The more common name for vitamin B-3 is niacin. This crucial nutrient has been shown to help lower cholesterol and triglyceride levels, as well as raise levels of HDL (aka good) cholesterol. Taking a niacin supplement sometimes has a dramatic effect, causing what’s known as niacin flush. Blood rushes to your skin, making it feel tingly and causing you to turn red. This effect is harmless but related to its benefits. Niacin is a vasodilator, causing your blood vessels to relax, which allows more blood to flow. This can be a big advantage when taken before workouts. Take about 100 to 500 milligrams of niacin with your preworkout protein shake to take advantage of the flush.