Calcium ascorbate is the calcium salt of ascorbic acid, or vitamin C. Calcium ascorbate crystals are sources of both calcium and vitamin C, but are not usually consumed as a health supplement. Instead, calcium ascorbate is typically used as a food additive to keep food fresh. Much like pure ascorbic acid, calcium ascorbate exhibits antioxidant and antimicrobial properties. Calcium carbonate and calcium citrate are more common supplemental forms, but the ascorbate form is absorbed well despite its very bitter taste. Calcium ascorbate is not appropriate if you want to mega-dose vitamin C.
Calcium Ascorbate
Calcium rarely exists in its elemental form because it prefers to be combined with other elements to form mineral salts. Calcium carbonate is readily combined with ascorbic acid to make calcium ascorbate, but carbonate forms of potassium, sodium and magnesium can also be combined with vitamin C, as cited in the "Dictionary of Food Science and Technology." Commercially it is synthesized by bacterial fermentation of glucose followed by chemical oxidation with calcium. This produces an off-white powder that is water soluble. When used as a food additive, calcium ascorbate is labeled as E302 in the ingredients. Your body can metabolize it into elemental calcium and vitamin C, nutrients that are essential for health.
Calcium Ascorbate Uses
Calcium ascorbate is commonly used as an antioxidant, preservative and source of vitamin C in foods. It is sprayed on fresh-cut fruits and vegetables to increase shelf-life and is especially effective at preventing apples from turning brown, according to the "Guide to Nutritional Supplements" by Benjamin Caballero. Calcium ascorbate is also added to dairy-based drinks, condensed milk, processed cheese, desserts, canned or bottled fruits and vegetables, breakfast cereals, batters, vinegars and mustards.
Supplemental Calcium Ascorbate
Calcium ascorbate powder can be consumed as a supplement and is well absorbed in your gut because calcium absorption is enhanced by higher acidity. This is why calcium is often added to orange juice, for example. Calcium ascorbate crystals are bitter, more so than pure vitamin C crystals, so they are a "tough sell" to most consumers. According to the book "Biochemical Pathways," consuming 10,000 mg of calcium ascorbate per day will supply you with 1,000 mg of calcium carbonate, which amounts to about 400 mg of elemental calcium being absorbed for use by your body.
Other Calcium Supplements
Calcium carbonate is the most common and least expensive calcium supplement available and should be taken with food. Calcium citrate is better absorbed and can be taken without food, but it contains less elemental calcium than the carbonate form and is more expensive, as noted by Gordon Wardlaw, author of "Contemporary Nutrition: Functional Approach." As such, the carbonate form is more "bang for your buck." Coral calcium is derived from fossilized coral reefs and contains calcium carbonate and other minerals in trace amounts. Vitamin D is also important because it induces the synthesis of intestinal proteins responsible for calcium absorption.
Caution
Calcium ascorbate is not appropriate to take if you want to mega-dose vitamin C because a calcium overload may result. Consult with your primary care physician about how much calcium and vitamin C is appropriate for you and what supplements, if any, would be best.
References
- "Dictionary of Food Science and Technology: 2nd Edition"; International Food Information Service; 2009
- "Guide to Nutritional Supplements"; Benjamin Caballero; 2009
- "Biochemical Pathways"; Gerhard Michal; 1999
- "Contemporary Nutrition: Functional Approach"; Gordon M. Wardlaw; 2009
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