Objective: At least one-third of pregnant women suffer from leg cramps. While the cause of these leg cramps is not fully understood, it starts during the third trimester, likely due to pregnancy-related physiological changes. The relation of serum 25-hydroxyvitamin D [25(OH)D] levels and leg cramps has been evaluate in this research.

Methods: The study included 95 pregnant patients who visited our gynecology and obstetrics outpatient clinic in January 2017 during weeks 24–39 of their pregnancies. Demographic characteristics, vitamin supplement use, and other factors that might have affected the 25(OH)D levels of the participating pregnant women were recorded.

Results: A statistically significant difference (p<0.0001) was found in the serum 25(OH)D levels between the patients who did and did not use supplemental 25(OH)D. A statistically significant difference was found in the groups of pregnant women regarding 25(OH)D levels and weight 69.60 ± 2.43 ng/dl among the patients who did not use supplemental 25(OH)D compared to 77.69 ± 2.20 ng/dl for those who did; p < 0.0162). There was no significant difference between the 25(OH)D serum levels and the number of cramps. A significant difference was found between the intensity and duration of the cramps and the number and duration of the cramps (p < 0.029 and p < 0.0001, respectively).

Conclusion: The use of supplemental 25(OH)D did not have a statistically significant effect on the occurrence of pregnancy-related leg cramps. The 25(OH)D levels were higher in the that supplemental 25(OH)D used group. A significant difference was found between the pregnant women’s weight and the occurrence of leg cramps (p < 0.0162). Vitamin D supplements may be used to prevent long period leg cramps for pregnant woman’s.