title: High dose of maternal folic acid supplementation is associated to infant asthma.
abstract: Maternal folic acid supplementation had a positive effect on preventing neural tube defects (NTDs), but its effects in infant asthma remained unclear. A hospital-based case-control study was conducted with outpatients between March 2010 and March 2011 including 150 onset infant asthma cases and 212 controls, together with a meta-analysis involving 14,438 participants, was performed. The association between maternal folic acid supplementation and the risk of infant asthma was not significant either in the meta-analysis (OR = 1.06, 95% CI =0.99-1.14) or in the case-control study (OR = 0.72, 95% CI =0.37-1.39). However, quantitative analysis of the supplementation dose demonstrated that the risk of infant asthma significantly increased for the infants whose mother were with high-dose supplementation (>72,000 µg•d; OR = 3.16, 95% CI =1.15-8.71) after adjusting for confounding factors in the case-control study. Meanwhile, the risk of infant asthma significantly decreased for the infants whose mother were with low-dose supplementation (<36,000 µg•d; OR = 0.36, 95% CI =0.17-0.77). A high dose of folic acid supplementation for mother during pregnancy was associated with an increased risk of infant asthma, whereas supplementation with a relatively low-dose was associated with a decreased risk of infant asthma. These findings should be further investigated in a large population.
authors.affiliation: Department of Epidemiology and Health Statistics, School of Public Health, Shandong University, Jinan, China; Jinan Municipal Center for Disease Control and Prevention, Jinan, Shandong, China.
authors.forename: Liu
authors.initials: L
authors.lastname: Yang
authors.affiliation: Department of Epidemiology and Health Statistics, School of Public Health, Shandong University, Jinan, China; School of Public Health, Fudan University, Shanghai, China.
authors.forename: Liwen
authors.initials: L
authors.lastname: Jiang
authors.affiliation: Department of Pediatrics, Jinan Central Hospital Affiliated to Shandong University, Shandong University, Jinan, China.
authors.forename: Meirong
authors.initials: M
authors.lastname: Bi
authors.affiliation: Department of Epidemiology and Health Statistics, School of Public Health, Shandong University, Jinan, China.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Jia
authors.affiliation: Department of Epidemiology and Health Statistics, School of Public Health, Shandong University, Jinan, China.
authors.forename: Youqing
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Epidemiology and Health Statistics, School of Public Health, Shandong University, Jinan, China.
authors.forename: Chuan
authors.initials: C
authors.lastname: He
authors.affiliation: Department of Epidemiology and Health Statistics, School of Public Health, Shandong University, Jinan, China.
authors.forename: Yao
authors.initials: Y
authors.lastname: Yao
authors.affiliation: Department of Pediatrics, Jinan Central Hospital Affiliated to Shandong University, Shandong University, Jinan, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Epidemiology and Health Statistics, School of Public Health, Shandong University, Jinan, China. Electronic address: zhipingw@sdu.edu.cn.
authors.forename: Zhiping
authors.initials: Z
authors.lastname: Wang
mesh_terms: D001249:Asthma / Q000097:blood* / Q000453:epidemiology / Q000517:prevention & control; D016022:Case-Control Studies; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D005260:Female; D005492:Folic Acid / Q000008:administration & dosage* / Q000009:adverse effects* / Q000097:blood; D006801:Humans; D007223:Infant; D016014:Linear Models; D008297:Male; D039382:Maternal Nutritional Physiological Phenomena; D009436:Neural Tube Defects / Q000188:drug therapy; D011247:Pregnancy; D012307:Risk Factors
chemical_list: D005492:Folic Acid
keywords: Case–control study; Folic acid supplementation; Infant asthma; Meta-analysis