Poster Topical Area: Maternal, Perinatal and Pediatric Nutrition

Location: Hall D

Poster Board Number: 358

P13-100 - Does dietary intake have a major influence on vitamin D status in early pregnancy? Results from a Canadian trial.

Sunday, Jun 10
8:00 AM – 6:00 PM

Objectives: Sub-optimal maternal vitamin D status in pregnancy is associated with reduced fetal bone length and infant/child bone mass. To assess adequacy of vitamin D status in Canadian women in early pregnancy we aimed to: 1) measure serum 25(OH)D for the D2 and D3 isomers; 2) Determine the major contributors to vitamin D status including diet (especially milk), supplements and season of the year.

Healthy pregnant women enrolled in the Be Healthy in Pregnancy (BHIP) randomized controlled trial (Southern Ontario, Canada) (NCT01689961) were assessed for vitamin D status (25(OH)D2 and D3 by LCMS-MS) and intake (3-day diet and supplement record analyzed by Nutritionist Pro) at 12-17 weeks gestation.

Of the 191 mothers included (94% Caucasian, mean pre-pregnancy BMI 25.8 kg/m2 (range 17.4-39.6 kg/m2)), 91% had adequate vitamin D status defined as > 50 nmol/L with mean ± SD = 71.9 ± 17.6 nmol/L. The 25(OH)D2 isomer was not detected in 92% of the population and averaged 0.5 ± 2.3 nmol/L in 15 subjects. Mean total vitamin D intake was 807 ± 1001 IU/d (range 32 - 11,062 IU/d), with 80% of subjects having intakes > EAR for vitamin D (400 IU/d) and 2% above the upper limit (4,000 IU/d). Prenatal vitamin supplements contributed 70% of the intake; 20% subjects also consumed a separate vitamin D supplement. Among food sources, milk contributed 39% of the intake of vitamin D, natural sources 30% and fortified foods 19%. In a regression analysis, non-milk dairy product consumption (e.g. cheese and cream, r2=0.12, p=0.05) and season of blood draw at recruitment (r2=0.12, p<0.001) were significantly associated with maternal vitamin D status in early pregnancy.

Most women achieved normal vitamin D status with intakes >EAR. The observed reliance on prenatal and other supplements during pregnancy as a source of vitamin D suggests lack of nutritional balance. In this healthy pregnant population, season appears to be a stronger factor than vitamin D intake in achieving adequate vitamin D status, likely due to sunshine exposure.

Funding Source: Supported by Dairy Farmers of Canada, CIHR and DFC/AAFC Dairy Research Cluster; in-kind by GayLea Foods & Ultima Foods.
MP is supported by a CIHR-Vanier scholarship and a Canadian Child Health Clinical Scientist Program award.

CoAuthors: Caroline Moore – McMaster University; Michelle Mottola – Western University; Stephanie A. Atkinson – McMaster University

Maude Perreault

PhD Student and Registered Dietitian
McMaster University
Hamilton, Ontario, Canada