I want to increase my Vit D supplemental intake to better reflect recent research. My multi-vitamin gives me 400 IU, and I was considering adding 1,000 IU to this. I am genetically predisposed to kidney stones. Passed one back in '93, and I currently have 2 tiny ones in one kidney. No evidence of any inbetween. Would supplementing my Vit D cause me greater chance of forming stones?