I myself remember having cod liver oil when we were small, but not very small. I think I must be around 10 or 11. No doubt, it has many health benefits and boosts immune system, increases memory and strengthens bones, but you must consult your kid's PD as how much dosage should be given to your kids and whether you should give them oil or capsules can also be given. http://www.indiastudychannel.com/resources/157993-Memory-Boosters-Sea-Cod-Cod-Liver-Oil-Advantages-Disadvantages.aspx
Cod liver is a good source of vitamins A and D, two nutrients that growing children need. They are absolutely safe and can be given to kids though you better consult your pediatrician first. It boosts the kids' immune system, reduces the risk of respiratory illness. http://www.livestrong.com/article/258969-what-are-the-benefits-of-cod-liver-oil-for-children/ https://www.seven-seas.com/en_MY/little-one/multivitamin-syrup-with-cod-liver-oil.html