Predictors of preconceptional folic acid or multivitamin supplement use: a cross-sectional study of Danish pregnancy planners

Heidi T Cueto,¹ Anders H Riis,¹ Elizabeth E Hatch,² Lauren A Wise,^2,4 Kenneth J Rothman,^2,3 Ellen M Mikkelsen<sup>1

1</sup>Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark; ²Department of Epidemiology, Boston University School of Public Health, Boston, MA, USA; ³RTI Health Solutions, Research Triangle Park, NC, USA; ⁴Slone Epidemiology Center, Boston University, Boston, MA, USA

Purpose: Compliance with the Danish preconceptional folic acid (FA) recommendation – a daily supplement of 400 µg – is reported to be poor. Uncertainty remains, however, about the prevalence of compliers and health-related predictors of compliance in the preconceptional period.
Methods: We used self-reported baseline data from 5383 women, aged 18–40 years, enrolled in an Internet-based prospective cohort study of Danish pregnancy planners during 2007–2011. We estimated the prevalence proportions of FA or multivitamin (MV) use in relation to selected sociodemographic, lifestyle, reproductive, and medical characteristics. Multivariate binomial regression was used to obtain prevalence proportion differences with 95% confidence intervals for each level of study predictors, adjusted for all other predictors.
Results: Overall, 7.7% of women used FA supplements, 20.4% used MV supplements, 34.0% used both, 1.5% used other single vitamins or minerals, and 36.4% did not use any dietary supplements. The prevalence of FA or MV supplement use was higher among older women, women with higher education and income, and women with healthy lifestyle factors such as being a nonsmoker, nondrinker, physically active, maintaining a normal body mass index and having regular pap smears. Greater intercourse frequency and a history of spontaneous abortion were also positively associated with FA or MV supplement use. We found no clear association between use of FA or MV supplements and a diagnosis of hypertension, diabetes, thyroid disease, pelvic inflammatory disease, or chlamydia.
Conclusion: A large proportion of pregnancy planners do not use FA or MV supplements. Pregnancy planners with generally risky lifestyle behaviors are less likely to comply with the FA recommendation.

Keywords: pregnancy, preconceptional supplement use, vitamins, folic acid