Suspension for a wheel of a vehicle, comprising a spring interposed between a body of the vehicle and the wheel, and a regenerative hydraulic shock-absorbing unit comprising a hydraulic shock-absorber arranged in parallel with the spring, a motor and pump unit with a volumetric hydraulic machine and an electric machine coupled to the hydraulic machine, wherein both the hydraulic machine and the electric machine are configured to operate alternatively as a working machine or as a motor, and an electronic control unit arranged to control the torque of the electric machine, whereby the regenerative hydraulic shock-absorbing unit is able to convert part of the vibrational kinetic energy of the suspension into electric energy, characterized in that it further comprises a single-effect hydraulic actuator arranged in series with the spring to control the vertical position of the body relative to the wheel, a reservoir (66, 54), and a hydraulic circuit (68, 70, 72, 74, 76, 78, 80, 84, 86, 88, 90) connecting the hydraulic shock-absorber, the hydraulic machine, the hydraulic actuator and the reservoir (66, 54) with each other, the hydraulic circuit (68, 70, 72, 74, 76, 78, 80, 84, 86, 88, 90) comprising valve means (76, 78, 84, 86) for controlling the flow of a working fluid between the hydraulic shock-absorber, the hydraulic machine, the hydraulic actuator and the reservoir (66, 54) so as to enable the suspension to operate selectively in one of the following operating conditions: - a first operating condition, in which the hydraulic actuator is isolated from the reservoir (66, 54) and remains therefore in a fixed position, thereby keeping the distance between the wheel and the body of the vehicle unchanged, and in which the hydraulic shock-absorber is connected to the hydraulic machine to enable the regenerative hydraulic shock-absorbing unit to operate in regenerative mode, that is to say, to convert part of the vibrational kinetic energy of the suspension into electric energy; - a second operating condition, in which the hydraulic actuator is connected to, and supplied by, the hydraulic machine to be extended and thus increase the distance between the wheel and the body of the vehicle, and in which the hydraulic shock-absorber is isolated from the hydraulic machine; and - a third operating condition, in which the hydraulic actuator is connected to the reservoir (66, 54) to be retracted and thus reduce the distance between the wheel and the body of the vehicle, and in which the hydraulic shock-absorber is isolated from the hydraulic machine. - a first operating condition, in which the hydraulic actuator is isolated from the reservoir (66, 54) and remains therefore in a fixed position, thereby keeping the distance between the wheel and the body of the vehicle unchanged, and in which the hydraulic shock-absorber is connected to the hydraulic machine to enable the regenerative hydraulic shock-absorbing unit to operate in regenerative mode, that is to say, to convert part of the vibrational kinetic energy of the suspension into electric energy; - a second operating condition, in which the hydraulic actuator is connected to, and supplied by, the hydraulic machine to be extended and thus increase the distance between the wheel and the body of the vehicle, and in which the hydraulic shock-absorber is isolated from the hydraulic machine; and - a third operating condition, in which the hydraulic actuator is connected to the reservoir (66, 54) to be retracted and thus reduce the distance between the wheel and the body of the vehicle, and in which the hydraulic shock-absorber is isolated from the hydraulic machine.