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Vitamin B3

WATER-SOLUBLE

Nicotinic acid, Nicotinamide, NAD+, NADP+

Niacin (vitamin B3) encompasses two biologically active forms: nicotinic acid and nicotinamide. Both serve as precursors for the coenzymes NAD+ and NADP+, which are central to virtually all aspects of cellular energy metabolism. NAD+ functions primarily in catabolic reactions, while NADPH serves as a reducing agent in anabolic reactions. Beyond energy metabolism, NAD+ has emerged as a critical signaling molecule involved in DNA repair and gene expression.

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Key Functions

  • Energy metabolism (NAD+/NADP+ coenzymes)
  • DNA repair and cell signaling
  • Cholesterol synthesis regulation
  • Skin and digestive system health
  • Nervous system function

Best Food Sources

Poultry, beef, and fishPeanuts and mushroomsBrown rice and fortified cerealsLiver and organ meats

Deficiency: Pellagra

  • Dermatitis (photosensitive rash)
  • Diarrhea
  • Dementia and confusion
  • Death if untreated
  • The "4 Ds" of niacin deficiency

High-Risk Groups

  • Populations dependent on corn/maize
  • Chronic alcoholics
  • People with carcinoid syndrome

Sources

Reviewed for accuracy: Content is based on guidelines from the NIH Office of Dietary Supplements, Harvard T.H. Chan School of Public Health, and peer-reviewed medical literature.

Recommended Daily Amount

Adult Men

16 mg

Adult Women

14 mg

Upper Limit (Tolerable)

35 mg

Did You Know?

Pellagra killed more than 100,000 Americans between 1900 and 1940 before niacin fortification eliminated it.

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