I know most people here know the importance of there EFA's, but flax oil is really not as great as an efa as you might believe. Yes it provides Omega-3(N3-PUFA) but there are the two types of omega-3 fatty acids:
Plant oils like flax seed oil contain alpha-linolenic acid (ALA), a short-chain omega-3 fatty acid(18 carbon short-chain fa).
Fish contain long-chain omega-3: eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are 20 and 22 long-chain fatty acids.
The real problem is we can convert at most 9-10% of ALA into EPA and DHA. I have read studies of 0.2% conversion(Pawlosky et al.) The conversion in the body has shown different results in studies but, it's mostly inefficient.
I just wanted to gives a heads up for those using flax thinking they are getting a good balance and source of efa's. You already know you need them, just make sure you're not leaving any out!