Update on the prevalence and determinants of folic acid use in Japan evaluated with 91,538 pregnant women: the Japan Environment and Children’s Study

Abstract

Objective: To provide the latest and most promising evidence on the prevalence and determinants for folic acid supplementation in pregnant women in Japan, including differences in prevalence between interview years and determinants across regions.

Materials and methods: The study participants were enrolled from 15 regional centers across Japan between January 2011 and March 2014. Information on the use of folic acid supplementation before and during pregnancy and the characteristics of the participants were collected using questionnaires, medical chart reviews, and interviews by research coordinators.

Results: Data for 91,538 women who provided sufficient data on folic acid supplementation were analyzed. The prevalence of adequate users was 8.0%, which, although low, tended to improve over the 4-year recruitment period. Various kinds of sociodemographic factors, lifestyle habits, and obstetrical and medication use history were significant and independent determinants for folic acid use. Associations between adequate preconception folic acid use and its major determinants tended to be similar across regions.

Conclusions: Although the prevalence of adequate folic acid use was low, it increased from 2011 to 2014. Reproductive-aged women who have determinants for inadequate folic acid use should be informed about the need for preconception folic acid supplementation to help prevent neural tube defects.

Keywords:

• Folic acid
• Japan
• neural tube defects
• preconception
• pregnancy

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Disclosure statement

Tomofumi Ishikawa is an employee of Pfizer Japan Inc. Tomofumi Ishikawa is also a graduate student at Tohoku University and contributed to the present study independent of Pfizer Japan Inc. The other authors report no conflicts of interest.

The findings and conclusions of this article are solely the responsibility of the authors and do not represent the official views of the government. The members of the JECS as of 2017 (principal investigator, Toshihiro Kawamoto) are: Hirohisa Saito (National Center for Child Health and Development, Tokyo, Japan), Reiko Kishi (Hokkaido University, Sapporo, Japan), Nobuo Yaegashi (Tohoku University, Sendai, Japan), Koichi Hashimoto (Fukushima Medical University, Fukushima, Japan), Chisato Mori (Chiba University, Chiba, Japan), Shuichi Ito (Yokohama City University, Yokohama, Japan), Zentaro Yamagata (University of Yamanashi, Chuo, Japan), Hidekuni Inadera (University of Toyama, Toyama, Japan), Michihiro Kamijima (Nagoya City University, Nagoya, Japan), Takeo Nakayama (Kyoto University, Kyoto, Japan), Hiroyasu Iso (Osaka University, Suita, Japan), Masayuki Shima (Hyogo College of Medicine, Nishinomiya, Japan), Yasuaki Hirooka (Tottori University, Yonago, Japan), Narufumi Suganuma (Kochi University, Nankoku, Japan), Koichi Kusuhara (University of Occupational and Environmental Health, Kitakyushu, Japan), and Takahiko Katoh (Kumamoto University, Kumamoto, Japan).

Additional information

Funding

The JECS was funded by the Ministry of the Environment, the Government of Japan.