If fermented cod or skate liver oil aren't possible for you due to a seafood
allergy, note that you can obtain fat soluble vitamins in other foods valued by other Traditional cultures such as raw, grassfed butter (must be deep yellow to orange in color — sources), fish eggs (many can
tolerate fish eggs even with a seafood
allergy), emu oil from emus eating their native diet (sources), deep orange yolks from pastured hens, and liver from land based
animals.
You will need to be capable of spending time with
animals, meaning
allergies, inability to
tolerate loud noises, or fear of bites and scratches will probably make things difficult.