I take a krill oil supplement, but I also try to eat of oily fish regularly. Krill oil is generally thought to be more easliy assimilated than fish oils, because of the chemical form. The 2 kinds of omega 3 you want are DHA and EPA. As far as I know, these are only in oily fish etc, there's no vegetarian option which would give you enough, and our bodies can't make enough to have an optimal level. I expect others will disagree because they want to promote a veggie approach, but that's what I've read. Take it or leave it or do some research of your own. Just a couple of other points - you probably won't notice much difference if you take omega 3s. The effect of being deficient though is long terms, as it is with some vitamins, so one day you get diagnosed with some illness which you then read that omega 3s could have helped to prevent. Also omega 3s are not vitamins.