A total of 390 patients (29%) had vitamin D insufficiency, while 714 patients (53%) had sufficient vitamin D. The mean preoperative PTH level was 41.0 ­pg/­ml (SD, 21.8) in patients with deficient vitamin D; 38.3 pg/ml (SD, 19.8) when the vitamin D level was classified as insufficient; and 31.9 pg/ml (SD, 12.8) in cases of sufficient vitamin D (Table 1). This evidence concerns the gene PTH and vitamin D deficiency.