Nutrition Diet: What is the niacin deficiency disease called?

October 24, 2025 •

3 min read

Historically, pellagra was an epidemic in the early 20th century in parts of the southern United States, causing widespread health issues. This severe nutritional illness, answering the question 'What is the niacin deficiency disease called?', is known as pellagra, a systemic condition that results from a chronic and severe lack of vitamin B3.

Quick Summary

Pellagra is the systemic disease caused by severe niacin deficiency, leading to the classic symptoms of dermatitis, diarrhea, and dementia. Causes range from inadequate dietary intake to underlying health conditions that hinder nutrient absorption.

Key Points

Pellagra is the niacin deficiency disease: The condition is known as pellagra, resulting from a severe deficiency of vitamin B3 (niacin).
Symptom Triad: Pellagra is characterized by the "3 Ds": dermatitis (sun-exposed skin rash), diarrhea, and dementia (neuropsychiatric symptoms).
Two Primary Causes: Pellagra can be primary (due to poor dietary intake) or secondary (caused by impaired absorption from other medical conditions).
Treatment is Effective: The condition is effectively treated with oral niacin supplements, particularly nicotinamide, and resolution of symptoms can occur within weeks.
Prevention is Key: Eating a balanced diet rich in niacin and tryptophan, and consuming fortified foods, is the most effective prevention strategy.
Modern Risk Factors: Today, pellagra in developed countries is most often linked to chronic alcoholism, malabsorption disorders, or certain medications.

The Diagnosis of Pellagra: A Systemic Nutritional Disorder

Pellagra is a complex disease resulting from a severe deficiency of niacin, or vitamin B3, and its precursor, the amino acid tryptophan. While once a widespread epidemic in certain regions, it is now rare in developed nations due to widespread food fortification. However, it persists in populations with limited food resources and can also occur due to secondary factors in industrialized countries. Understanding this condition is vital for proper diagnosis and treatment, which can lead to a quick recovery if caught early.

The Four Ds: The Classic Symptoms of Pellagra

Health professionals often refer to the classic signs of pellagra as the “3 Ds,” with a potential fourth if left untreated. These symptoms affect high-turnover cellular systems, such as the skin, the gastrointestinal tract, and the brain.

Dermatitis: This is one of the most recognizable symptoms, typically starting with a rash that resembles a severe sunburn. It is photosensitive and appears symmetrically on sun-exposed areas like the face, neck (often forming Casal's collar), hands, and feet. Over time, the skin can become rough, scaly, and hyperpigmented.
Diarrhea: Niacin deficiency can cause chronic inflammation and atrophy of the gastrointestinal tract's mucous lining. This leads to symptoms such as abdominal pain, indigestion, a red and swollen tongue (glossitis), and persistent, sometimes bloody, diarrhea.
Dementia: The central nervous system is also heavily affected, leading to a range of neuropsychiatric symptoms. Early signs can include lethargy, anxiety, and depression, which can progress to confusion, memory loss, disorientation, and even psychosis in severe cases.
Death: Untreated pellagra can be fatal, making timely diagnosis and intervention critical.

The Diverse Causes of Niacin Deficiency

Niacin deficiency can arise from two main types of causes, each requiring a different approach to long-term management.

Primary Pellagra: This form is caused by an inadequate dietary intake of both niacin and its precursor, tryptophan. It is most commonly associated with diets heavily reliant on unprocessed maize (corn), as the niacin in maize is in a bound, non-bioavailable form unless treated with an alkali. Poor and food-limited populations are particularly susceptible.
Secondary Pellagra: This is more common in industrialized nations and occurs when the body cannot properly absorb or utilize niacin due to underlying conditions.

Comparison of Primary vs. Secondary Pellagra


Feature	Primary Pellagra	Secondary Pellagra
Root Cause	Inadequate dietary intake of niacin and tryptophan.	Impaired absorption or utilization of niacin due to other medical issues.
Dietary Factor	Often linked to high consumption of untreated corn.	Can occur despite adequate niacin intake in the diet.
High-Risk Populations	Impoverished and food-limited communities.	Individuals with chronic alcoholism, GI diseases, or on certain medications.
Modern Context	Less common in developed countries, but can still occur.	More prevalent in developed countries, primarily affecting at-risk individuals.

Factors and Conditions Contributing to Secondary Pellagra

Secondary pellagra is linked to various health issues that affect niacin absorption or use. These include chronic alcoholism, gastrointestinal problems like malabsorption disorders, certain genetic conditions, carcinoid syndrome, and specific medications.

Diagnosis and Treatment of Pellagra

Diagnosing pellagra involves reviewing diet, symptoms, and sometimes urine tests. A positive response to niacin treatment helps confirm the diagnosis. Treatment with oral nicotinamide is effective, often showing improvement in symptoms within days. Addressing the underlying cause is also important, especially for secondary pellagra.

Prevention Through a Nutritious Diet

A balanced diet is the main way to prevent pellagra. Fortifying foods like bread and cereals with niacin is a successful strategy in many areas. Foods rich in niacin and tryptophan include meat, legumes, whole grains, and dairy.

Conclusion

Pellagra is a serious disease caused by niacin deficiency with distinct symptoms. While historically linked to poor diets, it now often results from other health problems. Food fortification has significantly reduced its prevalence. Early diagnosis and niacin treatment are effective, highlighting the importance of addressing both the deficiency and contributing medical issues.

For more information on pellagra's history and prevalence, see the {Link: NCBI Bookshelf https://www.ncbi.nlm.nih.gov/books/NBK557728/}.

Frequently Asked Questions

The main cause of primary niacin deficiency is a diet severely lacking in both niacin and its precursor, tryptophan. Historically, this has occurred in populations relying heavily on untreated corn as a staple food.

Early symptoms of pellagra are often vague but can include fatigue, loss of appetite, and depression. Gastrointestinal symptoms like mouth sores and a red tongue, often precede skin manifestations.

Casal's collar is a telltale skin manifestation of pellagra, where a dark, hyperpigmented, collar-like band appears on the neck. It is named after Don Gaspar Casal, the physician who first described pellagra.

Diagnosis is often based on the patient's diet history and clinical symptoms. A definitive diagnosis is typically confirmed by a patient's rapid recovery following treatment with niacin supplementation.

Yes, pellagra can be cured by replacing the missing nutrient. Niacin supplementation, most often using nicotinamide, is the standard and highly effective treatment.

Secondary pellagra can be caused by conditions such as chronic alcoholism, gastrointestinal diseases like inflammatory bowel disease, genetic disorders like Hartnup disease, and carcinoid syndrome.

Corn is linked to pellagra because it is low in the amino acid tryptophan, and the niacin it contains is in a bound, non-bioavailable form. Traditional alkaline processing (nixtamalization) releases this niacin, preventing deficiency.