Vitamin B3 (niacin) helps convert food into energy by forming NAD/NADP coenzymes, supports nervous system function, healthy skin and digestion, and prevents pellagra (a deficiency disorder). At therapeutic doses it can improve blood lipid profiles by raising HDL and lowering LDL and triglycerides. It also supports DNA repair and circulation; high supplemental doses should be used under medical supervision due to flushing and liver risks.

Vitamin B3 (niacin) deficiency—pellagra—causes the classic triad: dermatitis (symmetrical, photosensitive rash and hyperpigmentation, often around the neck and hands), diarrhea, and dementia (confusion, memory loss, irritability). Other signs include glossitis, stomatitis, mouth soreness, anorexia, weakness, headache, nausea, vomiting, and peripheral neuropathy. Symptoms typically develop gradually but can worsen without treatment; seek medical care if suspected.

Liver—especially beef liver—is the richest common food source of vitamin B3 (niacin). Other very high-niacin foods include tuna and other oily fish, chicken breast, turkey, pork, and peanuts. Including small portions of liver or frequent servings of fish and poultry can help meet niacin needs while providing other B vitamins and protein; choose lean, well-cooked preparations.

Niacin (vitamin B3) can raise HDL and lower LDL and triglycerides, but benefits are limited by common side effects (flushing, itching) and risks (liver toxicity, worsened blood sugar). Large trials showed no additional cardiovascular benefit when added to statins, so it’s not routinely recommended for heart-disease prevention. It may be considered in selected cases under medical supervision with monitoring.

Vitamin B3 (niacinamide) improves skin by strengthening the barrier—boosting ceramide production and reducing water loss—while calming inflammation and redness. It regulates sebum, shrinks visible pores, helps reduce acne, and evens tone by inhibiting pigment transfer. Niacinamide also supports collagen production and has antioxidant effects, aiding hydration, anti‑aging, and overall skin resilience.

Vitamin B3 (niacin/niacinamide) supports general hair health by improving scalp circulation and cellular metabolism; deficiency can contribute to hair thinning. Some topical and oral studies show modest gains in hair strength or fullness, but strong evidence for reversing hair loss is limited. Normal dietary intake is safe; very high supplemental doses can cause flushing and liver harm. Check with a healthcare professional.