Vitamin B3 Deficiency


Niacin deficiency may result from inadequate dietary intake of vitamin B3 (niacin) and/or ‘tryptophan’, a dietary amino acid from which NAD can also be synthesized (3).

Other nutrient deficiencies (e.g., vitamin B2B6, and iron) may also contribute to the development of niacin deficiency. 


The most common symptoms of niacin deficiency involve the skin, digestive system, and nervous system (2).

The symptoms of the late stage of severe vitamin B3 (niacin) deficiency ─ a disease called ‘pellagra’ ─ include inflammation of the skin (dermatitis), vomiting, diarrhea, headache, fatigue, and memory loss. If untreated, pellagra is ultimately fatal (3).

Authored by Dr Peter Engel in 2010, reviewed by Giorgio La Fata on 06.06.2017