Reduces D-xylose into xylitol. Preferentially utilizes NADPH as a cosubstrate. NAD(+) + xylitol = D-xylose + H(+) + NADH NADP(+) + xylitol = D-xylose + H(+) + NADPH Carbohydrate metabolism; D-xylose degradation. Belongs to the aldo/keto reductase family.