1. Characteristics of included trials with low risk of bias.
| Trial | Design | Number participants | Mean age | Suppl (Follow‐up)‐y | Beta‐carotene (mg) | Vitamin A (IU) | Vitamin C (mg) | Vitamin E (IU) | Selenium (µg) |
| SCPS 1990 | Parallel | 1805 | NA | 5 (5) | 50 | ||||
| Murphy 1992 | Parallel | 109 | NA | 0.003 (0.25) | 200000 | ||||
| NIT2 1993 | Parallel | 3318 | 54 | 6 (6) | 15 | 10000 | 180 | 60 | 50 |
| PPS 1994 | 2 x 2 | 864 | 61 | 4 (4) | 25 | 1000 | 440 | ||
| Pike 1995 | Parallel | 47 | 69 | 1 (1) | 2666 | 90 | 45 | ||
| AMDS 1996 | Parallel | 71 | 72 | 1.5 (1.5) | 12 | 750 | 200 | 50 | |
| CHAOS 1996 | Parallel | 2002 | 62 | 1.4 (1.4) | 600 | ||||
| NPCT 1996 | Parallel | 1312 | 63 | 4.5 (7.4) | 200 | ||||
| PHS 1996 | 2 x 2 | 22,071 | 53 | 12 (12.9) | 25 | ||||
| SKICAP AK 1997 | Parallel | 2297 | 63 | 3.8 (3.8) | 25000 | ||||
| MINVITAOX 1999 | 2 x 2 | 725 | 84 | 2 (2) | 6 | 120 | 16.5 | 100 | |
| NSCPT 1999 | 2 x 2 | 1621 | 49 | 4.5 (4.5) | 30 | ||||
| Correa 2000 | 2 x 2 x 2 | 976 | 51 | 6 (6) | 30 | 2000 | |||
| Jacobson 2000 | Parallel | 112 | 42 | 0.5 (0.5) | 12 | 500 | 400 | ||
| SPACE 2000 | Parallel | 196 | 65 | 1.42 (1.42) | 800 | ||||
| ALSRT 2001 | Parallel | 288 | 64 | 1 (1) | 1000 | ||||
| AREDS 2001 | 2 x 2 | 4757 | 68 | 6.3 (6.3) | 15 | 500 | 400 | ||
| HATS 2001 | 2 x 2 | 160 | 53 | 3 (3) | 25 | 1000 | 800 | 100 | |
| Graat 2002 | 2 x 2 | 652 | NA | 1 (1) | 1.2 | 2000 | 60 | 272 | 25 |
| HPS 2002 | 2 x 2 | 20,536 | NA | 5 (5) | 20 | 250 | 660 | ||
| REACT 2002 | Parallel | 297 | 68 | 3 (3) | 18 | 750 | 660 | ||
| VEAPS 2002 | Parallel | 353 | 56 | 3 (3) | 400 | ||||
| WAVE 2002 | 2 x 2 | 423 | 65 | 3 (3) | 1000 | 800 | |||
| White 2002 | Parallel | 100 | 63 | 0.23 (0.23) | 1000 | 223 | |||
| Wluka 2002 | Parallel | 136 | 64 | 2 (2) | 500 | ||||
| ASAP 2003 | 2 x 2 | 520 | NA | 6 (6) | 250 | 272 | |||
| ATBC 2003 | 2 x 2 | 29,133 | 57 | 6.1 (14.1) | 20 | 50 | |||
| Collins 2003 | 2 x 2 | 52 | 67 | 0.5 (2.5) | 400 | ||||
| Prince 2003 | Crossover | 61 | 58 | 0.25 (0.25) | 3 | 150 | 74.5 | 75 | |
| Allsup 2004 | Parallel | 164 | 83 | 0.15 (0.5) | 2666 | 120 | 60 | 60 | |
| CARET 2004 | Parallel | 18,314 | 58 | 4 (10) | 30 | 25000 | |||
| DATOR 2004 | Parallel | 24 | 51 | 0.5 (4.5) | 750 | ||||
| LAST 2004 | Parallel | 61 | 75 | 1 (1) | 10 | 2500 | 1500 | 500 | 200 |
| Meydani 2004 | Parallel | 617 | 84 | 1 (1) | 200 | 100 | |||
| Mezey 2004 | Parallel | 51 | 48 | 0.25 (1) | 1000 | ||||
| VECAT 2004 | Parallel | 1193 | 66 | 4 (4) | 500 | ||||
| DATATOP 2005 | 2 x 2 | 800 | 61 | 2.6 (13) | 2000 | ||||
| Graf 2005 | Parallel | 160 | 58 | 1.5 (1.5) | 5000 | ||||
| HOPE TOO 2005 | 2 x 2 | 9541 | 66 | 4.5 (7) | 400 | ||||
| Limburg 2005 | 2 x 2 | 360 | 47 | 0.83 (0.83) | 200 | ||||
| MAVIS 2005 | Parallel | 910 | 72 | 1 (1) | 2666 | 60 | 10 | ||
| Mooney 2005 | Parallel | 284 | 37 | 1.25 (1.25) | 500 | 400 | |||
| Tam 2005 | Parallel | 39 | 46 | 0.23 (2.67) | 500 | 800 | |||
| WHS 2005 | 2 x 2 | 39,876 | 55 | 10.1 (10.1) | 25 | 300 | |||
| Witte 2005 | Parallel | 32 | NA | 0.75 (0.75) | 2666 | 500 | 400 | 50 | |
| MAVET 2006 | Parallel | 409 | 63 | 4 (4) | 500 | ||||
| UK PRECISE 2006 | Parallel | 501 | 67 | 0.5 (0.5) | 200 | ||||
| Liu 2007 | Parallel | 763 | 85 | 1.6 (1.6) | 16 | 1333 | 80 | 74 | 20 |
| Plummer 2007 | Parallel | 1980 | NA | 3 (3) | 18 | 750 | 600 | ||
| WACS 2007 | 2 x 2 x 2 | 8171 | 61 | 9.4 (9.4) | 50 | 500 | 600 | ||
| ICARE 2008 | Parallel | 1434 | 69 | 1.5 (1.5) | 400 | ||||
| PHS 2008 | 2 x 2 x 2 | 14,641 | 64 | 8 (8) | 50 | 5000 | 500 | 400 | 25 |
| Garbagnati 2009 | 2 x 2 | 72 | 65 | 1 (1) | 19 | 240 | 700 | ||
| Grieger 2009 | Parallel | 115 | na | 0.5 (0.5) | 3 | 75 | 10 | ||
| SELECT 2009 | 2 x 2 | 35,533 | 62 | 5.5 (5.5) | 400 | 200 | |||
| SUVIMAX 2010 | Parallel | 13,017 | 49 | 7.54 (7.54) | 6 | 120 | 33 |
Abbreviation: NA, not available. Blank cells indicate that the supplement was not part of the trial.