I've heard it's best to take fat-soluble supplements, like CoQ10, curcumin, and vitamin D, with fats or oils to increase absorption. Would taking them with a fish oil capsule be enough?
The amount of fat in a fish oil supplement is only about 1 gram. While that might help a little, studies which have shown increased absorption of fat-soluble vitamins have involved taking them with foods or meals containing fats. Most meals provide at least 5 grams of fat (the amount of fat in a single egg, for instance), while a tuna wrap with mayo can have 40 grams.
In the case of vitamin D, taking it with a meal has increased absorption by 32% to 57% compared to taking it with just water. The bigger (and fattier) the meal, the better — at least for absorption!