Once A Day Bone Life provides vitamins and minerals which are essential for bone health. Vitamin D contributes towards normal absorption and utilization of calcium and for the maintenance of normal bones. Vitamin K works in balance with vitamin D and supports its action for bone health. Calcium and magnesium are some of the main minerals found in bones and work in balance with each other for normal bones and teeth. Zinc and copper also wok together. Zinc contributes towards the maintenance of bones and copper contributes towards normal connective tissue which is important for bone health.