Folic acid supplementation before and during pregnancy in the Newborn Epigenetics STudy (NEST).
BACKGROUND
Folic acid (FA) added to foods during fortification is 70-85% bioavailable compared to 50% of folate occurring naturally in foods. Thus, if FA supplements also are taken during pregnancy, both mother and fetus can be exposed to FA exceeding the Institute of Medicine's recommended tolerable upper limit (TUL) of 1,000 micrograms per day (μg/d) for adult pregnant women. The primary objective is to estimate the proportion of women taking folic acid (FA) doses exceeding the TUL before and during pregnancy, and to identify correlates of high FA use.


METHODS
During 2005-2008, pre-pregnancy and pregnancy-related data on dietary supplementation were obtained by interviewing 539 pregnant women enrolled at two obstetrics-care facilities in Durham County, North Carolina.


RESULTS
Before pregnancy, 51% of women reported FA supplementation and 66% reported this supplementation during pregnancy. Before pregnancy, 11.9% (95% CI = 9.2%-14.6%) of women reported supplementation with FA doses above the TUL of 1,000 μg/day, and a similar proportion reported this intake prenatally. Before pregnancy, Caucasian women were more likely to take FA doses above the TUL (OR = 2.99; 95% = 1.28-7.00), compared to African American women, while women with chronic conditions were less likely to take FA doses above the TUL (OR = 0.48; 95%CI = 0.21-0.97). Compared to African American women, Caucasian women were also more likely to report FA intake in doses exceeding the TUL during pregnancy (OR = 5.09; 95%CI = 2.07-12.49).


CONCLUSIONS
Fifty-one percent of women reported some FA intake before and 66% during pregnancy, respectively, and more than one in ten women took FA supplements in doses that exceeded the TUL. Caucasian women were more likely to report high FA intake. A study is ongoing to identify possible genetic and non-genotoxic effects of these high doses.
Department of Community and Family Medicine and Program of Cancer Detection, Prevention and Control, Duke University, PO Box 104006, Durham, NC 27710, USA. cathrine.hoyo@duke.edu
Cathrine
C
Hoyo
Amy P
AP
Murtha
Joellen M
JM
Schildkraut
Michele R
MR
Forman
Brian
B
Calingaert
Wendy
W
Demark-Wahnefried
Joanne
J
Kurtzberg
Randy L
RL
Jirtle
Susan K
SK
Murphy
D000328:Adult; D001741:Black or African American / Q000523:psychology / Q000706:statistics & numerical data; D001213:Asian / Q000523:psychology / Q000706:statistics & numerical data; D049628:Body Size / Q000208:ethnology; D002391:Catchment Area, Health; D002908:Chronic Disease / Q000208:ethnology / Q000523:psychology; D019587:Dietary Supplements / Q000706:statistics & numerical data*; D044127:Epigenesis, Genetic; D005260:Female; D005492:Folic Acid / Q000627:therapeutic use*; D005865:Gestational Age; D007722:Health Knowledge, Attitudes, Practice / Q000208:ethnology; D006630:Hispanic or Latino / Q000523:psychology / Q000706:statistics & numerical data; D006801:Humans; D007231:Infant, Newborn; D017533:Marital Status; D009657:North Carolina; D011247:Pregnancy; D011248:Pregnancy Complications / Q000208:ethnology / Q000517:prevention & control; D011295:Prenatal Care / Q000379:methods; D011446:Prospective Studies; D012907:Smoking / Q000208:ethnology / Q000523:psychology; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires; D044465:White People / Q000523:psychology / Q000706:statistics & numerical data
D005492:Folic Acid
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