Hi guys,
Your dog's Vitamin A requirement is related mainly to his weight and lifestage.
To find the safety zone for VitaminA, you need to follow these steps:
1) Find your dog's weight in kgs
2) Using your Microsoft computer, take that number to the power 0.75 (if you aren't sure how to do that let me know, it's easy)
3) Multiply THAT number by 50 for the RA (recommended allowance) and - get this - 2,099 for the SUL (safe upper limit). This will tell you how much you should aim to feed, but it also demonstrates that you have to really OD on A before it becomes toxic.
To sum up: You have to feed a lot of liver to get anywhere near the safety margins. However, liver is also high in phosphorus, copper and other nutrients that can unbalance a diet (especially in the area of mineral balance).
Ues it carefully, but don't panic.
Cat