Reduces D-xylose into xylitol. Has a preference for NADPH, but can also utilize NADH as cosubstrate. NAD(+) + xylitol = D-xylose + H(+) + NADH NADP(+) + xylitol = D-xylose + H(+) + NADPH NADP(+) is a potent inhibitor of both the NADPH- and NADH-linked xylose reduction, whereas NAD(+) showS strong inhibition only with the NADH-linked reaction. Optimum pH is 6.0. Carbohydrate metabolism; D-xylose degradation. Belongs to the aldo/keto reductase family.