 Blood tests on patients with OFC generally show high levels of calcium ( normal levels are considered to range between 8 @.@ 5 and 10 @.@ 2 mg / dL , parathyroid hormone ( levels generally above 250 pg / mL , as opposed to the " normal " upper @-@ range value of 65 pg / mL ) , and alkaline phosphatase ( normal range is 20 to 140 IU / L ) . 
