A voltage regulator includes a power field effect transistor and a control-loop circuit. The power field effect transistor has a threshold voltage, a drain terminal receiving an input voltage, a source terminal providing an output voltage and a load current, a gate terminal responsive to a control signal, and a bulk terminal. The control-loop circuit is responsive to the output voltage and providing the control signal, and is configured to adjust the control signal to such a value that the output voltage is regulated to a constant value. In addition, the threshold voltage of the power field effect transistor is modified dependent on the load current.