Vitamin D requires Vitamin A to bind to the Vitamin D Receptor (VDR). So unless there is some Vitamin A present, then amount of Vitamin D you take will never be utilised.
However, the capacity of Vitamin A to bind onto VDR means that excess Vitamin A in the system may block Vitamin D from binding to the VDR. It's all a question of balance. Dr Cannell, of The Vitamin D Council, makes the point that "a higher retinol intake, approximately greater than 4,800 IU/day, appears to counter the beneficial effect of vitamin D.”
40fYME® International D3 with Cofactors (5000iu) contains 250iu of Vitamin A.