Ascorbate Effects on Viral Infections in Vivo

The pathological or clinical symptoms produced by viruses shown to be inactivated by ascorbate in vitro can be alleviated upon administration of ascorbate in vivo (Stone, 1972 Pauling, 1986). 

The effect of vitamin C on the common cold has been a controversial subject. Pauling (1971a,b) reviewed four placebo-controlled trials that had been carried out prior to 1971 and concluded that vitamin C was effective in lowering the incidence and severity of this condition. Since the maximum benefit had been seen in studies by Ritzel (1961, 1976) using a dose of Ig/day, Pauling proposed that such amounts of vitamin C would be beneficial in the prevention and treatment of the cold. 

The lack of vitamin C effect on incidence of colds in the studies analyzed by Hemila (1994) may be related to the small amount of vitamin tested (Pauling, 1986). Thus, Cathcart has found that the maximum concentration of vitamin C tolerated by persons increases with illness and severity of disease. Based on initial observations made with 9000 patients who had been treated with large doses of vitamin C, Cathcart (1981) reported that while healthy persons can tolerate oral intakes from 4-15 g per day, their bowel-tolerance level—the amount slightly lower than that which produces a laxative effect—increased to values of 30-60 g during a mild cold, 60-100 g during a severe cold, and greater than 100 g during an attack of influenza or flu. In cases of severe viral illnesses such as infectious mononucleosis or pneumonia, the bowel-tolerance doses were found to approach 200 g per day. Cathcart found that vitamin C therapy for the common cold and infectious diseases was most effective when administered at the bowel-tolerance dose. Upon control of 

During the early years of the AIDS epidemic, Cathcart also monitored patients who had voluntarily ingested large doses of vitamin C and treated a small number of AIDS patients with 50 to 200 g of oral and intravenous ascorbate. From his initial observations, he concluded that vitamin C ameliorated the symptoms of AIDS and reduced the frequency and severity of opportunistic infections (Cathcart, 1984). By 1989 he had treated over 250 HIV-positive patients with similar findings (Cathcart, 

Because ascorbate is a potent antioxidant (Bendich, 1988 see also Chapter 17), supplementary vitamin C may provide cell protection by neutralizing extracellular and leaky oxidants generated during immune activation. While this reducing action of vitamin C may explain its beneficial effect, other functions of ascorbate may also be involved in its protective effect against viral infections. 

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