vitamin D might help as fish oil could be considered what they call VITAMIN F. vitamin d and f kind of antagonize each other. As vitamin D pulls calcium intothe blood and vitamin F puts calcium in the Tissue.
you also avoid eating fat for a while and let your body burn that off.
Was already taking 10.000 IU Vit D. After a week of stopping fish oil, symptoms seems to be clearing, brain fog is almost gone.