The nutrition contribution of dietary supplements on total nutrient intake in children and adolescents.

BACKGROUND/OBJECTIVES: The use of dietary supplements (DSs) by children and adolescents is increasing. The aim of this study was to identify the characteristics of DS users and examine the nutritional contributions of DSs to total nutrient intakes in children and adolescents, using data obtained from a national survey. SUBJECTS/METHODS: In total, 3134 subjects aged 9-18 years who participated in the 4th Korea National Health and Nutrition Examination Survey (2007-2009) were selected; the survey included 24-h recall questions on food intake and questions on DS use over the past year. Nutrient intakes from DSs were calculated using the aid of a label-based database on such supplements, and individual total nutrient intakes were derived by combining information on the foods and DSs consumed by each subject. RESULTS: There were 895 DS users (28.5%), 85.2% of whom (n=577) had complete DS nutrient information and were therefore defined as identified-DS users. Identified-DS users were slightly younger and had a greater household income and better nutritional knowledge than did non-users. The most frequently consumed type of supplement was a 'multivitamin and minerals' complex. For total nutrient intake, identified-DS users had a significantly higher intake of most of the nutrients, except for macronutrient and sodium than non-users. In all identified-DS users, the contribution of vitamins and minerals from DSs to total nutrient intake was higher than energy and macronutrients. CONCLUSIONS: DS use by children and adolescents can improve micronutrient status, but it also increases the risk of excessive intake of certain vitamins and minerals.

Dietary supplement use and its effect on nutrient intake in Korean adult population in the Korea National Health and Nutrition Examination Survey IV (2007-2009) data.

BACKGROUND/OBJECTIVES: Although there is an increasing trend of dietary supplement (DS) use, few researches have evaluated nutrient intake from DS. This study aimed to establish a nutrient database (NDB) for DS and estimate the effect of DS on total nutrient intake by Korean adults. SUBJECTS/METHODS: The NDB for DS was established using the label information of products reported in the Korea National Health and Nutrition Examination Survey (KNHANES) IV. Of the 16,031 participants who were ≥20 years old, 2053 products were reported as being taken by 5606 subjects. But nutrient composition could be identified by searching product name only in 1158 products consumed by 3844 subjects (DS users). Total nutrient intake of DS users was obtained by combining intakes from diet and DS. RESULTS: Dietary supplement use was higher in women, in middle-aged people and in those with higher education and low smoking and drinking preferences. Nutrients obtained from food were higher in DS users than in nonusers for most nutrients, particularly in women. When total nutrient intake was evaluated in DS users, the percentage of subjects whose intake was below the estimated average requirement for Koreans decreased for several vitamins and minerals, but the percentage of subjects whose intake was above the tolerable upper intake levels increased for vitamin A, vitamin C and iron. CONCLUSIONS: The newly developed NDB for DS will be an important resource for more accurate assessment of nutrient intake as well as evaluation of the relationship between nutrition and health. Further research is needed to update a more comprehensive NDB applicable to diverse populations.

Secular trends in dietary patterns and obesity-related risk factors in Korean adolescents aged 10-19 years.

BACKGROUND: Along with its rapid economic growth, Korea has been undergoing considerable changes in the diet. But the influence of these changes on nutrition and health profiles has scarcely been investigated. OBJECTIVE: We explored secular trends in dietary patterns to clarify their influence on obesity and its related risk factors among Korean adolescents using data from three consecutive Korean Nutrition Health and Nutrition Examination Survey (KNHANES). DESIGN: Using data from the three KNHANES, 4347 adolescents (1572 from 1998, 1484 from 2001, and 1291 from 2005), who completed a 24-h diet recall, were included in the analysis. Percentiles of BMI were used to determine obesity; abdominal obesity was identified by waist circumference; and serum triglycerides and HDL-cholesterol = high density lipoproteins (HDL)-cholesterol were measured for obesity-related risk factors. RESULTS: We identified evident three dietary patterns: 'traditional' (45.8% of total population), 'modified' (19%), and 'western' (35.2%). Secular trends were observed in dietary patterns, with a decline in the traditional diet pattern and gradual increases in the modified and western patterns. The percent of energy from fat increased over time, and it was positively associated with abdominal obesity in boys. The western dietary pattern increased the risk of being overweight (P = 0.05) and having elevated serum triglycerides (P = 0.07) in boys. CONCLUSIONS: Gradual changes over time in dietary patterns are occurring in Korean adolescents. The emerging western dietary pattern and high-fat intake could negatively affect the adolescent population studied here in later life; therefore, appropriate monitoring is suggested.

Serum extracellular superoxide dismutase activity as an indicator of zinc status in humans.

The present study focused on whether serum extracellular superoxide dimutase (EC-SOD) activity can be used as a functional indicator of marginal zinc deficiency in humans. Subjects in this study were 444 healthy adults over 30 yr of age living a normal rural life in Kyunggi province, Korea. The mean dietary zinc intake of subjects obtained from one 24-h recall was 6.41 +/- 4.35 mg and the average serum zinc concentration of the subjects was 11.06 +/- 2.44 micromol/L. Subjects were divided into three groups by serum zinc concentrations: adequate (serum zinc >10.7 micromol/L), low (serum zinc 9.0-10.7 micromol/L), and very low (serum zinc <9.0 micromol/L) groups. A total of 50 subjects were selected from the three groups for analysis of EC-SOD activities. The EC-SOD activity of subjects increased with increasing serum zinc concentrations, and the activities of the three groups were significantly different as indicated by the Kruskal-Wallis test (p = 0.0239). Also, serum EC-SOD activities were significantly correlated with serum zinc concentrations (r = 0.289, p = 0.04). Serum EC-SOD activities, however, were not significantly correlated to the dietary zinc intakes. In conclusion, these results show that EC-SOD activities are decreased in subjects with low serum zinc concentrations and suggest that EC-SOD activity may be a functional indicator of zinc nutritional status in humans.

Dietary habits, food intake and functional outcomes in those with a history of Hansen's disease in Korea.

This study shows that the nutrition and health status of ex-leprosy patients in Korea was marginal. Their nutrient intakes were low, especially from micronutrients which were associated with food from animal sources. Dietary quality was discriminated by food habits, such as skipping meals, irregularity of meals, food purchase and meal preparation. Dietary quality was best predicted by food habits followed by physical fitness and nutrition knowledge. Our subjects were nutrition-conscious, but they did not have accurate information. These findings suggest that our study population needs nutrition education.

Risk factors for the development of NIDDM in Yonchon County, Korea.

OBJECTIVE: To determine the risk factors for the development of NIDDM in Yonchon County of Korea. RESEARCH DESIGN AND METHODS: We studied 1,193 Korean nondiabetic subjects at baseline who participated in a 2-year follow-up study on diabetes in Yonchon County. A 75-g oral glucose tolerance test was performed 2 years after the baseline examination. Age, sex, and anthropometric and metabolic characteristics at baseline were analyzed simultaneously as potential predictors of conversion to NIDDM. We also designed a nested case-control study to determine the role of hyperinsulinemia and/or hyperproinsulinemia in the conversion to NIDDM in patients with newly developed diabetes and control subjects matched for age, sex, BMI, and waist-to-hip-ratio. RESULTS: At 2 years, 67 subjects developed diabetes, as defined by World Health Organization criteria. The age-adjusted incidence was significantly higher in men (6.4%) than in women (3.0%), and the incidence increased as age increased in both sexes. Multiple logistic regression analysis revealed age, male sex, and fasting and 2-h glucose levels to be significant risk factors for the development of NIDDM, whereas waist-to-hip ratio and BMI were not. In a nested case-control study, baseline proinsulin but not insulin levels were significantly higher in subjects who progressed to NIDDM than in those who did not. CONCLUSIONS: In the Korean population, beta-cell dysfunction, as measured by high proinsulin levels, seems to be associated with subsequent development of NIDDM, whereas regional and general obesity and fasting insulin levels, which may be a surrogate for insulin resistance, were not.

A high-risk group for prostatism: a population-based epidemiological study in Korea.

OBJECTIVE: To evaluate the effect of sociodemographic, dietary and physical factors on prostatism in Korean men aged 50 and over. SUBJECTS AND METHODS: A community-based cross-sectional epidemiological study was performed in Yonchon County, Korea. The Korean version of the International Prostate Symptom Score (IPSS) was used to assess the severity of prostatism. Data on occupation, marital status, education, smoking habits, alcohol intake, daily consumption of nutrients, body mass index, abdominal circumference, waist-to-hip ratio, blood pressure, serum glucose, cholesterol, triglyceride and high-density lipoprotein (HDL) levels were analysed. The age-adjusted relative risk of these factors was calculated for moderate to severe prostatism (IPSS > or = 8). A multivariate analysis of all significant factors was performed to examine the joint effect of risk factors. RESULTS: Of 514 subjects, 119 (23.2%) had moderate to severe prostatism, the risk for which was related to age and alcohol consumption; waist-to-hip ratio (which represents the degree of abdominal obesity) and the serum level of HDL showed a biphasic association with prostatism in the multivariate analysis. CONCLUSION: In addition to previously reported risk factors, these data suggest that there might be an association between the development of prostatism and abnormal lipid metabolism.

Comparative analysis of growth, diet, and urinary N excretion in elementary school children from urban and rural areas of Korea.

Weight and height measurements, dietary intake records and overnight urine samples for two days were collected from 38 children in Seoul and 36 children in rural area of Korea. Median percentages of height-for-age, weight-for-age and weight-for-height of the children in Seoul were significantly higher than those of the rural children. A mild degree of stunting was prevalent in the rural area, while overweight was more dominant among the children in Seoul. Dietary intake of energy, protein and fat as well as urinary excretions of N and creatine were also higher in the Seoul children. Animal protein intake correlated most significantly with height-for-age. Fat intake was a more important factor for weight-for-age and weight-for-height. Urinary excretion of N or creatinine, together with dietary factors, was a significant independent variable in regression models for the growth indices of the children. The results show the heterogeneity of nutritional problems among different subgroups of the Korean population at the present time.

Effects of several simple sugars on serum glucose and serum fructose levels in normal and diabetic subjects.

Fructose has a reaction constant 7.5 times as high as that of glucose in its nonenzymatic reaction with protein in vitro. The effects of glucose, sucrose and fructose ingestion on serum fructose and glucose levels were studied to evaluate the overall biohazard, i.e., the probability of their altering proteins while circulating in the blood. Normal and diabetic subjects were given either 75 g glucose, 75 g fructose, 75 g sucrose, or 112.5 g fructose after fasting, and their serum levels of sugars were measured at 0, 1, 2 and 3 h. In normal subjects, fructose ingestion produced significantly lower serum glucose levels and significantly higher serum fructose levels than did glucose ingestion, while sucrose produced intermediate results. The glycemic effect was found to be lowest for fructose and highest for glucose. The calculated overall biohazard was, however, highest for fructose and lowest for glucose in normal subjects. Furthermore, the serum fructosemic index was directly proportional to the amount of fructose ingested. In diabetic subjects, blood fructose clearance was significantly more delayed than in the controls when the same amount of fructose was ingested. These results suggest that an evaluation of the effects of simple in the diabetic diet requires a closer examination of the overall biological effects of the sugars.