by Kelly Ann Griffin
Catching a cold? Load up on your Vitamin C. This has been a common public prescription and an accepted staple in fighting sickness for several decades, as the vitamin is readily available in grocery and drug stores as a dietary supplement. The main reason for this now widespread belief can be traced to a book titled, Vitamin C and the Common Cold, which was published by Nobel Peace Prize winner Linus Pauling in 1970. He prescribed that the intake of 1,000 mg of the vitamin daily would eliminate the occurrence of the common cold by 45% and even help to delay the onset of most cancers. Dr. Stephen Barrett, vice-president of the National Council Against Health Fraud, reported in his article, The Dark Side of Linus Pauling's Legacy, that "Pauling himself reportedly took at least 12,000 mg daily and raised the amount to 40,000 mg if symptoms of a cold appear." The Recommended Dietary Allowances (RDAs) only advise 75 - 90 mg daily for adults, and a bit higher for adult smokers (110-125 mg). Certain Vitamin C supplements on the store shelf contain 1,000 mg of the vitamin in each dosage, and permit four doses per day. An overdose of Vitamin C does occur and is now being critically investigated by medical scientists.
So what does Vitamin C actually do?
Vitamin C, or Ascorbic Acid, benefits the body in several ways, from its ability to preserve skin elasticity, to providing better iron absorption, and efficient fighting against infection. The British Navy discovered its curing power against Scurvy, a Vitamin C deficiency, in the eighteenth century when Scottish surgeon, James Lind, proved the effectiveness of citrus foods in curing this common, yet sometimes fatal "sea disease." The main appeal to consumers today is the vitamin's antioxidant properties. Our bodies have natural levels of molecules known as free radicals, which contain an unpaired electron; however, they have the potential to cause grave damage if produced in abundance. Over generation of free radicals are linked to such chronic diseases as heart disease and the development of cancer. Antioxidants therefore are essential to maintain a healthy balance, for as they interact with free radicals, they can prohibit a damaging chain reaction of cell destruction. The body's main antioxidants are Vitamin E, Beta-Carotene, and needless to say, Vitamin C. Humans and a few other species do not have the ability to synthesize their own Vitamin C, making intake of the vitamin through foods and supplements vital.
Natural Intake Versus Supplements
Certain foods contain natural high amounts of Vitamin C. Citrus fruits are well known for their significant quantities of the vitamin, such as oranges, grapefruits, cantaloupe, kiwi, lemons, limes, mangos, papayas and strawberries. Vegetable also have the vitamin, including peppers, broccoli, cabbage, potatoes, Brussels sprouts, and spinach. Interestingly, there is a difference between natural food and vitamin supplement intake. Fruits and vegetables contain Vitamin C in its ascorbic and dehydroascorbic acid forms, whereas vitamin supplements contain only the former. The latter is the oxygenized form of ascorbic acid, and its importance lies in the fact that only dehydroascorbic acid can transport the barrier into the brain. The department of neurological surgery at Columbia University has completed a study on the necessity of dehydroascorbic acid, stating that, "Although the antioxidant ascorbic acid (AA) or vitamin C does not penetrate the bloodbrain barrier (BBB), its oxidized form, dehydroascorbic acid (DHA), enters the brain by means of facilitative transport. We hypothesized that i.v. [intravenous] DHA would improve outcome after stroke because of its ability to cross the BBB and augment brain antioxidant levels." Consequently, natural food may be a better route for the intake of this vitamin.
Signs of Overdose
The positive aspect of Vitamin C overdose is that it can be controlled by simply limiting one's intake. Vitamin C is nontoxic and not stored by the body; overdose tends to be rare. Increased levels above the RDAs recommendation can be legitimate in medical cases such as trauma, fever, or infection. However, continued excessive use of the vitamin can cause some negative, harmful symptoms of overdose. Overdose amounts often vary upon individual, as factors such as age, genes, and the ratio of other reactive elements in the body can affect the results. Diarrhea is the most common symptom of Vitamin C overdose, minimally requiring an intake between 500-2500 mg daily. Also, symptoms such as gas, stomach cramps, nausea, increased urination, insomnia, and back/joint pain can occur. Other negative side effects are possible, as the previous list contains the more common outcomes. Another notable damaging effect of Vitamin C overdose is its cause for the deficiency of copper, an essential element in our bodies. Present throughout the body and in the blood, copper helps in a variety of manners, from production
of connective tissues, to the aid in blood clotting and wound healing, to helping in production of red blood cells and bones. As to the long-term negative health effects of Vitamin C overdose, scientists remain inconclusive.
Can Vitamin C help your body? Of course, it is an essential vitamin for the body's overall health and performance. Many athletes take daily supplements to increase the optimization of the immune system and decrease time needed between exercising sessions. Vitamin C will still help in preventing sickness as it does boost our immune system, yet the widely accepted belief of super dosage should be cautioned by consumers, as it is currently with researchers. Overdose is possible and one should keep their intake within the RDA's boundaries. Pregnant women and children under 18 also require less of the vitamin. Catching a cold? Think twice about excessive intake of Vitamin C the next time the throat begins to pain and the nose clogs up. Vitamin C is beneficial, but within reason.
J. Huang, et al. "Dehydroascorbic Acid, a BloodBrain Barrier Transportable Form of Vitamin C, Mediates Potent Cerebroprotection in Experimental Stroke," http://www.pnas.org/cgi/reprint/98/20/11720.pdf
Nutritional Supplements Guide, "Vitamin C Overdose," http://www.nutritional-supplements-guide.com/vitamin
Stephen Barrett, "The Dark Side of Linus Pauling's Legacy," http://www.quackwatch.com/01QuackeryRelatedTopics/pa