Should we pay special attention to the supplementation for patients with a congenital foetal heart defect, whether they require special care, assuming that each subsequent pregnancy should be planned? Should patients with cardiac problems in their current pregnancy make any changes to their regular supplementation? In our short report we would like to discuss the issues of supplementation, especially folates and vitamin D, from the perspective of prenatal cardiology and specific problems affecting postnatal prognosis, paying special attention to the prevention of COVID-19 and pre-eclampsia during pregnancy. We propose that our observations be considered concerning mainly rich supplementation with folic acid as well as vitamin D for patients with cardiac problems in the foetus.