"l-tryptophan for relaxion and sleep. Did you ever hear of it?
"

Of course I have. Tryptophan is an essential amino acid. It is what is in turkey that makes some people very drowsy.

Cod liver oil is mostly a source of vitamin A and vitamin D. People take fish oil for the omega 3 fats. You can use both, just be careful about getting too much vitamin A when using cod liver oil. More than 20,000 units a day can be toxic. Some recommend taking 10,000 units a day or less of vitamin A long term.