It was conducted between 1966 and 1975 and involved thousands of men who had experienced a heart attack. Some took 3 grams of niacin a day — a large dose — and others took a placebo.

Men and women were excluded if their liver-associated ... both to be taken at night. After 30 days, niacin dose was raised to 1000 mg daily and maintained at this dose for 1 year.