Vitamin D Status and Effect on Blood Pressure in Pregnant Women in Latvia

Objectives. Vitamin D insufficiency is widespread in pregnant women, and it has been associated with the risk of hypertensive disorders during pregnancy. There is a debate as to whether serum vitamin D level impacts blood pressure.
Materials and Methods. The study has been implemented within the Latvian Council of Sciences project Nr.lzp-2019/1-0335. This cross-sectional study included 305 women up to the 7th day post-partum and pregnant in 8 hospitals from various regions of Latvia who consented to a face-to-face interview using a questionnaire on nutrition and lifestyle from July 2020 to December 2022. Blood samples were taken to measure serum vitamin D 25(OH) levels. IBM SPSS 28.0.1.1 was used to analyze the data.
Results. Only 51.80% (n=158) of the respondents reached the recommended optimal recommended vitamin D level (at least 30 ng/mL). 42.62% (n=130) denied the use of vitamin D3 supplementation (at least 1000 IU/day), and 29.51% (n=90) consumed 1000 IU/day or less each day during the last half year before delivery. Totally 8.85% (n=27) of all women have had at least one episode of elevated blood pressure (BP) (>140/90) during pregnancy. They had a mean vitamin D level of 30.68 ng/mL (SD±12.48), while the rest of the women had a mean level of 32.37 ng/mL (SD±13.84) (range, 8.0 to 91.3 ng/mL), but no statistically significant differences between the vitamin D level and both groups were found (U=3442,0, p=0.571).
Conclusions. Almost half of the women had insufficient serum vitamin D levels, and more than two-thirds of the women did not use vitamin D3 supplementation at all or below 1000 IU/day. The mean serum vitamin D level for women with at least one elevated BP episode could be assumed to be slightly lower than for the rest of the women.