💊 What it does
Niacin (vitamin B3) exists as nicotinic acid and nicotinamide (niacinamide). It is essential for energy metabolism as a component of NAD+ and NADP+ — coenzymes central to hundreds of metabolic reactions. It supports DNA repair, cell signalling, and gene expression. High-dose nicotinic acid (1–3 g/day) has a well-established lipid-modifying effect, significantly reducing LDL cholesterol and triglycerides and raising HDL. NMN and NR are NAD+ precursors that have attracted longevity interest.
👤 Who needs it
People with lipid abnormalities (under medical supervision) for high-dose nicotinic acid. Those interested in NAD+ metabolism and longevity (NMN/NR). People with pellagra (niacin deficiency — rare in developed countries). Those on a corn-heavy diet with limited tryptophan (tryptophan is converted to niacin).
🥦 Food sources first
Good plant sources: nutritional yeast, peanuts, sunflower seeds, mushrooms (especially cremini and portobello), wholegrains, lentils, asparagus, avocado, sweet potato. Tryptophan (from protein) also contributes to niacin synthesis. Most varied diets provide adequate niacin.
🗓 When to supplement
For lipid management at pharmacological doses (under GP supervision). For NAD+ support (NMN/NR). Not generally needed by those eating a varied diet with adequate protein.
🏷 Best form to look for
Niacinamide (nicotinamide) for general supplementation — no flushing, liver-friendly. Nicotinic acid for lipid management — causes flushing, use extended-release formulations to minimise. NMN or NR for NAD+ augmentation.
⏰ When to take it
With food. High-dose nicotinic acid: start low and increase gradually to reduce flushing. Niacinamide: any time.