Assessment of Vitamin D Status in Overweight Pregnant Women Living in High Latitude Environments

Researchers pay close attention to vitamin D status in pregnant women due to its influence on a number of physiological processes, including gestation. This is especially relevant for residents of northern territories. The purpose of this paper was to study changes in vitamin D levels by trimester in overweight pregnant women living in high latitudes. Materials and methods. The research involved 53 pregnant women aged between 22 and 39 years and living in the Khanty-Mansi Autonomous Okrug – Yugra. The anthropometric data were analysed based on the body mass index (BMI) calculation when measuring height and body weight in the 1st trimester of pregnancy. The main group included overweight patients (n = 23; BMI ≥ 25.0–29.9 kg/m²), while the control group consisted of subjects with normal body weight (n = 30; BMI = 18.5–24.9 kg/m²). Vitamin D concentrations were determined by chemiluminescent immunoassay using 25(OH)D test systems (Abbott, USA) on the Abbott Architect i2000 SR analyser (Abbott, USA). Blood samples were taken and vitamin D level was determined in overweight pregnant women in each trimester; in the control group, the measurements were taken once. In addition, the distribution of pregnant women by vitamin D status was studied. Results. Low serum vitamin D levels were found in both groups. In the 1st and 2nd trimesters, vitamin D deficiency was identified in 65.3 % of pregnant women. Its concentration increased by the 3rd trimester; however, only in 17.4 % of women it reached the optimal value. For women living in the North, vitamin D level needs to be determined prior to pregnancy and controlled during gestation in order to correct deficiency in a timely manner by means of supplementation.