This listing is for (3) units. 21st Century Calcium Citrate 400 Count is a dietary supplement designed to provide superior bone support. Each tablet contains calcium citrate, a highly absorbable form of calcium that helps maintain strong bones and teeth. Calcium is essential for bone health, and the citrate form is easier on the digestive system compared to other forms of calcium, making it ideal for individuals with lower stomach acid or digestive sensitivities. This product is ideal for adults looking to prevent calcium deficiency and support overall bone density. With 400 tablets per bottle, it offers a long-lasting supply, and the formula is free from artificial colors, flavors, and preservatives, ensuring you get only what you need for optimal bone health.