Evidence suggests that calcium from whole food sources may produce more favorable effects in bone health than isolated calcium supplements. The calcium complex in Bone Strength Take Care is whole-food Calcium of Red Marine Algae harvested from Iceland's pristine shores, Vitamin D3, Vitamin K2, and Magnesium. Bone Strength Take Care helps to keep you healthy and mobile. Calcium must be completely dissolved in order to be absorbed. The plant-based calcium found in Bone Strength Take Care is porous, which dramatically increases the calcium's surface area. Stomach acid can then come into greater contact with the calcium, making it easy to dissolve. In addition to the whole-food source of calcium and magnesium, they have also added other bone-nourishing nutrients to complete the food complex. Vitamin K is an essential co-factor in calcium absorption and retention. Bone Strength Take Care is formulated with the most bioavailable, bioactive, and longest-lasting form of Natural Vitamin K2 (MK-7) (from MenaQ7). This key nutrient helps put calcium into your bones where you need it, and helps keep calcium out of your arteries, where you don't. Probiotic Vitamin D3 completes the bone health complex. Natural Vitamin K2 partners with Vitamin D3 to promote bone health, support, and function - in particular, both vitamins promote calcium absorption and utilization.Gluten free; 100% vegetarian; no artificial flavors or colors.