Although the effects of PTH and vitamin D may have been mitigated as we analyzed the subjects with normal calcium levels, we still cannot preclude the possibility of secondary hyperthyroidism caused by low serum 25-hydroxyvitamin D levels which is prevalent in Korean subjects[39] and its influence on CVD considering the close association between PTH and CVD.[40] Third, we have no information on the dietary intake of calcium or vitamin D or medications, factors that could affect serum calcium, fibrinogen, and homocysteine levels. The gene discussed is PTH; the disease is hyperthyroidism.