Calcium-magnesium-zinc supplements contain three nutrients that may support bone health, mood, immunity, blood sugar control, and sleep quality. Calcium and magnesium may best be taken in the evening with food or before nighttime sleep. Since zinc should not be taken with calcium and apart from iron, it is most useful if taken earlier in the day either slightly before/after food. Bone and Muscle Health. Calcium and Vitamin D are essential nutrients for strong teeth and bones.