Polar coding is a recent channel coding technique invented by Arikan to achieve the 'symmetric capacity' of binary-input memoryless channels. Subsequently it was observed by Korada and Urbanke that such codes are also good for lossy channel coding, achieving the 'symmetric rate distortion' bound, when the representation alphabet is binary. In this note we extend this result to the case when the representation alphabet is q-ary, for q a prime number.