Most lipids (fat) are insoluble to water (hydrophobic). Only smallest lipids (fatty acids) can dissolve in watery blood plasma. In order to become soluble in blood plasma, other lipid molecules join with hydrophilic protein molecules. Lipid/protein are called Lipoproteins. They are able to be soluble because the proteins are on the outside and the lipids are on the inside.
Fat soluble vitamins are VITAMIN A, D, E, and K.
Water soluble vitamins are vitamin C, vitamin B6 and vitamin b12