In the wild, turtles and tortoises are exposed to ultraviolet light (UV) every day. Absolutely essential to their health and growth, UV plays a key role in the production of Vitamin D3, which is necessary in the absorption and metabolism of calcium, as well as other essential vitamins and minerals. Vitamin D3 deficiency can result in limited shell growth, metabolic bone disease, and often, a premature death. Supplying appropriate UV lighting in your pet's habitat is one of the many important responsibilities you carry as the owner of a turtle or tortoise.
To understand UV light more clearly, and the problems you may encounter when trying to supply it to your pet, you must first know that there are two main types: UVA and UVB. Your pet needs both, but he particularly needs UVB, the short wavelengths of light, for Vitamin D3 production. Exposure to UVA is also important for the activity level, feeding, and breeding in many species.
Each species of turtle/tortoise may have different Vitamin D requirements. The need for Vitamin D depends upon whether the turtle/tortoise is a land or water species, whether he is an herbivore (eats plants) or carnivore (eats meat), and upon his geographical origin (temperate or tropical). Depending upon the age of the animal, his species, and his diet, a combination of UVB light, calcium supplementation, and Vitamin D supplements may be needed. Research the needs of your particular pet to determine what will be best.
When using UVB light, there are several important things to remember: