Nordic Naturals Ultimate Omega-D3 contains 70% pure omega-3 with added vitamin D3 for children and adults who do not receive adequate sun exposure, experts recommend a minimum of 1000 I.U.s daily.  Best known for its role in building and maintaining strong bones, vitamin D also helps regulate the immune and neuromuscular systems, and is key to optimizing health¹. The recommended form of vitamin D is D3 (or cholecalciferol), the natural and most easily absorbed form, which the body makes from sunlight.