Sun allergy, also known as photosensitivity, is not caused by a single deficiency. However, one specific deficiency that can lead to photosensitivity is vitamin B3 (niacin) deficiency, which causes pellagra.
Pellagra is a condition characterized by the three "D's":
- Dermatitis: A skin rash, often appearing in sun-exposed areas.
- Diarrhea: Digestive issues.
- Dementia: Cognitive decline.
While vitamin B3 deficiency is a potential cause, other factors can also contribute to photosensitivity. These include:
- Genetic conditions: Like Hartnup disease.
- Drug-induced reactions: Some medications can make the skin more sensitive to sunlight.
- Malabsorption: Conditions affecting nutrient absorption.
It is important to note that not all cases of photosensitivity are caused by vitamin B3 deficiency. Other factors, such as allergic reactions to sunlight or medications that increase sensitivity to UV rays, can also lead to sun allergy.
