You can buy some enteric coated fish oils caplets. They cost a bit more, but they won’t give you “fish burps.” Also, if you need to increase the amount of omega 3
fatty acids in your diet, you may want to vary your intake.
Fish oil is a great primary source of omega 3
fatty acids, probably the best source.
However,
fish oil also may--I say may--be tainted with mercury. Normally, the species of fish that are used for the
fish oil supplements are less likely to accumulate mercury. Also, most mercury is found in fish meat and not
fish oil and the distillation process removes such contaminants. So I wouldn’t over-worry about mercury contamination, but be aware that it is possible.
Personally, I’d limit daily intake to about 6 grams of
fish oil. Then I'd take some
flaxseed oil if more is needed (or maybe a little evening primrose oil or black currant oil); be aware that your body will have to convert
fatty acids (alpha-linolenic acid to eicosapentaenoic acid; docosapentaenoic acid to docosahexaenoic acid), but that’s normally no problem.