Vitamin D
Another vitamin most companion birds lack is vitamin D3, which is vital to maintaining healthy, bright feathers. The best way for your bird to get his daily dose of vitamin D is through exposure to unfiltered -- not even window glass -- natural light or through the use of a full-spectrum light specifically made for birds. It is possible to for synthetic vitamin D to become toxic to a bird, but it is impossible for him to overdose on light-sourced vitamin D. When allowing your bird access to unfiltered light, guard against dangers such as predators, escape and other hazards. Provide a shady spot where he can escape the light if it becomes too hot or too bright for him. Usually about 30 minutes of light per day will provide him all the vitamin D the bird needs, which will in turn help keep his feathers bright and healthy.