by Meghan McMillin MS, RD

Did you know that vitamin D is not really a vitamin at all, but rather a hormone? And as a hormone, it plays an important role in fertility and reproduction. Vitamin D is necessary for the synthesis and metabolism of the reproductive hormones estrogen and testosterone. Additionally, multiple studies have shown that higher blood levels of vitamin D can improve glycemic control and insulin resistance in women with PCOS, decrease inflammation in women with endometriosis and is associated with better IVF outcomes.

Now, a new study published in July in the American Journal of Clinical Nutrition has revealed a connection between vitamin D deficiency and risk of miscarriage in the first trimester. The study tested the blood levels of vitamin D of 1,683 pregnant women prior to week 22 of gestation. Of the 1,683 participants, 58 had a miscarriage (3.5%), 25 in the first trimester and 33 in the second trimester. Those who had a miscarriage had lower blood concentrations of vitamin D at the time of sampling compared to those who did not. These findings suggest the protective role vitamin D may play against miscarriage and the importance of adequate intake.

So are you getting enough vitamin D? Knowing approximately 80-90% derives from sunlight-induced production in the skin, it’s safe to say most of us living in the northern hemisphere are likely deficient. Only a small amount of the body’s total vitamin D is derived from diet, so supplementation is often necessary to achieve adequate blood levels. At Pulling Down the Moon we recommend supplementing with 1000 IU of vitamin D daily. Depending on your levels you may need to supplement with more, so we always recommend having your doctor do a blood test first.