Niacin (Vitamin B3)

No E-numberVitamins & mineralsOrigin: Lab-made

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The short answer

Niacin is vitamin B3 in the nicotinic acid form, added to flour and cereals because many diets fall short of it. Fortification amounts are small and safe, but a 100 mg supplement is a bigger dose, and that much nicotinic acid makes many people flush.

78/100

Use in moderation

Safe in small amounts; may bother some people or raise blood sugar.

E-numberNone

Comes fromLab-made

What it doesVitamins & minerals

Glycemic index—

Daily limitNot set

Also calledNiacin, Vitamin B3

Rules by country

🇺🇸 US FDAApproved

🇪🇺 European UnionApproved with limits

🇨🇦 Health CanadaApproved

CaliforniaNo extra rules

In the United States, niacin is permitted as a nutrient additive under the FDA's food additive rules for special dietary and nutritional additives, and it counts towards the flour enrichment standard. It has no E-number: the EU authorizes it as a nutrient for fortification under Regulation (EC) No 1333/2008 rather than as an additive, and EFSA set an upper level of 10 mg a day for nicotinic acid in adults.

Daily limit: Experts haven’t set a number because normal food amounts are far below any level of concern.

What is it?

Niacin is one of two forms of vitamin B3; the other is niacinamide. Both do the same job in the body, releasing energy from food and keeping skin and nerves in working order, but nicotinic acid has one extra effect: it dilates small blood vessels, and that is what people feel as the flush. Enriched flour has to carry 24 mg of niacin a pound, so the label amount is a correction rather than a dose.

Where it comes from: Niacin is manufactured by chemical synthesis rather than pulled out of food. The vitamin was isolated from liver in the 1930s and its structure worked out soon after, which is what made cheap, stable fortification of flour and breakfast cereals possible.

Why it’s in food

Enriching white flour and grain products
Fortifying breakfast cereals and drinks
Multivitamin and B-complex tablets
Lowering cholesterol at gram-sized doses
Correcting diets short of B3

Often found in

Enriched white flourBread and rollsBreakfast cerealsMultivitamin tabletsFortified pasta

Also listed as: Niacin, Vitamin B3, Nicotinic acid, Niacin (vitamin PP)

Health & gut impact

Pellagra and the original deficiencyBenefit

Niacin was identified as the cure for pellagra, the disease that followed diets built on polished maize, and a WHO review of pellagra links it to daily intakes below about 7.5 mg. Adding the vitamin to flour and maize meal is what made the disease rare in the countries that did it.

WHO, pellagra

Flushing at higher dosesUnder study

Nicotinic acid widens small blood vessels in the skin, and doses of 50 mg or more often bring on a warm, itchy flush in many people. EFSA set an upper level of 10 mg a day for nicotinic acid from fortified food and supplements, which is why the acid form and the amide form are treated so differently.

EFSA Journal, scientific opinion on niacin

How much a dayBenefit

EFSA sets a dietary reference value of 16 mg of niacin equivalents a day for adults. Enriched flour has to carry 24 mg of niacin a pound, so a slice or two of white bread puts a couple of milligrams on the table before breakfast is over.

EFSA, dietary reference values for niacin

What can I use instead?

Niacinamide

Ratio: Use the same milligram amount

Best for: Getting vitamin B3 without the flush

Enriched bread and cereal

Ratio: Two slices of enriched bread, or a bowl of a cereal that lists niacin

Best for: The same nutrient from ordinary food

Meat, fish and peanuts

Ratio: Build meals around foods that carry niacin naturally

Best for: Diets that skip fortified grain

More vitamins & minerals:

CholineCholine is a nutrient most people get enough of from eggs, meat and soy, so it is rarely something to hunt down. It is added on purpose to infant formula, where the amount is regulated, and EFSA sets 400 mg a day for adults.Use in moderation Ferrous sulfateFerrous sulfate is the iron added to flour, bread and cereals, and it is safe at fortification amounts. The catch is the dose: a large single serving upsets the stomach, so read the milligram amount on the label, not the product count.Use in moderation Folic acid (Vitamin B9)Folic acid is the synthetic form of vitamin B9, and it is added to flour, bread and breakfast cereals on purpose. It is safe at fortification levels, but EFSA caps it at 0.6 mg a day for adults because a large intake can hide a vitamin B12 deficiency.Use in moderation NiacinamideNiacinamide is the mild form of vitamin B3: it does the same job as nicotinic acid but does not make you flush. It is safe at amounts beyond anything in a drink or a cereal, and it is the version most fortified products use.Use in moderation

Common questions

Why does niacin make me flush?

Nicotinic acid widens small blood vessels in the skin, and the extra blood shows as a warm, red, itchy rush that usually clears within an hour. Niacinamide does the same job inside the body without that effect, which is why most supplement labels use it.

Is niacin in bread the same as a niacin tablet?

No, and the gap is large. Enriched flour carries 24 mg of niacin a pound, roughly 5 mg per 100 g, while a single tablet is usually 100 mg.

Do I need a niacin supplement?

Most people get enough from a varied diet, and the body also makes a little from the amino acid tryptophan. Whole grains, meat and fish cover most adults, so a supplement is worth taking only on medical advice.

Is niacin bad for you?

Not at the amounts that turn up in food. The problem is the dose: past the EFSA upper level of 10 mg a day from fortified food and supplements, nicotinic acid flushes, and the gram-sized doses used for cholesterol bring liver and blood sugar trouble with them.

Is Vitamin B3 safe?

Use in moderation (78/100). In the United States, niacin is permitted as a nutrient additive under the FDA's food additive rules for special dietary and nutritional additives, and it counts towards the flour enrichment standard. It has no E-number: the EU authorizes it as a nutrient for fortification under Regulation (EC) No 1333/2008 rather than as an additive, and EFSA set an upper level of 10 mg a day for nicotinic acid in adults.

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Scientific sources & regulatory citations

WHO, pellagra
EFSA Journal, scientific opinion on niacin
EFSA, dietary reference values for niacin

CAS 59-67-6