E mālama with the verb marker would be best, but people do not always follow grammar rules when speaking. This has become a colloquialism.
Difference between mālama and mālama pono? I have seen both as correct answer.
mālama means to care for, and mālama pono means to care for properly E mālama pono is the most commonly said, but people say E mālama! or simply Mālama! as a colloquialism.