Villalba Nicole, Byrne Kayla, Abdelmageed Sunny, Votoupal Megan, Lam Sandi K, Garcia Roxanna M
Division of Pediatric Neurosurgery, Ann and Robert H. Lurie Children's Hospital, Chicago, IL, USA.
Department of Neurosurgery, Northwestern University Feinberg School of Medicine, Northwestern Memorial Hospital, 676 N St. Clair St, Ste 2210, Chicago, IL, 60611, USA.
BMC Public Health. 2025 Apr 9;25(1):1334. doi: 10.1186/s12889-025-22407-x.
In 1998, the United States (US) implemented mandatory folic acid fortification of enriched cereal grain products (ECGP) to prevent neural tube defects (NTD) in newborns. NTD rates remained highest among Hispanic births. Voluntary fortification of corn masa flour was approved in 2016, without improvement in NTD rates. This review aims to understand folic acid consumption among Hispanic women in the US before and after voluntary fortification.
A systematic search was conducted in PubMed, Embase, and Scopus from inception to September 2024 using the keywords folic acid, Hispanic Americans, and fortification. Study designs included descriptive, cross-sectional, and observational cohort. Studies in any language reporting the consumption of folic acid fortified foods among Hispanic women of reproductive age in the US were eligible. Study variables were compared to non-Hispanic White (NHW) women when available. Findings were summarized descriptively.
Of 446 publications, eight studies (n = 20,123) met inclusion criteria. All studies reported on folic acid fortified foods, four characterized folic acid intake and acculturation factors, three quantified red blood cell (RBC) folate concentrations, and two described NTD rates. Hispanic women consumed grains, cereals, bread, flour, pasta, and corn masa flour. Most Hispanic women obtained folic acid from ECGP only. Hispanic women consumed more dietary folic acid than NHW women pre-voluntary fortification (406-456 µg (mcg) versus 349 mcg daily, p < 0.001) but less total folic acid when supplements were included (244 mcg versus 332 mcg daily, p < 0.05). Monolingual Spanish-speakers had the lowest total intake (224 mcg daily, p < 0.05). RBC folate concentrations were lower among Hispanic women compared to NHW women pre-voluntary fortification (963 nmol per liter (nmol/L) versus 1043 nmol/L) but showed no improvement post-fortification. Voluntary fortification did not significantly increase folic acid intake or reduce the proportion with inadequate intake; however, monolingual Spanish-speakers demonstrated higher intake and RBC folate concentrations. NTD rates remained similar between Hispanic (7.5/10,000 live births) and NHW women (7.1/10,000 live births) post-fortification. The certainty of evidence, assessed using the Grading of Recommendations, Assessment, Development, and Evaluations framework, ranged from low to very low across outcomes.
There is a paucity of literature to describe the rate, influencing factors, and prevalence disparities in NTD among Hispanic women living in the US despite its public health importance. This review provides a current summary on the disparities in folic acid intake and NTD rates between Hispanic and NHW women, and the effectiveness of voluntary fortification targeting populations at higher risk. Research initiatives investigating the factors influencing these disparities and future targeted interventions are necessary.
1998年，美国对强化谷物制品实施了强制性叶酸强化措施，以预防新生儿神经管缺陷（NTD）。西班牙裔新生儿的神经管缺陷发生率一直最高。2016年，玉米粉的自愿强化措施获得批准，但神经管缺陷发生率并未得到改善。本综述旨在了解美国西班牙裔女性在自愿强化前后的叶酸摄入量。
从创刊至2024年9月，在PubMed、Embase和Scopus数据库中进行系统检索，关键词为叶酸、西班牙裔美国人、强化。研究设计包括描述性、横断面和观察性队列研究。任何语言报道美国育龄西班牙裔女性食用叶酸强化食品的研究均符合纳入标准。如有数据，将研究变量与非西班牙裔白人（NHW）女性进行比较。结果进行描述性总结。
在446篇出版物中，8项研究（n = 20,123）符合纳入标准。所有研究均报告了叶酸强化食品，4项研究描述了叶酸摄入量和文化适应因素，3项研究对红细胞（RBC）叶酸浓度进行了量化，2项研究描述了神经管缺陷发生率。西班牙裔女性食用谷物、谷类食品、面包、面粉、意大利面和玉米粉。大多数西班牙裔女性仅从强化谷物制品中获取叶酸。在自愿强化之前，西班牙裔女性摄入的膳食叶酸比非西班牙裔白人女性多（每日406 - 456微克（mcg）对349微克，p < 0.001），但在包括补充剂在内的总叶酸摄入量方面较少（每日244微克对332微克，p < 0.05）。只会说西班牙语的人总摄入量最低（每日224微克，p < 0.05）。在自愿强化之前，西班牙裔女性的红细胞叶酸浓度低于非西班牙裔白人女性（每升963纳摩尔（nmol/L）对1043纳摩尔/升），但强化后没有改善。自愿强化并未显著增加叶酸摄入量或降低摄入不足的比例；然而，只会说西班牙语的人叶酸摄入量和红细胞叶酸浓度较高。强化后，西班牙裔（每10,000例活产中有7.5例）和非西班牙裔白人女性（每10,000例活产中有7.1例）的神经管缺陷发生率仍然相似。使用推荐分级、评估、制定和评价框架评估的证据确定性在各个结果中从低到非常低不等。
尽管美国西班牙裔女性神经管缺陷问题具有公共卫生重要性，但描述其发生率、影响因素和患病率差异的文献却很匮乏。本综述提供了西班牙裔和非西班牙裔白人女性在叶酸摄入量和神经管缺陷发生率方面差异的当前总结，以及针对高危人群的自愿强化措施的有效性。有必要开展研究调查影响这些差异的因素以及未来的针对性干预措施。
