Vitamin
Niacin
Unusually, you can build niacin from tryptophan — an amino acid in protein. That is why pellagra struck maize-eating populations and not the people whose staple was wheat.
What it does
Niacin becomes NAD and NADP, which are the carriers that move hydrogen and electrons through hundreds of reactions. NAD is involved in more enzymatic steps than almost any other molecule in the body.
Deficiency produces pellagra: dermatitis on sun-exposed skin, diarrhoea, and dementia. It killed tens of thousands in the American South in the early twentieth century before the cause was understood.
The historical detail is worth knowing. Maize contains niacin in a bound form the gut cannot release. Mesoamerican cultures had for millennia soaked maize in lime water — nixtamalisation — which frees it. Maize was exported to Europe and America without the technique, and pellagra followed.
How much you need
| Who | Per day | Note |
|---|---|---|
| Infants, 0–6 months | 2 mg | Adequate Intake, as preformed niacin |
| Infants, 7–12 months | 4 mg NE | Adequate Intake |
| Children, 1–3 years | 6 mg NE | — |
| Children, 4–8 years | 8 mg NE | — |
| Children, 9–13 years | 12 mg NE | — |
| Men, 14 and over | 16 mg NE | — |
| Women, 14 and over | 14 mg NE | — |
| Pregnancy | 18 mg NE | — |
| Breastfeeding | 17 mg NE | — |
NE means niacin equivalents: 1 mg of niacin, or 60 mg of tryptophan, which the body converts at roughly that ratio. A diet with adequate protein therefore supplies a large share of its own niacin without any niacin being present.
From our own data
The foods highest in niacin
Meat, fish and poultry lead, then wholegrains, legumes and seeds. Remember that the table counts preformed niacin only — a high-protein food is contributing more than its number shows.
- 1
Tuna, cooked143% · DV - 2
Beef liver, braised110% · DV - 3
Peanut butter, low sugar102% · DV - 4
Chicken breast, skinless, fried92% · DV - 5
Anchovies89% · DV - 6
Sesame flour, full-fat84% · DV - 7
Veal topside, lean, pan-fried79% · DV - 8
Turkey breast, roasted73% · DV - 9
Bacon, low salt, cooked69% · DV - 10
Venison steak67% · DV - 11
Lamb tenderloin, lean, roasted60% · DV - 12
Açaí juice blend57% · DV
Per 100 g, from our copy of USDA FoodData Central, against a Daily Value of 16mg. Ranked by amount, not by how much of it your body actually takes up — read the next section before you act on the order.
The table above is per 100 g. The app weighs the portion you actually ate.
What helps, and what gets in the way
Helps
- Adequate protein, which supplies tryptophan the body converts
- Nixtamalised maize — masa, tortillas — rather than plain cornmeal
- Adequate riboflavin, B6 and iron, all of which the conversion pathway needs
Gets in the way
- Untreated maize as a staple, where the niacin is bound and unavailable
- Low protein intake, which removes the tryptophan route
- Carcinoid syndrome, which diverts tryptophan elsewhere
- Isoniazid, used for tuberculosis, which interferes with the conversion
High-dose nicotinic acid — a gram or more, prescribed historically for cholesterol — causes an intense flushing of the face and chest, and at those doses can damage the liver. That is a pharmacological effect at hundreds of times the dietary requirement, and has nothing to do with niacin from food.
Who tends to fall short
Groups where intake or absorption is commonly lower than the reference. It is a list of populations, not a list of symptoms — it cannot tell you anything about yourself.
- Populations dependent on untreated maize or sorghum
- People with alcohol use disorder
- People with carcinoid syndrome or Hartnup disease
- People on long-term isoniazid without supplementation
Cook it
Chicken thighs with paprika and tomatoes
Four, forty minutes
Ingredients
- 8 chicken thighs, bone in, skin on
- 2 tsp smoked paprika
- 1 tin chopped tomatoes
- 1 onion, sliced
- 4 cloves garlic, whole
- 1 tbsp olive oil
- A handful of parsley
Method
- 1Dry the skinKitchen paper, thoroughly, then season. Damp skin steams instead of crisping and you cannot fix it later.
- 2Render skin side downCold pan, medium heat, eight minutes without moving them. Starting cold lets the fat render out before the skin sets, which is what makes it crisp rather than leathery.
- 3Paprika off the heatOnion softened in the rendered fat, then the pan off the heat before the paprika goes in. It burns in seconds over direct heat and turns bitter.
- 4Braise skin side upTomatoes and garlic in, chicken back on top with the skin above the liquid, 25 minutes at 190°C. Parsley at the end.
Chicken supplies both preformed niacin and the tryptophan the body converts into more of it, which is why poultry covers this requirement so comfortably.
Sources
- NIH Office of Dietary Supplements — Niacin
- Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate and Vitamin B12
- USDA FoodData Central
This page is education, not medical advice. It does not diagnose anything and it is not a substitute for a clinician who knows your history. If you think you are short of niacin, the answer is a blood test and a conversation, not a supplement bought on the strength of an article.
Every food above, and 12,601 more, with the full panel — in the app.