• Journal of Nutrition and Health
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• v.44 no.1
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• pp.82-91
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• 2011

The present study reviewed the effects of excess iodine intake on thyroid function and the incidence of thyroid disease and discussed the scientific basis for establishing a tolerable upper intake level (UL) of iodine for Koreans. ULs are defined as "the highest level of daily nutrient intake that is likely to pose no risk of adverse effects to almost all individuals in the general population." Koreans consume excess iodine from seaweed, and iodine intake is strongly influenced by seaweed consumption. However, no dose-response data derived from subjects consuming excess iodine frequently but not continuously during a lifetime are available. Therefore, the Korean DRI committee set the iodine UL to reduce the risk of adverse health effects by excess iodine intake for Koreans with distinctive seaweed-eating habits.

• Nutritional Sciences
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• v.6 no.1
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• pp.48-52
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• 2003

The Dietary Reference Intakes (DRI's) are new nutrient intake standards that are being set for the United States and Canada. There are currently four types of DRI's: Estimated Average Requirements (EAR), Recommended Dietary Allowances (RDA), Adequate Intakes (AI), and Tolerable Upper Intake Levels (UL). The EAR is the nutrient intake that would be adequate for about half the population, while intake at the RDA should be adequate for 97-98% of the population. When the data are insufficient to set an EAR and RDA, then an AI is set. The UL is the highest intake level that does not pose a risk of adverse effects. The EAR, AI, and UL may be used to assess intakes of both individuals and of groups of people. For individuals, the EAR is used to calculate the probability that intake is inadequate, the AI is used to decide if the probability of inadequacy is low, and the UL is used to determine if a risk of excess intake is present. For groups. the EAR is used to estimate the prevalence of inadequacy, the AI is used to decide if the prevalence of inadequacy is low, and the UL is used to estimate the prevalence of excessive intakes. Because this approach to setting and applying nutrient standards is new, research recommendations include improving estimates of risk, improving dietary data, and improving statistical methods.

• Journal of Nutrition and Health
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• v.39 no.7
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• pp.692-698
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• 2006

The voluntary addition of vitamins and minerals to the appropriate foods may help reduce the risks associated with low intakes of these micronutrients, yet the potential of excessive intake, particularly for persons consuming very large amount of foods needs to be addressed. Using the Flynn's model to estimate the level of each vitamins and minerals that can be added safely to foods, maximum levels of fortification to conventional foods per 100 kcal portion were estimated. Critical factors in the Flynn's model included tolerable upper intake level (UL), each micronutrient intake at the $95^{th}$ percentile, the proportion of fortified foods in the diets of individuals, the proportion of foods to which micronutrients could be practically added, and a range of estimates for fractions of foods which might be actually fortified in each nutrient. Food vehicles included all foods except for fresh foods and alcoholic beverages, in general. With fortification of 50% of all potentially fortifiable foods, micrornutrients could be added safely to foods at levels per 100 kcal 1) > 100% Recommended Intake (RI) for vitamin $B_12$, 2) 1,200% RI for vitamin $B_1$ and niacin, 3) 1,000% $B_1$ for vitamins $B_2$ and $B_6$, 4) 400% RI for vitamin E, 5) 30% RI for calcium, 6) 20% RI for folic acid, iron and zinc, 7) 10% RI for manganese, 8) no fortification for magnesium, phosphorous and vitamin A, and 8) further consideration of vitamin D, copper and selenium due to insufficient evidence. Results of this study suggests a wide range of vitamins and minerals that can be added safely to foods in current diets of Koreans.

• Nutrition Research and Practice
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• v.16 no.sup1
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• pp.47-56
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• 2022

This paper examines the process and evidence used to create the Dietary Reference Intake (DRI) of alpha-linolenic acid (ALA) and eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA) for Koreans. ALA (18:3n3) is an essential fatty acid, and EPA and DHA are known to have beneficial effects on cardiovascular disease risk and reduction of triglyceride levels. Various international organizations have suggested dietary recommendations for n-3 polyunsaturated fatty acids (PUFAs), including ALA, EPA, and DHA. A DRI for Koreans was established for the first time in 2020, specifically for the adequate intake (AI) of ALA and EPA + DHA. This recommendation was based on the average intake of ALA and EPA + DHA from the Korea National Health and Nutrition Examination Survey 2013-2017. For Korean infants, the AI of ALA and DHA was based on the fatty acid composition of maternal milk. Estimated average requirement and a tolerable upper intake level have not been set for n-3 PUFA due to insufficient evidence. In addition, the intake level of n-3 PUFA for prevention of chronic disease has also not been determined. Future studies and randomized controlled trials are required to establish the UL and to define the level for disease prevention.

• Journal of Nutrition and Health
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• v.39 no.8
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• pp.786-794
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• 2006

The purpose of this study was to establish an association between the consumption of ready-to-eat cereal (RTEC), milk, and calcium within the context of the most current population dietary practice in Korea. Inadequate calcium intake among Korean children and adults is one of the important public health concern. Milk is one of the best calcium sources because or its bioavailability, and RTEC is one or the foods commonly consumed with milk. The most recent Korean National Health and Nutrition Survey, 2001 dataset was used as the source of data for this research. Subjects excluding pregnant women, were categorized according to gender and age ($1{\sim}5,\;6{\sim}11,\;12{\sim}19,\;20{\sim}49,\;50+$ years) and then by consumption of RTEC and milk. SAS and SUDAAN were used for statistical analyses. Sample weighted means, standard errors, and population percentages were calculated, and multiple regression model with adjustment for covariates were used to determine the predictability of total daily calcium intake from inclusion of RTEC and milk compared to the meal without RTEC and milk. RTEC was consumed by 2.4% or Korean people. Average calcium intake was 17 times greater when RTEC was consumed with milk than when RTEC was consumed without milk. Respondents who consumed RTEC with milk had significantly higher mean daily calcium and other nutrient intakes than respondents who consumed neither. in the multiple regression analysis, milk consumption with or without RTEC predicted total daily calcium intake after adjusting for age, income, and alcohol consumption (p<0.0001). The percentage of respondents below the estimated average requirement (EAR) level for calcium was lower for RTEC consumers than for RTEC non-consumers in all age-gender groups, especially significant differences were in children aged $1{\sim}5$, boys and girls aged $12{\sim}19$, men aged $20{\sim}49$, and women older than 50 years of age. RTEC consumption was not associated with intake in excess of the tolerable upper intake level (UL) for calcium. In conclusion, RTEC consumption was positively associated with both milk and calcium intakes in all age and gender groups in Korean population.

• Nutrition Research and Practice
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• v.17 no.6
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• pp.1211-1224
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• 2023

BACKGROUND/OBJECTIVES: This study aimed to evaluate the food sources of zinc and the usual intake of dietary zinc among Korean toddlers and preschool children. SUBJECTS/METHODS: A total of 2,679 children aged 1-5 years was selected from the 2009-2013 Korea National Health and Nutrition Examination Survey (KNHANES) data. Dietary data collected from a single 24-h recall were used to evaluate the food sources of zinc. To estimate usual zinc intake, the distribution obtained from single 24-h recall data in the total sample was adjusted using the ratio of within-to-between-person variance in zinc intake obtained from 2-day 24-h recall sub-sample data of the 2009 KNHANES. The proportion of children with usual zinc intake below the estimated average requirement (EAR) and above the tolerable upper intake level (UL) was assessed. RESULTS: The main sources of zinc in Korean children were grains, dairy products, and meat. The mean usual intakes of zinc among all individuals, those aged 1-2 yrs, and those aged 3-5 yrs were 5.50, 5.01, and 5.83 mg/d, respectively. In all participants, 1.1% of the children consumed zinc below the EAR, whereas 10.7% exceeded the UL. The proportion of children with excessive zinc intake was 25.6% in the 1-2 yrs age group and 0.6% in the 3-5 yrs age group. CONCLUSIONS: According to the current UL, the risk of excessive zinc intake appears to be high among Korean toddlers. Future studies that monitor the health effects of excessive zinc intake are needed to appropriately guide zinc intake in children.

• 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 Nutrition and Health
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• v.46 no.5
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• pp.447-460
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• 2013

Dietary supplement use is prevalent and represents an important source of nutrition. This study was conducted in order to assess the dietary maximum exposure of vitamins and minerals from various sources including regular diet, vitamin mineral supplements for non-prescription drug (VMS-NPD), vitamin mineral supplements for health functional foods (VMS-HFF), and fortified foods (FF). A total of 1,407 adolescent boys and girls attending middle or high schools were chosen from various cities and rural communities in Korea. Users of vitamin and mineral supplements (n = 60, 15-18 years of age) were chosen from the above 1,407 students. Intake of vitamins and minerals from a regular diet and FF was assessed by both food record method and direct interview for three days of two weekdays and one weekend, and those from VMS-NPD and VMS-HFF were assessed by both questionnaire and direct interview, and compared with the recommended nutrient intake (RNI) and the tolerable upper intake level (UL) for Korean adolescents. Daily average exposure range of vitamins and minerals from a regular diet was 0.3 to 4.4 times of the RNI. Some subjects had an excessive exposure to the UL in the following areas: from regular diets, vitamin A (1.7%) and niacin (5.0%); from only VMS-NPD, vitamin C (9.1%) and iron (5.6%); and from only VMS-HFF, niacin (8.6%) > vitamin $B_6$ (7.5%) > folic acid (2.9%) > vitamin C (2.3%). Nutrients of daily total intake from regular diet, VMS-NPD, VMS-HFF, and FF higher than the UL included nicotinic acid for 33.3% of subjects, and, then, in order, vitamin C (26.6%) > vitamin A (13.3%), iron (13.3%) > zinc (11.7%) > calcium (5.0%) > vitamin E (1.7%), vitamin $B_6$ (1.7%). Thus, findings of this study showed that subjects may potentially be at risk due to overuse of supplements, even though most of them took enough vitamins and minerals from their regular diet. Therefore, we should encourage adolescents to have sound health care habits through systematic and educational aspects.

• Journal of Nutrition and Health
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• v.42 no.4
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• pp.366-373
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• 2009

Codex Nutrient Reference Values (NRVs) were based on the 1988 Helsinki report and a single set of NRVs was established for the general population over 3 years for the purpose of food labeling in 1993. Dietary Reference Intakes (DRIs) with new concepts were developed in many countries recently. Hence there has been broad discussion regarding establishment of new NRVs using DRIs, which include estimated average requirement (EAR), recommended intake (RI or RDA), adequate intake (AI), and tolerable upper intake level (UL) in the world. This study was carried out to review various possible values for Codex NRVs such as population-weighted EAR, population-weighted RDA, and populationbased RDA. The values were simulated using DRIs and population distribution of Korea, USA, Japan, Philippines, Germany and England, and compared to the current Codex values and the highest RDA and the lowest UL among populations with different life-stage. Since population weighted/based values are necessary to be updated according to the population changes and are different across countries, inconsistency can be a serious barrier in international transactions. For some of nutrients such as vitamin A and zinc, values based on population-based RDA or the highest RDA were higher than the lowest UL. Therefore, careful considerations should be given before establishing Codex NRVs.

• Journal of Nutrition and Health
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• v.46 no.1
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• pp.50-60
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• 2013

The aims of this study were to estimate daily intake of macrominerals from beverages, liquid teas, and liquid coffees and to evaluate their potential health risks for Korean children and adolescents (1-to 19 years old). Assessment of dietary intake was conducted using the actual level of sodium, calcium, phosphorus, potassium, and magnesium in non-alcoholic beverages and (207 beverages, 19 liquid teas, and 24 liquid coffees) the food consumption amount drawn from "The Fourth Korea National Health and Nutrition Examination Survey (2007-2009)". To estimate the dietary intake of non-alcoholic beverages, 6,082 children and adolescents (Scenario I) were compared with 1,704 non-alcoholic beverage consumption subjects among them (Scenario II). Calculation of the estimated daily intake of macrominerals was based on point estimates and probabilistic estimates. The values of probabilistic macromineral intake, which is a Monte-Carlo approach considering probabilistic density functions of variables, were presented using the probabilistic model. The level of safety for macrominerals was evaluated by comparison with population nutrient intake goal (Goal, 2.0 g/day) for sodium, tolerable upper intake level (UL) for calcium (2,500 mg/day) and phosphorus (3,000-3,500 mg/day) set by the Korean Nutrition Society (Dietary Reference Intakes for Koreans, KDRI). For total children and adolescents (Scenario I), mean daily intake of sodium, calcium, phosphorus, potassium, and magnesium estimated by probabilistic estimates using Monte Carlo simulation was, respectively, 7.93, 10.92, 6.73, 23.41, and 1.11, and 95th percentile daily intake of those was, respectively, 28.02, 44.86, 27.43, 98.14, and 3.87 mg/day. For consumers-only (Scenario II), mean daily intake of sodium, calcium, phosphorus, potassium, and magnesium estimated by probabilistic estimates using Monte Carlo simulation was, respectively, 19.10, 25.77, 15.83, 56.56, and 2.86 mg/day, and 95th percentile daily intake of those was, respectively, 62.67, 101.95, 62.09, 227.92, and 8.67 mg/day. For Scenarios I II, sodium, calcium, and phosphorus did not have a mean an 95th percentile intake that met or exceeded the 5% of Goal and UL.