葉酸は神経管閉鎖障害の発生リスクを低減する : 妊婦の認知率・葉酸摂取率(2006年)

Abstract

2006年に実施した妊婦を対象とする葉酸認知率と, サプリメント摂取率の調査, 食事記録票の分析データを報告した。1251通のアンケート調査を分析した結果, 1)葉酸サプリメントが二分脊椎症を防止することを認識していたのは35%で, 高学歴群と高年齢群はそれぞれの対照群と比較してより多くがこの情報を承知していた。2)情報の入手源はマスメディアまたはインターネットと回答しており, 医療職からとの回答は13%であった。3)葉酸サプリメントの摂取率は認知率よりやや低かったが, アンケートに触発されて17%の妊婦が前向きの回答をしていた。4)86枚の食事記録票の分析では, 妊婦が摂取している葉酸は平均341μg/日で, 厚生労働省が推奨・期待する400μg/日には約60μg/日不足しており, 妊娠期別では妊娠前期が最も低値を示していた。尚, 400μg/日を満す妊婦は18%で, その中の4人はサプリメントも内服していた。不足していた82%のうち, 34%は葉酸サプリメントを内服していた。

Folic acid plays an important role in proliferating cells and tissues of the fetus. A randomized control trial demonstrated in 1991 that 4 mg of folic acid supplements successfully prevented 72% of recurrence of neural tube defects (NTDs) in women who had had afflicted pregnancy. In 2000, the Japanese Government recommended women of childbearing age to take 400 microgram of folate supplements per day from 4 weeks prior to and 12 weeks after conception. A questionnaire study was performed in pregnant women by post on their awareness of the role folic acid plays, their life style, and folate intake by dietary consumption. Thirty-five percent of 1, 251 pregnant women were aware of the important role of folic acid in the critical stage of fetal development and 31% actually took the supplement. Information on folic acid was obtained through mass media in 47% of the women, through the internet in 17%, through healthcare providers in 13% and so forth. The food record analysis revealed that the dietary intake of folic acid averaged 341 microg/day that was 60 microg less than what was recommended by the Government and that 33 of 86 women took the supplement. Overall, a half of pregnant women are required to take 400 microg folate supplement per day. It is to be stressed that primary prevention of NTDs by periconceptional intake of folic acid is a major public health opportunity and that prevention is more important than cure in the management of NTDs.