Vitamin D, which can be produced through sun exposure and is found in fatty fish and fortified milk, is perhaps the most highly researched vitamin in terms of sexual health. In men, vitamin D appears to support testosterone production and healthy endothelial function. (The endothelium is a thin layer of cells inside the heart and the blood vessels that is necessary for relaxing and contracting the blood vessels, controlling blood clots, and helping with the body’s immune response).

Researchers have found that vitamin D helps stimulate nitric oxide and antioxidants in the endothelium which reduces inflammatory diseases that can hurt a person’s vascular function. This, in turn, may improve vascular function, which is very important for erectile function.

Past studies have found correlations between healthy levels of vitamin D and improved male sexual function. One such study found that men with vitamin D deficiency had significantly lower International Index of Erectile Function (IIEF) scores than the men in the control group.

For women, vitamin D has been shown to help with the secretion of estrogen and the maturation of vaginal cells. Estrogen is a key hormone when it comes to female sexual function as it helps support healthy vaginal tissues and good lubrication, which makes sex more comfortable and enjoyable for women. In fact, intravaginal vitamin D suppositories have shown positive results in improving painful sex and vaginal atrophy symptoms in postmenopausal women when compared to a placebo.