The body converts vitamin D3 to 25-hydroxy vitamin D as needed and typically does not convert excess to 1,25-dihydroxy vitamin D unless a pathological process is present.

“the liver will basically convert as much as it wants a lot of it into 25 hydroxy vitamin d there's a fairly linear relationship between vitamin d3 consumption and 25 hydroxy vitamin d levels in the serum but the body usually doesn't convert excess 25 hydroxy vitamin d into 125 hydroxy vitamin d unless there is a pathological process involving granuloma formation or some other ectopic focus of formation of 125 hydroxy vitamin d”