Hyeon-Sook Lim

Measurable human milk folate is increased by treatment with α-amylase and protease in addition to folate conjugase

The application of trienzyme treatment prior to microbiological assay using Lactobacillus casei for the measurement of folate in human milk was evaluated. Trienzyme treatment consisted of α-amylase, protease, and folate conjugase. Human milk samples (n = 84) were heat treated for 5 min at 100 °C in 0.1 m potassium phosphate buffer containing 0.05 mol liter−1 ascorbic acid, pH 4.1, then incubated with the enzymes by stepwise addition. Following trienzyme treatment, folate was measured microbiologically using a 96-well microplate method. The results show that treatment at 37 °C with α-amylase for 4 h followed by protease for 8 h, and finally by folate conjugase for 3 h significantly increased the measurable folate in human milk by an average of 85% compared with values after folate conjugase treatment alone (p < 0.001). Neither the pH of the extraction buffer, the source of folate conjugase, nor the method/length of heat treatment of the samples were significant variables influencing the values of human milk folate. Data indicate that folate in human milk can be underestimated unless samples are treated with α-amylase, protease, and folate conjugase prior to microbiological assay using L. casei.

A cross sectional study of maternal iron status of Korean women during pregnancy

The purpose of this study was to determine the iron status of Korean women during pregnancy and to assess the relationship between maternal iron status and the outcome of their newborns. A total of eighty-one pregnant women living in Gwangju, Korea, participated in the study: 26 women were in the first trimester, 23 in the second trimester, and 32 in the third trimester. Maternal red blood cell (RBC) number, hemoglobin (Hb) concentration, and serum iron and ferritin levels were reduced significantly in the last trimester (p < 0.05) compared to the findings both in the first and second trimesters. On the other hand, total iron binding capacity (TIBC), transferrin level, and the ratio of sTfR to ferritin in the third trimester were higher (p < 0.05) than those both in the first and second trimesters. Dietary intake of iron in the three trimesters was 9.7 ± 2.3, 13.3 ± 4.3, and 10.6 ± 2.5 mg/day, respectively. All were far below the Korean Recommended Dietary Allowances (RDA) of iron for pregnant women. Approximately, ninety percent of the subjects consumed iron supplements after the 20th week of their pregnancies until delivery. The supplemental iron intake in the second and third trimesters was 40 ± 12 and 46 ± 11 mg/day, respectively. There was a significant correlation between the maternal Hb level in the third trimester and the birth weight of infants. In conclusion, maternal iron status deteriorated during pregnancy, although most subjects consumed more than the RDA of iron by taking iron supplements after the 20th week of pregnancy. The results confirm that maternal iron deficiency during pregnancy negatively affects the outcome of newborns.

Low intakes of energy, folate, iron, and calcium of child-bearing Korean women

Nutritional status in pre-pregnancy greatly affects pregnancy outcomes. Recently, young child-bearing women in Korea have tended to restrict their diets for the purpose of weight control. The purpose of this study was to examine the energy and nutrient intakes of child-bearing women. The subjects were a total of 91 female residents (16- to 49-years-old) of Gwangju, Korea, who were neither pregnant nor lactating. The mean body mass index (BMI) of all the subjects was 21.4±2.2. Among them, 27% of the teens and 45% of the women in their twenties were underweight (BMI < 20). Energy intake of all subjects was 1638±471 kcal/day, which is 81.4% of the Korean recommended dietary allowances (RDA). About half of the teens and 60% of those in their twenties consumed less than 1500 kcal/day. Mean folate, iron, and calcium consumption of all the subjects were 204± 92 μg/day, 10.3±4.3 mg/ day, and 518±238 mg/day, respectively. These represented only 81.7%, 57.2%, and 72.6% of RDA, respectively. Nutrient intakes of the women in their teens and twenties did not satisfy the RDA. Energy intakes were significantly positively related to folate, iron, and calcium intakes. In summary, for child-bearing women, increased bioavailability of folate, iron, and calcium with increasing energy intake is absolutely needed, and nutritional education is also important to raise the intakes of these nutrients.

Childbearing women of twenty and under are at greater risk than those of twenty-five and over for compromised folate status

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.

Influences of morning sickness on dietary iron intake and its bioavailability of pregnant women during early pregnancy

More than one-third of fertile women in Korea have depleted iron stores within their bodies and are at risk of developing iron deficiency during pregnancy. It is recognized that morning sickness during early pregnancy reduces dietary diversity and nutrient intake. This study was conducted to determine whether morning sickness influences dietary iron intake and its bioavailability. Over 80% of the subjects in this study experienced morning sickness. Morning sickness reduced dietary intakes of total iron and seemed to decrease both heme and non-heme iron and diminish iron bioavailability with a decline in the consumption of enhancing factors for iron absorption. These results imply that as pregnancy progresses, those women who experienced morning sickness, especially severely, are likely to be iron-deficient.