Holland barretts pure cod liver oil is high in essential omega 3 fatty acids and is also an excellent source of vitamins a and d contains the essential fatty acids dha and epa dha contributes to the maintenance of normal brain function and vision these beneficial effects are obtained with a daily intake of 250mg of dha when combined epa and dha contribute to the normal function of the heart these beneficial effects are obtained with a daily intake of 250mg of epa and dha both vitamins