How Did People Get Pellagra? Understanding Causes and History

October 15, 2025 •

3 min read

According to the World Health Organization, outbreaks of pellagra have been reported among displaced populations and refugees in recent history, though the condition was once widespread across Europe and the American South. The primary way people get pellagra is through a diet severely lacking in niacin (vitamin B3) or its precursor, tryptophan.

Quick Summary

Pellagra is a disease caused by a severe deficiency of niacin (vitamin B3) or tryptophan, typically resulting from poor diet or malabsorption. Historically, it was linked to a maize-based diet without proper processing and widespread poverty. Today, secondary causes like alcoholism or other medical conditions are more common in developed nations.

Key Points

Primary Deficiency: The most common historical cause of pellagra was a diet lacking in niacin or the amino acid tryptophan, especially prevalent in societies relying heavily on unprocessed maize.
Secondary Pellagra: People can also get pellagra if their body cannot absorb or metabolize niacin properly due to other health issues like alcoholism, gastrointestinal diseases, or certain medications.
Historical Epidemics: In the American South during the early 20th century, poverty and reliance on cheap, refined cornmeal led to widespread pellagra outbreaks before the cause was identified.
Dietary Prevention: Traditional corn processing methods, like nixtamalization, release bound niacin, which is why pellagra was historically less common in some indigenous American cultures.
The 'Four Ds': The classic symptoms of pellagra are dermatitis, diarrhea, dementia, and if untreated, death, which result from the body's inability to carry out cellular metabolism.
Eradication in Developed Nations: Improvements in diet, food fortification programs, and socioeconomic changes effectively eliminated endemic pellagra in the developed world by the mid-20th century.

Pellagra is a systemic disease caused by a severe deficiency of niacin (vitamin B3), a condition that tragically affected millions throughout history before its cause was fully understood. The name comes from the Italian words 'pella agra,' meaning 'rough skin,' referring to one of its most prominent symptoms. The disease is classically defined by the 'four Ds': dermatitis, diarrhea, dementia, and if left untreated, death. The reason people get pellagra is either due to a lack of dietary intake (primary pellagra) or the body's inability to absorb or use niacin effectively (secondary pellagra).

The Role of Niacin and Tryptophan

Niacin is a crucial water-soluble vitamin essential for converting food into energy, as it is a key component of coenzymes involved in cellular metabolism. The body can get niacin directly from food or synthesize it from the amino acid tryptophan, found in protein-rich foods. A balanced diet rich in meat, fish, eggs, and legumes provides enough of these nutrients to prevent deficiency. However, historical circumstances and certain health issues can disrupt this process, leading to pellagra.

Primary Pellagra and the Corn Connection

Historically, a major reason people got pellagra was a staple diet of non-alkali-treated corn. Corn contains niacin, but it's in a bound, non-bioavailable form that isn't easily absorbed. Traditional methods like nixtamalization, soaking corn in an alkaline solution, release the niacin, preventing deficiency. However, when corn was adopted in Europe and the American South without this step, pellagra became widespread, especially among impoverished populations. In the American South, poverty and reliance on cheap cornmeal exacerbated the problem.

Secondary Pellagra: The Challenge of Absorption

Secondary pellagra occurs when the body cannot properly absorb or utilize niacin, even with sufficient dietary intake. This form is more common in industrialized nations today.

Common secondary causes of pellagra:

Alcoholism: Interferes with nutrient absorption.
Gastrointestinal diseases: Conditions like Crohn's or cirrhosis impair nutrient absorption.
Bariatric surgery: Can damage the intestinal lining and hinder absorption.
Certain medications: Drugs like isoniazid can interfere with niacin metabolism.
Genetic disorders: Rare conditions like Hartnup disease impair absorption of amino acids, including tryptophan.

The Historical Eradication of Pellagra

Pellagra was a medical enigma for centuries, initially mistaken for an infectious disease. Dr. Joseph Goldberger's work in the early 20th century proved it was a dietary deficiency. In 1937, nicotinic acid (niacin) was identified as the missing factor. Food fortification with niacin, combined with better socioeconomic conditions and varied diets, led to the elimination of endemic pellagra in the United States by the mid-20th century.

Modern-Day Pellagra Risk and Prevention

Pellagra is rare in the developed world but still a risk for vulnerable groups and those with certain health issues. In less developed areas, limited food access and reliance on corn can still cause primary pellagra outbreaks. Prevention involves a balanced diet rich in niacin and tryptophan, or treating the underlying medical condition causing secondary pellagra.

Comparison of Niacin Deficiency to Other Vitamin Deficiencies


Feature	Niacin (B3) Deficiency (Pellagra)	Thiamine (B1) Deficiency (Beriberi)	Ascorbic Acid (Vitamin C) Deficiency (Scurvy)
Primary Symptoms	The "four Ds": Dermatitis, Diarrhea, Dementia, Death	Cardiovascular and neurological symptoms, such as nerve damage (dry beriberi) or heart failure (wet beriberi)	Weakness, fatigue, bleeding gums, easy bruising, and poor wound healing
Affects High-Turnover Cells?	Yes, especially skin, gastrointestinal tract, and nervous system	Yes, particularly heart and nerves	Yes, impacting connective tissues throughout the body
Dietary Cause	Insufficient intake of niacin or tryptophan, often from corn-based diets	Insufficient thiamine, often from diets of polished rice or refined carbs	Insufficient Vitamin C from a lack of fruits and vegetables
Modern Cause	Chronic alcoholism, malabsorptive diseases, certain medications	Alcoholism, chronic illness, and specific health conditions	Malnutrition, poor diet, and restrictive eating habits

Conclusion

The history of how people got pellagra highlights the impact of public health, nutrition, and social factors. Whether from a lack of bioavailable niacin in the diet or an inability to use it due to other conditions, pellagra's causes are clear. The disease's large-scale eradication was a success due to science, food fortification, and better economic conditions. However, it remains a risk in areas facing conflict or famine, and for individuals with specific medical issues.

(https://www.apollo247.com/health-topics/vitamin-deficiency-anemia//pellagra-understanding-symptoms-and-treatment)

Frequently Asked Questions

The main cause of pellagra is a severe deficiency of niacin (vitamin B3) or its precursor, the amino acid tryptophan.

Corn contains niacin in a form that is not easily absorbed by the human body. Historical epidemics occurred in cultures that relied on corn as a staple but did not use traditional processing methods, like nixtamalization, which make the niacin bioavailable.

Yes, chronic alcohol use is a common cause of secondary pellagra. It interferes with the absorption and metabolism of niacin and is often associated with a poor, nutrient-deficient diet.

The classic symptoms of pellagra are often remembered as the 'four Ds': dermatitis (a sunburn-like skin rash), diarrhea, dementia (including mental confusion and mood changes), and eventually death if left untreated.

Yes, while rare in developed countries due to fortified foods, pellagra remains a threat in developing regions, refugee camps, and for individuals with risk factors like alcoholism, gastrointestinal disease, or certain medications.

Pellagra is treated with niacin or nicotinamide supplements, often given orally, and a balanced, high-protein diet to ensure full recovery.

After decades of research, the cure was found to be the administration of nicotinic acid (niacin). Food fortification programs in the mid-20th century further helped eradicate endemic pellagra in the West.