Pellagra is a condition that chiefly occurs due to low levels of Vitamin B3 (i.e., Niacin) in the body. Marked by “the three Ds” i.e., dementia, diarrhea, and dermatitis, pellagra mainly affects the digestive system, skin, and nerves, resulting in skin, gastrointestinal and mental disorders.

Also known as Vitamin B3 or Nicotinic acid, Niacin is one of the eight essential B-vitamins that is extremely beneficial for the body. Like all B vitamins, niacin plays a key role in converting carbohydrates into glucose, metabolizing fats and proteins, and keeping the nervous system functioning smoothly. It also helps the body produce sex and stress-related hormones and improves blood circulation and cholesterol levels.

Also Read: Vitamin B3: Functions, Food Sources, Deficiencies and Toxicity
Pellagra: Vitamin B3 Deficiency

In a healthy individual, tryptophan is one of the amino acids that helps the body to make up protein. The liver then converts tryptophan from high-protein fruits, vegetables, meats and milk into niacin.

The condition must be diagnosed and treated on time as without proper medical intervention, it can be fatal and life-threatening.


Pellagra is categorized into two types- primary and secondary.

Primary pellagra occurs due to malnutrition when a person is not getting enough niacin or tryptophan in the diet, i.e., not consuming enough green vegetables, seafood, meat, and eggs. It is commonly noticed in developing countries that depend on corn as a staple food. Corn chiefly contains niacytin, a form of niacin that humans cannot digest and absorb unless prepared properly.

Also Checkout: Vitamin B3/Niacin: Eat These In Your Daily Diet To Stay Healthy - Infographic

On the other the main cause of secondary pellagra is when the body is unable to process the niacin properly due to gastrointestinal issues that inhibit the body from absorbing niacin.

Risk Factors

Certain causative factors that increase the risk of Pellagra include:

Gastrointestinal Diseases: People suffering from gut issues such as Crohn’s disease and Ulcerative colitis are more at risk of getting Pellagra.

Alcoholism: Excessive use of alcohol makes one prone to this Vitamin B3 deficiency.

Diet: A diet rich in corn or maize contains niacytin, a form that is not digested by humans, hence multiplying the chances of getting pellagra.

Eating Disorders: Conditions that cause problems in eating like Anorexia nervosa aggravates the chances of this syndrome.

Liver Cirrhosis: Scarring and damage of the liver tissue inhibits conversion of tryptophan into niacin, thus making one susceptible to this deficiency.

Health Conditions: Conditions like Hartnup disease and cancerous conditions carcinoid tumors aggravates the risk of pellagra.

Medications: Consumption of certain medications, including anti-convulsants and immunosuppressive drugs increases the chances of this niacin deficiency syndrome.


The main signs and symptoms of pellagra involve the ‘3-d’s’ which are dermatitis, dementia, and diarrhea. This is chiefly because vitamin B3 deficiency is most noticeable in body parts with high rates of cell turnover, such as the skin or gastrointestinal tract.

Gastrointestinal Symptoms

The main gut issue that is seen during niacin deficiency includes diarrhoea marked by passage of loose watery stools at least three times per day.

Other gastrointestinal symptoms include:

  • Dehydration
  • Abdominal pain
  • Nausea
  • Vomiting
  • Indigestion
  • Decreased appetite
  • Glossitis (tongue swelling)
  • Oral ulcers
  • Trouble while eating or drinking

Dermatological Symptoms

The main skin symptom related to Pellagra is dermatitis marked by thickened and scaly skin, rashes, and discoloration. Doctors and experts often refer to the appearance of these symptoms around the neck as a Casal collar or Casal necklace. The affected area of the skin may become sensitive to light and feel and look like a sunburn.

Other dermatitis symptoms include:

  • Thick, crusty, scaly, or cracked skin
  • Red, flaky skin
  • Areas of discoloration, ranging from red to brown
  • Itchy, burning patches of skin
  • Cheilitis (cracking and inflammation of the corners of the mouth)
  • Angular palpebritis (redness and cracking in the corners of the eyelid)

Neurological Symptoms

In some cases, this Vitamin B3 deficiency showcases neurological signs in the initial days but they’re often hard to identify. The main pellagra-related neural issue includes dementia.

Other neurological symptoms include:

  • Depression
  • Confusion, irritability, or mood changes
  • Apathy
  • Headaches
  • Restlessness
  • Anxiety
  • Disorientation or delusions
  • Memory loss
  • Psychosis

Lastly, in some cases of alcohol-induced pellagra that relate to the brain and nerves include:

  • Intermittent confusion
  • Exaggerated startle responses
  • Stiff muscles making difficulty in movement

Diagnosis And Treatment

Although, it is difficult to diagnose pellagra owing to its wide-range of symptoms, yet if you have the above-mentioned gastrointestinal issues or notice some sort of dermatitis near the neck or suddenly observe some neural abnormalities, don't waste time and consult a specialized doctor immediately. The doctor usually does a thorough physical checkup, acknowledges the patient’s dietary routine and medical history and conducts blood and urine tests to analyze whether there is a niacin deficiency along with other pellagra-associated abnormalities.


The two forms of pellagra are treated separately. If the patient is suffering from Primary Pellagra, treatment usually involves modifications in the daily dietary and a niacin or nicotinamide supplement which may be taken orally or need to be given intravenously.

On the other hand, the basic treatment for secondary pellagra usually focuses on treating and managing the underlying cause. However, in some cases of secondary pellagra, doctors may also prescribe niacin or nicotinamide either orally or intravenously.

While recovering from either primary or secondary pellagra, it is extremely important to keep any rashes moisturized and protected with proper sunscreen.