PR NAT VITAMIN D 1000IU 180'SAre you getting enough Vitamin D? Summer or winter, our need for Vitamin D is often far greater than we are getting. Researchers now know that previous recommendations for optimal levels of Vitamin D were much too low! Prairie Naturals Vitamin D3 is made with cholecalciferol, the most readily absorbed form. Be sure you get enough of this low cost, highly valuable vitamin.