In a vitamin C and E study, researchers noted that diabetics who have a heart attack produce abnormally high levels of unstable oxygen molecules that damage cells and theorized that the antioxidant vitamins C and E could help diabetics live longer after a heart attack. Doctors gave 122 diabetics who just had a heart attack 1,000 mg of vitamin C intravenously over 12 hours, followed by 400 mg of vitamin C plus 200 mg of vitamin E orally three times per day or a placebo. After 30 days, diabetics who had taken vitamins C and E were 68 percent less likely to have died than those who did not take vitamins C and E.
In an insulin study, researchers thought that vitamin K would increase insulin sensitivity in older adults who were not diabetic. Doctors followed 355 non-diabetic men and women, aged 60 to 80, who were taking 500 mcg of vitamin K (phylloquinone) per day as part of a study on bone loss. After 36 months, men who had taken vitamin K had significantly better insulin sensitivity than men who had taken a placebo. There was no effect for women. Insulin helps the body convert blood sugar (glucose) into energy. In diabetes, the body mishandles insulin, leading to chronically high blood sugar levels.