He has always had Kenyan citizenship. He was granted that citizenship on his birth from his Kenyan Father.
Furthermore, he has Indonesian citizenship from when he lived there and went to school there as a child. Non citizens couldn't go to school in Indonesia at the time.
His American citizenship is debatable depending on the obscured facts but assuming he has legit citizenship here it would give him 3 citizenship's. This is dangerous for a president to have because it divides his natural loyalties.
This is why we must push to end all dual citizenships or multiple citizenships within the government. You want to serve in any part of our government? Then you must give up all previous citizenships and swear allegiance to the US alone above and beyond the normal requirements. And if you want to be a Supreme Court Judge, Vice President, or President, then you must be not only born of the soil, but your parents must also have been citizens at the time of your birth. —The true definition of Natural Born