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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)
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