Trial Information

Physicians' Health Study II: Trial of Vitamins in the Chemoprevention of Cancer, CVD, and Eye Disease

OBJECTIVES:

Primary

- To determine whether vitamin E every other day reduces the risk of developing prostate
cancer in older healthy male physicians.

- To determine whether daily vitamin C and/or a multivitamin reduces the risk of total
cancer in these participants.

- To determine whether vitamin E every other day, vitamin C daily, or a multivitamin
daily reduces the risk of major cardiovascular events in these participants.

Secondary

- To determine whether vitamin E and/or multivitamins reduce the risk of developing total
cancer, colon cancer, and colon polyps in these participants.

- To determine whether vitamin E, vitamin C, or multivitamins reduce the risk of
myocardial infarction and stroke in these participants.

- To determine whether vitamin E, vitamin C, or multivitamins reduce the risk of
age-related macular degeneration or cataract in these participants.

- To determine whether vitamin E, vitamin C, or multivitamins reduce the risk of early
cognitive decline in participants aged 65 and over.

The Physicians' Health Study II was a randomized, double-blind, placebo-controlled,
factorial trial that began in 1997 and ended in 2011. It was designed to test four
supplements -- (1) alternate-day vitamin E (400 international units of synthetic
alpha-tocopherol) or its placebo; (2) daily vitamin C (500 mg synthetic ascorbic acid) or
its placebo; (3) a daily multivitamin (Centrum Silver) or its placebo; and (4) alternate-day
beta carotene (50 mg Lurotin) or its placebo -- in the prevention of cancer, cardiovascular
disease, eye disease, and early cognitive decline among 14,641 male physicians aged 50 years
or older. Participants were randomly assigned in a 2x2x2x2 factorial trial to receive
combinations of the four active supplements or their placebos. Pills and/or packaging were
provided by BASF Corporation, Pfizer (formerly Wyeth, American Home Products, and Lederle),
and DSM Nutritional Products (formerly Roche Vitamins).

The beta-carotene component was discontinued on March 8, 2003; the vitamin E and vitamin C
components ended as scheduled on August 31, 2007; and the multivitamin component ended on
June 1, 2011.