Niacin Deficiency Symptoms: Pellagra Signs and Who Is at Risk
Pellagra is the classic niacin shortage, and it shows up as skin sores in places the sun reaches, diarrhoea and changes in thinking. Those signs also have other causes, so a doctor sorts out what is going on.
At a glance
- What it is: the illness that follows too little niacin, too little tryptophan, or poor absorption of either.
- Classic signs: skin sores in sunny places, diarrhoea, poor appetite, stomach pain, confusion and weakness.
- Most at risk: people with poor food access, heavy drinking, gut disease, weight-loss surgery, anorexia or carcinoid syndrome.
- Quotable line: A skin sore in sunny places, with diarrhoea or confusion, is a question for a doctor, not a home test.
Prefer to listen? This post as a 2 min video · Watch the video
What is pellagra, and how does niacin fit in?
Niacin is vitamin B3. MedlinePlus says pellagra stems from too little niacin or tryptophan in the diet, or from the body failing to absorb them. Tryptophan is an amino acid, and MedlinePlus lists it alongside niacin as a cause of the disease.
Pellagra is useful to know about because its signs overlap with ordinary problems such as sunburn, mouth sores and other causes of confusion. A clear checklist helps you decide when to call a doctor, but it cannot replace the doctor’s check.
What are the signs of pellagra?
MedlinePlus gives the signs as one list. The table sorts that same list by body area, so you can see where each sign sits.
| Area | Signs listed |
|---|---|
| Skin | Scaly skin sores, especially in sun-exposed areas |
| Digestive | Diarrhoea, loss of appetite, abdominal pain, inflamed mucous membranes |
| Nervous system | Mental confusion or delusions, weakness |
Mouth and tongue changes have their own guides, including mouth ulcers and home remedies and a white or cracked tongue. Those pages cover those problems, not pellagra as a whole.
A sun-exposed skin sore, diarrhoea and a change in thinking together are a reason to see a doctor, not a reason to self-diagnose.
Who is at risk, and why does maize matter?
MedlinePlus says pellagra is most common among poor and food-limited populations. It links the disease to gut disorders, weight-loss surgery, anorexia, excessive alcohol use and carcinoid syndrome. It also names some medicines, including isoniazid, 5-fluorouracil and azathioprine, as possible triggers.
Maize has a history here. MedlinePlus says corn is a poor source of tryptophan. It also says niacin is released from corn that is soaked overnight in limewater, and notes this method is used to cook tortillas in Central America, where pellagra is rare. A household that eats maize roti often can learn from this history, but the lesson is about how grain is prepared, not a home remedy for symptoms.
When should you see a doctor, and what should you note first?
MedlinePlus tells you to contact a provider if you have any symptoms of pellagra. Left untreated, it can cause nerve damage, particularly in the brain, and it can lead to death. A doctor can check the cause, because the same signs come from other illnesses.
- Note where the skin sore sits and whether it gets worse on sunny days.
- Count the loose stools each day and note any change in appetite, sleep or thinking.
- List every medicine you take, including those bought without a prescription.
- Bring the list to your doctor and ask whether niacin status should be checked.
Before the visit
Take a daylight photo of the skin sore each time it appears, and write the date on a note beside it. A short series of photos shows the doctor the pattern more clearly than a memory of it.
See a doctor the same week if a skin sore in sunny places comes with diarrhoea, poor appetite, weakness or any change in thinking. Get emergency help if confusion or weakness comes on quickly. Pregnant people, people who drink heavily, and anyone with gut disease or past weight-loss surgery should be assessed rather than self-treated. Do not start, stop or change a prescribed medicine on your own, including any medicine named above; ask the prescriber first.
More nutrient guides sit in the Vitamins and Minerals hub.
Questions about niacin deficiency and pellagra
What are the signs of niacin deficiency?
The classic signs of pellagra are scaly skin sores in sun-exposed areas, diarrhoea, loss of appetite, stomach pain, confusion, delusions and weakness, according to MedlinePlus. Any of these needs a doctor’s assessment.
Vitamin B3 ki kami ke alamat kya hain?
The main signs are skin sores where the sun reaches, diarrhoea and changes in thinking, as MedlinePlus describes them. Those signs have other causes too, so see a doctor rather than guessing from a list.
Can low vitamin B3 cause memory problems?
It can, because pellagra can cause mental confusion, delusions and weakness, and untreated disease can damage nerves, particularly in the brain. A memory change needs a doctor’s check, since other causes exist too. For everyday forgetfulness, see normal forgetfulness or dementia signs.
Is pellagra still seen today?
Yes. MedlinePlus says pellagra is most common among poor and food-limited populations and is rare in the United States. It can also follow heavy drinking, gut disease or weight-loss surgery.
Who gets pellagra most often?
MedlinePlus links it to poor and food-limited populations, heavy alcohol use, gut disorders, weight-loss surgery, anorexia and carcinoid syndrome. Anyone with those risks should be alert to the signs.
Does a rash from the sun always mean pellagra?
No. Sun rashes have many causes. A doctor looks at the pattern, the other signs and your diet before deciding what is going on.
Can maize cause pellagra?
Maize is linked to the disease where people eat a lot of untreated corn. MedlinePlus says corn is a poor source of tryptophan, and that niacin is released when corn is soaked overnight in limewater.
Which foods contain niacin?
MedlinePlus lists milk, eggs, rice, fish, legumes, peanuts and poultry as sources of niacin. A varied plate with several of these covers more ground than any single food.
Do some medicines affect niacin levels?
Yes. MedlinePlus lists isoniazid, 5-fluorouracil and azathioprine among medicines that may cause pellagra. Do not start, stop or change a prescribed medicine on your own; ask the prescriber.
Should I buy a niacin product for these signs?
Not as a first step. The signs need a doctor to confirm the cause, since pellagra can lead to nerve damage and the same symptoms have other causes.
When is pellagra an emergency?
Get emergency help when confusion or weakness comes on quickly, or when thinking changes get worse. Contact a provider promptly for any symptom of pellagra, because untreated disease can damage nerves.