The concern is with sodium intake, and it doesn’t matter what the source is, so long as it is available to the body. According to a couple of recent studies, people are at their healthiest when getting 4-6 grams (4000-6000 mg) of sodium a day. This translates to 10-15 grams of sodium chloride, which we commonly call simply “salt,” or “table salt” when greater precision is needed. In U.S. nutrition labels, the word “salt” means sodium chloride (table salt) by definition. My rather imprecise measurements suggest that 5 grams of table salt are a U.S. teaspoon’s worth.
Since sea salt, kosher salt, Himalayn pink salt, and other varieties of table salt are all overwhelmingly composed of sodium chloride, I don’t believe it truly matters which kind you use.
Regular table salt sold for consumer use often has dextrose in it to prevent clumping. That might possibly account for the bloating you notice, especially if the brand of sea salt you use does not contain dextrose.
If the ingredients list on the can of cod liver you are thinking of buying mentions dextrose, you might consider buying another brand.
P.S.—In the U.S., the government dietary recommendation for sodium intake is woefully inadequate, bordering on an insufficient amount to maintain health.