Vitamin D3, or cholecalciferol, is the most effective form of vitamin D for the body, synthesized in the skin after UV-B exposure. Despite its importance, about one-third of Canadians are deficient in vitamin D due to inadequate sun exposure, poor diet, and other factors, with two-thirds having suboptimal levels. Vitamin D is crucial for calcium absorption, immune function, mood health, cardiovascular function, skin health, and gene expression, as its receptors are found in numerous tissues throughout the body. Cyto·D3 2500IU - Liquid helps prevent vitamin D3 deficiency, offering 2500IU per drop in a medium chain triglyceride oil base from organic coconut oil for optimal absorption.