Vitamin C, also known as ascorbic acid, is one of the essential vitamins for good health. The actual function of the vitamin is to maintain strong connective tissue. If a person has an inadequate amount over a long period of time they will suffer the deficiency disease called scurvy. Symptoms are seen in the body wherever connective tissue is poorly formed: there will be tiny pinpoint marks on the skin that look like tiny bruises, and bleeding gums are another symptom of this deficiency disease.
Back in the 1500’s, it was common for British sailors to die of scurvy during long journeys. Enough food was taken to last for long periods of time, but fresh fruit and vegetables were not among the supplies that lasted well into the trip. As a result, the sailors would end up perishing from scurvy. It was discovered that citrus fruits, even in small amounts, would prevent this disease from ending the lives of so many sailors, and subsequently large stashes of limes were taken on the voyages. Sailors were instructed to suck on a wedge of lime each day, and this provided enough vitamin C to keep them from developing the fatal symptoms of scurvy. This is how British sailors came to be known as “Limeys”!
The recommended intake for vitamin C has been increasing over the past several decades. Where 40-45 milligrams used to be the established guideline for intake, it has risen to 60 milligrams in the most recent daily value number, and smokers are recommended to keep their intake closer to 90 milligrams due to the cell damage caused by smoking. Vitamin C also acts as an antioxidant, protecting the cells from free radical damage.
Over the years, people have taken much higher amounts of vitamin C in the form of supplements to cure all sorts of ailments. To date, none of these–including preventing colds–has been conclusively proven to be effective.
The tolerable upper limit of vitamin C is set at 2000 milligrams. If someone takes this much to attempt to prevent or treat a cold, they probably will not suffer adverse effects, since the body eliminates unused ascorbic acid through the urine. There are people who continue to take large amounts, based on their interpretation of studies (and personal experience) that vitamin C does help them get over a cold more quickly. It has also been shown that taking higher amounts of viamin C results in a higher percent of the vitamin being absorbed by the body.
One of the drawbacks of taking high amounts of the vitamin is “rebound scurvy”. This occurs when the body becomes dependent on a higher level of vitamin C, and then the individual stops taking supplements after a period of time. The body has become used to using this higher level it was receiving, and suddenly does not have the amount available to perform bodily functions.
Good sources of vitamin C include many fruits and vegetables–citrus fruits, strawberries, kiwi, broccoli, and green pepper. A baked potato also provides 20-30 milligrams of vitamin C. Although french fries are not a great source (about 5 milligrams per serving), the diet of the typical American teenager is often so poor in fruits and vegetables that french fries are one of the leading sources of the vitamin!
One final fun-fact about vitamin C: Humans are one of the only mammals that do not make their own vitamin C. Cats, dogs, and most other animals do–that’s why you don’t see them eating fruit or vegetables very often! The exceptions are one variety of bat (the fruit-eating bat) and guinea pigs. This is one reason people talk about being a “guinea pig” for an experiment–guinea pigs were one of the only alternatives to human studies that scientists could use to find out what they wanted to know about vitamin C.
Image credit: Darwin Bell
Laurie Beebe is a registered dietitian with over 25 years of experience. She assists people from all walks of life in changing their diet for better health. Certified in Adult Weight Management, Laurie has transitioned into life coaching to better implement changes in people’s environments. No matter how much people know about what they ‘should’ be doing differently, they don’t alter their habits without making adjustments in their surroundings and their awareness. Coaching helps lead people to permanent changes by helping them set their own goals and design their own action plans. Please visit Laurie’s website for more free nutrition tips, a free monthly newsletter, or more information on coaching, at www.mycoachlaurie.com.