Understanding Vitamin B3 – Niacin


At the ordinary FDA level, niacin doesn’t do anything very dramatic. Except that we do need it for some of the most important functions in our body, like releasing energy in our cells, making hormones, and working with the other members of the B team to keep the body running smoothly.

The Role It Plays

Niacin is essential for more than 50 different processes in our body. Most of these processes boil down to helping the body produce energy from the foods we eat.

Niacin make enzymes that help our cells turn carbohydrates into energy. As part of the energy end of things, niacin also helps control how much glucose (sugar) is in our blood, which in turn helps give us energy when we need it.

Niacin also acts as an antioxidant within our cells – every bit helps when it comes to fighting free radicals. However, niacin only works as an on the spot antioxidant for mopping up the free radicals made when it’s being used to release energy. (It’s nowhere near as powerful as some other vitamins for battling free radicals).

Niacin works closely with all its B relatives, but it’s especially close to riboflavin and pyridoxine. All three work together to keep us in overall good health. They’re especially important for skin, nervous system, and digestion.

In very large amounts, niacin can be a valuable treatment for lowering high cholesterol but it doesn’t keep you from getting high cholesterol.

Another interesting role for niacin may be in helping people with the severe form of diabetes called insulin-dependent diabetes mellitus, or IDDM.

Types Of Niacin

Niacin, a water-soluble B vitamin, comes in two forms: nicotinic acid and niacinamide (also sometimes called nicotinamide). To avoid confusion with nicotine, the addictive substance in tobacco, the name nicotinamide isn’t used very often (niacin has nothing to do with nicotine). The word niacin is generally used to mean both forms. Niacinamide is the form usually found in supplements.


The RDA for niacin is based mostly on how many calories you eat – but which foods those calories come from is also part of the picture. The calorie part is easy: At a bare minimum, you need 6.6 mg of niacin for every 1,000 calories you eat. This ratio assumes that you eat 2,000 calories a day and get at least 13 mg of niacin a day. If you don’t eat that much, you still need the same amount of niacin.

The food part: About half of the niacin comes straight from the food we eat, but the other half is made in the body from the proteins we eat. When we eat protein (animal or plant), the body breaks the proteins down into their building blocks – amino acids. One of those building blocks is the amino acid tryptophan. The body uses about half the tryptophan for making 50,000-plus proteins we need. The other half gets converted to niacin.

The RDA ignores the tryptophan and only counts the niacin we get from food. That’s why even though average Americans only get about 11 mg a day of niacin from their diet, very few people are deficient – they make the rest from tryptophan.


Age Niacin
0 – 0.5 year 5.0 mg
0.5 – 1 year 6.0 mg
1-3 years 9.0 mg
4-6 years 12.0 mg
7-10 years 13.0 mg
Men 11-14 17.0 mg
Men 15 – 18 20.0 mg
Men 19 – 50 19.0 mg
Men 50+ 15.0 mg
Women 11-18 15.0 mg
Women 19-50 15.0 mg
Women 50+ 13.0 mg
Pregnant Women 17.0 mg
Nursing Women 20.0 mg



Safe Dosage

Not too many people need supplements of niacin alone – if you’re low on niacin, you’re almost certainly low on the other B vitamins and should take a complete B supplement.

If you really feel you need a niacin supplement due to an inadequates diet, you can buy tablets or capsules containing 100 mg, 250 mg, or 500 mg. You’ll have a choice of niacinamide or nicotinic acid. If you just want to supplement your niacin level, choose niacinamide in the smallest dose. Don’t overdo – even 100 mg of niacinamide can cause heartburn, nausea, and headaches for some people.

The only real reason to take nicotinic acid at all is to treat high blood cholesterol under a doctor’s supervision. There are some nasty side effects from the large doses you need to take – and some very good reasons why some people shouldn’t take them at all.

Doctor’s have known for many years that large doses of nicotinic acid – between 2 and 3 grams a day – lower LDL (“bad”) cholesterol and triglycerides and raise HDL (“good”) cholesterol. Niacin works on high cholesterol pretty well bu itself. Many people need a combination of drugs to really make a dent in their high cholesterol, though. Niacin can work well here too, especially when it’s combined with drugs such as lovastatin (Mevacor), pravastatin (Pravachol), or simvastatin ( Zocor). The one-two punch can bring your cholesterol way down. Do not try niacin supplements on your own to lower your cholesterol. The doses needed are so high that the niacin stops being a supplement and becomes a drug. You must work with your doctor and have your cholesterol and liver functions checked often. Also, if you are already on cholesterol drugs – do not stop taking them and switch to niacin. And do not keep taking your cholesterol drugs and start taking niacin. Discuss this with your doctor first.

Not everyone with high cholesterol should take niacin. If you have diabetes, extra niacin could cause your blood sugar to go up. If you have gout, niacin could trigger an attack. If you take medicine for high blood pressure, niacin could make your blood pressure drop too low. And if you have liver disease or ulcers, niacin could make these problems worse.

Large doses (and even not so large doses) of nictotinic acid cause a nasty side effect called the niacin flush. About 15 to 30 minutes after you take it, your face and neck get really red and hot. The flush can go on for half an hour or longer and then it wears off. You can build up a tolerance to niacin flushing by starting with smaller doses and gradually taking bigger ones. Taking the niacin on a full stomach also seems to help.

Another way to avoid flushing is to use the sustained-release (SR) form of nicotinic acid but don’t take it. It’s good at lowering your LDL cholesterol and triglycerides, but it doesn’t do much to raise your HDL level and it can also cause serious liver problems.

The best way to avoid flushing is to avoid nicotinic acid and take niacin in the form of inositol hexaniacinate (IHN). IHN works on cholesterol just as well as nicotinic acid, but without the side effects. You still need to talk to your doctor before taking it though.

Make It Work Better

Not too many people need supplements of niacin alone – if you’re low on niacin, you’re almost certainly low on the other B vitamins and should take a complete B supplement.

Good Sources

Niacin Rich Foods:

Almonds, asparagus, avocado, whole wheat bread, chick peas, corn, cottage cheese, cream of wheat, kidney beans, mushrooms, navy beans, nectarine, peanut butter, peanuts, peas, potato, brown rice, wild rice, spinach, sunflower seeds, sweet potato, tomato, and wheat germ

Tryptophan Rich Foods:

avocado, banana, black beans, chicken breast, corn cottage cheese, dates, egg, flounder, oatmeal, peanuts, pear, and turkey.


Because you don’t really need all that much niacin to begin with, and because you make niacin from the tryptophan in protein, real niacin deficiency is very rare in the developed world. However, pellagra, the deficiency disease caused by lack of niacin was a problem for poor people in Europe, Africa and North America back in the 1930’sand is still a problem in impoverished areas of Asia and Africa.

You could be likely to get pellagra or even be slightly deficient in niacin if you abuse alcohol. Alcohol blocks your uptake of all the B vitamins. Also if you’re a strict vegetarian or a vegan. You may not get enough protein.

Anyone who is low on niacin is low on all the B vitamins. The reason is always poor diet.

5 Responses to “Understanding Vitamin B3 – Niacin”
  1. Tom Humes says:

    Nice Site layout for your blog. I am looking forward to reading more from you.

    Tom Humes

  2. Cynth says:

    RE: niacin therapy
    Lots of information at http://www.cholesterolscore.com

  3. Rebecca Wagner says:

    I read an article recently about niacinamide having a very positive effect on Alzheimer’s in mice, and a positive cognitive effect in normal mice. I’m concerned about possible side effects, such as macular edema, which I already have some of, and blood pH levels. Does regular niacin cause lowering of blood pH? What is the difference between niacinamide and IHN? Thank you.

  4. francesca says:

    i really like the flushing feeling and i just started taking niacin yesterday and it already seems like i dont feel anymore flushing and i want to but i dont want to take too much.

  5. Linda Miller says:

    great news about niacin. Bless You Linda

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