From what i can tell, it does not really matter how you take your D3, as long as its D3 (not D2).
Everyone will absorb/utilise D3 in differing amounts....and supp type, sun exposure, food, gut function etc may well all have an influence to varying extents. The best advise i can give is just to supplement (what ever type you prefer) to a level that results in a D3 blood result (25ohD) of your preference.

Personally i supplement to ideally achieve a serum 25ohD level of between 60 and 70 ng/ml (150 and 175 nmol/L).

& i would also recommend that you make sure you are getting adequate amounts of Vitamin A (preferably from diet), so as you do not get the Vit A/D balance out of whack. I think you need to make sure you meet the RDA for Vitamin A on average per day; Retinol: 3000 IU adult male, 2333 IU adult female. http://lpi.oregonstate.edu/infocenter/vitamins/vitaminA/
I am no expert on Vitamin A & the A/D balance, so others can chime in here and offer advise/opinions (or facts).

....Back to your question; have a read of this article from the Vit D Council; Does it matter how you take vitamin D?
Here's some of the text;

....The fact is that the studies are so conflicting, and the 25(OH)D measurement techniques are so variable, that it simply does not matter if you take vitamin D in oil or as a powder, it does not matter if you take food with your vitamin D, or on an empty stomach. What matters is that you take enough so that you obtain vitamin D levels of 50 - 60 ng/ml. This means you are no longer suffering from substrate starvation (your vitamin D system has all the vitamin D it needs for all of its many uses and is beginning to store some vitamin D for the future)....

I stir my fish oil, vitamin D drops into a home made yoghurt together with a raw egg yolk. That makes a very nutritious, easy to eat quickly, breakfast and gets fish oil/vitamin d 3/and biotin/choline (egg yolk) sorted. The amount of vitamin D in cod liver oil is not tremendous. Typically a UK brand supplies about 400iu in a teaspoon or 90iu per capsule. Human skin given full body sun exposure for 20~30mins creates 10~20,000iu so by comparison MODERN STANDARDISED cod liver oil is no big deal. It may be, when CLO was traditionally harvested, fermentedit provided a lot more vitamin D and a more natural form of Vitamin A but now they take natural products apart and reassemble them in a standardised form it may not be the case.

I'd like to know the answer to this, too! I'm in the same boat.

Your body doesn't use fish oil without another fat present. Taking fish oil by itself is a waste because your body will burn off the fat I stead of absorbing it. So while it will be enough for vit d, it is a waste of fish oil. Slug some olive oil with the three and you will be golden.

what if you ate a teaspoon of coconut oil or almondbutter with it?

I was advised by my nutritionist that D3 is best when taken with Vita K2 and A. He recommended Vitamin D 3 Complete by Allergy Research Group as its the only product on the market to have all 3 (or at least it was a couple months ago.) Oddly, and per Daz's post above, the product recommended by the Vitamin D Council called D3 Plus by BioTech used to have Vitamin A in it (along with K) but then they reformulated it and took out the Vitamin A!

Depends on your vitamin D drops. I've been taking a couple 5k IU Vitamin D gelcaps/day (no fish oil recently) and my last Vitamin D test level was 73 (reference range 30-100). The gelcaps come with plenty of fat for absorbtion for me. Can't say the same for the powdered D/tablets. Get a blood test done and see where you're at. It's cheap enough.

Seafoods

Exclusively a handful of kinds of fish are normally found to possess tremendous amount of vitamin D. Fish such as tuna, mackerel, salmons and also sardines are usually rich in vitamin D. These types of oily fish and also classified as food items containing more vitamin D. In relation to greatest vitamin D concentrations inside fish, trout is certainly a guaranteed champion.

Fortified Dairy products

Vitamin D isn't really a naturally sourced nutritional inside normal milk. Therefore, vitamin D is certainly integrated. Commercially marketed milk, soya milk as well as rice milk obtainable in containers are seen to incorporate vitamin D.

Cod liver fish oil

Cod liver oil has been included in the listing of food resources of vitamin D. Aside from simply being a splendid method to obtain sources of vitamin d in vegetables, it's also discovered to be rich in various other wellness increasing vitamins and nutrients similar to vitamin A and also omega-3 efa's.