They perform many other vital functions, such as converting vitamin D to an active form necessary for proper bone development and producing the hormone erythropoietin, which stimulates red blood cell production in your bones.
وَتُسَاهِمُ كُلْيَتَاكَ أَيْضًا فِي ضَبْطِ نِسْبَةِ ٱلْمَعَادِنِ فِي دَمِكَ ،‏ وَكَذلِكَ فِي ٱلتَّحَكُّمِ بِضَغْطِ ٱلدَّمِ وَحُمُوضَتِهِ .‏