I don't know if the connection is there, but keep in mind until someone got the horrible idea of killing krill, on which the most endangered ocean species depend, so we can have another source of omega 3 oils, people have never consumed them. So who knows what sensitivities might be out there? Fish oil is pretty much as good, and maybe even better for DHA, so you should be fine using fish oil if you feel the krill oil is affecting you adversely.