What is Vitamin B3 (Niacin)?
Niacin (or vitamin B3) is a water-soluble B vitamin which has several important health benefits including:
- Part of a coenzyme used in energy metabolism and so helps to turn the food you eat into energy.
- important for the development and functioning of the cells in your body.
- keeps the skin, nervous system and digestive system healthy
- High doses may help regulate cholesterol control
- may help to prevent recurrent heart attack
Dietary Sources of Niacin
Niacin comes in 2 forms (nicotinic acid and nicotinamide) which are both found in food. Niacin is found naturally in many foods, and is sometimes added to some foods. It is found in:
- Animal foods, such as eggs, poultry, beef, pork, and fish
- Some types of nuts, legumes, and grains
- Enriched and fortified foods, such as many breads and cereals
- Brewer΄s yeast
How Much Niacin do I Need?
The daily requirements of niacin are 16.5mg for men and 13.2mg for women.
Niacin cannot be stored in the body as it is water-soluble and so it must be taken in your diet every day. It is usually found in dietary supplements as nicotinic acid or nicotinamide.
Nicotinamide is preferred as it does not cause the side effects associated with nicotinic acid. If you prefer to take nicotinic acid, do not buy slow-release products as they can be harmful to the liver. It should be taken with food in order to reduce the possibility of stomach upsets.
What Happens if I Take Too Much Niacin?
The niacin that food naturally contains is safe. Supplements with 30mg or more nicotinic acid can cause skin flushes which can lead to headaches, rashes, and dizziness. Taking high doses for a long time can lead to liver damage.
There is not enough evidence to suggest that high daily doses of nicotinamide supplements are harmful. Taking 17mg or less of nicotinic acid supplements a day, or 500mg or less of nicotinamide supplements a day, is unlikely to cause any harm.
Niacin Deficiency
The symptoms of niacin deficiency include fatigue, irritability, insomnia, diarrhoea, loss of appetite, and digestive problems. Niacin deficiency is rare in western countries as it is usually added to white flour.
Possible Side Effects of Niacin
Nicotinic acid can cause skin flushes (especially to the face, arms and chest) as it causes vasodilation. This vasodilation can also cause headaches, nausea and dizziness.
More serious side-effects include dark urine, yellow skin or eyes, and loss of appetite. If you have liver disease or low blood pressure do not take niacin. Use of niacin or nicotinamide may cause diabetes or glaucoma to become worse.
Possible Interactions
Niacin can decrease the effectiveness of insulin in diabetics and increase the effects of antihypertensive drugs.
High quality niacin supplements can be found here.