"Non-habit forming" sounds like a phrase invented by a drug-pushing marketeer. It seems to me that anything even mildly good for you, you'd want to become a habit.
A: Hey, take this pill!
B: Well, I don't know. I generally stay away from drugs.
A: This one's okay. It's "non-habit forming".
B: Well, gee. Since you put it that way!
My guess is that if there is any reason to say this, then it can't be all that good for you...