Аннотация:It seems that the loop integrals contributing to the β-function of N = 1 supersymmetric theories regularized by higher covariant derivatives are integrals of double total derivatives. This allows obtaining the NSVZ relation for the renormalization group functions defined in terms of the bare charges at least in the Abelian case. For the renormalization group functions defined in terms of the renormalized charges we discuss the prescription giving the NSVZ scheme in all orders for the Abelian theories. In the non-Abelian case we present the exact expression for the Adler D-function, which follows from the similar structure of quantum corrections.