The effect of ultraviolet index measurements on levels of vitamin D and inflammatory markers in pregnant women

Abstract

Background: Hypovitaminosis D is a risk factor for infertility and several adverse pregnancy outcomes. These negative effects of vitamin D deficiency may be due to inflammatory processes. T lymphocytes play a key role in the formation of immune response by producing some cytokines. Vitamin D is known to have significant effects on T lymphocytes and T regulator cells. The most significant determinant of vitamin D in the human body is sun exposure. The most important indicator determining the sun exposure in a region is the ultraviolet index (UVi). We tried to determine the effect of UV changes on vitamin D values during pregnancy and possible effects on inflammatory markers in a single region. Methods: The vitamin D serum values and blood count values of pregnant patients at the time of first admission were recorded in the months of April to September (AS) and October to March (OM). The daily UVi values of the Izmir region were obtained. These daily values were averaged according to the two groups. As inflammatory markers, the Neutrophil-Lymphocyte ratio (NLR), Platelet-Lymphocyte ratio (PLR), Monocyte-Lymphocyte ratio (MLR), mean platelet volume (MPV) and erythrocyte volume distribution (RDW) values were calculated from the blood count. Results: The UVi mean value was found to be 8 for AS and 3 for OM. There was a significant difference in the mean vitamin D values for the AS (42 patients) and OM (40 patients) periods. A predisposition to inflammatory processes was determined for the OM period in terms of the inflammation markers examined between the two groups. Our study showed lower levels of RDW and MPV and similar values for NLR, PLR and MLR according to the UVi values. Discussion: Vitamin D plays role in many systems as a hormone, a vitamin or an immunomodulator after activation in the skin tissue. Besides its known benefits to the musculoskeletal system, adequate serum vitamin D values reduce the risk of certain types of cancer, mental disorders, infectious diseases, cardiovascular diseases, type 2 diabetes mellitus, autoimmune disorders and adverse pregnancy outcomes. Additionally, lower UVi may be associated with lower vitamin D values in pregnant women and increased inflammatory markers in complete blood count. As a result, in order to avoid adverse pregnancy outcomes, the UVi values of regions may be useful for determining replacement of vitamin D during or before pregnancy.