Supplement use in relation to dietary intake in pregnancy: an analysis of the Swedish GraviD cohort.

We aimed to study supplement use in relation to dietary intake among pregnant women in Sweden, and adherence to the Nordic Nutrition Recommendations among supplement and non-supplement users. Pregnant women were recruited at registration to antenatal care in 2013–2014. In third trimester, supplement use was collected using a questionnaire, and dietary intake was collected using a FFQ. The majority (64 %) of the 1044 women reported use of one or more supplements. Among all, 0–23 % reported dietary intakes above recommended intake (RI) of vitamin D, folate, Fe and Se. Median dietary intakes of thiamine (1·4 . 1·3 mg = 0·013), phosphorus (1482 . 1440 mg = 0·007), folate (327 . 316 µg = 0·02), Fe (12 . 11·5 mg = 0·009), Mg (361 . 346 mg < 0·001) and Zn (10·7 . 10·4 mg = 0·01) were higher among supplement users compared with non-users. Larger proportions of supplement users than non-users adhered to RI of dietary intakes of thiamine (42 % . 35 % = 0·04) and Mg (75 % . 69 % = 0·05). Among non-users, a minority had dietary intakes above RI for vitamin D (6 %), folate (10 %) and Fe (21 %). The majority (75–100 %) of supplement users had total intakes above RI for most nutrients. In conclusion, supplement use contributed substantially to reaching RI for vitamin D, folate and Fe. Supplement users had a higher dietary intake of several nutrients than non-users. This highlights that non-supplement users are at risk of inadequate nutrient intakes during pregnancy, suggesting a need for heightened awareness of nutritional adequacy for pregnant women.