Parkinson Disease/etiology; Vitamin D/physiology; Animals; BCG Vaccine/therapeutic use; Calcitriol/adverse effects; Calcitriol/therapeutic use; Cholesterol/metabolism; Genetic Association Studies; Humans; Hypercalcemia/chemically induced; Mice; Mice, Knockout; NADPH Oxidases/physiology; Nuclear Receptor Subfamily 4, Group A, Member 2/deficiency; Nuclear Receptor Subfamily 4, Group A, Member 2/genetics; Nuclear Receptor Subfamily 4, Group A, Member 2/physiology; Parkinson Disease/drug therapy; Parkinson Disease/genetics; Parkinson Disease/metabolism; Parkinson Disease/prevention & control; Parkinsonian Disorders/etiology; Parkinsonian Disorders/genetics; Rats; Receptors, Calcitriol/deficiency; Receptors, Calcitriol/physiology; Ribonuclease, Pancreatic/physiology; Signal Transduction/physiology; Toll-Like Receptors/physiology; Tyrosine 3-Monooxygenase/physiology; Vascular Endothelial Growth Factor A/physiology; Vitamin D/therapeutic use; Vitamin D Deficiency/complications