Vitamin D3 can contribute to the maintenance of your bones, teeth, muscle function, and immune system. Additionally, it can play a role in how two minerals that contribute to bone health are absorbed - calcium and phosphate. Vitamin D3 is difficult to obtain naturally, however. It is not found in significant amounts in most foods, so the best way to obtain it is through sun exposure. While Ultra Violet B rays provide much of the D3 needed, those in the Northern Hemisphere may not spend as much time in the sun as is needed to obtain those levels. Each softgel of Nu U Nutrition Vitamin D3 contains 1,000 IU of Vitamin D3. Each bottle has 365 softgels in it, up to a full year's supply depending on how much you take each day. Easy to swallow and designed for easier absorption, softgels offer a low-hassle solution to daily Vitamin D3 intake.