UVB bulbs are vital for reptile health, providing the ultraviolet light needed for vitamin D3 production. This vitamin helps reptiles absorb calcium and prevents metabolic bone disease, a frequent issue for those in captivity. UVB lighting also helps regulate their daily rhythms and boosts their activity. When selecting a UVB bulb, consider the UVB strength, habitat size, and the light needs of your species to ensure your reptile flourishes in a well-lit environment.