Folate supplements in late pregnancy up the risk of child asthma
13 November 2009
Women should be cautioned against excess folate supplementation during pregnancy, Australian experts say.
In particular, they warn that supplemental folate should not be taken during late pregnancy. The comments follow the publication of Australian research finding an increased risk of asthma in the children of mothers who take folic acid in late pregnancy (American Journal of Epidemiology, online 30 October).
The researchers said it was an important reminder that women should adhere to recommendations on timing and dosage of folate supplementation.
The prospective study found use of folic acid supplements in late pregnancy (from 30 to 34 weeks) was associated with a 26 per cent increased risk of childhood asthma and a 32 per cent increase in persistent asthma in children aged 3.5 years.
Lead author, Associate Professor Michael Davies, from the Research Centre for the Early Origins of Health and Disease at the University of Adelaide, said: “Supplemental folic acid in late pregnancy was associated with an increased risk of asthma in children, but there was no evidence to suggest any adverse effects if supplements were taken in early pregnancy.”
Dr Alan Barclay (PhD), a dietitian at the University of Sydney, said although the evidence suggested an association between folate supplementation and childhood asthma risk, the data was hampered by reliance on a food frequency questionnaire, making further research necessary. He said the women in the study had a median intake in early pregnancy of 2948 micrograms of folate per day from standalone supplements, well above the recommended dose of 400 micrograms for pregnant women.
“If you are going to take a supplement, stick with the 400 micrograms per day, and make sure you are not getting extra folate from other sources like the multivitamins,” he advised.
Last Reviewed: 13 November 2009
- 1. Whitrow MJ, Moore VM, Rumbold AR, Davies MJ. Effect of Supplemental Folic Acid in Pregnancy on Childhood Asthma: A Prospective Birth Cohort Study. American Journal of Epidemiology Advance Access, online October 30, 2009
