Vitamin D, also known as calciferol, ergosterol and viosterol is a fat soluble vitamin absorbed through the skin from the sun or from foods you eat. It is ESSENTIAL for calcium and phosphorus regulation; maintains your nervous system; stimulates your immune function; normalizes your blood clotting; helps skin respiration; is responsible for the health and action of your bones, teeth, heart AND assimilates vitamin A. Taken together with Vitamins A and C can prevent colds, flues and speeds the body’s healing and regenerative process. Dr. Dane has added the potent immune enhancer K2 to this wonderful formula! 100 Tablets.