The prevalence of diabetes or metabolic syndrome (MetS) has steadily increased in Korea and obesity is one of the most important risk factors for them. The prevalence of MetS in Korea increased rapidly from 24.9% in 1998 to 31.3% in 2007 and so did the prevalences of diabetes and obesity. MetS was associated with an increased risk of cardiovascular diseases (CVDs), and in particular was associated with the risk of coronary heart disease (CHD) in men and stroke in women. Diverse risk factors for either diabetes or metabolic syndrome have been reported, such as age, dietary habits, physical fitness, sleep deprivation, and decreased heart rate recovery (HRR). It has also been reported that the serum calcium concentration is positively correlated with glucose level. In addition, serum bilirubin has been consistently shown to be negatively correlated with the cardiovascular diseases (CVDs) as well as with CVD-related diseases and risk factors such as arterial hypertension, diabetes, MetS, and obesity. We analyzed data from the Korean Health and Genome Study to examine the association of serum total bilirubin (TB) and corrected calcium levels with the risk of DM development. DM incidence increased across baseline TB and calcium tertile categories. Hazard ratio (HR) for developing DM was higher in the highest tertiles compared with the lowest after adjusting for confounding variables. These results suggest that there could be multiple, diverse risk factors for diabetes and metabolic syndrome, which should be considered in the development of prevention strategies.