I currently take 8,000 - 10,000 iu's of vitamin D every day. The brand I use is by Biotics research corp. It is called Bio-D-Mulsion Forte which is liquid and comes in a 1 oz bottle which costs $20. I've been using this for about 1 1/2 years now and my D level is at the higher end of normal range. It was extremly low before I started. My neuro thinks the drops are better because they are easily absorbed in the digestive tract.