Calcium/Magnesium are two important minerals that Swedish Supplements has chosen to put in the same capsule. Calcium is important for normal bone structure and is needed for normal muscle and nerve function. Calcium and magnesium act as opposites, where calcium is needed for muscle contraction and magnesium is important for relaxation. The balance between the minerals is therefore important.
The recommended reference intake of Magnesium is 375mg per day and Calcium is 800mg per day. However, the need for those who exercise is likely to be significantly higher.