Common Symptoms Of A Niacin Deficiency

March 12, 2024

A niacin deficiency is a rare condition that happens when an individual cannot properly absorb niacin or its precursor amino acid, tryptophan. Niacin is also known to be called nicotinic acid and vitamin B3. As one of the eight B vitamins, niacin is imperative to the syntonization of carbohydrates into glucose, preserving nervous system health, and metabolizing proteins and fats. Niacin also positively affects circulation and cholesterol.

The amino acid tryptophan is important when it comes to niacin because the liver has the ability to convert it into niacin from protein-rich foods such as milk and meats. A niacin deficiency is most commonly caused by an inability to absorb niacin or tryptophan from food correctly as the normal human diet contains more than enough niacin in it.

Depression And Apathy

Characterized by intense hopelessness and sadness, depression is a mood disorder that often interferes with an individual's daily life. Apathy is characterized by a lack of enthusiasm, interest, or concern. A niacin deficiency can cause a deficiency of serotonin in the brain. Depression and apathy can happen as a result of less transient receptor potential channels in the brain. Serotonin is the neurotransmitter in charge of anxiety, fear, mood, and the general sense of well-being. Serotonin is made by proteins and cofactors much like other types of neurotransmitters.

When not enough protein is provided to the body through diet, a deficiency in the vitamins and minerals needed to create serotonin occurs. This deficiency includes niacin or vitamin B3. When the components needed to build the neurotransmitters are not available, a neurotransmitter imbalance occurs as a result. A combination of less TRP channels in the brain and an imbalance in neurotransmitters including serotonin can cause an individual to feel hopeless, sad, fearful, uninterested, and unconcerned.

Canker Sores

Small, shallow, and painful ulcers in the mouth are called canker sores. These kinds of sores most often occur on the tongue, inside the cheeks, gums, and inside the lips. Usually, these sores are round shaped, small, have a red border and have a white or yellow center to them. Sometimes canker sores can be so painful that talking and eating are difficult. These sores usually last anywhere between seven and fourteen days. When an individual has a particularly severe case of canker sores, they may experience a fever, swollen lymph nodes, and physical sluggishness.

While canker sores can be caused by a number of things, a niacin deficiency is strongly associated with recurrent canker sore outbreaks. The exact mechanism of how niacin deficiency causes these sores to form is still unclear, however, research has suggested it is because niacin plays a key role in cell production and hormone regulation, both of which can trigger the immune system to kick into a state of overdrive where it attacks its own tissues in the mouth. Canker sores most often resolve easily on their own, however, recurrent episodes of painful canker sores can cause the niacin deficiency to worsen.

Thick And Scaly Rash

A thick and scaly rash can occur when a niacin deficiency has resulted in a disease called pellagra. This disease causes dermatitis, or red, dry, swollen, and inflamed patches of skin. Niacin deficiency and pellagra manifest in the body regions and parts with the highest rates of cell turnover, like the skin. The most common sites where pellagra-derived dermatitis occurs include the lips, hands, face, and feet. This rash can also occur around the neck. Usually, the skin involved in the rash will be flaky, red, discolored, thick, cracked, scaly, crusty, and itchy.

Dermatitis associated with a niacin deficiency typically starts off looking similar to a sunburn. The rash then can form blisters or lesions depending on the severity of the individual's deficiency. Dry brown scales and crusting may form between two and four weeks after the initial appearance of the rash. This type of rash occurs symmetrically, similar to the way canker sores caused by a niacin deficiency are symmetrical. Minor areas of the rash may be further irritated by heat, pressure, friction, or sunlight and become excessively scaly and red.

Bright Red Tongue And Swollen Mouth

A niacin deficiency can manifest as glossitis, or a bright red tongue and swollen mouth. This can often be the first sign individuals with a niacin deficiency will notice because the tongue is being used constantly on a daily basis. A lack of proper amounts of niacin causes the loss of the small projections that line the tongue or papillae. When this happens, the tongue becomes abnormally smooth (atrophic glossitis). A red tongue that appears to be unusually large accompanied by a swollen mouth can also occur as a result of niacin deficiency.

Mouth ulcers also occur as a result of the niacin shortage and will begin with pain throughout the mouth and redness of the tongue before advancing to ulceration. These ulcers will begin to form first on the lower lip and under the tongue. The swelling of the tongue and mouth can cause patients with a niacin deficiency to have difficulty with eating and speaking. Due to the absence of the papillae on the tongue, there will be less taste sensation but more sensitivity in regards to temperature and pain.


Indigestion is a condition that often signals an underlying health issue. It is characterized by excessive, recurrent, or frequent upper abdominal pain or discomfort. The sensation has been described as a burning feeling, feeling of fullness, feeling of excessive gas, and belching. In addition, nausea and vomiting, as well as a growling stomach and acidic taste, are also common occurrences. Indigestion is not a result of excess stomach acid. Instead, it is a result of too little stomach acid within the digestive tract.

When there are not adequate amounts of stomach acid, fungal and bacterial overgrowth may occur in the stomach and small intestine. This overgrowth can cause indigestion and other unpleasant digestive inflammatory symptoms like bloating. Having the proper levels of niacin in the body will allow the stomach and small intestine to make enough acid to keep the gut balanced. The good bacteria and fungus that live in the stomach and intestines are helpful at normal levels, but can be harmful in excessive levels.

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