Dietary Supplementation Before, During and After Pregnancy: Results of the Cluster-Randomized GeliS Study.

The nutritional status of women before, during, and after pregnancy plays an important role in the health of mother and child. In addition to a balanced mixed diet, the increased need for folic acid and iodine should be met and ensured with supplements. The aim of this study was to assess dietary supplementation in the context of pregnancy and to investigate the effect of targeted counselling on supplementation behavior during and after pregnancy. In the context of the "Gesund leben in der Schwangerschaft" (GeliS; "Healthy living in pregnancy") trial, women in the intervention group (IG) received four structured lifestyle counselling sessions during pregnancy as well as postpartum, during which they were informed about appropriate dietary supplementation. The women in the control group (CG) received routine prenatal care. The intake of dietary supplements was recorded at different points using a questionnaire. In total, 2099 women were included in the analysis. Prior to conception, 31.3% of the women in the IG and 31.4% of the women in the CG took folic acid supplements. Prenatally, about half of the women took folic acid (IG: 54.1%; CG: 52.0%) and iodine (IG: 50.2%; CG: 48.2%). Statistically significant differences between the groups with regard to supplementation behavior could not be observed, neither prior to inclusion in the study nor during the intervention. During pregnancy, 23.0% of all women took docosahexaenoic acid (DHA) supplements and 21.8% iron supplements. 49.4% of the women additionally took vitamin D supplements. A higher educational level (p < 0.001), advanced age (p < 0.001), primiparity (p < 0.001), and a vegetarian diet (p = 0.037) were all associated with a higher level of dietary supplementation. The GeliS lifestyle counselling did not significantly improve the supplementation behavior of women during and after pregnancy. Women should be informed about adequate dietary supplementation early on within the scope of gynecological prenatal care.