The 21st Century Calcium Magnesium Zinc + D3 supplement is a highly popular and affordable option, providing the three key minerals along with essential Vitamin D3. The inclusion of D3 is a significant advantage for bone health, ensuring better calcium utilization. However, the choice of less bioavailable mineral forms (carbonates and oxides) means that a portion of the nutrients might not be absorbed as efficiently as with more advanced chelated or citrate forms. Despite this, its accessibility and the presence of D3 make it a solid budget-friendly choice for general mineral supplementation.