You're getting 1,000mg of **Calcium**, 400mg of **Magnesium**, 15mg of **Zinc**, and 400 IU of **Vitamin D3** per three-tablet serving — a bone-support combination where the doses look generous on paper. **Vitamin D3** is in the right form (cholecalciferol), but 400 IU sits below the 1,000 IU minimum most research uses for maintaining adequate blood levels, so you'd likely need additional D3 from another source.

The synergies here make clinical sense — **Vitamin D** is essential for absorbing **Calcium**, and **Magnesium** is required to activate **Vitamin D** in your body. However, all three minerals use budget forms: **Calcium** carbonate requires stomach acid and absorbs poorly above 500mg per dose, **Magnesium** oxide has roughly 4% bioavailability, and **Zinc** oxide is among the least absorbed zinc forms available.

The biggest gap is absorption. At 1,000mg of **Calcium** carbonate in a single serving, you're losing most of it — splitting doses throughout the day would help, but the three-tablet serving makes that impractical. If bone health is your primary goal, the form quality here significantly limits what you'll actually absorb from these otherwise solid doses.