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Diet & Supplements > Ester C -New Forms and New Uses in Dogs

by L. Phillips Brown, D.V.M.
13 Jun 2010

The common wisdom is that humans, other primates, guinea pigs, and a few birds need to get vitamin C in their diets. Since the rest of the animals produce it within their own bodies, they no doubt make enough, right? Well, maybe not. In this article, a doctor of veterinary medicine looks at the effects of vitamin C supplementation in dogs and its benefit in fighting arthritis, and other ailments.

Dogs of all ages suffer with various joint and spinal disorders, including hip dysplasia, osteoarthritis, non-specific arthritis, osteochrondritis, spondylitis and spondylosis. Treatment often consists of rest. surgery and/or steroids, nonspecific anti-inflammatory drugs (NSAIDS), aspirin, penicillamine or methotrexate. Many therapeutic compounds produce only short-term benefits and may actually accelerate the progression of joint destruction.

Nutritional Considerations

Vitamin C is a vital nutrient in bone and cartilage metabolism. Although dogs, unlike humans, can manufacture their own vitamin C, they may not produce enough to counter the effects of aging, stress, inherited dysfunctions, environmental irritants and poor quality or high fat pet foods.

In fact, early studies in dogs and horses suggest that daily vitamin C supplementation might be beneficial in reducing chronic inflammation. Unfortunately; ordinary vitamin C may cause gastrointestinal upsets i dogs. A form of vitamin C that would promote higher levels of intracellular ascorbic acid without negative side effects would be a useful and unique product.

Clinical Study

The effect of different forms of vitamin C on various locomotor dysfunctions of dogs were investigated by veterinarians at The Best Friends Animal Sanctuary in Utah. Over 100 case studies were evaluated, using varying strengths and combinations of mineral ascorbates, ascorbic acid and microcrystalline cellulose during a six-month period. The results indicate that a patented vitamin C ascorbate / vitamin C metabolite complex, administered orally, may have application for the reduction of discomfort associated with nonspecific, chronic inflammatory disorders of dogs. The vitamin C ascorbate / metabolite complex used in the study was Ester-C.

Product Background

According to the manufacturer, Inter-Cal Corporation, of Prescott, Arizona, Ester-C is a patented ascorbate supplement containing calcium ascorbate, naturally occurring dehydroascorbate and the vitamin C metabolite, threonate. Threonate permits ascorbate to be more rapidly absorbed from the gastrointestinal tract, to cross cell membranes more efficiently, reach higher cellular levels and be excreted more slowly than ordinary vitamin C. Ester-C ascorbate is pH neutral and believed to be water and partially fat soluble.

Mechanism Of Action

Vitamin C may act as an immunoresponsive and chrondrogenerative agent. In degenerative (i.e., aging) or inflammatory conditions, collagen breakdown is excessive, resulting in joint discomfort and skeletal changes. A product that would provide high and prolonged levels of ascorbic acid would help compression resistance of cartilage, mobilized white blood cells to the site of inflammation, and enhance prostaglandin synthesis. The net result would be increased comfort and mobility.


78 percent of the study dogs receiving Ester-C calcium ascorbate showed improved mobility within four to five days.

The consistency and degree of response demonstrated that Ester-C calcium ascorbate provided symptomatic relief to the study dogs suffering from selected chronic joint and musculoskeletal disorders. The findings that the condition of many of the "improved" dogs deteriorated rapidly upon discontinuance of Ester-C ascorbate further verified its usefulness as primary or adjunctive therapy. These studies reinforced the earlier observations that supplemental Ester-C calcium ascorbate corrected mobility problems of dogs and horses.

The findings suggest that, although dogs can manufacture endogenous ascorbic acid, the amount produced my not be sufficient to prevent or counteract stresses associated with aging, injury or joint malpositioning.

From the results of this study, there is significant evidence to recommend oral Ester-C calcium ascorbate in the management of non-specific musculoskeletal disorders of dogs.


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