"It is good for you."
Translation:Det er godt for dig.
Could another possible translation be: "Den er god for dig." ? Or is it more usual to use "det"?
"om" is sort of like "about" or "on" in english I think, it might be a little weird/improper but I think it would still work colloquially. I think it would be the equivalent of someone saying in english "the cleaner is good for floors" vs. "the cleaner is good on floors". Even though both are understood, "good for" is more proper.