Vitamin C is the best-known vitamin and the most commonly ingested supplement. Even if your customers don't take a C tablet or capsule, they'll invariably encounter foods, beverages and even candy with added C throughout their day. Why do we need to worry about C - don't we get enough? And why write a column about it- isn't C old news?
Of course the answers are NO! I cannot emphasize enough the damage done to society by the simple lack of vitamin C. In a flash we could cut medical expenditures in half by having every adult take 1-2 g per day and every child 500 mg daily. Why suffer fatigue, aches, pains, hay fever, asthma, colds, flu, pneumonia and bronchitis when you can eliminate or reduce the severity of these conditions with a single supplement? Colds are not an inevitable part of back-to-school and colder wheather!
First, you must erase the notion that vitamin C has a single, fixed Recommended Daily Allowance (RDA) for everybody, everyday. This is surely the most misleading, incorrect notion in modern nutrition. For example, everybody with asthma, allergies or frequent upper respiratory infections can be helped by vitamin C - even if they ignore every other issue that could be affecting their disease - but not at the - 60 mg doses in a multivitamin. Doses for adult and children's asthma control start at 1,000 mg per day, and they may exceed 10 g/d (1-3).
Further, doses vary greatly based on the individual and his/her age, health, lifestyle and environment.
Vitamin C is the primary antioxidant in the lungs, and is a powerful antihistamine without side effects (5-7). As blood plasma levels of vitamin C fall below 1 mg per 100 ml blood, plasma histamine levels increase exponentially. This means that low vitamin C dramatically increases histamine levels, which puts your customers at greater risk for allergic reactions, rhinitis (chronic nasal drip) and asthma attacks. The solution is simple: 1 g of vitamin C for three days consistently reduces blood histamine to normal levels. Vitamin C also enhances and normalizes immune response, which reduces the severity of allergic responses. Your body "gobbles up" this vitamin during prolonged asthma or allergy attacks, and if it isn't replaced, attacks worsen over time.
Over a dozen human studies administering at least 1 g/d of vitamin C have shown clear improvements in lung function (8-13). Single doses of 2 g have been shown to result in an immediate increase in lung capacity, and a strong protective effect against exercise-induced asthma and airway hyperreactivity.
A 2006 study of 218 Buffalo, NY-area adults with asthma or chronic obstructive pulmonary disease found that their conditions were strongly associated with a lack of antioxidant vitamins and phytochemicals. Poor dietary habits were largely to blame (13).
Vitamin C unequivocally lessens the incidence, severity and length of colds (3, 19-21). The reason why controversy remains is that researchers don't use high enough and/or variable doses - especially for treatment studies where colds are already diagnosed.
To prevent colds in adults and children, at least 1 g/d and preferably over 2 g/d of vitamin C, the median decrease in cold duration was only 6 percent, whereas in two studies with children given 2 g/d the decrease was 26 percent (19). Lesser don't usually result in statistically significant preventive effects, espescially in short-term studies.
Cold weather, severe stress, combat and intensive athletic training increase the requirements for this vitamin but depress immunity, therefore supplementation is strongly recommended. A review of nine controlled clinical trials with military personnel or marathon runners under heavy exertion found a 45-91 percent reduction in cold incidence for subjects receiving vitamin C. Three of trials found an 80-100 percent reduction in pneumonia incidence with C (20).
In order to treat colds, it is necessary to start taking 1-5 g doses of the vitamin 3-4 times daily right at the onset of symtoms. Vitamin C powder is the easiest and most cost-effective way to do this. Research studies show no significant benefits for adult doses less than about 8 g/d once a cold is diagnosed (21). Further benefits are realized if you add bee propolis and favorite herbal teas along with each C dose - and get in bed! Invest in vitamin C and a day of rest at the onset of symtoms and you'll earn a week of good health instead of sniffles!
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3. Jaber R (2002). Respiratory and allergic diseases: from upper respiratory tract infections to asthma. Prim Care 29, 231-261.
4. Johnston CS, Corte C, Swan PD (2006). Marginal vitamin C status is associated with reduced fat oxidation during submaximal excercise in young adults. Nutr Metab (Lond) 3, 35 (Epub).
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18. Taylor CA, Hampl JS, Johnston CS (2000). Low intakes of vegetables fruits, especially citrus fruits, lead to inadequate vitamin C intakes among adults. Eur J Clin Nutr 54, 573-578.
19. Hemila H (1999). Vitamin C supplementation and common cold symtoms: factors affecting the magnitude of the benefit. Med Hypotheses 52, 171-178.
20. Hemila H (2004). Vitamin C supplementation and respiratory infections: a systematic review. Mil Med 169, 920-925.
21. Douglas RM, Hemila H, D'Souza R et al. (2004). Vitamin C for preventing and treating the common cold. Cochrane Database Syst Rev (4): CD00980.