Niacin or vitamin B3 is a water soluble vitamin that is important in energy production as it converts carbohydrates, fats and proteins into a usable form of energy. It is also required to produce DNA, produce and regulate cholesterol, sex hormones and stress-related hormones. Niacin also plays a role in optimizing insulin sensitivity. Good sources of niacin include brewer’s yeast, beef liver, beef kidney, fish, salmon, swordfish, tuna, sunflower seeds, and peanuts and fortified breads and cereals. The amino acid tryptophan can be converted into niacin. Vitamin E, vitamin C, selenium, glutathione and niacin are dependent on each other to maintain their metabolically active form and so sufficiency of these nutrients should be assessed together.
Excess niacin (>100mg) increases vasodilation and causes flushing of the skin and may increase the risk of liver damage. Other symptoms include stomach upset, headache, dizziness, and blurred vision. High doses of supplemental niacin can be used to lower cholesterol levels, however this should be assessed on an individual basis by your doctor.