Niacin, also known as vitamin B3, is an important nutrient. In
fact, every part of your body needs it to function properly.
As a supplement, niacin may help lower cholesterol, ease
arthritis and boost brain function, among other benefits.
However, it can also cause serious side effects if you take
large doses. This article explains everything you need to know
What Is Niacin?
Niacin is one of the eight B-vitamins, and it’s also called vitamin B3.
There are two main chemical forms and each has different
effects on the body. Both forms are found in foods as well as
Nicotinic acid: As a supplement, nicotinic
acid is the form of niacin that’s used to treat high
cholesterol and heart disease (1).
Niacinamide or nicotinamide: Unlike
nicotinic acid, niacinamide doesn’t lower cholesterol.
However, it can help treat type 1 diabetes, some skin
conditions and schizophrenia (2).
Niacin is water-soluble, so your body doesn’t store it. This
also means that your body can excrete excess amounts of the
vitamin if it’s not needed.
Your body gets niacin through food, but also makes it from the
amino acid tryptophan.
Bottom Line: Niacin is one of eight
water-soluble B vitamins. It’s also known as nicotinic acid,
niacinamide and nicotinamide.
How Does Niacin Work?
As with all of the B vitamins, niacin helps convert food into
energy by helping enzymes do their job.
You can get a sense of what a nutrient does by looking at what
happens when you’re deficient. These are some of the symptoms
of niacin deficiency:
- Memory loss and mental confusion
- Skin problems
That being said, deficiency is very rare in most Western
Severe niacin deficiency, or pellagra, mostly occurs in third
world countries, where diets are not varied.
Bottom Line: Niacin is a vitamin that makes
up two major cofactors, which are compounds that help enzymes
How Much Do You Need?
Therapeutic doses of niacin are higher than the recommended
amounts and should only be taken under medical supervision.
Here are the recommended dietary allowances (RDAs) for niacin
- 0–6 months: 2 mg/day*
- 7–12 months: 4 mg/day*
*Adequate Intake (AI)
- 1–3 years: 6 mg/day
- 4–8 years: 8 mg/day
- 9–13 years: 12 mg/day
Adolescents and Adults
- Boys and men, 14 years and older: 16 mg/day
- Girls and women, 14 years and older: 14 mg/day
- Pregnant women: 18 mg/day
- Breastfeeding women: 17 mg/day
Bottom Line: The recommended amount of
niacin depends on your age and gender. Men need 16 mg per
day, while most women need 14 mg per day.
9 Health Benefits of Niacin
1. Lowers LDL Cholesterol
Niacin has been used since the 1950s to treat high cholesterol
However, niacin is not the primary treatment for high
cholesterol due to its possible side effects (9).
2. Increases HDL Cholesterol
In addition to lowering LDL cholesterol, niacin also raises
“good” HDL cholesterol.
3. Lowers Triglycerides
Niacin’s third benefit for blood fats is that it can lower
triglycerides by 20–50% (7).
It does this by stopping the action of an enzyme that’s
involved in triglyceride synthesis (1).
Consequently, this lowers the production of low-density
lipoprotein (LDL) and very low-density lipoprotein (VLDL).
Therapeutic doses are needed to achieve these effects on
cholesterol and triglyceride levels (1).
4. May Help Prevent Heart Disease
Niacin’s effect on cholesterol is one way it can help prevent
But newer research also suggests another mechanism by which it
benefits your heart.
It can help reduce oxidative stress and inflammation, both of
which are involved in atherosclerosis, the hardening of the
Some research has suggested niacin therapy, either alone or in
combination with statins, could help lower the risk of health
problems related to heart disease (12).
However, the research is mixed.
A recent review concluded that niacin therapy doesn’t
significantly help reduce the risk of heart attack, stroke or
death from heart disease among people with heart disease or
those who are at a high risk (10).
5. May Help Treat Type 1 Diabetes
Type 1 diabetes is an autoimmune disease in which the body
attacks and destroys insulin-creating cells in the pancreas.
However, for people with type 2 diabetes, the role of niacin is
On one hand, it can help lower the high cholesterol levels that
are often seen in people with type 2 diabetes (14).
On the other hand, it has the potential to increase blood sugar
As a result, people with diabetes who take niacin to treat high
cholesterol levels also need to monitor their blood sugar
levels carefully (14).
6. Boosts Brain Function
Your brain needs niacin, as a part of the coenzymes NAD and
NADP, to get energy and function properly.
In fact, brain fog and even psychiatric symptoms have been
associated with niacin deficiency (15).
Some types of schizophrenia can be treated with niacin, as it
helps undo the damage to brain cells that occurs as a result of
7. Improves Skin Function
Niacin helps protect skin cells from sun damage, whether it’s
used orally or applied to the skin in lotions (19).
And recent research suggests it may help prevent some types of
skin cancer (20).
A 2015 study found that taking 500 mg of nicotinamide (a form
of niacin) twice daily reduced rates of non-melanoma skin
cancer among people at a high risk of skin cancer (20).
8. May Reduce Symptoms of Arthritis
Another study in lab rats found that an injection with the
vitamin reduced inflammation related to arthritis (22).
Although this is promising, more research is needed in this
9. Treats Pellagra
Thus, taking a niacin supplement is the main treatment for
Niacin deficiency is rare in industrialized countries. However,
it may occur along with other diseases, such as alcoholism,
anorexia or Hartnup disease.
Bottom Line: Niacin can help treat many
conditions. Most notably, it helps raise HDL levels, while
lowering LDL and triglycerides.
Top Food Sources of Niacin
Niacin is found in a variety of foods, especially meat,
poultry, fish, bread and cereal.
Some energy drinks are also loaded with B vitamins, sometimes
in very high doses.
Here is how much niacin you get from a serving of each of the
- Chicken breast: 59% of the RDI (24).
Light tuna, canned in oil: 53% of the RDI
- Beef: 33% of the RDI (26).
- Smoked salmon: 32% of the RDI (27).
- Bran flakes: 25% of the RDI (28).
- Peanuts: 19% of the RDI (29).
- Lentils: 10% of the RDI (30).
Whole wheat bread, 1 slice: 9% of the RDI
Bottom Line: Many foods deliver niacin,
including fish, poultry, meat, legumes and grains.
Should You Supplement?
Everyone needs niacin, but most people can get enough from
their diet alone.
However, if you are deficient or have another condition that
may benefit from higher doses, your physician may recommend a
In particular, niacin supplements may be recommended for people
with high cholesterol and heart disease risk factors, but who
can’t take statins.
Supplemental forms are prescribed in doses that are much higher
than the amounts found in food. Often, therapeutic doses are
measured in grams, not milligrams.
Since large amounts have many possible side effects, it’s
important that you tell your physician if you are taking niacin
as part of any supplement.
Bottom Line: Niacin supplements may be
recommended for certain conditions. However, they can have
negative side effects and should be discussed with your
Side Effects and Cautions for Supplemental Use
There’s no danger in consuming niacin in the amounts found in
But supplemental doses can have various side effects, including
nausea, vomiting and liver toxicity (4).
Below are some of the most common side effects of niacin
Niacin flush: Possibly the most common side
effect is a flush that results from the dilation of blood
vessels. In addition to a flush on the face, chest and neck,
people can experience a tingling, burning sensation or pain
Stomach irritation and nausea: Nausea,
vomiting and general stomach irritation can occur,
particularly when people take slow-release nicotinic acid. It
seems to be related to elevated liver enzymes (34).
Liver damage: This is one of the dangers of
taking high doses of niacin over time to treat cholesterol.
It’s more common with slow-release nicotinic acid, but it can
also result from the immediate-release form (35, 36).
Blood sugar control: Large doses of niacin
(3–9 grams per day) have been linked to impaired blood sugar
control in both short- and long-term use (37, 38).
Eye health: One rare side effect is blurred
vision, in addition to other negative effects on eye health
Gout: Niacin can increase levels of uric
acid in the body, leading to gout
Bottom Line: Supplemental niacin can cause
several side effects, especially in large doses. The most
common of these is the niacin flush, which can occur even at
Niacin is one of eight B-vitamins that are important for every
part of your body.
Luckily, you can get all the niacin you need through your diet.
However, supplemental forms are sometimes recommended to treat
certain medical conditions, including high cholesterol.