I'm looking for the most natural vitamin d supplement, and most pills I've come across are loaded with nasty fillers like soybean and corn oil. I found Carlson Vitamin D Drops:

http://www.vitacost.com/Carlson-Vitamin-D-Drops

So, these look pretty great. The only inactive ingredient is fractionated coconut oil, which I am thrilled about. They come in 2000 IU or 4000 IU, and have 365 drops per bottle. The 4000 IU is a better deal, because the increase in price is worth it. I've never supplemented with vitamin D. This time of the year, I do not get enough sunlight, although I do eat a lot of vitamin D rich fish. Based on this, which dosage should I take? Another concern would be the source of the vitamin d3 (cholecalciferol). This product is sourced from lanolin. Is lanolin a good choice for vitamin d3, or are there better sources? Basically, does it matter where the cholecalciferol comes from, and do our bodies absorb it the same regardless of the source?