5 Ways to Increase Vitamin C Levels

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Vitamin C levels, 5 Ways to Increase Vitamin C Levels

Vitamin C levels, 5 Ways to Increase Vitamin C Levels

5 Ways to Increase Your Vitamin C Levels

Vitamin C is made naturally in almost all living animals except humans, primates and guinea pigs.  Dogs and cats produce their own vitamin C from ingested food that have metabolized into glucose.  This mechanism keeps their vitamin C levels up without the need to consume vitamin C rich foods.

Humans must consume vitamin C from its food sources or it risks severe health problems.  There is an intimate relationship between glucose and vitamin C that has a dramatic impact on immunity and overall cellular health.  In this article, you will discover 5 keys to increasing your vitamin C levels.

Most animals and plants are able to synthesize their own vitamin C.  This is done through a biochemical pathway that depends on 4 key enzymes which convert glucose to vitamin C.  In mammals, the glucose is extracted from stored sugar (glycogen) and the transformation into vitamin C is produced in the liver (1, 2).

Vitamin C levels, 5 Ways to Increase Vitamin C Levels

Glutathione Recycles Vitamin C

Humans lack the L-gulonolactone oxidase enzyme that is critical for the last step of vitamin C synthesis.  Humans require a good amount of vitamin C in order to build healthy tissue collagen and promote strong immune function (3, 4).

When vitamin C levels are low the body makes due by recycling the oxidized version of vitamin C.  This redox cycling is performed by the master anti-oxidant glutathione.  As long as enough glutathione is present the vitamin C redox cycle can continue (5).

The Nobel prize winning chemist Linus Pauling discovered that white blood cells need very high doses of vitamin C in order to function effectively.  In the late 1960’s, he developed the understanding of using high dose vitamin C to combat the common cold.  This technique has worked effectively for many individuals; however, there is more to the story when it comes to vitamin C (6).

Vitamin C levels, 5 Ways to Increase Vitamin C Levels

The GAA Theory

In the 1970’s, Dr. John Ely discovered the Glucose-Ascorbate-Antagonism (GAA) theory.  Glucose and vitamin C (ascorbate) have a very similar chemical makeup.  This theory proposes that elevated glucose levels compete and effectively restrict vitamin C from entering cells.  Both glucose and vitamin C depend upon the pancreatic hormone insulin and its signaling effects in order to get into cells (7).

There is an important receptor called the Glut-1 receptor that activates in response to insulin to  allow both glucose and vitamin C to enter the cell.  However, glucose has a greater affinity for the insulin receptor.  This means that the greater the content of circulating blood sugar the less vitamin C will enter the cell (8, 9).

Vitamin C levels, 5 Ways to Increase Vitamin C Levels

White Blood Cells and Insulin Pumps

White blood cells have more insulin pumps than any other type of cell and may contain 20 times the amount of vitamin C as other cells.  They also need 50 times more vitamin C inside the cell than in the blood plasma in order to handle the oxidative stress that occurs when they encounter a pathogenic substance (10, 11).

When white blood cells encounter pathogenic bacteria and viruses they must ingest or phagocytize these organisms in order to neutralize them.  The phagocytic index measures how effective a particular white blood cell is at destroying viruses, bacteria & cancer cells.  Elevated blood sugar impairs this phagocytic index.  In fact, a blood sugar of 120 reduces the phagocytic index by 75% (12).

Vitamin C levels, 5 Ways to Increase Vitamin C Levels

Vitamin C and the HMP Shunt

Glucose and ascorbic acid also work on the hexose monophosphate (HMP) shunt.  The HMP is a biochemical pathway that produces NADPH.  White blood cells need NADPH to create superoxide and other reactive oxygen species that oxidize and destroy pathogens (13).

Vitamin C not only helps produce NADPH but also regulates quantities so the white blood cell does not create too much oxidative stress in its attempt to protect the body.

Vitamin C activates this important shunt while glucose inhibits it.   This HMP shunt also produces ribose and deoxyribose which provide important raw materials for the formation of new white blood cell RNA/DNA (14).

When the immune system is under attack it needs to quickly produce new immune cells.  If blood sugar is high enough to turn off the HMP shunt it will reduce the quantity of RNA/DNA and the amount of new immune cells formed.

Vitamin C levels, 5 Ways to Increase Vitamin C Levels

Best Food Sources of Vitamin C:

The current adult RDA for vitamin C is 60 mg, however, as a practicing clinician, I recommend my clients get at least 200 mg from food and ideally supplement with another 500mg -1 gram daily.  In cases of chronic disease, I will recommend much higher dosages.

Vitamin C levels, 5 Ways to Increase Vitamin C Levels

5 Ways to Increase Your Vitamin C Levels

Vitamin C is obviously extremely important for our overall health and there are 5 key things you can do to improve your levels.

1)   Avoid Sugar:  Avoid sugar as much as possible and stick to a lower carbohydrate diet to improve your vitamin C levels

2)  Use Vitamin C:  Load up on high quality vitamin C that also contains bioflavonoids with it to prevent illness – 1-2 grams per day is great for supplementation.  I recommend Super C here

Vitamin C levels, 5 Ways to Increase Vitamin C Levels

3)  Vitamin C Rich Foods:  Use low sugar whole food forms of vitamin C such as bell peppers, broccoli, lemon, lime, & green leafy veggies as much as possible to support your vitamin C levels.

4)  Intermittent Fasting:  Combining intermittent fasting with vitamin C supplementation and lemon water can be of great benefit for improving blood sugar regulation and immunity.

5)  Boost Glutathione:  I have many of my clients boost their glutathione levels through natural stategies and key supplements such as Super Glutathione.  Glutathione helps to recycle vitamin C and it may be more important as a supplement than vitamin C, although vitamin C can be of great benefit.

Vitamin C levels, 5 Ways to Increase Vitamin C Levels

Sources For This Article Include:

1. Drouin G, Godin J-R, Pagé B. The Genetics of Vitamin C Loss in Vertebrates. Current Genomics. 2011;12(5):371-378.
2. Nishikimi M, Yagi K. Molecular basis for the deficiency in humans of gulonolactone oxidase, a key enzyme for ascorbic acid biosynthesis. Am J Clin Nutr. 1991 Dec;54(6 Suppl):1203S-1208S. PMID: 1962571
3. Nishikimi M, Yagi K. Biochemistry and molecular biology of ascorbic acid biosynthesis. Subcell Biochem. 1996;25:17-39. PMID: 8821967
4. Boyera N, Galey I, Bernard BA. Effect of vitamin C and its derivatives on collagen synthesis and cross-linking by normal human fibroblasts. Int J Cosmet Sci. 1998 Jun;20(3):151-8. PMID: 18505499
5. Winkler BS, Orselli SM, Rex TS. The redox couple between glutathione and ascorbic acid: a chemical and physiological perspective. Free Radic Biol Med. 1994 Oct;17(4):333-49. PMID: 8001837
6. Linus Pauling – Biographical Link Here
7. Ascorbic Acid and Other Modern Analogs of the Germ Theory Link Here
8. Cunningham JJ. The glucose/insulin system and vitamin C: implications in insulin-dependent diabetes mellitus. J Am Coll Nutr. 1998 Apr;17(2):105-8. PMID: 9550452
9. Afkhami-Ardekani M, Shojaoddiny-Ardekani A. Effect of vitamin C on blood glucose, serum lipids & serum insulin in type 2 diabetes patients. Indian J Med Res. 2007 Nov;126(5):471-4. PMID: 18160753
10. Qutob S, Dixon SJ, Wilson JX. Insulin stimulates vitamin C recycling and ascorbate accumulation in osteoblastic cells. Endocrinology. 1998 Jan;139(1):51-6. PMID: 9421397
11. Wilson JX. Regulation of vitamin C transport. Annu Rev Nutr. 2005;25:105-25. PMID: 16011461
12. Role of sugars in human neutrophilic phagocytosis Link Here
13. Varma SD, Bauer SA, Richards RD. Hexose monophosphate shunt in rat lens: stimulation by vitamin C. Invest Ophthalmol Vis Sci. 1987 Jul;28(7):1164-9. PMID: 3110091
14. Glucose-6-phosphate in Metabolic Processes Link Here

Vitamin C levels, 5 Ways to Increase Vitamin C Levels

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  1. I read your “helpful article” and was wondering if you knew how much more Vitamin C is absorbed by including bioflavonoids with vitamin C and more importantly, for a type 2 diabetic why you would not suggest maybe 10 times more Vitamin C that you recommend in your article,since perhaps only 30% is absorbed since the cells prefer glucose instead?

    Let me know.


    Richard Iacino

  2. Does taking glutathione supplement take away or decrease a body’s ability to produce it? You are supplementing so it stops producing since it is being supplied or will body continue to produce? If u stop supplements with u be at a greater deficit?

    1. Good question Liss, this is a common concern. If done for long-term, it is possible that your body will lower endogenous production. The key is to cycle. Something like 5 days on, 2 days off or even 2-3 weeks on, 1 week off would be a good strategy!

    1. A number of factors like your exposure to certain chemicals, chronic infection, nutrition, etc. can inhibit or deplete glutathione stores faster than they can replenish. This makes supplementation helpful in certain situations! Something like an organic acids test or a micronutrient analysis could give you insight into this! Both can be found here: https://drjockers.com/lab-testing/

  3. Hello, Dr. David Jockers. My body loves when I take either supplement or food high in Vitamin C. However I passed calcium oxalate kidney stones three times & Vitamin C is promoting it (same as for my late father). Any suggestions?
    Thank you for your time. Leon

    1. Hi Leon, here’s my 2¢ worth. Limit supplementation to ½ gram of true vitamin-c/d. With Dysbiosis you don’t have the normal gut bacteria that metabolize the oxalic acids, thus your hyperoxaluria has also overrode sulfation. Since many excellent foods also have oxalates, you can address those issues by consuming some magnesium citrate with each meal assuming that your kidneys are otherwise healthy.
      Your remark about vitamin-c promoting kidney stones is misleading. It would be the same if I said that fire wood is promoting fires. The problem is the damage to your gut microbiome, which is usually the result of taking antibiotics. Your don’t get calcium oxalate kidney stones from vitamin-c, you get them from Dysbiosis. And you normally get Dysbiosis from taking antibiotics.

      1. Hello, Louise; Thank you for your detail explanation. Because my late father passed kidneys stones many times in his life, I think not only Dysbiosis but genetic weakness plays role as well. Best wishes. Leon

  4. Hi Leon, if you’re interested in the genetic aspects of oxalates, you should consider the Organic Acid Test (OAT), which is offered by Dr. Jockers. It tests for two different genetic oxalic markers plus your urine concentration. Whereas, Dysbiosis will usually consist of a fungal overgrowth (also on the OAT), a low or absent Oxalobacter formigenes count, plus other idiosyncrasies, which can elevate oxalates. Your concern should not be limited to the kidney stones and it would be wise to seek professional guidance. Note also that with oxalates the genetics may only be an issue subsequent to Dysbiosis.

  5. Dr. Jockers: Don’t stomach acid and digestive enzymes render oral glutathione useless unless it is presented in the liposomal state or as NAC which is one of the three amino acid precursors?

  6. i have also found from other sources that both leafy vegetables can be combined with fruits listed for higher content of vitamin c that can also help absorb iron (spinach and strawberries).

  7. “Of equal importance was the recognition about twenty years ago that the optimum intakes of several of the vitamins, far larger than the usually recommended intakes, lead to further improvement in health, greater protection against many diseases, and great value as an adjunct to the appropriate conventional therapy in the treatment of diseases.”

    “Limit your mineral intake to the recommended amounts.”

    Dr. Linus Pauling — HOW TO LIVE LONGER AND FEEL BETTER. (1986, p 11 f.)

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