Niacin deficiency, leading to pellagra, is a vitamin deficiency that causes sun rash (photosensitivity).
Pellagra and Photosensitivity
Pellagra is a disease caused by a deficiency in niacin (vitamin B3) or tryptophan, an amino acid that the body can convert into niacin. One of the hallmark symptoms of pellagra is photosensitivity, meaning the skin becomes extremely sensitive to sunlight. This sensitivity can manifest as a rash or other skin changes in areas exposed to the sun.
Symptoms of Pellagra
Besides photosensitivity, other symptoms of pellagra include:
- The 3 D's:
- Dermatitis: Skin inflammation, often with a rash, especially in sun-exposed areas. This is the sun rash people refer to.
- Diarrhea: Digestive issues leading to frequent bowel movements.
- Dementia: Cognitive impairment and neurological problems.
- Other symptoms:
- Mouth sores
- Swollen tongue
Why Niacin Deficiency Causes Sun Rash
Niacin plays a crucial role in DNA repair and the maintenance of healthy skin. When deficient, the skin becomes more vulnerable to damage from ultraviolet (UV) radiation in sunlight. This increased vulnerability leads to inflammation and the characteristic rash associated with photosensitivity.
Treatment and Prevention
Pellagra, and therefore the sun rash associated with it, can be treated with niacin supplementation and a diet rich in niacin-containing foods. Good sources of niacin include:
- Meat (especially liver, chicken, and turkey)
- Fish
- Whole grains
- Legumes
- Nuts and seeds
- Fortified foods
Preventing niacin deficiency involves maintaining a balanced diet that provides adequate amounts of niacin and tryptophan.
