“…Overall, 1548 (873 intervention: 675 control) participants were included in clinical trials and 5,868,641 (9764 intervention: 5858877 control) participants were included in NRIS. Most studies were conducted in Spain [ 3 , 6 , 14 , 25 , 26 , 33 , 34 ], with three in France [ 4 , 5 , 28 ] and Italy [ 15 , 30 , 35 ], two in India [ 8 , 13 ], and one each in Brazil [ 12 ], Britain [ 31 ], Canada [ 27 ], Iraq [ 11 ], Saudi Arabia [ 9 ], Turkey [ 29 ], Mexico [ 10 ], and United States [ 32 ]. A total of five studies (one RCT [ 27 ] and four NRIS [ 11 , 14 , 31 , 32 ]) targeted vitamin D supplementation as primary prevention, five studies (two RCTs [ 8 , 10 ] and three NRIS [ 4 , 15 , 30 ]), as secondary prevention and thirteen studies (six RCTs [ 3 , 9 , 12 , 13 , 25 , 26 ] and seven NRIS [ 5 , 6 , 28 , 29 , 33 , 34 , 35 ]), as tertiary prevention.…”