The active form of vitamin D, known as calcitriol, plays a crucial role in reproductive health. Research indicates that it helps regulate the genes involved in estrogen production, embryo implantation, and immune function.

​

Vitamin D, often referred to as “the sunshine vitamin,” is produced by the body in response to sun exposure. It can also be found naturally in foods such as fish, cod liver oil, dairy products, and fortified dairy and grain items. Additionally, vitamin D can be obtained through dietary supplements. Women who avoid sun exposure, are allergic to dairy products, or follow a strict vegan diet may be at risk for vitamin D deficiency. According to the National Institutes of Health, deficiency is diagnosed when blood levels fall below 30 ng/mL. However, it is recommended that vitamin D levels be maintained between 55 ng/mL and 80 ng/mL, as research suggests that these levels offer optimal protection against disease.

​

In the body, there are two primary forms of vitamin D: vitamin D 25(OH)D (also known as vitamin D 25-hydroxy) and vitamin D 1,25(OH)2D (calcitriol). Vitamin D 25-hydroxy is the biologically active form and is the preferred form for testing.