According to recent studies, in the vitamin D deficiency state (VDD), pregnancy can be complicated and the optimal level of VD in the blood is one of the conditions for the realization of reproductive potential. The objective: the possibility to preventing calcitriol-associated pregnancy complications by the correcting VD deficiency at the preconception period. Materials and methods. 57 women with VDD were examined. A history of all women had a pregnancy complicated by placental dysfunction (PD); 27 of them were observed from the preconception period (main group – IA) and 30 – from the 1st trimester of pregnancy (comparison group – IB). The VD status by the blood level of the 25-hydroxyvitamin D by ELISA was determined. Women of both groups, in addition to the vitamin-mineral complex (VMC) were prescribed supplementation colecalciferol at a dose of 4.000 IU per day. Pregnant women of both groups received VMCs up to 16 weeks. After optimizing the level (3–4 months), women continued to take VD at a dose of 2.000 IU per day throughout pregnancy. Results. At the initial study, the VD level was 15.72±2.59 ng/ml in ІА and 16.1±1.99 ng/ml in ІВ group (U=883; p>0.05); after treatment increased to 38.31±3.29 ng/ml and 36.13±2.99 ng/ml (U=900; p>0.05). In group IA, the course of pregnancy was characterized by a lower frequency of complications: PD was diagnosed in 22.2% in group IA and 50% in group IB (F=0.0001; p<0.01); fetal distress in 3.7% and 10% (F=0.16; p<0.05): signs of amnionitis – in 18.5% and 33.3% (F=0.035; p<0.05); placental hypertrophy or hypotrophy – in 7.4% and 36.7% (F=0.00001; p<0.01), preeclampsia in 3.7% and 6.7% of women (F=0,54; p<0.05). The frequency of cesarean section in the comparison group was significantly higher (40% VS 25.9%, F=0.034; p<0.05). Conclusions. During pregnancy, which occurred in conditions of VDD, the frequency of some pregnancy complications, including preeclampsia, the threat of miscarriage, placental dysfunction was in 2–4 times higher than in women with optimized VD status. One of the directions of the individual management plan for women with a negative obstetric history can be the determination of the level of VD in the blood and correction of the VDD at the preconception period. This approach is a pathogenetically substantiated and promising direction for the prevention of some pregnancy complications and improvement of perinatal outcomes. Keywords: pregnancy, deficiency vitamin D, placental dysfunction, preconception period.