title: Folate and asthma.
abstract: Findings from experimental studies and animal models led to the hypothesis that folic acid supplementation during pregnancy confers an increased risk of asthma. This review provides a critical examination of current experimental and epidemiologic evidence of a causal association between folate status and asthma. In industrialized nations, the prevalence of asthma was rising before widespread fortification of foodstuffs with folic acid or folate supplementation before or during pregnancy, thus suggesting that changes in folate status are an unlikely explanation for "the asthma epidemic." Consistent with this ecologic observation, evidence from human studies does not support moderate or strong effects of folate status on asthma. Given known protective effects against neural tube and cardiac defects, there is no reason to alter current recommendations for folic acid supplementation during conception or pregnancy based on findings for folate and asthma. Although we believe that there are inadequate data to exclude a weak effect of maternal folate status on asthma or asthma symptoms, such effects could be examined within the context of very large (and ongoing) birth cohort studies. At this time, there is no justification for funding new studies of folate and asthma.
authors: Department of Pediatrics, Children's Hospital of Pittsburgh, PA, USA.
authors: Joshua
authors: J
authors: Blatter
authors: Yueh-Ying
authors: YY
authors: Han
authors: Erick
authors: E
authors: Forno
authors: John
authors: J
authors: Brehm
authors: Lisa
authors: L
authors: Bodnar
authors: Juan C
authors: JC
authors: Celedón
mesh_terms: D000818:Animals; D001249:Asthma / Q000139:chemically induced*; D019587:Dietary Supplements / Q000009:adverse effects*; D005260:Female; D005492:Folic Acid / Q000009:adverse effects*; D006801:Humans; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects
chemical_list: D005492:Folic Acid
references: J Allergy Clin Immunol. 2013 Jan;131(1):226-8.e1-2
references: 23040888
references: Br J Nutr. 2008 Jun;99 Suppl 3:S48-54
references: 18598588
references: Int J Epidemiol. 2006 Aug;35(4):954-61
references: 16766537
references: NCHS Data Brief. 2012 May;(94):1-8
references: 22617340
references: Thorax. 2009 Jun;64(6):476-83
references: 19237391
references: Eur J Clin Nutr. 2011 Aug;65(8):937-43
references: 21559033
references: Zhonghua Jie He He Hu Xi Za Zhi. 2003 Mar;26(3):161-4
references: 12816682
references: Curr Allergy Asthma Rep. 2012 Jun;12(3):211-20
references: 22451193
references: J Nutr. 2012 Apr;142(4):731-8
references: 22399526
references: Intern Med. 2011;50(3):205-11
references: 21297321
references: J Nutr. 2005 Jan;135(1):137-43
references: 15623845
references: Am J Respir Crit Care Med. 2008 Mar 15;177(6):567-73
references: 18187692
references: J Allergy Clin Immunol. 2012 Jun;129(6):1602-10.e6
references: 22277202
references: J Nutr. 2012 May;142(5):886-93
references: 22437563
references: Am J Clin Nutr. 2011 Jul;94(1):337S-342S
references: 21593497
references: Pediatrics. 2011 Jul;128(1):e135-44
references: 21690114
references: J Allergy Clin Immunol. 2009 Jun;123(6):1260-1
references: 19447481
references: Allergy. 2010 Nov;65(11):1446-54
references: 20456312
references: FASEB J. 1996 Mar;10(4):471-80
references: 8647346
references: Am J Epidemiol. 2009 Dec 15;170(12):1486-93
references: 19880541
references: Clin Exp Allergy. 2008 Feb;38(2):320-8
references: 18070159
references: J Allergy Clin Immunol. 2009 Jun;123(6):1253-9.e2
references: 19409604
references: J Allergy Clin Immunol. 2013 Mar;131(3):918-20
references: 23237419
references: Am J Obstet Gynecol. 2012 Jan;206(1):72.e1-7
references: 21982024
references: Pediatr Allergy Immunol. 2011 Feb;22(1 Pt 1):69-74
references: 20561231
references: J Food Sci. 2009 Nov-Dec;74(9):R114-22
references: 20492126
references: J Allergy Clin Immunol. 2011 Jan;127(1):262-4, 264.e1
references: 21094522
references: Nature. 2012 Jul 12;487(7406):249-53
references: 22763435
references: Pediatr Allergy Immunol. 2011 Feb;22(1 Pt 1):19-24
references: 20961335
references: Am J Clin Nutr. 2010 May;91(5):1455S-1460S
references: 20219964
references: Proc Natl Acad Sci U S A. 2002 Apr 16;99(8):5606-11
references: 11929966
references: Arch Dis Child. 2009 Mar;94(3):180-4
references: 19052032
references: J Clin Invest. 2008 Oct;118(10):3462-9
references: 18802477
references: Eur Respir J. 2012 Jun;39(6):1468-74
references: 22034647
references: Am J Respir Crit Care Med. 2012 Jan 15;185(2):124-32
references: 22016447
references: Am J Clin Nutr. 2006 Oct;84(4):903-11
references: 17023719
references: J Am Diet Assoc. 2011 Feb;111(2):258-68
references: 21272700
references: Indian J Dermatol. 2011 Nov;56(6):673-7
references: 22345769
references: Am J Clin Nutr. 2003 Sep;78(3):414-21
references: 12936923
references: Nat Genet. 1995 May;10(1):111-3
references: 7647779
references: J Nutr. 1999 Apr;129(4):779-82
references: 10203550
references: J Nutr. 2002 Aug;132(8 Suppl):2333S-2335S
references: 12163687
references: Am J Epidemiol. 2010 Feb 15;171(4):488-97
references: 20061366
references: Thorax. 2006 May;61(5):388-93
references: 16467075