2％ of the Korean RDA respectively for pregnant women in the first half of Pregnancy. Results show that they consume less folate and energy due to morning sickness. Morning sickness correlated negatively with the intakes of energy, folate, ana Kimchi also. Their levels of serum folate, erythrocyte folate, and plasma homocysteine were 5.5$\pm$1.9 ng/mL, 266.6$\pm$75.0 ng/mL, and 7.0$\pm$1.8 $\mu$mol/L, respectively. Results indicate that 7.8% were deficient and 60.3% were borderline deficient in serum folate, 4.3% were deficient in erythrocyte folate, however, all had normal levels of plasma homocysteine. Results indicate that the folate status was not poor Contributing factors influencing serum folate concentrations ($R^2$= 0.724, p = 0.0001) were self-reported health status (+), folate intake (+), age (-), length of gestation (-), and homocysteine levels (-). Factors influencing erythrocyte folate concentrations ($R^2$ = 0.570, p = 0.0029) were the infant birth height of the last pregnancy (+), energy intake (+), age (-), plasma homocysteine concentration (-), and education level (-). Factors influencing plasma homocysteine concentrations ($R^2$= 0.450, p = 0.0051) were income level (+), prepregnancy weight (+), serum folate concentration (-), and the infant birth weight of the last pregnancy (-). These results indicate that pregnant women are likely to have a folate deficiency if they are in poor health status, having a history of delivering small infant and low energy and/or folate intake, and/or are older. And folate status is likely to decline as pregnancy progresses.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.3
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• pp.533-541
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• 2004

The purpose of this study was to investigate using of diet therapy materials and the compliance of diet therapy by distribution of body weight in diabetic patients. The percentage of diabetic patients who was distributed by BMI was 18.5% in under weight group, 51.5% in normal weight group, 16.9% in over weight group and 13.1% in obesity group. Of 130 diabetic patients, 62.3% experienced weight loss after the diagnosis. 35.4% of the diabetic patients had ever been in the hospital. 38.5% of the diabetic patients had prevalence of the complications. Knowledge for diet therapy showed low score in over weight and obesity group, specially in the items on the amount of food that I have to consume or the method selecting foods using the food exchange list. Diet therapy practice was also lower in obesity group than the other groups. Most of diabetic patients thought the diet therapy was important and got diet therapy materials through dietitian or doctor. But using of diet therapy materials was 50.0% in under weight group, 41.8% in normal weight group. 22.7% in over weight group and 35.3% in obesity group. Food exchange list was diet therapy item considered as the most difficult for diabetic patients to understand. Diet therapy items considered as the most necessary by diabetic patients were to be attended to choose foods and how to make out menu. This study showed that the diabetic patients were different in using of diet therapy materials or diet therapy practice by distribution of body weight. Therefore it is suggested that the program composed of necessary contents by body weight distribution of diabetic patients need to be developed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.5
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• pp.847-885
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• 2002

The purpose of this study was to develop a web-based internet program for nutritional assessment and diet Prescription by renal diseases. Renal diseases were classified by nephrotic syndrome, renal failure, hemodialysis and peritoneal dialysis. The system consisted of five parts according to their functions and contents. The first part is to assess the general health status such as body weight, obesity index, basal metabolic rate and total energy requirement by the input of age, sex, height, weight and degree of activity. The second part was designed to investigate dietary history of patient, that is, to find out his inappropriate dietary habit and give him some suggestions for appropriate dietary behavior by investigating his dietary history. This part also offers the diet and nutrition management by personal status with renal disease, and the information for food selection, snacks, convenience foods, dine-out, behavioral modification, cooking methods, food exchange lists and terms. The third part is evaluating their energy and nutrients intake by comparing with recommended dietary allowance for Koreans or standardized data for patient with renal disease. In this part, it is also analyzing energy and nutrients of food consumed by food group and meals, and evaluating the status of nutrient intake. The fort]1 one, a major part of the system, is implementing the diet and menu planning by using food exchange lists. This Part Provides the patient with menus lists and I day menu suitable to his weight, activity and the status of renal disease. The fifth part is providing information on energy and nutrients of foods and drinks, and top 20 foods classified by nutrients. These results are finally displayed as tabular forms and graphical forms on the computer screen.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.8 no.3
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• pp.251-261
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• 2003

As a part of an on-going project investigating flux of materials in Gomso Tidal Flat, we have monitored temporal and spatial distribution of nitrogen components(TN, PON, DON, DIN) and have sought the relationships with the freshwater input(tidal range, salinity), the biological activities(chlorophyll-${\alpha}$, TP, DIP, silicate) and the resuspended bottom sediment in seawater(SPM) from 1999 to 2000. TN in seawater was 39.05 $\mu\textrm{m}$ol 1$\^$-1/ (31.03∼42.93 $\mu\textrm{m}$ol 1$\^$-1/) without any statistical difference(p<0.05) between the studied periods. Organic nitrogen (DON and PON) occupied 75％, 95％, 73％, and 75％ in April, August, September and November, respectively. DON and PON have been found within the narrow concentration ranges of 11.30∼16.38 $\mu\textrm{m}$ol 1$\^$-1/ and 13.16∼20.04 $\mu\textrm{m}$ol 1$\^$-1/ in spite of severe environmental differences through the studied periods. Dissolved fractions of nitrogen(DON and DIN) occupied 53∼65％ of TN. Only DIN varied with an evident temporal variability: low concentrations(1.325∼1.616 $\mu\textrm{m}$ol 1$\^$-1/) in August and high enrichment(8.377∼14.65 $\mu\textrm{m}$ol 1$\^$-1/) in September. High consumption rate of DIN by phytoplankton and a long-lasted drought probably induced such low concentration of DIN in August. Eventually heavy precipitation probably introduced plenty of new nitrogen sources into Gomso Bay in September. The portion of PON, DON and DIN in the total nitrogen was 40％, 38％ and 22％, respectively. Their contents were in the order of DON>PON>DIN for the year round except PON>DON>DIN only in September. The highest DON portion in August probably due to the active microbial decomposition of organic material in summer. Only in April, some evident negative correlations have been found between chlorophyll-${\alpha}$ and DIN mostly nitrate(-0.64, p<0.01), phosphate(-0.46, p<0.01) and silicate(-0.55, p<0.01). The Si(OH)$_4$/DIN/DIP ratios in the water column suggests the limitation of DIN for the growth of phytoplankton during the dry summer in Gomso Bay, which was the case of August in this work. Even with some difference between the studied periods, the primary factors on the distribution of nitrogen components in seawater overlying the Gomso Tidal Flat have been the tidal range and the freshwater input, but the additional variations were due to the biological activities.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.3
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• pp.119-126
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• 2005

Soil erosion at Jawoon-Ri in Hongcheon highland is one of serious problems since saprolite piling on farmland has been typically practiced at 2-3 year's intervals. The objective of the case study was to survey management practices such as tillage, application of saprolite, and cultivating crops and to propose best management practices (BMP) to reduce soil loss in Jawoon-Ri, Hongcheon-Gun. Jawoon-Ri is located in the upper stream of Naerinchun. Upland areas of Jawoon 2 and 4Ri were 206.9 and 142.3 hectare, respectively. Estimation of soil loss in this study was based on USLE (Universal soil loss equation). Annual averaged soil losses were 15.6 MT per hectare in Jawoon-2Ri and 9.0 MT per hectare in Jawoon-4Ri, respectively. This case study tried to find methods to reduce soil erosion below tolerant soil loss level which is $11MT\;ha^{-1}\;yr^{-1}$. Estimated soil losses in more than 40% of uplands in Jawoon-2Ri and 4Ri were higher than tolerant soil loss level. Especially, edge of uplands undergone excessive soil erosion by concentrated runoff water. Therefore consolidation of upland edge was included as one of the proposed Best management practices BMP). The proposed BMP in this area were buffer strips, contour and mulching, diversion drain channel, grassed water-way, detour watet-way and cover crops and so on. Amounts for BMP requirements were 7,680 m for buffer strips, 123 ha (35%) for contour and mulching, 201 ha (57%) for diversion drain channel, 13,880 m for grassed water-way, 3,860 m for detour drainage, 8,365 m for sloping side consolidation and 3,492 ha for cover crops, respectively. Application of BMP are urgently needed in uplands which is direct conjunction with stream.

• Journal of Nutrition and Health
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• v.53 no.1
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• pp.27-38
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• 2020

Purpose: This study assessed the food intake and nutritional status of the elderly in long-term care facilities in order to provide adequate food services and improve the nutritional status. Methods: The survey was carried out from August 2019 to October 2019 for the elderly in long-term care facilities located in Gwangju Metropolitan City. The survey was conducted to collect data from 199 elderly persons (34 males and 165 females) aged over 65 years old. The food intake was assessed using a 1-day 24-hour recall method. Results: More than 90% of the subjects were over 75 years old. Forty five percent of the subjects were active, 44.2% of the subjects perceived themselves as not being healthy. Dementia and Parkinson's disease were the most common diseases, followed by hypertension, musculo-skeletal disease, diabetes, and stroke. Only 25.6% of the subjects had most of their teeth intact, and 44.7% of the subjects had difficulty in chewing and swallowing. The total food intake was 1,127 g in males and 1,078 g in females. The most frequently consumed foods were kimchi, cooked rice with multi-grains, soybean soup, cooked rice with white rice, yogurt, pumpkin porridge, soy milk, and duck soup. The average energy intake of the subjects was 1,564.9 kcal in males and 1,535.5 kcal in females. The overall nutritional status of the elderly in the long-term care facilities was poor. In particular, the intake of vitamin D and calcium, vitamin C, riboflavin, and potassium were very low. The intake of vitamin D was 5 ㎍, and 86.4% of the elderly were below the estimated average requirement, while the intake of sodium was high. Conclusion: The results of this study can be used to understand the health and nutritional status and to improve the food services and nutrition management for the elderly in longterm care facilities.

• Journal of Nutrition and Health
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• v.49 no.5
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• pp.358-366
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• 2016

Purpose: This study was conducted to assess the nutritional status of female marriage immigrants attending Korean language class in Gwangju, Korea by analyzing daily food and nutrient intake. Methods: Eighty-three female immigrants completed a survey. Anthropometric measurements were obtained, and dietary food intake was assessed using a 1-day 24 hour recall method. Results: The average length of residence in Korea was 5.3 years, and mean age of subjects was 31.0 years old. The home countries of subjects were Vietnam (50.6%), China (24.1%), Philippines (13.3%), and others (12%). Due to the length of residence, there were significant differences in body weight (p < 0.05), BMI (p < 0.05), percent body fat (p < 0.05), and diastolic blood pressure (p < 0.05). The subjects who were 30~49 years old consumed more vegetables and less seaweed than the subjects who were 20~29 years old. The other kinds of consumed foods were similar among groups in different age groups or lengths of residence in Korea. Average energy intake of subjects was 1,641.0 Kcal. The group with less than 5 years of residence showed higher cholesterol intake than the group with 5 or more years of residence in Korea (p < 0.05). There was no significant difference in nutrient intake between the groups of different age or length of residence. There was a positive association among dietary cholesterol intake and consumption of eggs, milk. and dairy products, and blood pressure. Conclusion: The study shows that length of residence affects rate of obesity and nutritional status. Further extensive research is needed to understand the effect of dietary changes and nutritional status of female marriage immigrants as well as for their successful adaptation to develop a more active and long-term nutrition education program.