Tandem mass spectrometry determined levels of 25(OH)D<sub>3</sub> and the active 1,25(OH)<sub>2</sub>D<sub>3</sub>.<h4>Results</h4>Women with and without PCOS did not differ in age, weight, insulin resistance, or systemic inflammation (C-reactive protein did not differ), but the free androgen index was increased. The gene discussed is CRP; the disease is Insulin resistance.