Nordic Naturals Kids and Adults Vitamin C 250 mg Gummies in addition to all the benefits of Omega-3 formula, each serving of Omega-3D includes 1000 I.U. of vitamin D3, meeting the daily recommendation for children and adults who do not receive adequate sun exposure. Vitamin D3 (or cholecalciferol) is the natural form of vitamin D produced by the body, and is better absorbed and utilized than other forms. This powerful formula offers combined support for a healthy heart and brain, bones, mood, and immunity.