Vitamin B3 (Niacin)

Energy Metabolism Circulation Cardiovascular Cholesterol Vitamin Acne B-vitamin Niacin Nicotinic acid Nicotinamide Niacinamide HDL LDL Triglycerides Heart health Skin health Rosacea Blood sugar Glucose Flush Pellagra

Published on December 20, 2025 by Guy

Vitamin B3 is an essential water-soluble B vitamin that exists in two primary forms: nicotinic acid and nicotinamide (niacinamide). It plays a crucial role in energy metabolism, converting food into cellular fuel, and is vital for healthy skin, nerves, and digestive function. Niacin is well-known for its cholesterol-modifying effects—particularly its ability to raise HDL ("good") cholesterol—and for producing the characteristic "niacin flush" at higher doses of nicotinic acid.

Effects and Benefits

Core Identification

Common Names:
- Niacin
- Vitamin B3
- Nicotinic acid
- Nicotinamide
- Niacinamide

Latin Name: N/A (synthetic vitamin)

Category: Vitamin

Uses

Traditional Uses

  • Energy production and metabolism - Essential nutrient recognized since discovery in 1937
  • Treatment of pellagra - Historic deficiency disease causing "the 4 D's": dermatitis, diarrhea, dementia, and death
  • General nutritive support - Traditional component of B-complex supplementation

Modern Uses

  • Cholesterol management - Nicotinic acid lowers LDL cholesterol and triglycerides while raising HDL cholesterol | Research quality: Strong
  • Key findings: Shown to reduce risk of both non-fatal and fatal heart attacks at therapeutic doses; recognized by JAMA (1986) as first supplement to use after diet for cholesterol management

  • Source citations: Brewer, Sarah - TDT Encyclopedia of Vitamins; Mars, Brigitte - The Country Almanac of Home Remedies

  • Skin health (niacinamide form) - Anti-inflammatory properties for acne and rosacea | Research quality: Strong

  • Key findings: NICOS trial showed niacinamide combination (750mg with zinc, copper, folic acid) reduced severity of acne and rosacea comparable to antibiotics after 4-8 weeks

  • Source citations: Moyad, Mark - The Supplement Handbook; Lee, Sandra - Put Your Best Face Forward

  • Blood sugar regulation - Forms Glucose Tolerance Factor (GTF) with chromium | Research quality: Moderate

  • Key findings: Essential for insulin action and glucose uptake into cells; deficiency associated with impaired glucose tolerance

  • Source citations: Brewer, Sarah - TDT Encyclopedia of Vitamins

  • Circulation improvement - Vasodilator that widens blood vessels | Research quality: Moderate

  • Key findings: Increases cardiac output, dilates blood vessels, decreases circulatory resistance; helpful for conditions requiring improved blood flow

  • Source citations: Mars, Brigitte - The Country Almanac of Home Remedies

  • Joint support - May reduce arthritis symptoms | Research quality: Preliminary

  • Key findings: Research shows potential for reducing symptoms of both osteoarthritis and rheumatoid arthritis
  • Source citations: Brewer, Sarah - TDT Encyclopedia of Vitamins

Active Compounds

Primary Active Ingredients:
- Nicotinic acid - The form that produces the "niacin flush" and is used therapeutically for cholesterol management; converts to NAD/NADH for cellular energy
- Nicotinamide (Niacinamide) - Does not cause flushing; has anti-inflammatory properties particularly beneficial for skin conditions
- NAD/NADH (Nicotinamide Adenine Dinucleotide) - The coenzyme forms that participate in over 400 enzymatic reactions in the body

Dosage Information

Standard Dosage:
- Form: Capsule, tablet
- Amount: 15-20 mg per day
- Frequency: Once daily with food
- Notes: RDA is 15-18 mg; can also be obtained as "niacin equivalents" from dietary tryptophan (60 mg tryptophan = 1 mg niacin)

Therapeutic Dosage:
- Form: Nicotinic acid or nicotinamide
- Amount: 50-500 mg per day for general support; 750-1500 mg for specific conditions
- Purpose: Cholesterol management, skin conditions, circulation
- Duration: Under medical supervision for doses above 100 mg

Maximum Safe Dosage:
- Daily maximum: 35 mg without medical supervision (to avoid flush and side effects)
- Warning threshold: Doses above 500 mg require medical monitoring including liver function tests

Bioavailability Notes:
- Well absorbed from the gastrointestinal tract
- Sustained-release forms may have higher liver toxicity risk than immediate-release
- Body can synthesize niacin from dietary tryptophan (found abundantly in eggs and cheese)

How to Take It

Timing:
- Take with food to reduce stomach upset and flushing
- Best taken with meals
- For those sensitive to flushing: low-dose aspirin (75-300 mg) taken 30 minutes before nicotinic acid can reduce flush effect

Synergies - What It Works Well With

Complementary Supplements:
1. Chromium - Together they form Glucose Tolerance Factor (GTF), essential for insulin function | Enhanced blood sugar regulation
2. Vitamin B1 (Thiamin) & B2 (Riboflavin) - Work synergistically for energy metabolism | Improved energy production from carbohydrates
3. Zinc + Copper + Folic Acid (with niacinamide) - NICOS trial combination for skin health | Enhanced anti-inflammatory effects for acne and rosacea

Avoidance - What NOT to Combine With

Supplement Interactions:
1. High-dose niacin + Antioxidant combinations - May reduce effectiveness; one study showed antioxidants (vitamin E, C, beta-carotene, selenium) blocked beneficial effects of niacin on HDL cholesterol

Drug Interactions:
1. Statin medications (HMG-CoA reductase inhibitors) - Combined use may cause myopathy (muscle disorders) that can become serious (rhabdomyolysis) | Severity: Moderate to Severe - consult physician
2. Blood pressure medications - Niacin can lower blood pressure; may enhance hypotensive effects | Severity: Moderate
3. Diabetes medications - High-dose niacin can elevate blood glucose levels | Severity: Moderate
4. Blood thinners - May enhance anticoagulant effects | Severity: Moderate

Food Interactions:
- Alcohol may slow absorption but doesn't significantly affect effectiveness
- Coffee and tea may interfere with general B vitamin absorption

Safety Information

Contraindications:
- Diabetes (niacin can elevate glucose levels)
- Low blood pressure
- Gout (niacin can increase uric acid)
- Liver disease
- Glaucoma
- Peptic ulcers
- Active bleeding disorders

Side Effects:
- Common (nicotinic acid): Flushing, warmth, redness, itching of skin (typically lasts 10-30 minutes)
- Less common: Nausea, stomach upset, headache
- Rare/high dose: Liver toxicity (hepatitis), skin thickening/darkening (acanthosis nigricans), palpitations

Long-Term Use:
- Safe at RDA levels (15-20 mg)
- Therapeutic doses (500+ mg) require regular liver function monitoring
- Sustained-release forms have higher liver toxicity risk than immediate-release
- Inositol hexaniacinate (IHN) may be safer alternative for long-term use

Special Precautions:
- Pregnancy: Safe at RDA levels; avoid high therapeutic doses without medical supervision
- People who flush easily appear more sensitive to the niacin flush effect
- May increase absorption of zinc and iron from the gut

Primary Uses At-a-Glance

Primary:
- Cholesterol management (high LDL, low HDL, high triglycerides)
- Energy metabolism and fatigue
- Skin health - acne and rosacea (niacinamide form)
- Circulation support
- Blood sugar regulation support

Secondary:
- Joint discomfort (arthritis)
- Cognitive support
- Thyroid function support
- Cold weather circulation (Raynaud's-like symptoms)

Sources

Local Library:
- Brewer, Sarah - TDT Encyclopedia of Vitamins
- Moyad, Mark - The Supplement Handbook
- Mars, Brigitte - The Country Almanac of Home Remedies
- Lee, Sandra - Put Your Best Face Forward
- Gaby, Alan R. - A-Z Guide to Drug-Herb-Vitamin Interactions 2nd Ed
- Balch, Phyllis - Prescription for Herbal Healing
- Curtis, Susan - Neals Yard Remedies
- Weil, Andrew - Eating Well for Optimum Health
- Ali, Naheed - Diabetes and You
- Lust, John - The Natural Remedy Bible

General Knowledge:
- Standard clinical references for vitamin biochemistry and RDA values