Its the vitamin A youve got to watch its posinous in high doses.
A good way to get rid of the fishy burps is stick your fish oils in the freezer and use them frozen
thats the one, pretty sure vit d is poisonous in high dose aswell just couldn't remember what was in cod liver oil.
As for fishy burps, one way would be have flax seed oil instead, no fish, no fishy burps
I had all kinds of weirdness with knee's, in the end after having scar tissue removed from the membrane that holds the sinovial fluid in, i also had back of my knee cap shaved as it had been worn down, was jaggy and in the final weeks before ops was essentially cutting into my knee on the inside... not fun.
Thing thats weird is I was told by every physio for YEARS not to do anything heavy, that swimming was the only cardio I should try and things like squats/running would be the worst things I could do. years of problems, I finally said smeg it, it will hurt but i'll walk/run/weight lift to lose weight and work through the pain. It turns out squats, running were fine, load and impact were no problem it was the high rep and ackward movements of cycling and swimming that hurt my knee the most.
Personally I think squats and other leg strengthening proper movements have helped my knee immeasurably.
The only problem with these things is not knowing what the main cause is, I changed everything in one go, diet, exercise, glucosamine, omega 3's and together i'm doing great. I have no idea if one single thing is responsible, everything together is working so I'm going to stick with it.
But thats also why some people find glucosamine does nothing, they take that and eat harribo while putting on weight and getting worse. It might not work for all I know but its incredibly hard to without question know whats working or why one thing might not work.
IN other words, I personally recommend, for joints and for knee's, eating well, omega's, glucosamin/chondritin/msm(can normally find all in one pill) and for me proper strengthening has helped no end. As long as you're comftable and feel no reaction do whatever helps, but I'd also get some advice from a physio if you're recovering from something specific. IE if a physio says don't do squats for 6 weeks after condition X is diagnosed, I wouldn't do it, then I'd start back in slowly and ultra carefully. But I can't say for sure any of that would work for you, try it yourself, if you think any of it helps, stick with it.