Vitamin C and the Common Cold As much as I'd like to indulge in denial, it has to be acknowledged: Labor Day has passed on by. Summer (please don't shoot the messenger) is over. We can pause slightly before we turn and go on, but there's no getting around it. It's time for autumn. And as pleasant as autumn often is, there's one characteristic of the season that all of us would surely like to avoid: The common cold. Here's how… In 1970, Nobel Prize-winning chemist Linus Pauling published "Vitamin C and the Common Cold." This book is largely responsible for the perception that vitamin C intake will produce beneficial effects when it comes to colds. But can vitamin C supplements actually keep you from getting a cold? Can they shorten a cold's duration? Can they reduce the severity of symptoms? To address these questions, scientists at Tokyo's Research Center for Cancer Prevention and Screening created a long-term vitamin C intervention study. As reported last month in the European Journal of Clinical Nutrition, researchers enlisted more than 240 subjects who were already participating in an annual screening program for gastric cancer. (Each of the subjects had been diagnosed with a gastric condition.) For five years, approximately half the group received 50 mg of vitamin C daily, while the other half received 500 mg. There was no placebo control group. Analysis of the data showed that the total number of colds per 1,000 person-months was more than 21 for the low dose group and about 17 for the high dose group. And although these results led researchers to conclude that "vitamin C supplementation significantly reduces the frequency of the common cold," supplements appeared to have no effect on the duration or severity of colds. The report I read on the Tokyo study wasn't specific about what type of vitamin C was given to the subjects. This is a key detail because, like vitamin E, some forms of C are more advantageous than others. And these variables almost certainly play a role in the disparity of vitamin C study results over the past 35 years. To begin with, most multivitamins barely scratch the surface when it comes to supplying vitamin C. In the e-alert "Multi-Talented" (4/23/03), HSI Panelist Allan Spreen, M.D., explained: "The amount of vitamin C in a multivitamin is far less than I'd want a person to take. I nearly always start with a minimum of 1000 milligrams 2x/day." And in the e-Alert "Attack of the Vapors" (1/6/04), Dr. Spreen offered a quick rundown of different types of C, along with some guidelines for choosing a supplement. Here are a few of Dr. Spreen's highlights: - ASCORBIC ACID: This is the standard form of vitamin C. Calcium ascorbate is one of the salt forms of the nutrient (as opposed to the acid form). It is usually synthetic, as are other forms, such as sodium ascorbate, magnesium ascorbate, etc. (The synthetic vitamin C molecule is chemically identical to natural forms. The difference arises in other nutrients that accompany the C, such as bioflavonoids, which make the C more effective.)
- ROSE HIPS: This natural form of vitamin C is very expensive, so nobody sells it exclusively (to my knowledge). Manufacturers put a little in with the synthetic source for marketing purposes.
- ACEROLA VITAMIN C: This is another natural form (from a tropical American shrub). Like rose hips, acerola is usually mixed with synthetic.
- ESTER C: There is some issue concerning Ester C, touted as stronger than the standard form. I don't think it's any stronger, and
neither did Dr. Linus Pauling, though you'll see commercials that indicate otherwise. Some people do feel it has less of a tendency to upset their stomach, however. - FAT SOLUBLE VITAMIN C: The fat-soluble form of vitamin C is called ascorbyl palmitate, and is better absorbed and stored by the body than water-soluble forms. (All the other forms of C are water-soluble.) Ascorbyl palmitate is harder to find, and more expensive.
Dr. Spreen also points out that absorption may be facilitated by the regular use of vitamin C. "Assuming you take enough (RDA amounts won't do it), high doses of vitamin C 'awaken' dormant enzyme systems that can utilize the additional doses of the nutrient. Over a period of time they get used to having the higher dose and 'jack up' to accommodate." And finally, Dr. Spreen recommends that vitamin C (as well as other vitamins) be taken in capsule form or powdered. If you take a hard pill form, make sure it dissolves quickly in water. Sources:
"Effect of Vitamin C on Common Cold: Randomized Controlled Trial" European Journal of Clinical Nutrition, advance online publication, 8/24/05, nature.com/ejcn/journal
"Vitamin C May Reduce Frequency of Common Cold " Natural Products Insider, 8/26/05, naturalproductsinsider.com
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