The prevalence of vitamin D deficiency in women with PCOS is about 67-85%. Vitamin D deficiency may play a significant role in many symptoms of PCOS including metabolic syndrome, insulin resistance, menstrual irregularities, infertility, hyperandrogenism, obesity and increase risk of cardiovascular diseases. Vitamin D can be found in salmon, cod liver oil, tuna, egg yolk, and mushrooms, though the best source that is most bioavailable is from sun exposure.