For supplementation, Mayo Clinic notes a
typical recommendation of 800 to 1,000 IUs per day for adults whose vitamin D levels are low, but this varies according to
age.
We have frequency
recommendations based on a pet's overall health,
age, chronic medications or health problems, and any anesthetic procedures being planned for that patient... A
typical screening for patients of all
ages includes a chemistry panel and a complete blood cell count [CBC].»