• Nutrition Research and Practice
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• v.12 no.1
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• pp.47-51
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• 2018

BACKGROUND/OBJECTTIVES: The purposes of the study were to investigate folate intakes and plasma folate concentrations as well as estimate folate status in Korean healthy adults. SUBJECTS/METHODS: A total of 254 healthy 19- to 64-year-old adults (68 men and 186 women) living in Seoul metropolitan area, Gumi, and Kwangju, Korea participated. Three consecutive 24-hour dietary recalls, information on folate supplementation, and fasting blood samples were collected from the subjects. RESULTS: The mean dietary folate intakes were 587.4 and $499.2{\mu}g$ dietary folate equivalent (DFE)/day for men and women, respectively. The median dietary intakes of men and women were 566.6 and $474.6{\mu}g\;DFE/day$, respectively. Forty subjects (16.7% of total) less total folate than the estimated average requirement (EAR). Folate intakes of 23.3% of men and 34.8% of women aged 19-29 years did not meet the EAR for folate. Major food sources consumed for dietary folate were baechukimchi (Chinese cabbage kimchi), rice, spinach, eggs, and laver, which provided 44% of dietary folate intake for the subjects. Plasma folate concentrations were 23.4 nmol/L for men and 28.3 nmol/L for women, and this level was significantly lower in men than in women. Approximately 13% of men and 3% of women were folate-deficient, and the percentages of subjects showing folate concentrations lower than 10 nmol/L were 27.9% of men and 6.4% of women. CONCLUSIONS: Folate intakes of Korean adults in this study were generally adequate. However, one-third of young adults had inadequate folate intakes.

• Journal of Nutrition and Health
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• v.33 no.8
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• pp.840-847
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• 2000

This study was out to evaluate the folate nutritional status of Korean pregnant women and to investigate the relationship between serum folate levels of maternal-umbilical cord blood and pregnancy outcomes. Folate intakes of the pregnants was estimated by dietary folate intakes obtained from semiquantitative frequency questionnaire and supplementary folate intakes. The serum folate levels in both maternal blood and umbilical cord of 29 pregnant women at delivery and 13 nonpregnant controls were measured by redioimmunoassay. The total folate intakes(dietary and supplementary)of the pregnant women was 465. 4$\mu\textrm{g}$/d which was 93% of the Korean RDA for folate. Maternal mean serum folate levels of the pregnants was 6.1$\mu\textrm{g}$/ml, significantly lower than that of nonpregnant women(8.9ng/ml). Mean serumfolate level of umbilical cord blood was 14.2ng/ml, which was 2.3 folds higher than that of maternal blood. This finding indicates that the uptake of folate in the fetus may be due to an active placental transport mechanism. Maternal serum folate level correlated positively with that of umbilical cord blood, showing that folate concentration of umbilical cord blood is affected by maternal status. There was no significant correlation between the serum folate levels in maternal-umbilical cord blood and the pregnancy outcomes.(Korean J Nutrition 33(8) : 840-847, 2000)

• Nutrition Research and Practice
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• v.1 no.2
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• pp.120-125
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• 2007

Folate is important for multiple metabolic processes such as nucleic acid synthesis and interconversions, and cell division. Folate deficiency may be a risk factor for several pathologies, such as neural tube birth defects, dementia, and cardiovascular diseases. The objectives of this study were to estimate folate intakes and plasma concentrations of young children living in Kwangju, Korea. Three consecutive 24-h food recalls and fasting blood samples were obtained from 24 boys and 30 girls, aged 2-6 y, living in Kwangju, Korea. The daily folate intake ($mean{\pm}SD$) of the children was $146.7{\pm}73.6{\mu}g$ dietary folate equivalents. No differences in folate intakes were observed by gender ($p{\geq}0.05$). The mean folate intakes of the 2 and 3 y old groups were significantly lower (p<0.05) than those of 5 and 6 y old groups. Over half of subjects consumed $mean{\pm}SD$) of all subjects was $19.2{\pm}8.7nmol/L$, and there was no significant difference by age nor gender ($p{\geq}0.05$). No significant correlation was observed between folate intakes and plasma folate concentrations. One subjeci (1.9%) in this study had a plasma folate concentration <6.8 nmol/L, which is indicative of folate deficiency. Approximately 24% of subjects had plasma folate concentrations of 6.8-13.4 nmol/L, which is representative of marginal folate status. In conclusion, some young children may have less than adequate folate status in Korea.

• Journal of Nutrition and Health
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• v.33 no.3
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• pp.296-303
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• 2000

We examined the folate intakes and assessed folate nutritional status of Korean women with childbearing potential. A total of 91 healthy women aged between 15 and 49 participated. They were divided into three groups by their age : A(15-24 yrs), B(25-34 yrs) and C(35-49 yrs). Folate intakes were determined by direct analysis. The foods consumed for 24 hours were collected proportionally and assessed folate. Their blood drawn in fasting state were analyzed folate levels. Folate contents of food homogenate, plasma and erythrocyte were determined a microbiological method using Lactobacillus. casei (ATCC 7469). Prior to the micro-assay, the food homogenate were treated with alpha-amylase, protease and folate conjugase. Mean daily folate intake of the total subjects was 145.8$\mu\textrm{g}$/d and in each group of A, B, and C was 114.0$\mu\textrm{g}$/d, 141.6$\mu\textrm{g}$/d, and 164.6$\mu\textrm{g}$/d, respectively. That of group C was significantly higher than that of group A(p<0.05). However, those of all the groups were lower than compared to the Korean Recommened Dietary Allowances(RDA) for folate. Especially the subjects in the group A consumed folate least that was below the half of the Korean RDA. The mean energy intake of all subjects was 1638㎉/d and those in each group of A, B, and C did not meet the Korean RDA for energy. The energy intake were significantly correlated with folate intakes(r=0.5050, p<0.001). Mean plasma and erythrocyte folate concentrations of total subjects were 6.9ng/mL and 266.3ng/mL, respectively. None were found to be deficient both in plasma(<3ng/mL)and erythrocyte (<140ng/mL) folate levels. There was only one subject who had red blood cell folate level below 157ng/mL concentration. These results show that folate status of the Korean women of reproductive age is not much bad. But it should be better that letting them improve their folate status by increasing energy intake, choosing high folate foods.

• Nutrition Research and Practice
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• v.1 no.4
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• pp.254-259
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• 2007

This study assessed folate intakes, folate concentrations in plasma and erythrocytes, plasma total homocysteine (tHcy) concentration, and urinary excretion of folate metabolites in Korean women with childbearing potential. A total of 23 women voluntarily participated in this study. Precise dietary intakes for 3 consecutive days were determined by weighing all foods consumed and folate intake was calculated using a computer-aided dietary analysis system. Folate concentration of plasma and erythrocytes was determined by a microbiological method. Plasma tHcy concentration was assayed using an HPLC analysis method. Urine excreted over the same period of time was collected and folate catabolites, para-aminobenzoylglutamate (pABG) and para-acetamidobenzoylglutamate (ApABG), were evaluated using a reverse-phase HPLC method after affinity chromatography. Young women of 20 and under were likely to consume less folate with low energy intake, had lower folate concentration in plasma and erythrocytes, and excreted a lesser amount of ApABG and total folate catabolites than women of 25 years and over. The results of this study confirmed that young Korean women with childbearing potential, especially those under 21 years of age, might be at risk for compromised folate status due to insufficient folate intakes from inadequate energy consumption.

• Nutritional Sciences
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• v.9 no.1
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• pp.35-41
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• 2006

It should be concerned to the women with mutated genotype of methylenetetrahydrofolate reductase (MTHFR), C677T or A1298C, since they need more folate than those with wild genotypes. In this study, we evaluated the folate status of Korean women of childbearing age according to their MTHFR polymorpiysm. Dietary folate intakes, plasma and erythrocyte folate concentrations, plasma homocysteine concentrations, and urinary excretions of para-aminobenzoylglutamate (pABG) and para-acetoamidobenzoylglutamate (ApABG) of twenty-five subjects aged between 19 and 35 years old were determined Folate intakes seemed to be inadequate, being only three-quarters of the Korean RDA of folate. More than one-quarter of the subjects was exposed to folate deficiency risk as determined by erythrocyte folate concentration and almost one-quarter of the subjects showed hyperhomocysteinemia, although they had normal plasma folate concentrations. Urinary excretions of pABG and ApABG seemed to be low and ApABG constituted more than $85\%$ of total folate catabolites. There were no significant differences in dietary folate intakes, plasma concentrations of folate and homocysteine, and urinary excretions of pABG and ApABG among the geneotypes of both C677T and A1298C. However, the subjects with 1298AC genotype had significantly lower erythrocyte folate concentration than those with 1298AA. Erythrocyte folate concentration showed an inverse relationship with plasma homocysteine concentration and positive relationships with urinary excretions of pABG and ApABG. The results of this study imply that mutations of 677C$\rightarrow$T and 1298A$\rightarrow$C in the study were not associated with decreased plasma folate and raised plasma homocysteine concentrations. A1298C polymorphism night be, however, more influential on erythrocyte folate concentration than C677T polymorphism, and urinary excretions of folate catabolites, pABG and ApABG, might be reliable indexes of folate nutritional status like plasma homocysteine concentrations.

• Journal of Nutrition and Health
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• v.26 no.4
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• pp.433-442
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• 1993

Dietary folate intake and serum folate levels were measured in 26 pregnant, 25 lactating, and 17 non-pregnant, non-lactating women. Dietary folate comsumption was estimated by calculating folate intake based on the information obtained from food frequency quesionnaires and serum folate levels were determined microbiologically using Lactobacillus casei. The total folate (from food and supplements) intakes of pregnant and lactating women were 326.9ug and 407.9ug, which was significantly higher than that of the non-pregnant, non-lactating women(139.5ug). However, with regard to food folate intake, there were no differences among the three groups (160ug for pregnant women, 143.4ug for lactating women). Forty-two percent and 36% of the pregnant and lactating subjects, respectively, were found to be taking commercially available nutritional supplements containing folate. The concentrations of folate in these supplements were in the range of 83ug~1, 000ug per tablet. For lactating women, serum folate levels were significantly higher when folate supplements were voluntarily used. The amount of folate intake was positively correlated with the serum folate levels in pregnant women, but not in lactaing women and non-pregnant, non-lactating women. Serum folate levels were negatively correlated with the ages of the pregnant women, and for lactating women, serum folate was positively correlated with their body weights.

• Journal of Community Nutrition
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• v.6 no.2
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• pp.91-96
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• 2004

The purpose of this study was to evaluate the folate nutritional status of Korean pregnant women and to investigate the relation between folate levels of maternal-umbilical cord blood, placenta tissue, and pregnancy outcomes. The study subjects consisted of 25 pregnant women who have had normal term deliveries. Dietary folate intakes of the pregnants were estimated by semi quantitative frequency questionnaire and the serum and placenta tissue folate level was measured by microbiological analysis. The total folate intakes of the pregnant women was 655.6 ${\mu}$g/d, which was 131.1% of the Korean RDA for pregnants. Maternal serum folate level was 16.18ng/ml, which was significantly lower than that of umbilical cord blood (34.98ng/ml, p<0.05). Mean folate concentration of the placental tissue was 998.0ng/ml, which was the highest compared to maternal and umbilical cord serum level. Umbilical cord serum folate level and placental tissue folate level were highly influenced by maternal serum folate level. The umbilical cord folate levels of the infant group whose birth weight was higher than 3500g were significantly higher than the group whose birth weight was less than 3500g (p<0.05). The placental folate level was significantly higher in maternal group who showed desirable weight gain during pregnancy (11 - 14kg). In conclusion, the birth weigt was related to the umbilical cord folate level and the maternal weight gain was affected by the placental folate level.

• Journal of Nutrition and Health
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• v.48 no.1
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• pp.94-104
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• 2015

Purpose: The purpose of this study was to estimate dietary folate intake and food sources of children and adolescents using a nutrient database revised based on measured folate in selected foods. Methods: Folate content in 51 foods known as folate sources was measured by microbiological assay after trienzyme extraction. Folate intake was estimated from a part of the data of 'Dietary Intake Survey of Infants, Children and Adolescents in 2007~2008' conducted by the Korea Food and Drug Administration (KFDA) and the Korea Health Industry Development Institute (KHIDI). The study subjects were 567 children aged 1~19 years living in the Chungcheong area who completed two 24-hour recalls. Results: Folate values were revised by replacing the values in the current database with the analyzed values except when the value in the current database was between the analytical values or was not different from the mean analytical value by more than 10%. Among the revised values of 40 food items, folate values of 36 foods were lower than the current values. Mean folate intakes estimated with the revised database were approximately 70~80% lower than those estimated with the current database. Mean folate intakes of males aged 12~14 and females aged 12~19 were lower than the 2010 Recommended Nutrient Intakes (RNIs). Chicken's eggs, Kimchi, rice, mandarin, and laver were found to be main food sources of folate. Conclusion: In this study, mean dietary folate intakes were lower than those estimated with the current database. Further analyses for folate content especially in cooked foods commonly consumed in Korea are needed using a reliable assay in order to accurately assess folate intake of the Korean population. In addition, nutrition education should be provided for adolescent females in order to increase consumption of folate-rich foods.

• Journal of Nutrition and Health
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• v.33 no.3
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• pp.250-256
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• 2000

Hyperhomocysteinemia has been shown to be associated with increased risks for macrovascular angiopathy. The present study was conducted to document the relationship between plasma homocysteine levels and the presence of macrovascular angiopath in patients with Type II diabetes mellitus. Plasma total homocysteine was determined by a HPLC-fluorescence detection method in a total of 238 subjects, 127 diabetic patients and 111 control. Dietary information including folate intake was assessed by a 24-hour recall in a total 113 subjects, 70 diabetic patients and 43 control. Folate intake was significantly lower inn patients with diabetes mellitus than that in the control. The lowered folate intake in the diabetic patients was mainly due to reduced intakes of fruits and vegetables. The average plasma homocysteine level of patients with MA was 14.2$\mu$㏖/L, which was significantly higher than that of either the patients without MA(11.4$\mu$㏖/L) or the control(11.5$\mu$㏖/L). Twenty five percent of the diabetic patients were positively correlated with age (r=0.20), body weight (r=0.28), body mass index (r=0.28), body mass index (r=0.18), diastolic blood pressure (r=0.20), and total cholesterol (r=0.14). cigarette smokers had significantly higher levels of plasma homocysteine than the non-smokers. Further prospective studies are needed to investigate whether folate or other B vitamin supplementation could be beneficial for the prevention of hyperhomocysteinemia or macrovascular angiopathy in the diabetic patients.