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Vitamin B3

Vitamin ·Strong evidence ·Reviewed May 2026

Critical for NAD+ production, energy metabolism, DNA repair, and cellular signaling. Available as niacin (causes flushing) or niacinamide (no flush).

Evidence tier
Strong
Indexed sources
17 2005–2025
Interactions
12
Cost / month
$1.20 budget
Read the sources → Compare profiles
What it's good for
  • Energy production
  • NAD+ support
  • Cholesterol management (niacin; raises HDL but no CV outcome benefit when added to statins, prescription-level intervention)11,1
  • Skin health (niacinamide)12,4
  • DNA repair15
What to watch for
  • Flushing (niacin)
  • GI upset
  • Liver stress at very high doses
  • Liver disease10,14
  • Active peptic ulcer

The bottom line

Evidence rating strong. Most-documented uses: energy production, nad+ support, cholesterol management (niacin; raises hdl but no cv outcome benefit when added to statins, prescription-level intervention). 17 sources indexed (2005–2025), with 12 interaction records on file.

The science

How it works, mechanistically.

Core mechanism

Converted to NAD+ and NADP+, which participate in over 400 enzymatic reactions including glycolysis, Krebs cycle, electron transport chain, DNA repair via PARPs, and sirtuin-mediated longevity pathways.15,10

Class
B Vitamin
Found in food
Chicken breast, Tuna, Turkey
Low-status signs
Pellagra (dermatitis, diarrhea, dementia), Fatigue
Absorption
Water-soluble; take with food
Dosing

Dosing & protocol.

Common range
RDA-level use unless clinician-directed; niacinamide 500–1,000 mg or niacin 1,000–2,000 mg are pharmacologic doses requiring medical supervision and liver/glucose/urate monitoring
Recommended form
Niacinamide (no flush) or extended-release niacin

Take with food to reduce flushing (niacin form)16,8

Dosing protocol

Maintain · 100-500 mg/day (nicotinamide) or 500-2000 mg (niacin) split with meals

Niacin (flushing form) at higher doses raises HDL but can elevate liver enzymes; nicotinamide does not flush or affect lipids.16

No cycling requiredNo tolerance buildup
Forms

Forms & what to buy.

Ranked by evidence and value.

Nicotinamide Riboside Recommended
Rank 1: NAD precursor form. Limited direct form-comparison evidence; ranking is based on review or mechanistic data (PMID: 30559273). More expensive and outcome evidence is still developing.
Premium250-500 mg/day
Niacinamide
Rank 2: non-flushing B3 form. Does not produce classic niacin flushing.
Budget50-500 mg/day
Nicotinic Acid Niacin
Rank 3: flush form with lipid-drug history. High-dose use requires medical monitoring.
BudgetUse medical guidance for high doses
Inositol Hexanicotinate
Rank 4: flush-reduced niacin ester. May deliver less free niacin than expected.
MidUse label dose
Cost

What it actually costs.

Real-world pricing across three quality tiers. Assumes Niacinamide / Niacin.

BudgetBest value
$1.20 /mo
$0.04 per dose
Mid
$2.70 /mo
$0.09 per dose
Premium
$6.00 /mo
$0.20 per dose

Assumes niacinamide 500-1,000 mg/day when specifically indicated. Vendor basis: NOW/iHerb, Vitacost, Life Extension, and Amazon marketplace; extended-release niacin is treated as premium. Updated 2026-05-28.

From food

The same dose, as food.

How much you'd eat to match a supplemental dose.

RDA-level niacin or clinician-directed pharmacologic dosing
About 4-6 ounces chicken breast, tuna, turkey, salmon, peanuts, mushrooms, or fortified grains can cover daily niacin needs.

Pharmacologic niacin doses such as 1,000 mg or more should not be approximated with food and require medical supervision.

Goals

Goal-based dosing.

Metabolic Health

Dose: 500-2,000 mg daily only clinician-directed

Timing: With meals

Clinical dose evidence: PMID 22085343. Pharmacologic niacin dosing needs clinician monitoring for liver, glucose, uric acid, and flushing risk.

Lab work

Markers to track.

What to test, the optimal window inside the conventional range, and how long a response takes.

Urinary N-Methylnicotinamide NMN (urine)

Niacin supplementation increases urinary N-methylnicotinamide proportional to intake.2,1

Optimal
2–4 mg/g creatinine
Conventional
1.6–4.3 mg/g creatinine
Responds in
Urinary output reflects intake within days.

Spot urine corrected to creatinine. Serum niacin is unreliable for status assessment.

Lipid PanelLDL Cholesterol

LDL Cholesterol LDL-C

At pharmacologic niacin doses, vitamin B3 tends to modestly lower LDL cholesterol, with effects that are dose-dependent and clearest when baseline LDL is elevated.1,2

Optimal
0–70 mg/dL
Conventional
0–100 mg/dL
Responds in
6 to 12 weeks

Requires a 9 to 12 hour fast. Pharmacologic niacin doses warrant clinician supervision and periodic liver enzyme and glucose monitoring; flushing is common. Keep diet and other lipid-active medications stable before retesting.

HDL CholesterolTriglyceridesLipoprotein(a)Non-HDL Cholesterol

HDL Cholesterol HDL-C

At pharmacologic niacin doses, vitamin B3 tends to modestly raise HDL cholesterol, with effects that are dose-dependent and clearest when baseline HDL is low, though this surrogate change has not reliably translated to clinical benefit in trials.1,2

Optimal
60–90 mg/dL
Conventional
40–90 mg/dL
Responds in
6 to 12 weeks

Requires a 9 to 12 hour fast. Use clinician supervision at pharmacologic doses with periodic liver enzyme and glucose checks. Keep alcohol intake, exercise, and other lipid-active medications stable before retesting.

LDL CholesterolTriglyceridesTotal CholesterolNon-HDL Cholesterol

Triglycerides TG

At pharmacologic niacin doses, vitamin B3 tends to modestly lower triglycerides, with effects that are dose-dependent and clearest when baseline triglycerides are elevated.1,2

Optimal
0–100 mg/dL
Conventional
0–150 mg/dL
Responds in
4 to 8 weeks

Requires a 9 to 12 hour fast. Recent alcohol or high-carbohydrate intake transiently raises triglycerides. Pharmacologic niacin doses warrant clinician supervision with periodic liver enzyme and glucose monitoring.

HDL CholesterolLDL CholesterolVLDL CholesterolNon-HDL Cholesterol
Why people use it

Symptoms it's matched to.

Where this appears in the symptom-to-supplement map, ranked by relevance.

High triglycerides

78% relevance

Niacin inhibits adipose lipolysis and hepatic triglyceride synthesis, lowering VLDL and circulating triglyceride output.11,1

CardiometabolicModerate evidenceImmediate-release niacin (nicotinic acid)

Causes flushing and can worsen glucose and uric acid, so use under clinical supervision and avoid sustained-release forms due to hepatotoxicity risk.

Low HDL cholesterol

78% relevance

Niacin (vitamin B3) at pharmacologic doses reduces hepatic clearance of HDL and is one of the most effective agents for raising HDL cholesterol.1,2

CardiometabolicModerate evidenceImmediate-release or extended-release niacin (vitamin B3), clinician-directed dose

Only HDL-raising doses are pharmacologic and require clinician oversight; high-dose niacin causes flushing, can raise blood glucose, and stresses the liver. Do not self-dose, and review with your clinician.

Rosacea / facial redness

72% relevance

Niacinamide supports skin barrier function and may reduce redness and transepidermal water loss, though the evidence is strongest for topical use and oral data for rosacea are limited.12,4

AppearanceEmerging evidenceNiacinamide (non-flushing B3)

Choose niacinamide rather than nicotinic acid, since the latter can trigger flushing that mimics rosacea.

Raynaud / cold-triggered fingers

55% relevance

Niacin causes vasodilation and flushing, which is theorized to transiently improve peripheral blood flow.1,2

CardiometabolicInsufficient evidenceNiacin (immediate-release), low starting dose under clinician guidance

Flushing can be uncomfortable and high doses affect the liver and blood sugar; secondary Raynaud or skin ulcers warrant prompt medical care.

High cholesterol

54% relevance

Niacin can change lipids but side effects and risk-benefit tradeoffs limit casual use.11,1

CardiometabolicModerate evidenceNiacin

Use only with a clear rationale and not just because it is available over the counter.

Protocols

Featured in protocols.

Evidence-based stacks that include it, with the exact dose and timing each one uses.

NAD+ Anti-Aging Protocol

LongevityCoreModerate evidenceAdvanced$70-130/mo
Dose here
250-500 mg (as nicotinamide riboside)
Timing
Morning, with breakfast

Vitamin B3 in the nicotinamide riboside form is an NAD+ precursor that elevates whole-blood NAD+ in human trials and is generally well tolerated, offering a complementary route to NAD+ repletion alongside NMN.1,3

Cholesterol & Lipid Support Protocol

Heart HealthOptionalModerate evidenceIntermediate$35-60/mo
Dose here
500-1000 mg of immediate-release niacin (lipid dose), only under clinician supervision
Timing
With the evening meal to reduce flushing, starting low and titrating up slowly

At pharmacologic lipid doses, Vitamin B3 (niacin) can lower LDL and triglycerides and raise HDL, but it commonly causes skin flushing and can affect liver enzymes and blood glucose. Large outcome trials have not shown added cardiovascular benefit when niacin is added to statins, so lipid-dose niacin requires clinician oversight and lab monitoring and is never self-prescribed.1,2

Safety

Full safety detail.

Side effects

  • Flushing (niacin)
  • GI upset
  • Liver stress at very high doses
  • Sustained-release niacin is significantly more hepatotoxic than immediate-release
  • Niacin for cholesterol: no CV outcome benefit when added to statin therapy (AIM-HIGH, HPS2-THRIVE)

Contraindications

  • Liver disease10,14
  • Active peptic ulcer
  • Gout (niacin)1,2
Interactions

Interaction records.

InfoSynergy

Vitamin B2

B2 (riboflavin) is needed for the synthesis of NAD+ from niacin (B3) via the kynurenine pathway.

Recommendation: Taking B-complex ensures adequate co-factor support for all B vitamin interconversions.

InfoCaution

NMN

Both are NAD+ precursors through different pathways. Taking both may be redundant and could lead to excessive NAD+ precursor supplementation.

Recommendation: Choose one NAD+ precursor strategy. NMN is generally preferred for direct NAD+ boosting via the salvage pathway.

InfoSynergy

PQQ

PQQ and vitamin B3 converge on NAD+ metabolism. This is an on-pathway analog of the better-known PQQ plus NMN/NR combination: PQQ promotes NAD+ generation and mitochondrial biogenesis through the SIRT1/PGC-1alpha pathway, while B3 furnishes an upstream precursor that the NAD+ salvage pathway requires. Combining them is mechanistically rational for supporting cellular energy and NAD+ status, with effects that appear complementary rather than competing.

Recommendation: These can be taken together without separation. Typical PQQ dosing is 10 to 20 mg per day; vitamin B3 dosing depends on the form (for example, nicotinamide around 50 to 500 mg per day, or smaller niacin doses to limit flushing). If using flush-form niacin, take with food and titrate to tolerance. No timing conflict applies.

InfoSynergy

Chromium

Combining niacin with chromium has been studied as a way to improve glucose handling. Controlled work in older adults found that niacin-bound or co-administered chromium produced greater improvements in glucose tolerance than chromium without niacin, consistent with niacin acting as part of the active chromium-nicotinate complex. This is generally a beneficial, additive relationship rather than a risk.

Recommendation: For people specifically targeting glucose metabolism, taking chromium (typically 200 to 1000 mcg/day) together with a modest niacin intake is reasonable and may modestly enhance chromium's glucose effect. No timing separation is needed; they can be taken in the same dose. People on diabetes medication should monitor blood glucose, since improved glucose handling can add to the effect of those drugs.

InfoSynergy

L-Tryptophan

Tryptophan and niacin are linked through a single biosynthetic pathway. Supplemental tryptophan contributes to niacin/NAD+ status, and conversely, ensuring sufficient niacin reduces the diversion of tryptophan into niacin synthesis, leaving more tryptophan for serotonin production. This shared-pathway relationship is a well-established principle in nutrition science and is the basis for expressing niacin needs as niacin equivalents that include tryptophan.

Recommendation: No avoidance is needed; the relationship is generally complementary. If using L-Tryptophan (commonly 500 mg to 2000 mg, often at night for mood or sleep support), maintaining adequate niacin intake helps preserve tryptophan for serotonin synthesis. Cofactors for the conversion (vitamin B6, vitamin B2) should also be sufficient. They can be taken together; tryptophan is often dosed away from high-protein meals to aid uptake, which is a separate practical consideration.

ModerateCaution

Atorvastatin

High-dose niacin (>1g/day) combined with atorvastatin may increase the risk of myopathy and rhabdomyolysis. The AIM-HIGH and HPS2-THRIVE trials also showed no cardiovascular benefit from adding niacin to statin therapy. Low-dose niacin for general health is unlikely to pose significant risk.

Recommendation: Avoid high-dose niacin (>500mg/day) with atorvastatin without medical supervision. Report any muscle pain, tenderness, or weakness immediately. Low-dose niacin supplementation (<100mg/day) for general health is generally safe.

ModerateCaution

Rosuvastatin

High-dose niacin combined with rosuvastatin increases myopathy risk. Clinical trials have shown that adding niacin to statin therapy does not provide additional cardiovascular benefit but does increase the incidence of muscle-related adverse effects.

Recommendation: Avoid high-dose niacin (>500mg/day) with rosuvastatin without medical supervision. Low-dose niacin for general health purposes is generally safe. Report any muscle pain or weakness promptly.

ModerateCaution

Simvastatin

The combination of high-dose niacin with simvastatin carries an elevated risk of myopathy and rhabdomyolysis. Simvastatin already has a higher baseline myopathy risk than some other statins, making this combination of particular concern at higher doses.

Recommendation: Avoid high-dose niacin (>500mg/day) with simvastatin. The FDA recommends limiting simvastatin dose to 20mg/day when combined with niacin >1g/day. Report any muscle symptoms immediately.

ModerateConflict

Allopurinol

High-dose Vitamin B3 products that contain niacin or nicotinic acid can raise uric acid and have been associated with drug-induced gout. This can work against allopurinol's goal of keeping serum urate below target. The concern is mainly with lipid-dose niacin or high-dose supplements, not small dietary amounts.

Recommendation: Avoid starting high-dose Vitamin B3 while gout is active or serum urate is above target unless your clinician specifically recommends it. If niacin is necessary, check serum urate after starting or changing the dose and watch for new flares. Do not stop allopurinol during a flare unless your prescriber tells you to.

ModerateConflict

Febuxostat

High-dose Vitamin B3 products containing niacin or nicotinic acid can increase serum uric acid and precipitate gout. That effect can work against febuxostat's urate-lowering goal, particularly if urate is not yet at target. The risk is most relevant for high-dose niacin products, not normal dietary Vitamin B3 intake.

Recommendation: Do not add high-dose Vitamin B3 during febuxostat therapy without checking with your prescriber. If niacin is required, monitor serum urate after dose changes and report any increase in flares. Keep taking febuxostat as prescribed unless your clinician changes the plan.

ModerateCaution

Lovastatin

High-dose Vitamin B3 as niacin can add muscle, liver, and glucose-related adverse effects to statin therapy. Large statin-era niacin trials found no cardiovascular outcome benefit from adding high-dose niacin, while adverse events increased. Low-dose nutritional niacin is different from pharmacologic niacin doses.

Recommendation: Avoid high-dose niacin, especially 500 mg/day or more, with lovastatin unless it is specifically prescribed and monitored. If the combination is used, monitor liver enzymes, glucose control, and any new muscle pain or weakness.

ModerateCaution

Pravastatin

High-dose Vitamin B3 as niacin can increase adverse effects when added to statin therapy, even though pravastatin has fewer CYP3A4 interaction concerns. Large trials of niacin added to statins did not show cardiovascular benefit and did show more adverse events, including glucose and liver-related problems. Ordinary dietary-dose niacin is not the concern.

Recommendation: Do not add high-dose niacin to pravastatin unless your prescriber has a specific reason and monitoring plan. If used, monitor liver enzymes, blood sugar, and any muscle pain or weakness.

Search all 12 interaction records for Vitamin B3 →

Sources

Sources, by evidence tier.

Numbered references. Citations throughout the page link here.

Meta-analyses & systematic reviews

5

Randomized controlled trials

7

Reviews & position papers

3

Reference material

2
Keep exploring

Deep dives & adjacent profiles.

NMNOtherPQQOtherApigeninOtherVitamin B5VitaminVitamin B2VitaminVitamin B12Vitamin

This page is educational. Do not start, stop, or change a supplement or medication based on it without checking with a qualified healthcare professional.

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NutriStack is an informational and organizational tool, not a medical service, and not a substitute for professional advice. Always consult a qualified healthcare professional before starting, stopping, or changing any supplement or medication.