Vitamin D3, also known as the "sunshine vitamin" is an essential fat-soluble vitamin that is naturally present in very few foods. Although classified as a vitamin, it should be considered a prohormone because it is involved in many metabolic processes in the body. GNA Fast Absorb Liquid D3 is emulsified and blended with organic sunflower oil. Vitamin D3 is important as a daily supplement helping with bone health, immune function, cell production, mood and hormone health.