The daily supplement bar contained 3.3 g of l-arginine, 250 mg of vitamin C, 200 IU of vitamin E, 25 mg of niacin, 2 mg of vitamin B6, 4.8 mcg of vitamin B12, and 200 mcg of folic acid, plus a healthy balance of fat, carbohydrates, sugars, and protein. Compared to placebo, women who took l-arginine were less than half as likely to have pre-eclampsia. Women who got the supplement without l-arginine were also less likely to have pre-eclampsia, but l-arginine had a much greater benefit.