Table 2.

Large randomised trials of antioxidant vitamins

Trial	Study participants	Follow up (years)	Vitamin dose	Outcomes	% Reduction in relative risk (95% CI)
Trials of vitamin E
Alpha-tocopherol, beta carotene cancer prevention study (ATBC)13  14 15	29 133 male smokers in Finland	6.1	50 mg/day	Total mortality	−2 (−9 to 5)†
				Death from cardiovascular disease	2 (−8 to 11)
				Angina	9 (1 to 17)
Chinese study16	29 584 adults in Linxian province	5.2	30 mg/day*	Total mortality	9 (0 to 17)
				Death from cerebrovascular disease	9 (−8 to 24)
Cambridge heart antioxidant study (CHAOS)17	2002 patients with coronary artery disease in the United Kingdom	1.4	800 IU or 400 IU/day	Total mortality	−29 (−119 to 24)
				Death from cardiovascular disease	−10 (−96 to 39)
				Non-fatal myocardial infarction	77 (53 to 89)
Trials of β carotene
Alpha-tocopherol, beta carotene cancer prevention study (ATBC)13 14	29 133 male smokers in Finland	6.1	20 mg/day	Total mortality	−9 (−17 to −2)†
				Death from cardiovascular disease	−11 (−23 to 1)
				Death from cancer	−9 (−23 to 3)
β Carotene and retinol efficacy trial (CARET)18	18 314 male smokers, former smokers and workers exposed to asbestos in the United States	4.0	30 mg/day‡	Total mortality	−17 (−33 to −3)
				Death from cardiovascular disease	−26 (−61 to 1)
				Death from cancer	−46 (−100 to −7)
Physicians health study (PHS)19	22 071 male physicians in the United States	12.0	50 mg/alternate days	Total mortality	−2 (−11 to 7)
				Death from cardiovascular disease	−9 (−27 to 7)
				Death from cancer	−2 (−18 to 11)
Skin cancer prevention study (SCPS)19a	1188 men and 532 women in the United States	8.2	50 mg/day	Total mortality	−3 (−30 to 18)
				Death from cardiovascular disease	−16 (−64 to 18)
				Death from cancer	17 (−29 to 56)

^*In addition to vitamin E, selenium and β carotene supplements were used. 

^†Minus sign indicates an increased risk. 

^‡Patients randomised to β carotene also received 25 000 U/day of retinol (vitamin A)