Which vitamin is primarily obtained from sunlight?

Vitamin D is primarily obtained from sunlight due to the body's ability to synthesize it when the skin is exposed to UVB rays from the sun. When exposed to sunlight, a compound called 7-dehydrocholesterol in the skin is converted into vitamin D3 (cholecalciferol). This process is vital for maintaining various bodily functions, including calcium absorption and bone health. Unlike other vitamins which must be obtained mainly through diet or supplements, vitamin D's unique production method highlights its reliance on environmental factors, such as sunlight exposure.

The other vitamins listed each have different sources and functions. For instance, vitamin A is primarily found in animal products and some plant sources as beta-carotene, while vitamin C is mainly sourced from fruits and vegetables, and vitamin E can be obtained from nuts, seeds, and vegetable oils. These vitamins do not have the same sunlight-dependent synthesis as vitamin D, making it distinctive in this context.