There is only speculation. However, there has been increasing interest in the use of a number of reducing agents and antioxidants such as vitamin C, vitamin E and selenium in preventing cancer. A new study does show that the cancer itself may not improve with large doses of vitamin C, but patients taking the vitamin in massive quantities do live longer. Why? I’m not yet sure.
Normally only 1.5 grams of vitamin C is in the entire body, and only a small part (3%) is metabolized each day (so that it would take almost two months to deplete the pool of vitamin C in the body before even the mildest symptoms of scurvy started to develop). The body attempts to keep that pool of vitamin C at approximately the same level. When presented with a dose of vitamin C by mouth, 70% is absorbed if 180 mg, or less are given. However, if 1-1½ grams are given, only 50% is absorbed. And when we provide doses up to 12 grams, absorption drops to only 16%. The remainder that is unabsorbed can cause the same kind of diarrhea that is caused by the excess sugars in lactose intolerance. Of what is absorbed, the kidneys eliminate what is unused. The ascorbic acid and the products of its breakdown can both produce kidney stones in susceptible patients.
Moreover, this extra acid in the body may produce a severe anemia among patients with glucose 6-phosphate deficiency that is relatively common among blacks, Middle Eastern and southern European people. The membranes of their red blood cells are fragile and can be destroyed by certain chemicals; including excessive vitamin C. this has resulted in death in several cases. What is also amazing is that the high vitamin C dosage can promote scurvy when it is rapidly discontinued. If a pregnant woman were taking large doses of vitamin C, at birth her baby would no longer be receiving those large supplies. That baby’s metabolism has been cranked up to handle increased amounts of vitamin C, and with the sudden stoppage of the vitamin C, scurvy could develop.
Normally only 1.5 grams of vitamin C is in the entire body, and only a small part (3%) is metabolized each day (so that it would take almost two months to deplete the pool of vitamin C in the body before even the mildest symptoms of scurvy started to develop). The body attempts to keep that pool of vitamin C at approximately the same level. When presented with a dose of vitamin C by mouth, 70% is absorbed if 180 mg, or less are given. However, if 1-1½ grams are given, only 50% is absorbed. And when we provide doses up to 12 grams, absorption drops to only 16%. The remainder that is unabsorbed can cause the same kind of diarrhea that is caused by the excess sugars in lactose intolerance. Of what is absorbed, the kidneys eliminate what is unused. The ascorbic acid and the products of its breakdown can both produce kidney stones in susceptible patients.
Moreover, this extra acid in the body may produce a severe anemia among patients with glucose 6-phosphate deficiency that is relatively common among blacks, Middle Eastern and southern European people. The membranes of their red blood cells are fragile and can be destroyed by certain chemicals; including excessive vitamin C. this has resulted in death in several cases. What is also amazing is that the high vitamin C dosage can promote scurvy when it is rapidly discontinued. If a pregnant woman were taking large doses of vitamin C, at birth her baby would no longer be receiving those large supplies. That baby’s metabolism has been cranked up to handle increased amounts of vitamin C, and with the sudden stoppage of the vitamin C, scurvy could develop.
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