I take fish oil every day and it has done me no harm, only increased my visual acuity. From what I have seen you can take a tbsp. or more a day, if an adult, with no ill effects. Fish oil is also an excellent source of vitamin D which apparently most people are deficient in, especially if they are not getting some direct sunshine every day. (The best defense against cancer is sunshine as it is the best source for causing Vitamin D to be procedssed in the bone marrow.)

I use Norwegian cod liver oil as that is reputed to be the least likely to have mercury contamination.

they have fish for children in much lower doses. is flax seed oil the same? because I use Flax seeds (grounded) and they say people who can't take fish oil can use flax seed instead. (omega threes).