Function: Energy production, formation of steroid compounds, red blood cell formation, cognitive function and mood

Sources: Organ meats, peanuts, fish, yeast, poultry, legumes, milk, eggs, whole grains, orange juice

Optimal Intake: 50-100 mg

Deficiency Signs: Pellagra, a condition characterized by dermatitis, diarrhea, dementia; depression, schizophrenia, weakness, lassitude, anorexia

Toxicity: Large doses can cause dilation of the blood vessels and flushing of the skin. Use a nonflushing form (inositol hexaniacinate) if you are sensitive to regular niacin. Time-released niacin products may result in liver damage.