Dietary Supplement 2:1 Ratio Plus D-3 & K-2 The Calcium and Magnesium in this product are bonded or chelated with natural citric acid to form Calcium Citrate and Magnesium Citrate. This formula combines high-potency natural source D-3 Cholecalciferol with a clinically supported serving of K-2 Menaquinone-7 (MK-7) from natural source natto. They are intended to provide nutritive support for healthy bones and a well-functioning cardiovascular system. These great-tasting and naturally flavored orange chewables provide a convenient alternative to our popular capsule formula.