Deficiency diseases: is pellagra making a comeback?

What is pellagra?

Pellagra is a deficiency disease caused by lack of vitamin B3 (niacin) and tryptophan in the diet. Tryptophan is an amino acid that converts to niacin in the body.

Pellagra is diagnosed by a classic triad of symptoms – the three Ds: diarrhoea, light-sensitive dermatitis and dementia. Psychotic delusions can also occur. Untreated, pellagra leads to the final D: death.

What causes it? And who suffers?

Pellagra is reported in countries where people are chronically malnourished, or over-dependent on foods poor in niacin and tryptophan, such as corn. Pellagra is less common in societies where people have access to a wide variety of foodstuffs. Inability to absorb niacin can also cause pellagra.

In the early 1900s, pellagra was epidemic in parts of the United States. Once its nutritional cause was identified, however, niacin supplementation made treatment possible.

More recently, pellagra has been identified in vulnerable members of so-called developed societies: individuals suffering from HIV, alcoholism and anorexia nervosa; psychiatric patients who refuse nourishment; and homeless, or otherwise poverty-stricken, people who have no access to fresh, wholesome food but depend on processed junk for price and convenience.

An article (2008) in the American Journal of Therapeutics discusses the potential resurgence of pellagra among HIV and anorexia nervosa patients who neglect proper nutrition. The authors discuss a case of pellagra, identified by the three Ds and correctly treated. Click on the link to read the abstract: ‘Pellagra: rekindling of an old flame‘.


Pellagra is easy to diagnose and treat but doctors can miss (or misinterpret) vital clues, especially in countries where the disease is rare.


Taking vitamin B3 and tryptophan is the only cure for pellagra. Doses are likely to vary, depending on the patient. Some are niacin-dependent, meaning they need ultra-high doses of niacin to get (and remain) well. Others need lower doses.

Vitamin B3 comes in several forms (niacin, niacinamide, inositol hexaniacinate, etc.). Each exerts a slightly different effect on the body, while still being useful for pellagra. The doctor might prescribe any one of these, depending on the patient.

He or she might also prescribe tryptophan supplements, or tryptophan-rich foods.

Pellagra sufferers need prompt medical attention, preferably from a doctor who understands deficiency diseases.

As supplements can interact with pharmaceuticals, it is imperative to seek medical advice.

Sub-clinical pellagra

Some doctors and researchers believe that widespread reliance on nutrient-poor, processed foods is leading society to mental illness through nutritional imbalances. The psychological symptoms of niacin deficiency, for example, parallel those of schizophrenia.

One practical finding suggests reactive hypoglycaemia, sub-clinical pellagra and vitamin-B deficiencies might be a root cause of anger, mania, paranoia and violence in modern society. For more on this fascinating topic, see ‘Could chronic niacin deficiency be a root cause of increase in “deranged” violent crimes?

Further reading

Welcome back: pellagra in the developed world

Will pellagra make a comeback?

Pellagra encephalopathy following B-complex vitamin treatment without niacin‘, International Journal of Psychiatry in Medicine (2004)

Dr Joseph Mercola’s review of Niacin: The Real Story by Abram Hoffer, Andrew W Saul and Harold D Foster

Vitamin B-3: niacin and its amide‘ by A Hoffer

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