The Current Recommended Vitamin D Intake Guideline for Diet and Supplements During Pregnancy Is Not Adequate to Achieve Vitamin D Sufficiency for Most Pregnant Women

Fariba Aghajafari; Catherine J Field; Bonnie J Kaplan; Doreen M Rabi; Jack A Maggiore; Maeve O'Beirne; David A Hanley; Misha Eliasziw; Deborah Dewey; Amy Weinberg; Sue J Ross; APrON Study Team

doi:10.1371/journal.pone.0157262

The Current Recommended Vitamin D Intake Guideline for Diet and Supplements During Pregnancy Is Not Adequate to Achieve Vitamin D Sufficiency for Most Pregnant Women

PLoS One. 2016 Jul 1;11(7):e0157262. doi: 10.1371/journal.pone.0157262. eCollection 2016.

Affiliations

¹ Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.
² Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada.
³ Research and Development, Doctor's Data, Inc., St. Charles, Illinois, United States of America.
⁴ Department of Public Health and Community Medicine, Tufts University, Boston, Massachusetts, United States of America.
⁵ Department of Obstetrics and Gynecology, University of Alberta, Edmonton, Alberta, Canada.

Abstract

Background: The aims of this study were to determine if pregnant women consumed the recommended vitamin D through diet alone or through diet and supplements, and if they achieved the current reference range vitamin D status when their reported dietary intake met the current recommendations.

Methods: Data and banked blood samples collected in second trimester from a subset of 537 women in the APrON (Alberta Pregnant Outcomes and Nutrition) study cohort were examined. Frozen collected plasma were assayed using LC-MS/MS (liquid chromatography-tandem mass spectrometry) to determine 25(OH)D2, 25(OH)D3, 3-epi-25(OH)D3 concentrations. Dietary data were obtained from questionnaires including a Supplement Intake Questionnaire and a 24-hour recall of the previous day's diet.

Results: Participants were 87% Caucasian; mean (SD) age of 31.3 (4.3); BMI 25.8 (4.7); 58% were primiparous; 90% had education beyond high school; 80% had a family income higher than CAN $70,000/year. 25(OH)D2, 25(OH)D3, and 3-epi-25(OH)D3) were identified in all of the 537 plasma samples;3-epi-25(OH)D3 contributed 5% of the total vitamin D. The median (IQR) total 25(OH)D (D2+D3) was 92.7 (30.4) nmol/L and 20% of women had 25(OH)D concentration < 75 nmol/L. The median (IQR) reported vitamin D intake from diet and supplements was 600 (472) IU/day. There was a significant relationship between maternal reported dietary vitamin D intake (diet and supplement) and 25(OH)D and 3-epi-25(OH)D3 concentrations in an adjusted linear regression model.

Conclusions: We demonstrated the current RDA (600 IU/ day) may not be adequate to achieve vitamin D status >75 nmol/L in some pregnant women who are residing in higher latitudes (Calgary, 51°N) in Alberta, Canada and the current vitamin D recommendations for Canadian pregnant women need to be re-evaluated.

MeSH terms

Adult
Dietary Supplements*
Female
Humans
Mothers
Nutritional Status
Practice Guidelines as Topic*
Pregnancy
Vitamin D / blood
Vitamin D / chemistry
Vitamin D / pharmacology*
Vitamin D Deficiency / prevention & control

Substances

Vitamin D

Grants and funding

This work was funded by Bridge funding from the Cumming School of Medicine, University of Calgary, and Janus Research Award from College of Family Physicians of Canada. The funder provided support in the form of research materials but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.