Vitamin B3 · Dietary family · Names that matter
Niacin
One vitamin family. More than one molecule.
Niacin helps build coenzymes involved in energy metabolism. [1]
Vitamin B3 is the family name; nicotinic acid and nicotinamide are individual members. Following those names makes the connection between food chemistry and skincare clearer without treating eating and skin application as the same experiment.
Meet the family
Read beyond “B3.”
B3 is a vitamin family, not one chemical formula. [1]
Nicotinic acid
C₆H₅NO₂. Also called pyridine-3-carboxylic acid: a nitrogen-containing ring bearing a carboxy group, –COOH, at position 3. ChEBI records it as 15940. [2]
Nicotinamide
C₆H₆N₂O. Also called niacinamide or pyridine-3-carboxamide. The corresponding group is an amide, –CONH₂. Its distinct ChEBI record is 17154. [3]
“Niacinamide” and “nicotinamide” name the same compound. Neither means that all B3 forms are interchangeable. This dietary family guide complements, rather than replaces, the separate Niacinamide skincare entry.
Inside the body
Building the helpers, not supplying a shortcut.
Niacin contributes to NAD and NADP. These coenzymes support electron-transfer reactions: NAD helps release food energy; NADP supports synthesis and antioxidant systems. [1]
They are larger, related molecules, not alternative names for a spoonful of niacin.
On the plate
The food description is part of the number.
Roasted seed kernels
About 1.24 mg niacin per 28 g of pumpkin and squash seed kernels, roasted without salt. This is the edible kernel, not the whole seed with its shell. [4]
Roasted chicken breast
About 11.66 mg per 85 g of cooked, roasted broiler/fryer breast meat only. The figure excludes skin and does not describe every chicken dish. [4]
These example portions are calculated from USDA’s 2018 SR Legacy values of 4.43 and 13.712 mg per 100 g, respectively. They are reference-food estimates, not laboratory results for your meal. Match edible part, preparation and portion before comparing.
A useful accounting unit
Why “niacin equivalents” needs an explanation.
The body can also make NAD from tryptophan, an amino acid in protein. The conventional accounting unit is 1 mg niacin equivalent (NE) = 1 mg niacin or 60 mg tryptophan. Conversion varies among people; this is not a guaranteed yield. [5]
The food figures above count niacin, without adding a calculated tryptophan contribution.
A small human study shows the distinction.
Fukuwatari and colleagues (2004) housed ten young Japanese women together for seven days, providing a niacin-free purified diet and a common activity schedule. They collected urine to measure metabolites and estimate conversion from dietary tryptophan. [5]
The estimated weight ratio was about 67 mg tryptophan to 1 mg niacin, using an assumed urinary recovery percentage. That is an estimate from a particular experimental model, not a replacement rule for food labels.
What the small conversion study can establish
Ten participants, one week and a purified diet limit generalization. Urinary metabolites are also not a direct measurement of skin appearance or a test of a finished skincare product. The accessible abstract supports this summary; the full methods were not reviewed.
Quick label reference
Amount, unit, serving.
Niacin and niacin equivalents are not identical accounting terms. The first food numbers above describe niacin already measured in the food; NE can also account for a contribution from tryptophan. A comparison should state which quantity is being used.
B3 groups related vitamin forms.
Nicotinamide and nicotinic acid have distinct identities.
NAD is a larger working molecule, not a synonym for the vitamin family.
A food label and a cosmetic ingredient list answer different questions. The amount listed in food is not a topical-use concentration.
Sources to follow
Revised October 25, 2026. Sources below distinguish chemical identity, food composition and the particular preparations or populations studied. Research methods and interpretation remain alongside the findings.
- NIH Office of Dietary Supplements: Niacin.
- EMBL-EBI ChEBI: Nicotinic acid.
- EMBL-EBI ChEBI: Nicotinamide.
- USDA: Niacin, SR Legacy 2018.
- Fukuwatari and colleagues, 2004: Tryptophan conversion. Original research abstract.
Recipe provenance: Eat for Your Skin, “Mango + Blueberry Kefir Parfait.”
