Liquid supplements deliver maximum absorbing capacity, and NOW Foods Liquid Vitamin D-3 is no exception. It is the best vitamin D in the form of drops on the market. You can find this top-quality product in 400IU and 1,000 IU extra strength dosing, powering your body to function properly. The formula will also support your immune system and help you maintain strong bones. Lastly, the product is kosher-certified and non-GMO.