top of page
  • Writer's pictureDr. H. Singh, ND

The Incredible Role of Vitamin D in Polycystic Ovarian Syndrome (PCOS)

Polycystic Ovarian Syndrome (PCOS) is one of the most common reproductive disorders, estimated to affect about 5-10% of the population in conservative estimates and as high as 15% of higher risk populations. PCOS is looked at differently depending on which healthcare provider you see. For a lot of healthcare providers when they hear that you have PCOS they are inclined to prescribe a birth control pill because what they hear is "irregular cycles." For fertility doctors they are already thinking "letrozole or clomid, they are going to have a hard time ovulating and getting pregnant." For others it may go to "recommend weight loss, it is worsening their condition." But the reality is that PCOS affects the entire body, so we have to assess at wholistic methods to support your health from every aspect. Not just your cycles, ovulation, body-mass index, or hair growth. But instead looking at underlying causes and supporting all of the above in addition to a healthy gut microbiome, reducing inflammation, improving blood sugar balance and insulin sensitivity, improved hormone balance, and correcting nutrient deficiencies.

Does Vitamin D Deficiency affect PCOS?

One of the important nutrients that can affect PCOS is Vitamin D. Vitamin D deficiency has been shown a correlation to increased free testosterone, reduced sex-hormone binding globulin (SHBG - strongly binds free testosterone making it hard for the hormone to bind to receptors in various tissues of the body), increased hair growth, and irregular cycles.

A new study looked at the impact of supplementing with 50'000 IU of Vitamin D in patients with PCOS and Vitamin D deficiency. After 12 weeks of supplementation the levels of Vitamin D increased on blood tests, the available free testosterone decreased, there was a decrease in hirsutism scores, healthier ultrasound results when assessing for Ovarian cysts, and patients reported more regular cycles when compared to the control group.

Vitamin D, especially in Canada, can be something many are deficient in. Nonetheless, it is important to have a blood test done to determine your blood level of the vitamin as well as determine a safe supplement dose since Vitamin D in toxic levels can have serious adverse effects as well.

How Does Vitamin D affect Hormones?

Vitamin D has been shown to affect levels of anti-mullerian hormone (AMH) in the body, as well as increasing the production of SHBG. SHBG helps to bind extra free testosterone and prevents it from stimulating the androgen receptors on the ovary (as well as other tissues). It also leads to a decrease in parathyroid hormone (PTH - affects calcium homeostasis).


  1. Al-Bayyari, N., Al-Domi, H., Zayed, F., Hailat, R., & Eaton, A. (2020). Androgens and hirsutism score of overweight women with polycystic ovary syndrome improved after vitamin D treatment: A randomized placebo controlled clinical trial. Clinical Nutrition.

This article is in no way a replacement for medical advice or medical care, it is advised that anyone concerned about their Health should speak with their Naturopathic Doctor. Please discuss with your healtcare provider and only make changes to your medications regimen if recommended by your doctor and under their guidance.

220 views0 comments

Recent Posts

See All


bottom of page