Utah Esthetics Written State Practice Exam

What vitamin is primarily synthesized in the skin when exposed to sunlight?

1. Vitamin A

2. Vitamin B12

3. Vitamin C

4. Vitamin D

The correct answer is: Vitamin D

The synthesis of vitamin D in the skin occurs when ultraviolet (UV) rays from sunlight interact with a cholesterol derivative found in the skin known as 7-dehydrocholesterol. This process triggers a chemical reaction that converts it into vitamin D3 (cholecalciferol), a form of vitamin D that is crucial for various bodily functions, including the regulation of calcium and phosphorus, and it plays a significant role in maintaining bone health and immune function. While vitamins A, B12, and C are important for overall health, they are not synthesized in the skin as a direct response to sunlight. Vitamin A is primarily obtained from dietary sources, and while there are some components of vitamin B12 that the body can absorb, its synthesis involves other biological processes unrelated to sun exposure. Vitamin C is also not synthesized in the skin; it's primarily acquired through diet. Therefore, vitamin D is unique in its synthesis mechanism involving sunlight, making it a vital component of skin health and overall well-being.