Poster Topical Area: Maternal, Perinatal and Pediatric Nutrition
Location: Hall D
Poster Board Number: 358
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.
Methods: 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.
Results: 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.
Conclusions: 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.
PhD Student and Registered Dietitian
Hamilton, Ontario, Canada