Solaray TSTR Super Bio Buffered Vit C 100vegicaps is formulated using a two-stage, timed-release technology. The formula is designed to release half of the Vitamin C in this product rapidly and the other half gradually over a period of up to 12 hours. One capsule in the morning and another 12 hours later extends the availability of Vitamin C to the body over a 24-hour period. Vitamin C provides antioxidant activity and is intended to provide nutritive support for normal, healthy collagen synthesis, cartilage and bone development, immune function, capillary and blood vessel integrity, and nerve impulse transmission. This product also contains Calcium Carbonate and Magnesium Oxide to buffer the natural acidity of Vitamin C.