I have CKD, stage 4, and currently taking prescription Vitamin D (50,000 IU 1 X weekly). I have been researching different methods to help reverse some of the damage. All sources recommend Vitamin D3 supplementation instead. The one I purchased is 5,000 IU daily. I also want to take a good multi-vitamin, but it contains 1,000 IU per day. Is 6,000 IU too much, since my kidneys are no longer producing any on their own.