Reading a number of threads and blogs on Vitamin D (like Whole Health Source), it seems that increased Vitamin D requires increased Vitamin A. I am planning on radically bumping up my Vitamin D intake from 1,000 IU to 5,000 IU per day. But I am a little worried that I'll end up being deficient in Vitamin A. This is an even greater issue for my parents, especially my mother who is diabetic, who I also plan to put on a high Vitamin D regimen; I can't get her to eat enough naturally high Vitamin A foods. I also plan to put both of them on Vitamin K2.
What are people's thoughts on Vitamin A needs when on taking high levels of Vitamin D? How much per day is required? Any recommendations on supplemental forms of Vitamin A?