Due to the types of patients included in the study, nutritional limitations should not exist in calcium intake in their normal diet. Prenatal control was early in most patients, without significant difference in supplying supplements among the groups related to gestational age (Table 3), controlling this potentially confounding factor; this study did not show a preventive effect on preeclampsia with the use of only calcium and the effect of the ethnicity as a risk factor agreed with the results from previous studies 3,5,11