If your meat is grass-fed, do you even need to take fish oil?
Regarding the multivitamin, I don't think most generic multivitamins have much effect. I used to take organic multivitamins, but they're really expensive.
This is something interesting from Mel Siff you could try:
The evidence that every vegetable and fruit contains a
huge number of what are now called 'phytochemicals' made me conclude that
the use of isolated macro and micro-nutrients probably lowers their
efficacy, so I began to take all of my supplements together with the natural
plants which contain them.
It seems obvious that life evolved in a synergistic way with complex
mixtures of biochemicals, not commercialised isolates claimed by various
researchers to be the most important substances in achieving something or
other in the body.
Thus, if you are supplementing with vitamin C, it is probably more sensible
to take it after or with a meal containing citrus fruit (to supply the
various bioflavenoids) or green peppers. If you are taking beta-carotene,
then one should do so in a meal with carrots. Similarly, vitamin B complex
(which is hardly a complex of all the substances acting synergistically with
the B group) should accompany a meal of liver, whole grains and so on.
This approach which I might term ' natural-synthetic complexing' is one
which remains with me today.