Holland & Barrett Calcium, Magnesium, Vitamin D & Zinc A four-nutrient powerhouse designed for comprehensive bone, muscle and immune support. Calcium and Vitamin D work together for bone mineralisation; Magnesium acts as a natural muscle relaxant and energy enabler; Zinc contributes to normal cognitive function, immune response, and the maintenance of normal hair, skin and nails. Ideal for those with active lifestyles or nutritional gaps.