Vitamins

Vitamin B3 (Niacin)

An essential water-soluble vitamin crucial for energy metabolism, DNA repair, skin health, and nervous system function

Quick Facts

Daily Needs

14-16 mg NE for adults, with variations based on age, sex, and life stage

Importance

Niacin is essential for energy metabolism, DNA repair, skin health, nervous system function, and cholesterol regulation.

Key Functions

  • Energy production from carbohydrates, fats, and proteins
  • DNA repair and cell signaling
  • Antioxidant and detoxification processes
  • Cholesterol synthesis and regulation
  • Nervous system function
  • Hormone production
  • Circulation and reduced blood pressure
  • Digestive system function
  • Skin health maintenance
  • Brain function and cognition

Deficiency Signs

  • Pellagra (characterized by dermatitis, diarrhea, dementia)
  • Skin rashes and inflammation, especially in sun-exposed areas
  • Bright red tongue
  • Vomiting and diarrhea
  • Fatigue and weakness
  • Digestive disturbances
  • Depression
  • Headaches
  • Memory loss and confusion
  • Aggression and irritability
  • In severe cases, dementia-like symptoms

Excess Signs

  • Flushing (redness, warmth, and itching of face, arms, and chest)
  • Nausea and vomiting
  • Liver damage with high-dose supplements
  • Increased blood sugar
  • Peptic ulcers
  • Skin rashes
  • Irregular heartbeat
  • Blurred vision
  • High uric acid levels (may trigger gout)
  • Low blood pressure (from vasodilation)

Best Food Sources

  • Meat (beef, pork, chicken)
  • Fish (tuna, salmon)
  • Liver and other organ meats
  • Peanuts and peanut butter
  • Whole and enriched grains
  • Legumes (beans, lentils)
  • Seeds (sunflower, pumpkin)
  • Nutritional yeast
  • Coffee
  • Mushrooms

Absorption Facts

  • Water-soluble - excess is excreted in urine
  • Two primary dietary forms: nicotinic acid and nicotinamide
  • Can be synthesized from tryptophan (inefficiently, 60:1 ratio)
  • Absorbed in the small intestine
  • Alcohol interferes with absorption and conversion from tryptophan
  • Requires vitamin B6, riboflavin, and iron for conversion from tryptophan
  • High doses of nicotinic acid cause temporary vasodilation (flushing)
  • Low-acid conditions in the stomach can reduce absorption
  • High-fiber diets may slightly decrease absorption

Special Considerations

  • Therapeutic doses can lower cholesterol but require medical supervision
  • Flushing reaction can be reduced with sustained-release forms or aspirin
  • Sustained-release forms may increase risk of liver damage
  • Diabetes may be worsened by high-dose supplementation
  • Can interact with certain medications (statins, diabetes drugs)
  • High corn diets with low animal protein increase risk of deficiency
  • The amino acid tryptophan can be converted to niacin in the body
  • Those with liver disease should be cautious with supplements
  • May help certain skin conditions (acne, rosacea) when applied topically
  • Inositol hexaniacinate has effects similar to niacin with less flushing

About Vitamin B3 (Niacin)

Loading nutrient information...

Track your Vitamin B3 (Niacin) intake with Microgram