Introduction. Pregnancy increases demand for many minerals and vitamins. Most of them should be provided primarily in a well-balanced diet, not just by supplementation using pharmaceutical products. Aim. The aim of the paper was to determine whether a correctly managed individual dietary intervention in pregnant patients leads to improvement of their nutrition and hence provision of necessary minerals and vitamins vital in terms of pregnancy. Material and methods. 57 healthy pregnant women with a correct body mass index, aged 22–41 were enrolled. Diet of the participants was assessed three times: upon enrolment (before the dietary intervention was introduced), after week 10, and after week 18 based on their food diaries filled in on an on-going basis. Results. Insufficient intake of most minerals and vitamins was noted prior to the dietary intervention. After 18 weeks of the intervention, clearly too low intake expressed as a percentage of recommended intake was noted for iron and folates. The diet did not provide the required amount of potassium as well. Conclusions. Patients who underwent an 18 week dietary intervention during pregnancy are capable of providing sufficient amounts of most minerals and vitamins through a proper dietary balance. Folic acid is an exception and it should be provided from other sources as well. Pregnant women should also consider supplementation of iron as, according to the study, patients are capable of providing only half of the recommended intake of this important mineral. In order to complement potassium, intake of foodstuffs rich in this mineral should be increased.

Key words: diet in pregnancy, dietary intervention, pregnancy, supplementation, diet.