How does melanin affect the body's production of vitamin D?

Melanin, the pigment that gives skin its color, can reduce the body's ability to produce vitamin D when exposed to sunlight. This is because melanin acts as a natural sunscreen, absorbing and blocking some of the UVB rays needed for vitamin D synthesis. As a result, individuals with darker skin tones may require more sun exposure to produce adequate levels of vitamin D compared to those with lighter skin tones.