20 grams a day would be described as high dosage in most information I have read.
Please do check out the side effects Linnus Pauling etc. (primarily from recollection blood thinning and certain relatively rare but none the less real cardiac events)
Do talk to your advisors.
Smart Fats by M Schmidt contains addresses of companys that do assay tests to determine individual fats profiles.
General diet greens fibre etc are important too.
Check out the compostion of fish oils and supplements - as a general rule based just on other peoples opinion and the basic premsis it is what we are used to the closer to the whole food the better. They contain a range of fats from c14 including oleic etc.
http://www.nutritiondata.com/fatty-acids.html
If it was me and I had the resources I would do all I could to regularly monitor all I could to try and get an indication as to what was going on.
But as usual as there is limited data everybody simply has to come to their own conclusions.
RB