Research shows that optimizing your vitamin D level can lower systolic blood pressure within weeks People with low vitamin D levels saw the most dramatic improvements, making testing your level a smart first step if you struggle with high blood pressure Vitamin D helps lower blood pressure by reducing fluid retention and relaxing blood vessels Taking vitamin D alongside magnesium and vitamin K2 increases its effectiveness and reduces the dose needed to reach optimal levels Have your vitamin D level checked to establish a baseline. From there, you'll be able to determine whether you need more sunlight exposure or need to take an oral supplement