How much flaxseed should a vegan have daily to get the recommended amount of omega 3 fatty acids?

The daily requirement for omega 3 is 2-4 grams per day.

2 tablespoons of ground flaxseeds provide 3.2 grams of omega 3.

It is best to grind whole linseeds in a coffee grinder just before you sprinkle over your cereal.

I would like to point you towards a new vegetarian omega-3 source - Echium seed oil. It is relatively new, and many people will not have heard of it. There is currently only one manufacturer of it that i am aware of (in the UK, that is). If you look at detailed composition charts, the omega-3 fat SDA is a closer relative to EPA and DHA found in fish oil, and converts to these long-chain fats up to 5 times more than ALA in flaxseed oil. I haven't tried it myself as i take fish oils, but i have heard very positive things about echium oil.