You're right about the Sea-salt. Just a word about Vitamin C. It's best to use powdered if you can, as the pills contain many types of filler. As someone who's been taking large amounts of vitamin C for years, I can tell you, not only should you up the dosages slowly enough, but when going off it, go off it just as slowly, very important. Try to take it half an hour after a meal if you're taking it after eating, not directly after - this will prevent excess gas it causes some people.
12 grams isn't that much, so don't worry about it. I took 18 grams a day for a month once and felt great.