Vitamin B3 (Niacin)
Overview
Vitamin B3 (niacin) is a water-soluble vitamin family that includes nicotinamide (niacinamide) and nicotinic acid. These forms supply precursors for nicotinamide adenine dinucleotide (NAD⁺), a central coenzyme in cellular energy metabolism. NAD⁺ is essential for oxidative phosphorylation, acting as an electron carrier that enables ATP generation in mitochondria. Niacin also supports sirtuin signalling and mitochondrial biogenesis, making it important for neuronal energy metabolism. As part of the broader B-vitamin group, niacin works interdependently with other B vitamins to support brain energy production and neurochemical synthesis Kennedy 2016.
Nicotinamide
Nicotinamide, also called niacinamide, is a form of vitamin B3. Cells recycle it through the salvage pathway to replenish nicotinamide adenine dinucleotide (NAD⁺) Covarrubias et al. (2021). NAD⁺ can also be made de novo from tryptophan. The share supplied by that route is not established Covarrubias et al. (2021). Nicotinamide is chemically distinct from nicotinic acid.
Evidence limitations: Nicotinamide is a vitamin B3 form used in NAD⁺ salvage. Total-niacin measurements do not establish its individual concentration. Measurements following hydrolytic extraction describe the recovered analyte and may not represent native free nicotinamide (EN 15652:2009). Food-composition results do not establish brain delivery, tissue-specific NAD⁺ replenishment or neurological benefit.
Nicotinic acid
Nicotinic acid is a form of vitamin B3 that enters synthesis of nicotinamide adenine dinucleotide (NAD⁺) through the Preiss–Handler pathway, a separate route from nicotinamide salvage Covarrubias et al. (2021). The high-dose niacin study in mitochondrial myopathy does not establish an equivalent effect from ordinary food intake Pirinen et al. (2020).
Evidence limitations: Nicotinic acid is a vitamin B3 form used in the Preiss–Handler pathway. Total-niacin measurements do not establish its individual concentration. Hydrolytic extraction can affect the recovered amount and vitamer distribution; results must not automatically be interpreted as native free nicotinic acid (EN 15652:2009). Food-composition results do not establish pathway-specific brain uptake or clinical benefit.
Recipes
2 recipes containing this substance
Mixed-Leaf Tahini Caesar Salad
A Caesar-style mixed-leaf salad with a tahini, anchovy, caper and Parmesan dressing, using extra virgin olive oil retained from oil-packed capers.
Turkey Wing Stew
A collagen-rich, glycine-heavy slow-cooked stew made from affordable turkey wings — rich in protein, tryptophan, and B vitamins.
Foods
12 foods
Anchovies
Small oily fish, typically canned and drained, providing EPA, DHA and niacin
Beef
High creatine, CoQ10, and bioavailable heme iron
Chicken
Niacin, zinc, and tryptophan
Lion's Mane Mushroom
Medicinal mushroom with bioactive compounds that may support nerve health and neuroprotective pathways
Maitake Mushroom
Medicinal mushroom rich in beta-glucans, particularly D-fraction, supporting immune function
Oyster Mushroom
Culinary mushroom rich in beta-glucans and B vitamins, supporting immune function
Peanuts
Niacin, resveratrol, and plant protein for NAD+ and mitochondrial support
Sardines
Small oily fish rich in EPA/DHA, CoQ10, and calcium
Shiitake Mushroom
Culinary and medicinal mushroom rich in beta-glucans, supporting immune function and providing umami flavor
Tuna
Fish providing omega-3, niacin, selenium, and complete protein
Turkey
High tryptophan and niacin for serotonin synthesis and NAD+ production
White/Button Mushroom
Agaricus bisporus — canonical entry for white/button, cremini, chestnut (UK), and portobello; niacin and UV-exposed vitamin D
Biological Mechanisms and Implications
| Biological Target | Mechanism of Action |
|---|---|
| BRS1 - Neurotransmitter Regulation | Member of the interdependent B-vitamin network essential for brain energy production and neurochemical synthesis; adequate NAD⁺ from niacin supports the ATP-dependent enzymatic context in which catecholamine pathways operate alongside cofactors such as B6, iron, and folate |
| BRS4 - Mitochondrial Function & Bioenergetics | Directly converted to NAD⁺ via the salvage pathway; NAD⁺ is a central coenzyme in oxidative phosphorylation, sirtuin signalling, and mitochondrial biogenesis; sustaining NAD⁺ availability supports neuronal ATP production for attention, motivation, and goal-directed behaviour |
References
- Niacin replenishes NAD⁺, supporting oxidative phosphorylation, sirtuin signalling, and mitochondrial biogenesis; key for neuronal energy metabolism
- In patients with adult-onset mitochondrial myopathy, high-dose niacin supplementation (750–1,000 mg/day) restored blood and muscle NAD⁺ levels by up to eightfold, improved mitochondrial biogenesis, and enhanced muscle performance Pirinen et al. 2020
- NAD⁺ is a central coenzyme in oxidative phosphorylation, acting as an electron carrier that enables ATP generation; incorporating NAD⁺ precursors into the BRAIN Diet reinforces mitochondrial energy metabolism, particularly in contexts of deficiency
- B vitamins function as indispensable enzymatic cofactors across brain biology pathways, including neurotransmitter synthesis and mitochondrial energy production; their availability can determine whether amino acid precursors and other nutrients exert their intended effects Kennedy 2016
- Riboflavin coenzymes facilitate the metabolism of B12, vitamin B6, and niacin, linking B-vitamin network sufficiency to homocysteine recycling and broader one-carbon metabolism Aragão et al. 2024