• Nutrition Research and Practice
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• v.16 no.sup1
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• pp.126-133
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• 2022

Choline is a water-soluble organic compound that is important for the normal functioning of the body. It is an essential dietary component as de novo synthesis by the human body is insufficient. Since the United States set the Adequate Intakes (AIs) for total choline as dietary reference values in 1998, Australia, China, and the European Union have also established the choline AIs. Although choline is clearly essential to life, the 2020 Dietary Reference Intakes for Koreans (KDRIs) has not established the values because very few studies have been done on choline intake in Koreans. Since choline intake levels differ by race and country, human studies on Koreans are essential to set KDRIs. Therefore, the present study was undertaken to provide basic data for developing choline KDRIs in the future by analyzing data on choline intake in Koreans to date and reference values of choline intake and dietary choline intake status by country and race.

• Nutrition Research and Practice
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• v.12 no.6
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• pp.459-468
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• 2018

BACKGROUND/OBJECTIVES: The Dietary Reference Intakes for Koreans (KDRIs), a set of reference intake values, have served as a basis for guiding a balanced diet that promotes health and prevents disease in the general Korean population. In the process of developing DRIs, a systematic review has played an important role in helping the DRI committees make evidence-based and transparent decisions for updating the next DRIs. Thus, the 2015 KDRI steering committee applied the systematic review framework to the revision process of the KDRIs. The purpose of this article is to summarize the revision process for the 2015 KDRIs by focusing on the systematic review framework. MATERIALS/METHODS: The methods used to develop the systematic review framework for 2015 KDRIs followed the Agency for Healthcare Research and Quality and the Tufts Evidence-based Practice Center. The framework for systematic review of the 2015 KDRIs comprised of the 3 following steps: (1) development of an analytic framework and refinement of key questions and search terms; (2) literature search and data extraction; and, (3) appraisal of the literature and summarizing the results. RESULTS: A total of 203,237 studies were retrieved through the above procedure, with 2,324 of these studies included in the analysis. General information, main results, comments of reviewers, and results of quality assessment were extracted and organized by study design. The average points of quality appraisals were 3.0 (range, 0-5) points for intervention, 6.1 (0-9) points for cohort, 6.0 (3-9) points for nested case-control, 5.4 (1-8) points for case-control, 14.6 (0-22) points for cross-sectional studies, and 7.0 (0-11) points for reviews. CONCLUSIONS: Systematic review helped to establish the 2015 KDRIs as a useful tool for evidence-based approach. Collaborative efforts to improve the framework for systematic review should be continued for future KDRIs.

• Journal of Nutrition and Health
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• v.55 no.4
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• pp.441-449
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• 2022

This review is focused on analyzing the limits and shortage of zinc (Zn) for the 2020 Dietary Reference Intakes for Koreans (KDRIs), and provides suggestions for the future establishment of the 2025 KDRIs for Zn. The 2020 KDRIs for Zn have been established to estimate the adequate requirement (EAR), recommended nutrient intakes (RNI), adequate intake (for only 0-5 mon) and tolerable upper intake level (UL). EAR was estimated in 2-stages: the first stage was to construct of the frame of analysis for Zn requirement and the second stage involved a factorial approach by considering the various factors which affect Zn requirement, such as intestinal and urine Zn loss, Zn requirement for growth and development, and Zn absorption rate. For a more precise and accurate establishment of the Zn requirement, we suggest for the following to be considered: 1) considering that Zn is present in minuscule amounts as a trace element in our body, the present values for Zn EAR (as 6-9 mg/d) should be expressed as a decimal point for more accurate DRIs; 2) the frame of analysis for Zn requirement has to be more specifically and should includes the factors which affect Zn requirement; 3) both, the factorial approach and extrapolation method need to be well reviewed and thoroughly understood for establishing precise Zn requirement; 4) currently, human clinical study and balance study (Zn intake, excretion and absorption rate) are limited and more human Zn subject studies are required. All these suggestions are provided to better establish the Zn requirement in the 2025 KDRIs.

• Nutrition Research and Practice
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• v.16 no.sup1
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• pp.89-112
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• 2022

An accurate assessment of the recommended calcium (Ca) intake may contribute to reducing the risk of fractures and chronic diseases, ultimately improving quality of life. This review was performed to summarize key findings of Ca studies, investigate the effect of Ca intake on health outcomes, and determine the adequacy of evidence to revise the 2015 Dietary Reference Intakes for Koreans (KDRIs) for Ca in 2020. Databases were searched for intervention studies that assessed health outcomes by providing Ca in diets or as supplements. The framework of the systematic review comprised conducting literature searches, data extraction, quality assessment of the literature, and summarizing key findings relevant to set the Estimated Average Requirement (EAR) and Tolerable Upper Intake Level (UL) for Ca for the 2020 KDRI. The final search was performed in June 2019. A total of 13,309 studies were identified through databases and manual search. Sixtyfive studies were included in the final quality assessment and were summarized according to health indicators. As bone health was used as an indicator of the EAR for Ca, literature reports on bone health were further categorized by the life-cycle stage of the participants. This systematic review did not find new evidence that could be applied to the general Korean adult population, including postmenopausal women, for defining a new EAR for Ca in the 2020 KDRIs. Evidence in most of the reviewed literature was considered weak; however, some evidence was found that could improve the criteria on how the EAR for Ca was determined in children and adolescents. A review of the literature for the 2020 KDRIs for Ca did not find strong evidence in order to change the recommended values of the 2015 KDRIs. More clinical interventions are required among Koreans to strengthen the body of evidence to warrant the revision of the KDRIs.

• Journal of the East Asian Society of Dietary Life
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• v.17 no.4
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• pp.483-489
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• 2007

This study was performed to investigate dietary habits, and to evaluate the relationship between nutritional status and certain blood parameters in premenopausal and postmenopausal women living in Daejeon. Adult Korean females(n=110) that had visited the Health Promotion Center of Eulji University Hospital were analyzed. We examined blood parameters, body composition, and life style factors such as food habits and physical activity in pre- and post-menopausal women. The collected data were then analyzed to evaluate the various items. Overall, there were no differences between the pre- and post-menopausal women for food habit score, or for intakes of energy, protein, Int, iron, vitamin A, vitamin $B_1$, vitamin $B_2$, niacin, vitamin C, and calcium. However, carbohydrate intake was significantly higher in the postmenopausal women than in the premenopausal women. The Dietary Reference Intakes for Koreans(KDRIs), in terms of energy, fat, calcium, vitamin A and vitamin $B_1$, were less than 100% in both the premenopausal women and postmenopausal women. All intakes of protein, iron, vitamin $B_2$, niacin, and vitamin C satisfied the KDRIs in both groups. Finally, the postmenopausal women had higher serum fasting blood glucose, total cholesterol, LDL-cholesterol and alkaline phosphatase levels than the premenopausal women.

• Nutrition Research and Practice
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• v.16 no.sup1
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• pp.70-88
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• 2022

Sodium is a physiologically essential nutrient, but excessive intake is linked to the increased risk of various chronic diseases, particularly cardiovascular. It is, therefore, necessary to accomplish an evidence-based approach and establish the Korean Dietary Reference Intakes (KDRIs) index, to identify both the nutritional adequacy and health effects of sodium. This review presents the rationale for and the process of revising the KDRIs for sodium and, more importantly, establishing the sodium Chronic Disease Risk Reduction Intake (CDRR) level, which is a new specific set of values for chronic disease risk reduction. To establish the 2020 KDRIs for dietary sodium, the committee conducted a systematic literature review of the intake-response relationships between the selected indicators for sodium levels and human chronic diseases. In this review, 43 studies published from January 2014 to December 2018, using databases of PubMed and Web of Science, were finally included for evaluating the risk of bias and strength of evidence (SoE). We determined that SoE of the relationship between dietary sodium and cardiovascular diseases, cerebrovascular disease, and hypertension, was moderate to strong. However, due to insufficient scientific evidence, we were unable to establish the estimated average requirement and the recommended nutrient intake for dietary sodium. Therefore, the adequate intake of sodium for adults was established to be 1,500 mg/day, whereas the CDRR for dietary sodium was established at 2,300 mg/day for adults. Intake goal for dietary sodium established in the 2015 KDRIs instead of the tolerable upper intake level was not presented in the 2020 KDRIs. For the next revision of the KDRIs, there is a requirement to pursue further studies on nutritional adequacy and toxicity of dietary sodium, and their associations with chronic disease endpoint in the Korean population.

• Journal of Nutrition and Health
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• v.55 no.4
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• pp.419-429
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• 2022

Water accounts for the largest proportion of body weight and is an essential element for the physiological functioning of the human body. According to 2013-2017 Korea National Health and Nutrition Examination Survey (KNHANES) data, the average water intake of Koreans was 2,167.3 mL/day and 62% of them did not meet the Dietary Reference Intakes for Koreans (KDRIs) for water. However, the consumption of beverages is continuously increasing. KDRIs sets the adequate intake (AI) for water, but tolerable upper intake level (UL) and chronic disease risk reduction intake (CDRR) are not provided. Compared to 2015, the AI of total water from both food and fluids in the 2020 KDRIs slightly increased or decreased according to age. The AI for children 1-2 years old, boys 6-8 years and 9-11 years old, and girls 6-8 years old decreased by 100 mL/day, while that of boys 12-14 years old increased by 100 mL/day. The AI of total water was the sum of the water intake from food and fluids reported by the KNHANES, with an extra milk intake of 200 mL/day. Therefore, it is not appropriate to use the AI of total water intakes for the reference of beverage intakes. It is preferable to consume water or milk rather than beverages containing sugar and others including caffeine, sodium, etc. when drinking fluid water. We suggest the following improvements in the future KDRIs for water: improving the adequacy of the water content ratio of Korean conventional foods, supplementing the fluid water intake survey, reflecting the current water intake status by life cycle, setting KDRIs for water for the elderly considering the physiological changes, health status and dietary habits, and promotion of research on the relationship between water intake and health for Koreans.

• 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.

• Nutrition Research and Practice
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• v.13 no.1
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• pp.32-40
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• 2019

BACKGOUND/OBJECTIVES: This study investigated nutritional status of the elderly with dementia in a care facility with the aim of improving the meal quality of the facility. SUBJECTS/METHODS: Data were collected from 30 dementia patients aged more than 65 years in a long-term care facility in Hongseong. The data were obtained from questionnaires and medical records. The food intake data was obtained using food photographs and the nutrient intakes were calculated using the CAN-Pro 5.0. The data were compared with the dietary reference intakes for Koreans (KDRIs). The nutrient density, diet quality such as nutrient adequacy ratio (NAR), mean adequacy ratio (MAR), and index of nutritional quality (INQ), as well as dietary diversity score (DDS) were evaluated. The data were analyzed using SPSS statistical programs. RESULTS: The average daily energy intakes for men and women were much lower than the estimated energy requirements of the KDRIs. The average intakes of energy and most nutrients in the general diet group were significantly higher than those of the other two groups. Significant differences in diet quality and diet diversity were observed according to the meal type groups. The NARs of some minerals (calcium, iron, and zinc) and vitamins (vitamin $B_6$ and folic acid) were less than 0.5 in all study groups. The NARs of protein, iron and MAR of the general diet group were significantly higher than those of the liquid diet group. The DDS scores of meats, fruits and diary food group were very low in all meal type groups, meaning that the diet qualities of the study subjects were not appropriate in all meal type groups. CONCLUSIONS: The food intakes of the study groups showed some limitations by a direct comparison with KDRIs because of the very low physical activities of the study subjects. The diet quality and diet diversity indices suggest the need for improvements in the nutritional quality in all types of diet. Overall, new intervention strategies targeting facility residents with dementia in Korea are needed as soon as possible.

• Nutrition Research and Practice
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• v.16 no.sup1
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• pp.113-125
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• 2022

In the current years, it has now become necessary to establish standards for micronutrient intake based on scientific evidence. This review discusses issues related to the development of the 2020 Dietary Reference Intakes for Koreans (KDRI) for magnesium (Mg), zinc (Zn), and copper (Cu), and future research directions. Following issues were encountered when establishing the KDRI for these minerals. First, characteristics of Korean subjects need to be applied to estimate nutrient requirements. When calculating the estimated average requirement (EAR), the KDRI used the results of balance studies for Mg absorption and factorial analysis for Zn, which is defined as the minimum amount to offset endogenous losses for Zn and Mg. For Cu, a combination of indicators, such as depletion/repletion studies, were applied, wherein all reference values were based on data obtained from other countries. Second, there was a limitation in that it was difficult to determine whether reference values of Mg, Zn, and Cu intakes in the 2020 KDRI were achievable. This might be due to the lack of representative previous studies on intakes of these nutrients, and an insufficient database for Mg, Zn, and Cu contents in foods. This lack of database for mineral content in food poses a problem when evaluating the appropriateness of intake. Third, data was insufficient to assess the adequacy of Mg, Zn, and Cu intakes from supplements when calculating reference values, considering the rise in both demand and intake of mineral supplements. Mg is more likely to be consumed as a multi-nutrient supplement in combination with other minerals than as a single supplement. Moreover, Zn-Cu interactions in the body need to be considered when determining the reference intake values of Zn and Cu. It is recommended to discuss these issues present in the 2020 KDRI development for Mg, Zn, and Cu intakes in a systematic way, and to find relevant solutions.