What is the relationship between sunlight and melanin production?

Sunlight plays a significant role in the production of melanin, the pigment responsible for the color of our skin, hair, and eyes. When the skin is exposed to UV radiation from sunlight, it triggers a response from melanocytes, which are the cells that produce melanin. This process is a natural defense mechanism designed to protect the skin from damage caused by UV exposure.

As a result of increased sunlight exposure, melanocytes produce more melanin, leading to a darker pigmentation in the skin, commonly referred to as tanning. This increased melanin serves to absorb and dissipate UV rays, thereby reducing the risk of DNA damage to skin cells which can lead to skin cancer.

In contrast, some other options suggest that sunlight has no effect, decreases, or inhibits melanin production, which is not supported by the physiological responses of the skin to UV exposure. Melanin production is inherently stimulated by sunlight, exemplifying the body's adaptive mechanism to protect itself against harmful UV radiation.