Is there anyone who gives there dogs Vitamin D3? I really don't mean in combination with anything else such as a multi vitamin for dogs or Nupro or such as that, I strictly mean Vitamin D3. If so, what is the dosing amount you give for age/weight? Thanks. My vet recommends 300IU per 25lbs once daily of liquid Vitamin D3. I would think for chis that would be 100IU or less and a liquid Vitamin D3 I found at GNC that is literally 1 drop per day. Please advise what any of you do.