Dietary folate intake and food sources of children and adolescents in Chungcheong area - Using nutrient database revised by measured folate in selected foods / 한국영양학회지

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.

Effects of parental folate deficiency on the folate content, global DNA methylation, and expressions of FRalpha, IGF-2 and IGF-1R in the postnatal rat liver

We examined the effect of parental folate deficiency on the folate content, global DNA methylation, folate receptor-alpha (FRalpha), insulin-like-growth factor-2 (IGF-2) and -1 receptor (IGF-1R) in the liver and plasma homocysteine in the postnatal rat. Male and female rats were randomly fed a folic acid-deficient (paternal folate-deficient, PD and maternal folate-deficient, MD), or folic acid-supplemented diet (paternal folate-supplemented, PS and maternal-folate-supplemented, MS) for four weeks. They were mated and grouped accordingly: PSxMS, PSxMD, PDxMS, and PDxMD. Pups were killed on day 21 of lactation. The hepatic folate content was markedly reduced in the PDxMD and PSxMD and PDxMS as compared with the PSxMS group. The hepatic global DNA methylation was decreased in the PDxMS and PSxMD groups as much as in the PDxMD group, and all the three groups were significantly lower as compared to the PSxMS group. There were no significant differences in the hepatic FRalpha, IGF-2 and IGF-1R expressions among the groups. Positive correlations were found between the hepatic folate content and global DNA methylation and protein expressions of FRalpha, IGF-2 and IGF-1R, whereas an inverse correlation was found between hepatic folate content and plasma homocysteine level in the 3-week-old rat pup. The results of this study show that both paternal and maternal folate deficiency at mating can influence the folate content and global DNA methylation in the postnatal rat liver.

Folate Content and Availability in Malaysian Cooked Foods

Introduction: Data on folate availability of Malaysian cooked foods would be useful for estimation of dietary folate intake; however such information is scarce. Methods: A total of 53 samples of frequently consumed foods in Malaysia were selected from the Nutrient Composition of Malaysian Foods. Folate content was determined using HPLC method hyphenated with a stainless steel C18 column and ultraviolet detector ( = 280 nm). The index of folate availability was defined as the proportion of folate identified as monoglutamyl derivatives from the total folate content. Results: Total folate content of different food samples varied from 30-95 μg/100g fresh weight. Among rice-based dishes, the highest and the lowest total folate was in coconut milk rice (nasi lemak) and ghee rice (nasi minyak), respectively. In noodle dishes, fried rice noodle (kuey teow goreng) and curry noodle (mee kari) had the highest folate contents. The highest index of folate availability was in a flat rice noodle dish (kuey teow bandung) (12.13%), while the lowest was in a festival cake (kuih bakul) (0.13%). Folate content was found to be negatively related to its availability. Conclusion: This study determined folate content and folate availability in commonly consumed cooked foods in Malaysia. The uptake of folate from foods with high folate content may not be necessarily high as folate absorption also depends on the capacity of intestinal deconjugation and the presence of high fibre in the foods.