You've probably heard vitamin C is good for you, but do you know why? This essential nutrient is in the news regularly, but there are many misconceptions about it.
About Vitamin C
Vitamin C is also known as ascorbic acid. It is a water soluble vitamin.
Discovery
Hungarian biochemist Dr. Albert Szent-Gyorgi first isolated vitamin C in 1928. He isolated the vitamin from the adrenals of animals as part of ongoing research on the chemistry of cell respiration. Later, he noted paprika was a good source of the vitamin he had discovered.
Functions in the Body
Vitamin C performs and supports numerous essential functions in the human body. The Linus Pauling Institute at Oregon State University lists the following essential functions for vitamin C:
- It is an essential nutrient for the formation and maintenance of collagen in the body, which is necessary for the growth, health, and repair of bones, tendons, and cartilage.
- It serves as an antioxidant, minimizing the effects of oxidative stress in the body.
- It plays an important role in brain function by participating in the synthesis of norepinephrine, a neurotransmitter.
- Vitamin C is also critical for the formation of eight distinct enzymes that help regulate a variety of chemical body processes, and it is a powerful antioxidant that protects that health and integrity of cells.
- It plays an essential role in the synthesis of carnitine, which helps convert fat to energy.
- It enhances absorption of heme iron, which is an important element of hemoglobin. Hemoglobin is the part of blood that transports oxygen throughout the body.
Biology of Vitamin C
According to an article in a 2010 issue of Nature Education, humans and other primates, as well as bats and Guinea pigs don't have the ability to produce vitamin C by biosynthesizing it from glucose, but other animals can. Other interesting facts on the biology of vitamin C include:
- A 2008 study showed that humans and primates with this inability to biosynthesize vitamin C have adapted to the issue with red blood cells that readily absorb the oxidized form of the vitamin, l-dehydroascorbic acid (DHA). The cells then transform DHA back to vitamin C.
- Despite its natural abundance, Vitamin C is a relatively delicate nutrient. It begins to denature at 86 degrees Fahrenheit. Therefore, it can be destroyed through broiling, grilling, or frying.
- Boiling fruits and vegetables that contain Vitamin C will not destroy the nutrient, but it does leech easily into the water. If that water is discarded, the nutritional benefits are lost.
- Your body absorbs vitamin C in different levels depending on the dose. It absorbs between 70 and 90 percent of vitamin C when taken at 30 to 180 mg/day. Doses higher than one gram per day drop off sharply, as absorption is less than 50 percent. The rest is excreted in urine within about 30 minutes of consumption.
Sources
Vitamin C is relatively abundant and can be found in most fruits and vegetables. Foods high in vitamin C include:
- Kiwi
- Papaya
- Citrus fruits (oranges, limes, lemons, grapefruits, etc.)
- Sweet peppers
- Parsley
- Broccoli
- Potatoes
- Bananas
- Carrots
Several types of meat also contain small amounts of Vitamin C, most notably liver and oysters, and it can be found in different types of milk, including human breast milk.
Recommended Dosage
Different health advisory boards disagree on the optimum daily dosage of Vitamin C for healthy adults. Recommended guidelines vary from 40 milligrams to 1,000 milligrams, though larger doses should be broken up throughout the day to ease absorption. According to the Mayo Clinic:
- Men need at least 90 mg daily with an upper limit not exceeding 2,000 mg.
- Women need at least 75 mg daily with an upper limit not exceeding 2,000 mg.
- Pregnant women need at least 85 mg daily with an upper limit not exceeding 2,000 mg.
- Smokers require a minimum of 35 mg daily more than non-smokers.
For individuals who do not get enough Vitamin C through their regular diets, the nutrient is available in a wide range of supplemental forms, including capsules, tablets, drink powders, and lozenges, along with wide spectrum multivitamins. In fact, Vitamin C is the most widely taken supplement in the world, and it is often added to fortified cereals, drinks, and breads as well.
At the same time, overdosing on Vitamin C can produce unhealthy side effects such as diarrhea, nausea, insomnia, and headaches. Different individuals may develop these symptoms at different dosage levels based on the rate of absorption of the nutrient.
Health Benefits
Some of the most interesting facts about Vitamin C relate to its nearly universal benefits for overall good health. In addition to its body maintenance properties, Vitamin C has a wide range of additional health benefits, including:
- Lowering risks for certain cancers
- Improving cholesterol
- Increasing white blood cell counts
- Controlling allergies and autoimmune responses
- Improving regulation of blood glucose levels
- Protects against cognitive impairment
- Lowering the risk of developing cataracts
With such a wide range of health benefits, large doses of Vitamin C have been used as part of experimental treatments for different terminal cancers, AIDS, and other diseases.
Deficiency
If you eat a healthy and varied diet containing an array of fruits and vegetables, it is unlikely you will become deficient in vitamin C. However, according to the Office of Dietary Supplements, certain people may be more at risk of vitamin C deficiency than others including:
- Smokers
- People frequently exposed to second-hand smoke
- People with malabsorption disorders
- People who have a very limited diet
- Infants fed cow's milk as their main source of nutrients
Scurvy
People suffering from a severe deficiency of vitamin C may develop a condition called scurvy. While it is rare in the modern United States, some people may be more prone to it including:
- Alcoholics with poor nutrition
- Isolated elderly people
- People in institutions
Historically, scurvy was observed among sailors in the 16th and 17th centuries. They went long stretches without eating fresh fruits and vegetables. Scurvy symptoms include:
- Lethargy
- Aches and pains in the legs
- Red and blue spots on the skin
- Swollen gums
- Severe joint pain
- Bruising
Vitamin C and the Common Cold
Many individuals regularly increase their Vitamin C intake to combat the common cold. According to the Mayo Clinic:
- There does not appear to be a statistically significant correlation between taking vitamin C and preventing colds.
- Taking vitamin C before or during colds does not appear to affect the type or intensity of symptoms.
- Taking vitamin C does appear to reduce the duration of a cold by about 10 percent in adults and 15 percent in children.
- People living in extreme circumstances (such as athletes and soldiers at war) may have a reduced risk of developing a cold when they supplement vitamin C.
More Interesting Facts About Vitamin C
Other interesting vitamin C facts include:
- English sailors were called limeys because they sucked on limes to prevent scurvy.
- Inuit people have very few fresh fruits and vegetables, but they do not get scurvy. That's because the traditional sea foods they eat such as seal meat and Arctic char are high in vitamin C.
- Ascorbic acid as a food additive helps preserve colors and flavors in canned food.
- Vitamin C and coffee can be used to develop black and white photo film.
- Nobel prize winner Linus Pauling popularized the concept of mega-doses of vitamin C. He studied the effects of vitamin C on cancer and common colds. His conclusions have been refuted in later studies by the Mayo Clinic and many others.
- It is the most widely researched nutrient on the Internet.
- Many people think oranges are the food highest in vitamin C, but there are others with higher levels including red bell peppers, papaya, broccoli, and kale.
Healthy Vitamin C
Vitamin C is essential for your health, and the best way to get it is through the foods you eat. Talk with your doctor before supplementing vitamin C to ensure you find the dosage correct for you.
