Evaluating folic acid supplementation among Japanese pregnant women with dietary intake of folic acid lower than 480 µg per day: results from TMM BirThree Cohort Study

Association of serum docosahexaenoic acid and eicosapentaenoic acid levels with dietary intakes and supplement use during pregnancy: a prospective observational study

This study aimed to determine the association of serum docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) levels with dietary intakes and supplement use during pregnancy. This prospective observational study was conducted at a university hospital in Tokyo, Japan. Participants in their second and third trimesters were given a self-administered questionnaire assessing the frequency of DHA and EPA supplement use in the past month and a brief-type self-administered diet history questionnaire. Non-fasting serum DHA and EPA levels were analysed using gas chromatography. Differences in biomarkers by frequency of supplement use were determined using multiple comparison analyses, and Spearman's correlation coefficient was used to determine biomarkers and DHA and EPA intakes by food group. Of the 116 participants, 11 (9⋅5 %) in the second trimester and 18 (15⋅5 %) in the third trimester regularly used supplements (≥5 times per week). Regular users had higher serum DHA and EPA levels than never users in the second and third trimesters. Dietary DHA and EPA intake from fish and shellfish was positively correlated with serum DHA and EPA in the second and third trimesters. Supplement use ≥5 times per week and fish and shellfish intake were associated with high serum DHA and EPA levels.

Maternal Serum Folic Acid Levels and Onset of Kawasaki Disease in Offspring During Infancy

Importance

Kawasaki disease is an acute systemic vasculitis that primarily affects infants and young children. No reproducible risk factors have yet been identified, but a possible association between maternal folic acid supplementation and Kawasaki disease has been reported previously.

Objective

To investigate the associations of exposure to maternal serum folic acid levels and maternal folic acid supplementation with onset of Kawasaki disease during infancy among offspring.

Design, Setting, and Participants

This cohort study used data from the Japan Environment and Children's Study, a nationwide birth cohort, which has enrolled children since 2011. This study used the data set released in October 2019, and analysis was performed in January 2023.

Exposures

Maternal serum folic acid levels (≥10 ng/mL classified as exposed) during the second and third trimesters and the frequency of maternal folic acid supplementation during the first trimester and during the second and third trimesters of pregnancy (once a week or more was classified as exposed).

Main Outcomes and Measures

The primary outcome was onset of Kawasaki disease in offspring up to age 12 months. Odds ratios (ORs) for each exposure were estimated, and propensity score-adjusted logistic regression was conducted on the basis of the sets of variables.

Results

The study population comprised 87 702 children who were followed-up for 12 months. Of these, 336 children developed Kawasaki disease. Mothers who took folic acid supplements (31 275 mothers [35.7%]; mean [SD] age, 32 [5] years) had higher serum folic acid levels than those who did not take supplements. Higher maternal serum folic acid levels were associated with a significantly lower risk of Kawasaki disease in offspring than lower levels (folic acid ≥10 vs <10 ng/mL, 56 of 20 698 children [0.27%] vs 267 of 64 468 children [0.41%]; OR, 0.68; 95% CI, 0.50-0.92). Children whose mothers took folic acid supplementation during the first trimester had a lower prevalence of Kawasaki disease than children whose mothers did not take folic acid (131 of 39 098 children [0.34%] vs 203 of 48 053 children [0.42%]), although the difference was not statistically significant (OR, 0.83; 95% CI, 0.66-1.04). Supplementation during the second and third trimesters was associated with a significantly lower risk of Kawasaki disease compared with no supplementation (94 of 31 275 children [0.30%] vs 242 of 56 427 children [0.43%]; OR, 0.73; 95% CI, 0.57-0.94).

Conclusions and Relevance

In this cohort study, higher serum folic acid levels (≥10 ng/mL) and maternal folic acid supplementation more than once a week during the second and third trimesters were associated with reduced risk of Kawasaki disease in offspring during infancy.

Prenatal folic acid supplement/dietary folate and cognitive development in 4-year-old offspring from the Japan Environment and Children's Study

We evaluated the association between maternal prenatal folic acid supplement use/dietary folate intake and cognitive development in 4-year-old offspring (N = 3445) using data from the Japan Environment and Children's Study. Cognitive development was evaluated using the Kyoto Scale of Psychological Development 2001. Multiple regression analysis revealed that offspring of mothers who started using folic acid supplements pre-conception had a significantly higher language-social developmental quotient (DQ) (partial regression coefficient 1.981, 95% confidence interval 0.091 to 3.872) than offspring of mothers who did not use such supplements at any time throughout their pregnancy (non-users). Offspring of mothers who started using folic acid supplements within 12 weeks of gestation had a significantly higher cognitive-adaptive (1.489, 0.312 to 2.667) and language-social (1.873, 0.586 to 3.159) DQ than offspring of non-users. Regarding daily dietary folate intake from preconception to early pregnancy, multiple regression analysis revealed that there was no significant association with any DQ area in the 200 to < 400 µg and the ≥ 400 µg groups compared with the < 200 µg group. Maternal prenatal folic acid supplementation starting within 12 weeks of gestation (but not adequate dietary folate intake from preconception to early pregnancy) is positively associated with cognitive development in 4-year-old offspring.

Dietary Supplement Use during Pregnancy: Perceptions versus Reality

This study aimed to examine the prevalence, associated factors and perceptions of dietary supplement use among pregnant Chinese women. A cross-sectional study was conducted to collect data about prevalence, purchase channels, perceptions, and related factors of dietary supplement use from 572 pregnant women, through a face-to-face survey, using a self-designed questionnaire. Of the respondents, 94.8% used at least one dietary supplement, whereas 29.8% used more than four supplements in the previous month. The majority of the pregnant women were highly educated (81.2% had a bachelor’s degree or above) and had the perception that dietary supplements could prevent and improve (89.2%), or treat, nutrition-related diseases (78.7%). Multivariate analysis showed that pregnant women who had used multiple (more than four) supplements were more likely to have a larger gestational age, received fertility treatment, more prenatal visits, and hypothyroidism during pregnancy. Furthermore, pregnant women not only purchased dietary supplements through hospitals (72.6%) and pharmacies (45.1%), but overseas Daigou or online purchases (31.8%) were also a major channel of purchase. A high prevalence of dietary supplement use during pregnancy was observed, with extensive and repeated consumption of nutrients. Pregnant women’s craze for dietary supplements calls for more comprehensive guidelines in China.