CPP patients exhibited significantly higher levels of luteinizing hormone (2.51 vs. 0.23 mIU/mL), kisspeptin (1.59 vs. 0.96 μg/L), and estradiol (25.86 vs. 13.41 pg/mL) and lower vitamin D levels (20.13 vs. 25.90 ng/mL) compared to controls (all p < 0.001). This evidence concerns the gene KISS1 and central precocious puberty.