What can you say about something as basic as vitamins? Well, several things. Most Vitamin D supplements that I found were 2000 IU or more, while the US RDA is 400-800 IU, though some studies suggest a higher amount. I want enough that my doctor isn't concerned, but not too much, as there is also a connection between Vitamin D and Kidney stones, so this was the right answer. Remember that sometimes more isn't better--you want the amount that is right for you. I've been pleased with the bottle that this uses. It has a nice pop-open top, with is incredibly simple and fast. If you have any humidity at all, the caplets will stick together, but a good tap of the bottle will loosen some, so that has never been a problem (that's an issue with any softgel capsule)