Vitamin B3 (Niacin / Nicotinamide)
Niacin (vitamin B3) is the umbrella term for nicotinic acid and nicotinamide — two forms that share the same vitamin activity but have different non-vitamin properties. Both are precursors of NAD⁺ and NADP⁺, the universal redox cofactors of cellular energy metabolism. UK NRV is 16 mg niacin equivalents (NE)/day. Six authorised UK Article 13.1 health claims apply at ≥15 % NRV. Pharmacological-dose nicotinic acid (500–2,000 mg/day) for lipid modification is a different intervention with prescribing-tier side effects (flushing, hepatotoxicity) — not relevant to typical food-supplement use.
Camden Medicals editorial · Last reviewed 12 June 2026 · Next review June 2027
- Cross-checked against
- NHS
- NICE
- BNF
- EFSA
- FSA
Camden's editorial team independently graded each health claim below on the strength of the published evidence — see the grade beside every condition.
- Class
- Vitamin
- Typical daily dose
- NRV 16 mg/day. Common supplement doses 10–50 mg/day (typically nicotinamide). Pharmacological lipid-modifying nicotinic acid is 500–2,000 mg/day under medical supervision.
- Top use evidence
- Insufficient
On this page
What it is
Niacin is the umbrella name for two molecules with vitamin B3 activity: nicotinic acid (the original "niacin") and nicotinamide (also called niacinamide). Both are precursors of nicotinamide adenine dinucleotide (NAD⁺) and its phosphorylated form NADP⁺ — the redox coenzymes that drive most of cellular energy metabolism, biosynthesis, DNA repair, and antioxidant defence.
The two forms share identical vitamin activity once incorporated into NAD⁺ but have different non-vitamin pharmacology. Nicotinic acid at pharmacological doses (500–2,000 mg/day) lowers LDL cholesterol and triglycerides and raises HDL — historically used as a lipid-modifying drug, now largely supplanted by statins — and produces a characteristic skin-flushing reaction at >50 mg via prostaglandin D2 release. Nicotinamide does not flush at any dose and lacks the lipid-modifying effect; it is the form used in non-flushing supplement labels and in dermatology research.
The body also synthesises niacin endogenously from the amino acid tryptophan (~60 mg tryptophan → 1 mg niacin). UK NRV is expressed as "niacin equivalents" (NE) to account for both dietary niacin and tryptophan-derived contribution.
Common supplement forms are nicotinamide (standard, non-flushing), nicotinic acid (lipid-context, flushing), and inositol hexanicotinate ("flush-free niacin", debated lipid efficacy). Nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN) are separate molecules with their own encyclopaedia entries — NAD⁺ precursors but technically distinct vitamers with different regulatory status.
At a glance
- Vitamin B3 is the umbrella term for two interchangeable forms — nicotinic acid (flushing) and nicotinamide (non-flushing) — both precursors to the NAD⁺/NADP⁺ energy cofactors.
- UK NRV is 16 mg niacin equivalents/day, generally well-supplied via meat, fish, fortified bread and peanuts.
- 6 authorised UK Article 13.1 claims at ≥15% NRV: energy metabolism, nervous-system function, psychological function, mucous membranes, skin, and reduction of tiredness/fatigue.
- High-dose nicotinic acid (≥500 mg/day) is a lipid-modifying drug with flushing + liver-toxicity risk — a prescribing decision, not a food-supplement use.
What people use it for
Adults seeking niacin at NRV intake for the authorised claim list
At ≥15 % NRV (≥2.4 mg) the GB NHC register authorises 6 niacin claims covering energy metabolism, nervous-system function, psychological function, mucous-membrane and skin maintenance, and tiredness/fatigue reduction. [2]
Popular, not provenInsufficientAdults at low intake — restricted-meat diets, alcohol misuse, malabsorption
Routine NRV-tier supplementation returns intake to target. Pellagra is rare in the UK; alcohol misuse is the most common at-risk context. [1]
Popular, not provenInsufficientPeople considering high-dose nicotinic acid for lipid modification
This is a prescribing-tier decision, not a food-supplement use. Statins, ezetimibe, PCSK9 inhibitors, and bempedoic acid are first-line in UK lipid pathways. Nicotinic acid retains a niche specialist role. [3]
Popular, not provenInsufficient
How it works
NAD⁺ accepts electrons in over 200 oxidation reactions across glycolysis, the TCA cycle, fatty-acid β-oxidation, and the pentose phosphate pathway. NADP⁺ provides reducing power for biosynthesis (cholesterol, fatty acids) and is the cofactor for glutathione reduction and other antioxidant pathways. Niacin deficiency therefore impairs energy generation, biosynthesis, and tissue repair — explaining the dermatological, GI, and neurological presentations of pellagra ("the 4 Ds": dermatitis, diarrhoea, dementia, death if untreated).
Common myths
Myth"Niacin flushing is the supplement working / cleansing toxins."
RealityIt is a prostaglandin D2-mediated cutaneous vasodilation. Not a "cleansing" effect. Flushing occurs with nicotinic acid; not with nicotinamide. The two forms share vitamin activity but not flushing pharmacology.
Myth"Niacin "cleans" arteries / reverses heart disease."
RealityPharmacological nicotinic acid modifies lipids modestly. Large outcome trials (AIM-HIGH, HPS2-THRIVE) failed to show cardiovascular event reduction when added to statins; safety signals (myopathy, GI bleeding, infection) led to UK / European de-emphasis. Statins remain first-line. [6,7,3]
Common online questions
Synthesised from the questions UK shoppers most often ask online about Vitamin B3 (Niacin / Nicotinamide). Each answer is editorial and links to its evidence in the Sources list below.
Niacin or nicotinamide — which form?
For routine food-supplement vitamin coverage, nicotinamide is the standard (no flushing). Nicotinic acid is the form used pharmacologically for lipid modification — at much higher doses, with flushing and hepatotoxicity considerations, and that is a prescribing decision not a supplement decision.
Is niacin flushing dangerous?
At pharmacological doses the flushing itself is uncomfortable but not dangerous. The bigger safety concerns at chronic high-dose nicotinic acid are hepatotoxicity, hyperuricaemia, and hyperglycaemia — reasons the cardiovascular use case has receded. Nicotinamide does not produce flushing.
⚖️ The official position
What may lawfully be claimed about Vitamin B3 (Niacin / Nicotinamide) in Great Britain. This is a regulatory position, not an evidence grade.
A health claim is authorised in Great Britain.
“Niacin contributes to normal energy-yielding metabolism”
“Niacin contributes to normal functioning of the nervous system”
“Niacin contributes to normal psychological function”
“Niacin contributes to the maintenance of normal mucous membranes”
“Niacin contributes to the maintenance of normal skin”
“Niacin contributes to the reduction of tiredness and fatigue”
This claim is authorised for use in Great Britain under the GB Nutrition and Health Claims regulation. A product may carry it when it provides at least 15% of the UK NRV per recommended daily portion.
Authorised UK health claims
Verbatim from the GB Nutrition and Health Claims Register (Reg 432/2012 as assimilated in GB). A product can carry these claims when it provides at least 15% of the UK NRV per recommended daily portion.
6 authorised claims — show / hide
- "Niacin contributes to normal energy-yielding metabolism"
- "Niacin contributes to normal functioning of the nervous system"
- "Niacin contributes to normal psychological function"
- "Niacin contributes to the maintenance of normal mucous membranes"
- "Niacin contributes to the maintenance of normal skin"
- "Niacin contributes to the reduction of tiredness and fatigue"
🔬 Camden’s evidence review
The research Camden reviewed, graded on its strength. This is our own appraisal — it sits beneath the official guidance above, never above it.
Pellagra / niacin deficiency
StrongEvidencestrongThe research Camden reviewed: niacin is a defined essential micronutrient with an established deficiency syndrome (pellagra), and replacement resolves its features — recent reviews report symptom resolution within roughly four weeks of vitamin B3 supplementation. Pellagra is rare in the modern UK; alcohol misuse, post-bariatric states, malabsorption and certain medicines (for example isoniazid) are the principal at-risk contexts. [8,9]
Lipid modification (high-dose nicotinic acid)
ModerateEvidencemoderateThe research Camden reviewed: high-dose nicotinic acid measurably lowers LDL cholesterol and triglycerides and raises HDL, but two large randomised trials adding it to statin therapy (AIM-HIGH, HPS2-THRIVE) found no reduction in cardiovascular events and HPS2-THRIVE found more serious side effects. NICE NG238 therefore advises against using niacin to prevent cardiovascular disease; the UK pathway prefers statins, ezetimibe and PCSK9 inhibitors. This is a prescribing-tier decision, not a food-supplement use. [6,7,3]
Skin-cancer prevention (nicotinamide, dermatology)
LimitedEvidencelimitedThe research Camden reviewed: one phase-3 randomised trial (ONTRAC, NEJM 2015) reported that nicotinamide 500 mg twice daily lowered the rate of new non-melanoma skin cancers over 12 months in patients with a history of multiple skin cancers, with the benefit not persisting after stopping. This is a specialist dermatology decision for high-risk patients, not a general-population use; a later transplant-recipient trial did not replicate the benefit. [10]
Safety
Nicotinamide at typical food-supplement doses is very well tolerated. Nicotinic acid above ~50 mg produces flushing; chronic high-dose nicotinic acid (>500 mg/day) is a pharmacological-tier intervention with hepatotoxicity, glucose, and uric-acid considerations.
Talk to your pharmacist or GP first if you:
- You have liver disease — high-dose nicotinic acid is hepatotoxic.
- You have diabetes or impaired glucose tolerance — high-dose niacin can worsen glycaemic control.
- You have a history of gout / hyperuricaemia — nicotinic acid raises serum urate.
- You take statins or other lipid-modifying medication — discuss with your prescriber before adding high-dose niacin.
- You are pregnant or breastfeeding — NRV-tier supplementation is appropriate.
Common side effects: Nicotinic acid: flushing, GI upset, headache. Nicotinamide: very well tolerated.
Pregnancy and breastfeeding
UK dietary reference values do not add a pregnancy increment for niacin (the requirement is set relative to energy intake). Niacin from a varied diet, or NRV-tier supplementation where intake is low, is appropriate. High-dose nicotinic acid: avoid. Talk to your GP, midwife or pharmacist before starting any supplement in pregnancy.
UK dietary reference values add a small breastfeeding increment for niacin (about +2 mg niacin equivalents/day). Niacin from a varied diet, or NRV-tier supplementation, is appropriate; high-dose nicotinic acid: avoid.
Talk to your GP, midwife, or pharmacist before starting any supplement during pregnancy or breastfeeding.
More clinical detail (for clinicians and informed readers)
Contraindications
- Active liver disease (high-dose nicotinic acid).
- Active gout (high-dose nicotinic acid).
- Known hypersensitivity.
Drug interactions
- Statins — additive myopathy risk at high-dose niacin; specialist supervision.
- Anticoagulants — modest INR effect at high doses.
- Diabetes medication — high-dose nicotinic acid can worsen glycaemic control.
- Allopurinol / urate-lowering — high-dose nicotinic acid raises urate.
This is not an exhaustive list. Always tell your prescriber and pharmacist about every supplement you take.
Common side effects
- Flushing (nicotinic acid only) — typically lasts 30–60 minutes, intensity reduces with continued use.
- Mild GI symptoms.
Rare side effects
- Hepatotoxicity — high-dose nicotinic acid (>500 mg/day chronic).
- Hyperglycaemia / glucose dysregulation — high-dose nicotinic acid.
- Hyperuricaemia / gout exacerbation — high-dose nicotinic acid.
- Allergic reactions — rare.
How to take it
- Typical supplemental range
- NRV 16 mg/day. Common supplement doses 10–50 mg/day (typically nicotinamide). Pharmacological lipid-modifying nicotinic acid is 500–2,000 mg/day under medical supervision.
- Timing
- No specific timing requirement.
How to spot quality
Look for
- Form named — nicotinamide (non-flushing) or nicotinic acid (flushing).
- NRV percentage stated.
- Avoid "inositol hexanicotinate" / "flush-free niacin" without clear declaration of the active form.
- GMP-certified manufacture.
Red flags
- Generic "vitamin B3" with no form named — for daily supplement use, nicotinamide is the safer default.
- High-dose nicotinic acid (>50 mg) sold for general wellness rather than under medical supervision.
- Marketing implies cardiovascular event prevention — not supported.
Where Camden lands · meets the bar
Camden Medicals does not currently sell a standalone vitamin B3 SKU. Niacin appears as an adjunct active in two multi-active B-vitamin products Camden is evaluating — a daily B-complex (18 mg NE/cap as nicotinamide, 113 % NRV — claim-eligible) and a Ginkgo B+ blend (16 mg/cap as nicotinamide, 100 % NRV). Both clear the look-for bar — both use the non-flushing nicotinamide form, both declare NRV.
Commonly combined with
Other ingredients that share a biological pathway, cofactor relationship, or evidence-backed protocol with this one. Mechanisms below cite primary physiology — not folk pairing. Doses are literature ranges, not recommendations. Talk to your pharmacist or GP before changing your stack, especially if you take prescription medication.
Niacinamide (Topical, Vitamin B3 amide form)
Moderate evidenceTopical sister entry — niacinamide is the topical-skin form of vitamin B3 amide.
Same molecule (nicotinamide / niacinamide); different delivery context — topical for stratum corneum barrier rebuild + melanosome transfer + sebum modulation. Camden niacinamide covers topical.
Evidence: Camden niacinamide covers topical context.
Doses studied: Oral 16 mg/day NRV. Topical 5-10%.
NAD+ (Nicotinamide Adenine Dinucleotide)
Insufficient evidenceNAD+ precursor cluster — B3 (niacin / nicotinamide) → NAD+ via salvage pathway.
Niacinamide is the most-direct NAD+ precursor via the salvage pathway. UK Article 13.1 B3 energy-metabolism + nervous-system claims.
Evidence: Camden nad-plus + nmn NB-161 cluster.
Doses studied: 16 mg B3 + nicotinamide riboside / NMN per Camden nad-plus + nmn.
Found in Camden: Clarifera™ NMN Complex 90 Delayed Release Capsules
NMN (β-Nicotinamide Mononucleotide)
Limited evidenceNAD+-precursor cluster — different precursor classes.
B3 nicotinamide salvage pathway → NAD+; NMN via NRK / NMNAT pathway → NAD+. Mechanism complementary.
Evidence: Camden nmn NB-161 covers FSA novel-food regulatory-watch context.
Doses studied: 16 mg B3 + 250-1000 mg NMN daily.
Found in Camden: Clarifera™ NMN Complex 90 Delayed Release Capsules