How Much Vitamin C for Good Health?

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How Much  Vitamin C  Do you Need for good health?

From reading  the Benefits of Vitamin C  and Vitamin C Deficiency, it  is clear that Vitamin C is an important nutrient essential for good health.

But how much do you need?

               …Here is where the controversy begins and doesn’t appear to end.

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How Much  Vitamin C  Does the Body Retain?

The main issue in the dust up over Vitamin C is how much the human body can retain? It is a valid question. 

Vitamin C is water soluble. This means  theoretically it ought to be excreted  in urine when tissue saturation is achieved. 

The benefit of its water solubility is that you won't overdose on C, like you might on minerals or fat soluble vitamins that can build up in tissue.

The disadvantage of too much Vitamin C, critics of mega-doses argue,  is  that too much results in  high priced urine.  Mega-doses of Vitamin C are a waste - literally.

How Much  Vitamin C  To Reach Tissue Saturation? Which Tissue?

How much Vitamin C to reach "tissue saturation" is a complex issue because various organs contain and retain differing levels of the vitamin.

The adrenals, eyeball, prostate and brain have very high concentrations of Vitamin Cblood plasma, the tissue generally tested for Vitamin C levels,  has lesser concentrations. Since various tissue may metabolize Vitamin C differently, it makes sense that one test for blood levels of Vitamin C may not be applicable to other tissue.

How Much  Vitamin C  - It varies for age, whether you smoke or are lactating?


The US government suggests the proper intake is the RDA, less than a 100 mg per day for adults across the board, except for smokers or lactating women who need slightly more; other experts claim the amount of Vitamin C to achieve maximum tissue saturation is a few hundred milligrams per day in healthy young adults but under 500 mg per day, with more needed during disease periods; other nutrition therapy based experts suggest a total of 1,000 mg daily of Vitamin C taken in two divided doses but combined with other antioxidants for full effect.  Proponents of Vitamin C mega-dosing claim several grams per day are needed in healthy states with more during disease periods.

These are huge variations. No wonder the average Joe gets confused!

How Much Vitamin C - The experts vary

For some clarity, one can categorize the differing  Vitamin C suggested intakes for a healthy person into four types. 

  1.  Those who claim the RDAs are adequate, namely 90 mg for adult men and 75 mg for non-pregnant non-lactating women The government scientists at the US Office of Dietary Supplements at the National Institutes of Health as well as many doctors suggest these levels.
  2. Those who, claim the RDAs are only adequate to prevent Vitamin C deficiency scurvy and urge daily mega dosing of several thousand grams per day. Linus Pauling in his famous, or as the case may be infamous, book Vitamin C and the Common Cold and Flu is a proponent of this along with practitioners such as  Dr. R. Cathcart III and Dr. Fred R. Klenner along with  those associated with The Vitamin C Foundation. You can read about these in Dr. Abram Hoffer’s Orthomolecular Medicine for Everyone – Megavitamin Therapeutics for Families and Physicians,  Steve Hickey Phd’s Vitamin C: The Real Story – The latest research on Vitamin C – Proper dosage and safety recommendations and Vitamin C for infections, cancer and heart disease as well as Robert McCracken’s Injectable Vitamin C and The Treatments of Viral and Other Diseases – A compilation of Pioneering Literature, 2nd Edition: They make for interesting reading! 
  3.  Those who urge daily intakes of a few hundred milligrams of vitamin C, namely 400 mg per day for healthy adults, which is more than the RDA but certainly less than mega-doses that Pauling and others have urged. Ironically, these modest suggestions are the opinion of the current Linus Pauling Institute at the University of Oregon.
  4.  A number of nutrition therapy based doctors and scientists, like Dr. Paul Clayton in his book Health Defence and Lester Packer in The Antioxidant Miracle, suggest  between 500  and 1,000 of Vitamin C daily taken in two dosesThese experts insists that Vitamin C works synergistically with other antioxidants and for full effect should be combined with other nutrients including Vitamin E,  Co-enzyme Q10, beta carotene, and alpha-lipoic acid among others.   


How Much Vitamin C to get the health benefits of Vitamin C and What Source is Best – Diet or Supplements?

Factors  to keep in mind when trying to figure out how much Vitamin C you and your family need to be healthy, as well as what source (diet or supplements) is best.

The issue is important because, while dietary Vitamin C has some distinct advantages over supplemental sources, only the RDA for Vitamin C is easily got through the typical Western diet alone. 

When adhering scrupulously to a healthy well balanced diet, with an emphasis on Vitamin C rich fruits and vegetables, one could attain without much effort between 500 and 1000 mg Vitamin C per day. Intakes beyond this would most likely require Vitamin C supplements to achieve.

How Much Vitamin C - To Supplement or Not to Supplement, That is the Question.

Consider some of the below points when figuring whether to supplement Vitamin C or not.

  •  Many of the studies that supposedly disprove the benefits of Vitamin C supplementation use relatively low doses of Vitamin C taken infrequently or for short duration or  consumed without other antioxidants or nutrients that may enhance Vitamin C’s benefits. This means the scientific jury is still out on large dose Vitamin C therapy, including mega-doses of several grams or more.
  • There is agreement among many experts that your need for Vitamin C fluctuates depending on your age, weight, health and activity level.  For example, a high performance athlete or sick person will use considerably more Vitamin C than a sedentary, disease free, young adult.
  • If you are ill, stressed or suffering a chronic condition like heart disease or diabetes, your needs for Vitamin C may go way up so keep this in mind when figuring out you and your family’s Vitamin C needs and whether you’ll use supplements, in addition to dietary sources of Vitamin C.
  • Remember that some of the organs that have the highest Vitamin C concentrations are the adrenal glands (where stress hormones are produced), the eyes, the brain and the prostate. If you are dealing with health issues affecting these organs like excessive stress or infertility, you may want to consider additional Vitamin C via supplements to manage your condition.
  •  Vitamin C levels of specific foods  may not be as listed on the tables because Vitamin C  is fragile and destroyed easily if foods are old,  heated or exposed to air. The result is, if you are not careful, you and your family may be getting less Vitamin C through diet than you think.
  • Vitamin C is not well absorbed in the presence of glucose, so avoid high glycemic diets containing excess refined sugars if trying to maximize your Vitamin C benefit. If you or your family eat a lot of refined sugar, whether in food or drinks, keep this in mind when assessing how much Vitamin C you’ll need.
  •  Vitamin C rich fruits and vegetables provide many identified and unidentified nutrients including vitamins and flavonoids that enhance the benefits of Vitamin C. No supplement could adequately reproduce these effects of whole food, making dietary sources of Vitamin C arguably superior in quality, if not quantity, to supplemental sources. 

Arguments about How Much Vitamin C is best

Who would have thought that vitamins could cause such controversy but that is the case of Vitamin C. … and who said nutrition couldn’t get gnarly?


The most famous representative of the benefits of Vitamin C mega dose was Linus Pauling who had won the Nobel Prize for Chemistry (as well as Peace) before he started extolling the benefits of Vitamin C in large doses to improve health and increase longevity. His book Vitamin C and the Common Cold became a hit but was lambasted by a more conservative medical establishment who promoted the US Governments RDA’s for Vitamin C.  

Things got personal on both sides. Insults lobbed like balls at a tennis match.

Critics of Vitamin C mega dose therapy called Pauling a quack;  fans of Vitamin C therapy referred to the RDA’s as the “ridiculously deficient amounts”.

How Much Vitamin C does the US Government Recommend?

The US Government’s Recommended Dietary Allowance

The US government’s recommended Dietary Allowance( RDA’s) per day are as follows:

  • 0-6 month - 40 mg
  • 7-12 months - 50 mg
  • 1-3 years - 15 mg
  • 4-8 years - 25 mg
  • 9-13 years - 45 mg
  • 14-18 years - 75 mg for men; 65 mg for women; 70 mg for pregnancy; 115 mg for lactation
  • 19+ years - 90 mg for men; 75 mg for women; 85 mg for pregnancy; 120 mg for lactation

For those who smoke, an additional 35 mg per day is recommended.

NB. These figures increased somewhat in 2000.

The Opposing View to the RDA’s – The Benefits of Vitamin C Megadoses

As mentioned, some experts recommend mega-doses to achieve the benefits of Vitamin C.

The Vitamin C Foundation, a proponent of large dose Vitamin C supplements for maintaining health and preventing disease, suggests the following Vitamin C intake:

  •  3,000 mg per day for every man, woman and child over 3 years.
  •  6,000 mg per day during pregnancy.
  •  20,000 to 300,000 mg per day during disease periods.

When you look at dietary sources of Vitamin C, it becomes readily apparent that achieving the above intakes of Vitamin C would be difficult, if not impossible via food alone. Vitamin C supplements are necessary to achieve this intake.


A Middle Ground for How Much Vitamin C Supplements are helpful

There is a body of experts who, when it comes to how much Vitamin C is right,  take a middle ground between the US government’s and the high dose expert’s position.

We’ll use the Linus Pauling Institute’s recommendations as an example of this school.

Linus Pauling Institute recommends the following:

  • 400 mg daily  for young healthy adults for disease prevention, with those who are older or suffering from certain disease possibly requiring “substantially large amounts of Vitamin C”.


While not impossible, to get this maintenance amount via food alone if following a healthy balanced diet, many would have to take Vitamin C supplements to achieve the above intake.


With all this conflicting advice about how much Vitamin C is right – what one mother does to Ensure the Benefits of Vitamin C..

With all this contrary evidence on the table, what does a consumer who’s not a Vitamin C researcher or medical doctor do?

After researching the issue, I have concluded the case for Vitamin C supplements is a sound one. It goes without saying that I try to include as many vitamin C rich fresh fruits and vegetables in my and my daughter’s diet daily. But Vitamin C supplements will play a convenient role in our harried life where optimum nutrition is sometimes more good intentions and less hard reality.

….So I take 1,000 mg of Vitamin C supplement per day split in two or more doses. This is, in addition to the minimal amount in my multi-vitamin. I also ensure I consume rich Vitamin E rich seeds and nuts as well as much carotenoid rich green, red and orange veg as I can for the antioxidant boost they give. I want my Vitamin C to boost the antioxidants I get from supplements and via diet.

Why that level of Vitamin C?

I likely use a lot of Vitamin C and need its benefits more than others- I’m fifty (middle aged in fact, if not in mind), tall, a single Mom who’s often stressed and overrun by a delightful but exhausting eight year old, and the day to day of modern life including flailing around a tennis court, a horse ring and running route on a regular basis. While I try to eat a healthy balanced diet that includes a multitude of fresh fruit and veg, some days are better than others. Vitamin C supplements, with a large increase in dosage (six to 10 grams per day) when fighting active viral and bacterial infections, are part of my routine. I also drink enough water to avoid that theoretical concern about kidney stones.

My eight year old gets a 500 gram vitamin C supplement in a chewable orange flavored tablet that she loves – I think it a yum substitute for candy with a health kick. I make sure she brushes her teeth and drinks plenty of water with it because ascorbic acid can harm teeth enamel. She also takes a multi that ensures she gets a minimal of other antioxidants, should her diet not be up to snuff, despite my best efforts.

How Much Vitamin C When Sick?

As mentioned, when sick or under stress, our Vitamin C requirements can skyrocket and the above daily doses for a healthy adult, regardless of which you opt, go out the window.

Many of the double blind placebo controlled studies are with doses of Vitamin C so minimal that it is not surprising the results are minimal.

Some of the most startling evidence of the benefits of Vitamin C to combat illness  are anecdotal observations from the clinical practice of Frederick R. Klenner.

Dr. Klenner, a board certified internist, claimed to have successfully treated thousands of patients with mega doses of Vitamin C for a smorgasbord of  conditions including  viral and infectious diseases. The diseases range from the common cold, to pneumonia to polio with herpes, hepatitis and a host of others in between including mushroom poisoning and snake bites.  He would use intravenous or intramuscular injection of sodium ascorbate to gain greater tissue saturation than via oral doses alone. 


As a general rule, Dr. Klenner’s therapeutic dose guidelines were 350 mg of Vitamin C per kilogram (2.2 pounds) of body weight. He published extensive clinical observations in the 1950’s and 1940s. Some of his previously published  papers along with those of other clinicians using Vitamin C are published in Robert McCraken’s Injectable Vitamin C and The Treatments of Viral and Other Diseases – A compilation of Pioneering Literature.


Dr. Klenner’s Therapeutic Doses of Vitamin C - .

Body Weight Vitamin C Per Day # of Doses Individual Dose

100 kg (220 lbs), 35,000 mg, 17-18 times per day, 2,000 mg per dose

75 kg (165 kg), 26,000, 17-18 times per day, 1,500 mg per dose

50 kg (110kg), 18,000 mg, 18 times per day, 1,000mg per dose

25 kg (55lbs), 9,000 mg, 18 times per day, 500 mg per dose

12.7 kg (28 lbs), 4,500 mg, 9 times per day, 500 mg per dose

7 kg (15.5 lbs), 2,300 mg, 9 times per day, 250 mg per dose

3.5 kg (15.5lbs), 1,200 mg, 9 times per day, 130-135 mg per dose

How Much Vitamin C  –  The Downside  of too Much Vitamin C.  Are there any?

We’ve talked about the downside to  too little Vitamin C. What are the health risks, if any, from too much?

Generally, Vitamin C is an extremely safe vitamin. The main side effect, as mentioned, is diarrhea  which is dose related. When you decrease intake of C, the symptoms go away.

Because  of its water soluble nature where excess is excreted in urine, it is hard to get too much Vitamin C. Nevertheless, some have raised concerns about Vitamin C supplements.


  • Excess Iron Absorption Vitamin C improves the absorption of non-heme iron (iron from plant foods like spinach as opposed to iron from animal products) . While sufficient iron stores are essential for proper immune function, too much can act as an oxidant and create havoc in the body. There is a theoretical concern that the body could absorb  too much iron, in the event of excess Vitamin C intake.   Individuals with hemochromatosis, a genetic condition that disposes a person to excess iron, should consult their health care provider before supplementing Vitamin C.   By contrast, some experts believe that Vitamin C’s  antioxidant function cancels the risk of excess iron stores in the body.
  • Kidney Stones -  There is a theoretical concern about excess Vitamin C promoting kidney stones, however the evidence doesn’t support this. A review of the research by the New York Academy of Sciences shows kidney stones and Vitamin C supplementation are not a problem. As a precaution, ensure you drink sufficient water when taking Vitamin C supplements.
  • Vitamin C as a pro-oxidant – Some experts speculate that in very large doses Vitamin C may act as  pro-oxidant – generating free radicals instead of quenching them. Because of this, it could interfere with certain chemotherapy drugs. Best to discuss Vitamin C supplementation with your doctor when dealing with a specific health conditions like cancer.


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