Introduction:
The state of the health and diet of the pregnant woman directly affect the development and growth of the fetus and newborn child. Pregnancy increases the demand for nutrients and minerals, and their primary source for the future mother should be a balanced diet. Supplementation is recommended only in the case of a deficiency of vitamins and minerals. The aim of the study was to determine the effect of socioeconomic factors (income, education, employment status, place of residence) on supplementation of the diet of pregnant women.

Material and methods:
The research material consisted of information obtained by means of an anonymous questionnaire survey among 1842 women in the first days after birth, hospitalized in the Department of Gynaecology and Obstetrics of the Medical University of Silesia in Ruda Slaska. The of research period was 15.04.2013–30.09.2014.

Results:
92.3% of respondents with higher education supplemented their diet with folic acid, and only 65.1% of women with primary education. In the case of multivitamins it was respectively 79.2% and 51.6%, while in relation to omega-3 – 44.1% and 14.3%. Folic acid was taken by 94.1% of women in the highest range of net income per family member and 75% in the lowest range. In the case of multivitamins it was respectively 74.3% and 59.3%, while omega-3 – 46.1% and 23.6%.

Conclusions:
Women with higher education, living in big cities or villages, professionally active and with a higher net income per family member more often take supplements during pregnancy. Marital status does not affect the decision to take dietary supplements by a pregnant woman.