Vitamin D is primarily generated in the skin, in response to direct absorption of ultraviolet B radiation. Vitamin D can also be obtained through fortified foods and oral supplements. Lipid abnormalities are common in the general population, and are regarded as a modifiable risk factor for cardiovascular disease. Recently low vitamin D status has been shown to be associated with increased risk of developing hyperlipidemia. Statins are normally the first-line therapy for hypercholesterolemia. It is also reported that vitamin D can improve serum lipid levels. However, its effects on hypercholesterolemia patients remain unclear. The investigators planned to determine the efficacy of combination therapy with statins and vitamin D in a cohort of hypercholesterolemia patients. This study may shed light as to whether oral vitamin D supplementation can be an adjunct therapy in hypercholesterolemia patients.