- Calcium ascorbate is a mineral salt of ascorbic acid (vitamin C) and calcium, with the chemical formula C₁₂H₁₄CaO₁₂.
- It combines the nutritional benefits of both vitamin C and calcium into a single compound, offering a buffered, non-acidic form of ascorbic acid. This makes it particularly suitable for individuals who experience gastrointestinal discomfort from the acidity of pure vitamin C. Calcium ascorbate appears as a white to pale yellow, odorless, crystalline powder that is highly soluble in water and stable under dry conditions.
- As a dietary supplement, calcium ascorbate is widely used to support immune function, collagen synthesis, antioxidant protection, and wound healing, all roles traditionally associated with vitamin C. The calcium component contributes to bone health, nerve function, and muscle contraction, making the compound especially beneficial for people needing supplemental calcium as well. It is often marketed as a “gentle” or “stomach-friendly” form of vitamin C, ideal for those with sensitive digestive systems or chronic gastrointestinal issues.
- In comparison to ascorbic acid alone, calcium ascorbate provides a slower release of vitamin C, which can lead to more sustained plasma levels of the vitamin without the sharp spikes and drops sometimes observed with regular vitamin C supplementation. This property is particularly useful for maintaining consistent antioxidant protection and reducing oxidative stress over time.
- Calcium ascorbate is also used in the food and beverage industry as a preservative and antioxidant, where it helps delay oxidation and spoilage, particularly in processed meats, fruit juices, and other perishable goods. It functions similarly to ascorbic acid but with added buffering and less impact on the pH of the final product. In Europe and other regions, it is identified by the food additive code E302.
- Another advantage of calcium ascorbate is its contribution to increased calcium intake without the gastrointestinal side effects sometimes caused by other calcium salts such as calcium carbonate. However, the calcium content in calcium ascorbate is relatively modest—approximately 9–10% by weight—so it is often not used as a primary calcium supplement but rather as a dual-purpose supplement with both antioxidant and bone-health benefits.
- In terms of safety, calcium ascorbate is generally well tolerated, even in high doses, although excessive intake may lead to mild side effects such as bloating or diarrhea, primarily due to the vitamin C component. As with other supplements, individuals with kidney disease or those prone to calcium oxalate kidney stones should consult a healthcare provider before prolonged or high-dose use.
