Nutrameltz Calcium + Vitamin D3 is an essential supplementation for proper bone health. It also helps in normal functioning of nerves, cells, muscle, and bone. Vitamin D enhances the absorption of calcium, eventually building strong bones. Calcium is not naturally found in the body. Thus, we need to absorb it from our diet. However, without vitamin D, the body can only absorb about 10-15% of the calcium in your diet.