I know that typical Black Holes dont feed on Dark matter because they are tiny, so the direct hit is unlikely. While normal matter has friction and can slow down close to the BH, Dark matter just pass it by. What's about supermassive (>10^10 solar masses) black holes? Do they consume significant amounts of the dark matter? Radius of the event horizon is proportional to the mass, and the probability of the 'direct hit' - is M squared. Supermassive BH can consume up to 10^20 times more Dark matter than Sun. Even more, supermassive BH usually resides in the center of galaxies, and that position favours the consumpiton of DM.