Health Articles

Vitamin C

What is vitamin C and what does it do?

Vitamin C, also known as ascorbic acid, is a water-soluble nutrient found in some foods. In the body, it acts as an antioxidant, helping to protect cells from the damage caused by free radicals. Free radicals are compounds formed when our bodies convert the food we eat into energy. People are also exposed to free radicals in the environment from cigarette smoke, air pollution, and ultraviolet light from the sun.

The body also needs vitamin C to make collagen, a protein required to help wounds heal. In addition, vitamin C improves the absorption of iron from plant-based foods and helps the immune system work properly to protect the body from disease.

How much vitamin C do I need?

The amount of vitamin C you need each day depends on your age. Average daily recommended amounts for different ages are listed below in milligrams (mg).

Life Stage

Recommended Amount

Birth to 6 months

40 mg

Infants 7–12 months

50 mg

Children 1–3 years

15 mg

Children 4–8 years

25 mg

Children 9–13 years

45 mg

Teens 14–18 years (boys)

75 mg

Teens 14–18 years (girls)

65 mg

Adults (men)

90 mg

Adults (women)

75 mg

Pregnant teens

80 mg

Pregnant women

85 mg

Breastfeeding teens

115 mg

Breastfeeding women

120 mg

If you smoke, add 35 mg to the above values to calculate your total daily recommended amount.

What foods provide vitamin C?

Fruits and vegetables are the best sources of vitamin C. You can get recommended amounts of vitamin C by eating a variety of foods including the following:

  • Citrus fruits (such as oranges and grapefruit) and their juices, as well as red and green pepper and kiwifruit, which have a lot of vitamin C.
  • Other fruits and vegetables—such as broccoli, strawberries, cantaloupe, baked potatoes, and tomatoes—which also have vitamin C.
  • Some foods and beverages that are fortified with vitamin C. To find out if vitamin C has been added to a food product, check the product labels.

The vitamin C content of food may be reduced by prolonged storage and by cooking. Steaming or microwaving may lessen cooking losses. Fortunately, many of the best food sources of vitamin C, such as fruits and vegetables, are usually eaten raw.

What kinds of vitamin C dietary supplements are available?

Most multivitamins have vitamin C. Vitamin C is also available alone as a dietary supplement or in combination with other nutrients. The vitamin C in dietary supplements is usually in the form of ascorbic acid, but some supplements have other forms, such as sodium ascorbate, calcium ascorbate, other mineral ascorbates, and ascorbic acid with bioflavonoids. Research has not shown that any form of vitamin C is better than the other forms.

Am I getting enough vitamin C?

Most people in the United States get enough vitamin C from foods and beverages. However, certain groups of people are more likely than others to have trouble getting enough vitamin C:

  • People who smoke and those who are exposed to secondhand smoke, in part because smoke increases the amount of vitamin C that the body needs to repair damage caused by free radicals. People who smoke need 35 mg more vitamin C per day than nonsmokers.
  • Infants who are fed evaporated or boiled cow's milk, because cow's milk has very little vitamin C and heat can destroy vitamin C. Cow's milk is not recommended for infants under 1 year of age. Breast milk and infant formula have adequate amounts of vitamin C.
  • People who eat a very limited variety of food.
  • People with certain medical conditions such as severe malabsorption, some types of cancer, and kidney disease requiring hemodialysis.

What happens if I don't get enough vitamin C?

Vitamin C deficiency is rare in the United States and Canada. People who get little or no vitamin C (below about 10 mg per day) for many weeks can get scurvy. Scurvy causes fatigue, inflammation of the gums, small red or purple spots on the skin, joint pain, poor wound healing, and corkscrew hairs. Additional signs of scurvy include depression as well as swollen, bleeding gums and loosening or loss of teeth. People with scurvy can also develop anemia. Scurvy is fatal if it is not treated.

What are some effects of vitamin C on health?

Scientists are studying vitamin C to understand how it affects health. Here are several examples of what this research has shown.

Cancer prevention and treatment
People with high intakes of vitamin C from fruits and vegetables might have a lower risk of getting many types of cancer, such as lung, breast, and colon cancer. However, taking vitamin C supplements, with or without other antioxidants, doesn't seem to protect people from getting cancer.

It is not clear whether taking high doses of vitamin C is helpful as a treatment for cancer. Vitamin C's effects appear to depend on how it is administered to the patient. Oral doses of vitamin C can't raise blood levels of vitamin C nearly as high as intravenous doses given through injections. A few studies in animals and test tubes indicate that very high blood levels of vitamin C might shrink tumors. But more research is needed to determine whether high-dose intravenous vitamin C helps treat cancer in people.

Vitamin C dietary supplements and other antioxidants might interact with chemotherapy and radiation therapy for cancer. People being treated for cancer should talk with their oncologist before taking vitamin C or other antioxidant supplements, especially in high doses.

Cardiovascular disease
People who eat lots of fruits and vegetables seem to have a lower risk of cardiovascular disease. Researchers believe that the antioxidant content of these foods might be partly responsible for this association because oxidative damage is a major cause of cardiovascular disease. However, scientists aren't sure whether vitamin C itself, either from food or supplements, helps protect people from cardiovascular disease. It is also not clear whether vitamin C helps prevent cardiovascular disease from getting worse in people who already have it.

Age-related macular degeneration (AMD) and cataracts
AMD and cataracts are two of the leading causes of vision loss in older people. Researchers do not believe that vitamin C and other antioxidants affect the risk of getting AMD. However, research suggests that vitamin C combined with other nutrients might help keep early AMD from worsening into advanced AMD.

In a large study, older people with AMD who took a daily dietary supplement with 500 mg vitamin C, 80 mg zinc, 400 IU vitamin E, 15 mg beta-carotene, and 2 mg copper for about 6 years had a lower chance of developing advanced AMD. They also had less vision loss than those who did not take the dietary supplement.

More research is needed before doctors can recommend dietary supplements containing vitamin C for patients with AMD. However, people who have or are developing the disease might want to talk with their doctor about taking dietary supplements.

The relationship between vitamin C and cataract formation is unclear. Some studies show that people who get more vitamin C from foods have a lower risk of getting cataracts. But further research is needed to clarify this association and to determine whether vitamin C supplements affect the risk of getting cataracts.

The common cold
Although vitamin C has long been a popular remedy for the common cold, research shows that for most people, vitamin C supplements do not reduce the risk of getting the common cold. However, people who take vitamin C supplements regularly might have slightly shorter colds or somewhat milder symptoms when they do have a cold. Using vitamin C supplements after cold symptoms start does not appear to be helpful.

Can vitamin C be harmful?

Taking too much vitamin C can cause diarrhea, nausea, and stomach cramps. In people with a condition called hemochromatosis, which causes the body to store too much iron, high doses of vitamin C could worsen iron overload and damage body tissues.

The safe upper limits for vitamin C are listed below:

Life Stage

Upper Safe Limit

Birth to 12 months

Not established

Children 1–3 years

400 mg

Children 4–8 years

650 mg

Children 9–13 years

1,200 mg

Teens 14–18 years

1,800 mg


2,000 mg

Are there any interactions with vitamin C that I should know about?

Vitamin C dietary supplements can interact or interfere with medicines that you take. Here are several examples:

  • Vitamin C dietary supplements might interact with cancer treatments, such as chemotherapy and radiation therapy. It is not clear whether vitamin C might have the unwanted effect of protecting tumor cells from cancer treatments or whether it might help protect normal tissues from getting damaged. If you are being treated for cancer, check with your health care provider before taking vitamin C or other antioxidant supplements, especially in high doses.
  • In one study, vitamin C plus other antioxidants (such as vitamin E, selenium, and beta-carotene) reduced the heart-protective effects of two drugs taken in combination (a statin and niacin) to control blood-cholesterol levels. It is not known whether this interaction also occurs with other statins. Health care providers should monitor lipid levels in people taking both statins and antioxidant supplements.

Tell your doctor, pharmacist, and other health care providers about any dietary supplements and medicines you take. They can tell you if those dietary supplements might interact or interfere with your prescription or over-the-counter medicines or if the medicines might interfere with how your body absorbs, uses, or breaks down nutrients.

Where can I find out more about vitamin C?

  • For general information on vitamin C:
  • Office of Dietary Supplements Health Professional Fact Sheet on Vitamin C
  • Vitamins, MedlinePlus®
  • For more information on food sources of vitamin C:
  • U.S. Department of Agriculture's (USDA) National Nutrient Database
  • Vitamin C Content of Selected Foods, USDA
  • For more advice on buying dietary supplements:
  • Office of Dietary Supplements Frequently Asked Questions: Which brand(s) of dietary supplements should I purchase?
  • For information on the government's food guidance system:
  • MyPlate
  • Dietary Guidelines for Americans


Escott-Stump S, ed. Nutrition and Diagnosis-Related Care. 6th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2008.

Sarubin Fragaakis A, Thomson C. The Health Professional's Guide to Popular Dietary Supplements. 3rd ed. Chicago, Il: American Dietetic Association; 2007.

Institute of Medicine. Food and Nutrition Board. Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids. National Academy Press, Washington, DC, 2000.

Douglas RM, Hemila H, Chalker E, Treacy B. Vitamin C for preventing and treating the common cold. Cochrane Database Syst Rev; 2007(3):CD000980.


This fact sheet by the Office of Dietary Supplements provides information that should not take the place of medical advice. We encourage you to talk to your health care providers (doctor, registered dietitian, pharmacist, etc.) about your interest in, questions about, or use of dietary supplements and what may be best for your overall health. Any mention in this publication of a specific brand name is not an endorsement of the product.


The Strong Connection Between Your Snooze Time and Your Waistline

Many years ago in my college days, I went home for the holiday break.   I didn’t really watch what I was eating (although I did not overindulge,) nor did I exercise.  I still drank alcohol a few nights a week as well.  After my 4 weeks of fun I was back at the university, and all of a sudden my 3 roommates are begging me to tell them how I lost weight.  Lost weight??  I did?? To my surprise, I realized I did look slimmer than before and my clothes were a bit loose.  I had no idea how that had happened.  Then it hit me:  the only real change I’d made (although unwittingly) was getting a full 8-9 hours of zzz’s a night at fairly constant times, when previously I certainly had not been.  (Let me put it this way; a nickname I had in college was “Vampire” because I had such an erratic sleep schedule.)   So as you may guess, I am now a firm believer in how important sleep is in regards to maintaining a healthy weight, as well as in regards to weight loss. 


A recent study published in the Journal of the American Medical Association confirms that inadequate sleep promotes overeating and weight gain.  As more studies are being done, more information is gathered to support and explain this occurrence.


Sleep deprivation often has a staggering effect on hormones related to appetite and satiety.  Levels of leptin, a hormone that suppresses the appetite, are reduced, while the levels of ghrelin, the appetite-stimulant hormone, are elevated.  Therefore, these two hormones cannot accurately signal calorie need.  A recent study done at the University of Chicago restricted a group’s sleep time for a couple days.  Not only did their appetites increase substantially in proportion to the lack of sleep, but also their desire for high-carbohydrate, high-density foods increased by a whopping 45%.


Sleep loss appears to also have a significant effect on the hypothalamic pituitary system and the autonomic nervous system.  These changes then affect glucose metabolism and insulin resistance, which are both often a definitive step in the direction of type II diabetes and obesity.  Furthermore, cutting short your zzz’s alters your growth hormone secretion pattern, reduces your thyroid-stimulating hormone levels, increases evening cortisol levels, increases sympathetic activity, and decreases parasympathetic activity, all of which negatively affect proper glucose metabolism.


If getting enough sleep is much easier said than done, or if you think you may have a sleep disorder, make an appointment with your physician so that you can get on the right path to getting a great snooze.

By Lauren Murphy


Many Americans May Benefit From Eating A Higher-Protein Diet

Current protein recommendations were established with the goal of preventing deficiency, but newer research indicates that many adults may benefit from eating more than the minimum requirement. These findings are presented in a supplement in the May issue of the American Journal of Clinical Nutrition1 describing the conclusions of a Protein Summit held last spring, which brought together the world's leading scientists in protein research.

The summit's attendees report in the supplement that eating a higher protein diet - still within the recommended range, but toward the top of it - may play a role in optimal health, as higher protein diets are linked with a lower risk for many health conditions such as type 2 diabetes, metabolic syndrome, cardiovascular diseases and osteoporosis as well as sarcopenia, the degenerative loss of skeletal muscle mass and strength.

The current U.S. recommendation according to the Institute of Medicine is that adults should consume between ten and 35 percent of their calories from protein. The summit participants said that many adults, such as those who are overweight or obese and older Americans may benefit from eating up to 35 percent of their calories from protein.

The summit's conclusions complement examination of evidence by the International Dietary Energy Consultancy Group (IDECG), World Health Organization/Food and Agricultural Organization and Dietary Reference Intakes (DRI) panel, which has determined that there is either a benefit or no harm with protein intakes three to four times the minimum requirement. This means that adults can safely eat up to 35 percent of their total calories as protein, and there may be some health benefits in doing so. Since most Americans are consuming protein in the lower end of this range (about 13-16 percent), there is room for adding more high-quality protein to their diets while still being in the recommended range outlined as safe.2

The 2005 Dietary Guidelines for Americans do not specifically address protein as a required nutrient, and summit participants agreed that greater focus and attention to protein should be given in the 2010 Dietary Guidelines in light of grounded science supporting protein's role in disease prevention and emerging research supporting its role in optimal health.

How to Get More Protein - and the Best Kind

Protein supports growth and repair of muscle, bone and other body tissues and can help to promote satiety. While looking for protein choices, it's important to know that animal sources of protein, such as dairy, meat, eggs, poultry and fish, are defined as high-quality or "complete" proteins because they contain the right proportion of amino acids essential for the body's functioning. One easy way to increase protein intake - and high-quality protein intake at that - is to eat the recommended 3 servings or more of dairy products like milk, cheese or yogurt each day.

"Taking simple steps such as choosing a glass of low-fat or fat-free milk at a meal, or eating a piece of low-fat cheese with fruit as a snack, will help increase protein in the diet which may lead to a reduced risk of heart disease, diabetes, obesity and osteoporosis." said Greg Miller, Ph.D., M.A.C.N., executive vice president of research, regulatory and scientific affairs at the National Dairy Council® and Protein Summit participant.

In addition to protein, nutrient-rich dairy foods contain eight other essential nutrients including calcium, potassium, phosphorus, vitamins A, D and B12, riboflavin and niacin (niacin equivalents). The Dietary Guidelines for Americans recommends 3 servings of low-fat or fat-free dairy products each day and recognize that people who consume more dairy foods have better overall diets, consume more nutrients and have improved bone health.3  Additionally, the U.S. Surgeon General recommends consuming 3 daily servings of low-fat or fat-free dairy foods, and the National Medical Association and American Academy of Pediatrics recommend consuming 3 to 4 daily servings of low-fat or fat-free dairy foods.4,5,6


1. American Journal of Clinical Nutrition Supplement: Protein Summit 2007: Exploring the Impact of High-Quality Protein and Optimal Health. American Journal of Clinical Nutrition 2008;87:1551S-1583S.

2. Fulgoni V. Current protein intake in America: Analysis of the National Health and Nutrition Examination Survey, 2003-2004. American Journal of Clinical Nutrition 2008;87

3. U.S. Department of Health and Human Services and U.S. Department of Agriculture. Dietary Guidelines for Americans, 2005. 6th Edition, Washington, DC: U.S. Government Printing Office, January 2005

4. Surgeon General's Report on Bone Health, 2004.

5. Wooten, WJ and Price, W. Consensus Report of the National Medical Association: The Role of Dairy and Dairy Nutrients in the Diet of African Americans. J Natl Med Assoc 2004; 96(12): 1S-31S.

6. American Academy of Pediatrics, Optimizing bone health and calcium intakes of infants, children, and adolescents. Pediatrics. 2006; 117(2):578-585.

Source: NDC Media Hotline
Edelman Public Relations

Article adapted by Medical News Today from original press release.

Source: NDC Media Hotline 

Edelman Public Relations

Why Most Diet Systems Don’t Work

 Most diet plans have been, at best, disappointing.  At worst, many are outright frauds. Many cause major side effects and untold damage to your health.  In a nutshell, most promotional diets fall into four categories, all of which you should stay away from, because they can be hazardous.  And gaining back any weight you lose as a result is almost a certainty.


CATEGORY 1 - Drugstore Pills

This category has three of its own sub-categories:

1. Appetite suppressants, which reduce your hunger and make you eat less

Not only is this unnatural, but eventually it causes your body to snap and binge eat. What’s more, when you radically decrease your caloric intake it actually slows down the burning of fat because your body gets scared and goes into survival mode, turning every little morsel it gets into fat. What’s worse, when you go off your starvation diet, your body will overcompensate and the starvation response will continue, which basically means you usually end up gaining back more weight than you have temporarily lost. 

2. Starch, fat or carbohydrate blocker

The advertising for these little pills really play on your emotions because they tell you it’s possible to consume all sorts of fattening food like pastries and pizzas without gaining any weight.  How?  They claim to be able to separate the fat and zip it through your body without any of it sticking.  Yeah, right.  Many people experience horrific side effects such as diahrrea, sick stomachs or blinding headaches.  However the worst part of all is that the myth these pills perpetuate actually encourages people to establish bad eating habits.

3. The metabolism booster

Otherwise known as the thermogenic pill, these are the most dangerous of all because they often contain ephedrine (otherwise known as ephedra or mua hung) which is extremely dangerous, as it is a very strong stimulant which puts untold amounts of pressure on your heart, especially when you are reducing calories. It also contains massive amounts of caffeine and causes intense energy ups and downs, insomnia and mood swings.  Many people get addicted to them because they cheat by adding diuretics, which quickly knocks off the water weight and causes dehydration which can weaken muscles including, your heart.  The scales may say you have lost weight as a result, but in reality no fat has been lost: just water.


CATEGORY 2  - Meal Replacement Shakes

These claim to have all the nutrients you would get in a proper, healthy meal.  However, often they are very high in sodium which is known to raise your blood pressure and zap moisture from your muscles and organs.  Common sense tells you this can’t be good for you. What’s more, many people also find they feel like they have skipped a meal so they end up eating extra for their next meal to make up for it.


CATEGORY 3 - Fad Diets

This group includes any starvation diet and diets such as the South Beach Diet, The Atkins Diet, The Hollywood Diet, The Grapefruit Diet, the Low Carb Diet, the Cabbage Soup Diet and dozens of others you may have heard of.  Dozens of new fad diets pop up every year and they can deliver fast, although temporary results.  However, just about everybody who uses them binge eats.  At some point they get so sick and tired of eating in such an unnatural way that their sense of deprivation kicks in and they start pigging out.  For instance, you may go a few days following your plan and then something just snaps inside of you and you scoff down a few burgers and a quarter tub of ice-cream.


CATEGORY 4 - Shot Doctors

Some medical weight clinics offer an injection that they claim will help you keep your energy up and lose inches at the same time.  Part of the increased energy sometimes comes from vitamin B12.  They also claim that it is important to get this particular vitamin from an injection because it is not absorbed well when taken orally.  Vitamin B6 may also be included in each injection.  One of the more popular ingredients in these injections is adenosine, which is a substance that occurs naturally in your body. It is also sometimes used in the treatment of chronic fatigue syndrome and fibromyalgia.

            The story goes that while treating people for these conditions researchers discovered there was a side effect of using adenosine.  The patients had a noticeable reduction in their waistlines and other areas.  They now suppose that adenosine has a cellular level effect on the body, causing fat cells to release their stored fat to be burned as energy, although locating clinical research on these claims is spotty.

            After having the injection, many people notice an increase in energy that day. They normally claim it will be very subtle, not a burst of energy.  They also sometimes claim you should notice that in the late afternoon and early evening, when you start feeling lethargic, you will instead find the stamina to keep going.

They claim the adenosine should stay in your system for approximately two days and that some patients have felt their effects for as long as five days, so the marketing pitch sometimes claim the best results come from people who receive three to four injections per week.

Many shot doctors claim these injections will not curb your appetite and will not keep you awake. When they try to put it in simple terms, they claim that it alters your metabolism rather than speeds it up.  However, the question begging for answers are, What are the short term side effects?  What are the long term side effects?  Do the patients lose fat or both fat and muscle, organ and skin tone?  



Here’s the dirty little secret the diet industry doesn’t want you to know: they’re well aware of the fact you are doomed to fail with their fad diets, pills and meal replacement shakes.  Just like nobody wants to build a car that lasts a lifetime, and just like kitchen appliances are designed to malfunction after the warranty expires, diet promoters want you to fail so you’ll line up and buy the next diet.  Try asking any large national weight loss center who they mail to the most and you’ll find it is to past members who have already completed their program several times.  They know that if people started losing the weight and keeping it off, it would cost them dearly.


So do your research.  Don’t believe the marketing hype unless they can back it up with science.  And, by all means, ask yourself if the diet program you’re considering makes common sense.  There are no magic pills that work, to my knowledge.

By Mike Beatty, CEO of ITG Diet