1,25(OH)D, 1,25-hydroxyvitamin D or calcitriol; 25OHD, 25-hydroxyvitamin D; BMI, body mass index; CRP, C -reactive protein; IL, interleukin; MetS, metabolic disease; PASI, psoriasis area and severity index; RDAs, recommended dietary allowances; TNF, tumor necrosis factor; VDR, vitamin D receptor. The gene discussed is CRP; the disease is metabolic syndrome.