Writing in the journal Nutrients, researchers from Peking University and PLA Rocket Force Characteristic Medical Center in Beijing, China, conducted a systematic review outlining optimal folic acid supplementation practices with or without dietary exposure to the acid to reduce NTDs.
“This study synthesized the best available evidence regarding folic acid supplementation for preventing NTDs in women of childbearing age, providing an evidence-based foundation to inform clinical practice, particularly for healthcare systems and populations in regions without mandatory folic acid food fortification,” the researchers wrote.
Low awareness
The global prevalence of neural tube defects (NTD) is 18.6 to 10,000 live births, making it a major global public health concern. Approximately 75% of people born with NTDs die before they reach the age of five, according to the authors.
NTDs, such as anencephaly and spina bifida, occur when the embryonic neural tube does not adequately close by the 28th day after conception. This can result in fetal death, stillbirth or significant lifelong disability.
NTD prevalence is greater in low-and middle-income countries. Folate deficiency impacts more than 20% of reproductive age women in many lower-income nations, though, in general, folate insufficiency was greater than 40% in most countries surveyed.
“Folic acid (vitamin B9), an essential nutrient that must be obtained from the diet or supplements, is pivotal in preventing these defects when taken adequately during the periconceptional period, underscoring its role as a primary prevention strategy,” the researchers wrote.
However, low awareness about folic acid among women is due to structural factors like low educational attainment, low income and limited access to healthcare.
“There is an urgent need to synthesize the best available evidence on folic acid for preventing fetal NTDs, establishing a standardized knowledge base and developing new health education approaches to effectively enhance [women’s] folic acid-related knowledge and ultimately improve intake behaviors,” the review noted.
Study details
The researchers searched multiple databases and professional websites containing information over the last two decades. Their review included 17 publications in Chinese and English that covered guidelines, expert consensus and recommended practices.
Five themes emerged from the review: risks of neural tube defects and the role of folic acid, time window of neural tube closure, timing and dosage of folic acid supplementation, relationship between dietary folic acid and folic acid tablets, and folic acid-related testing.
The primary recommendations included:
- Initiating supplementation at least three months preconception
- Daily doses should include 0.4 mg for low-risk, 1 mg for moderate-risk, and 4 to 5 mg for high-risk women,
- Supplementation should continue through the first trimester and that dietary intake alone is insufficient,
- The researchers advised against routine folate testing.
They noted that women should avoid taking multivitamins to achieve high-dose folic acid supplementation because this could lead to obtaining harmful levels of other vitamins, like vitamin A, which is teratogenic.
“This knowledge base will provide direct, reliable core knowledge support for developing evidence-based health education materials and clarifying key points for clinical counseling,” the researchers wrote. “Ultimately, it will serve clinical practice and public health interventions, helping to bridge the gap between knowledge, belief and action.”
Source: Nutrients. doi: 10.3390/nu18040641. “Best Evidence Summary of Folic Acid Supplementation for Prevention of Neural Tube Defects in Women of Childbearing Age”. Authors: Jiahe Lee et al.
