Sally K. Norton

Vitality Coach, Speaker & Health Consultant

  • Home
  • About
    • Interviews and Talks
  • Symptoms
  • Relief
    • Nourishment
    • Results
  • Science
    • Oxalate Basics
  • Books
    • Data Companion
  • Support
    • Upcoming Events
    • Support Groups
    • Shop / Downloads
    • Sign-up for News and Updates
    • Speaking and Presentations
  • Recipes
    • Fundamentals
    • Sauces and Condiments
    • Beverages
    • Finger Foods
    • Soups
    • Salads
    • Side Dishes
    • Meats and Seafood
    • Treats
  • Blog
    • Table of Contents
  • Contact
    • Share Your Success Story!
    • Coaching and Consulting
    • Speaking
    • Webmaster
    • Privacy Policy

August 20, 2015 by Sally K Norton

Taking Vitamin C? Try a Salad Instead.

If you are taking 500 mg or more vitamin C daily, there is something you need to know. Vitamin C (in excess) can become a toxin that can lead to kidney stones, arthritis, other pain conditions, and perhaps, compromised brain function.  For decades we have been told that vitamin C is good for us and may help prevent colds. But too much of a good thing can make trouble. (Research has not been able to confirm the theory that vitamin C supplements help to prevent colds unless you routinely engage in physically demanding work or endurance sports.)

The body tends to metabolize excess vitamin C into a corrosive acid called oxalic acid. This acid immediately steals minerals like calcium as it becomes oxalate. As the kidneys remove oxalate from the blood, calcium oxalate can grow into crystals in the kidneys or elsewhere in the urinary tract causing painful stones. Over time, if the kidneys are forced to handle excessive amounts of oxalate everyday, kidney failure is likely. This is how taking 500 mg or more of vitamin C can promote a loss of kidney function. Perhaps the modern habit of taking extra vitamin C is contributing to the rising rates of kidney stones. One estimate suggests that half of us will get a kidney stone in our lifetime.

Oxalates in the body that are not removed by, or stuck in, the (perhaps struggling) kidneys can get lodged in other tissues of the body and cause trouble there too.  Oxalate crystals have been found in every human tissue including bones, joints, glands – especially the thyroid, blood vessels, arterial plaque, eyes, lungs, and skin.  These crystals are sharp and irritating, and they may trigger an immune response and promote inflammation. They may also generate free-radicals that can damage cell membranes and damage the cell organelles, especially the mitochondria which are important energy producers.

When a cell attempts to dissolve the oxalate crystal deposits, oxalate molecules or ions may move around and trigger episodic pain or difficulty with brain and nerve functions. Sleep, concentration, memory, and thinking can all be affected by the movement of oxalates in and around neurological tissues.  Likewise, bone problems and joint pain can result from calcium oxalate deposits which may become more likely when excess amounts of vitamin C are taken.

How much vitamin C is safe?

The RDA for C (ascorbic acid) is 75 mg for adult females and 90 mg for adult males. This sounds like very little, but even as little as 10 mg is enough to avoid scurvy – the vitamin C deficiency disease.  A daily intake of 150-200 mg of C is considered safe for most people and is under the threshold that seems to generate additional oxalate in the body. Most people can get that much from typical diets that contain some vegetables or fruits. To illustrate the point, see the tables below. I offer two hypothetical diets: 1) a diet with many healthy fresh foods, and 2) a diet of mostly fast food. (Just major ingredients are listed in the tables.)

The diet of healthy, fresh foods listed in Table 1 is not necessarily my recommended diet, but it comes close. Notice that a lunch of beef stew with a salad composed of romaine lettuce and ¼ of a red bell pepper provides over 60 -70% of the RDA by itself. If the dressing was made with lemon juice, that would add 5 mg more and bring the vitamin C content of the lunch up to 59 – 66 mg. Add 2 sliced radishes (~4 mg vit C.) to bring the vitamin C content of lunch to nearly 70 mg (78 – 93% of the RDA). Of course, many people skip the salad option at lunch and instead select convenience foods, as in my hypothetical fast food diet in Table 2 below.

Lets a look at the diet of fast foods with no extra fruits or vegetables (Table 2) which only gets us about 25% of the RDA. The addition of just ¼ of a fresh bell pepper (38 mg C) and 1/2 cup of raw cantaloupe (23 mg C) would bring the fast-food diet up to the RDA for vitamin C.  Of course, adding bell pepper and cantaloupe cannot correct the many other deficiencies and problems created by a fast-food diet.

These tables are intended to illustrate the point that vitamin C requirements can be met when fresh vegetables or citrus fruits are included in the diet. There is no need for a daily vitamin C supplement if you eat fresh vegetables daily – broccoli with dinner or a simple salad can get you there. Remember, however, that the body does not store vitamin C, so you need to eat foods with vitamin C every day.  Make my favorite dressing tonight, and  enjoy a delicious salad tomorrow.

There is no need for a daily vitamin C supplement if you eat fresh foods – everyday. If you do take vitamin C containing supplements or C fortified foods keep it at a safe level – which seems to be between 150 – 250 mg.

Table 1: A day with plenty of vitamin C (values from Pennington & Spungen, 2010)

Food Amount Vit C Content in mg
Breakfast
(Yogurt) with

Apple, unpeeled raw OR

Raw blueberries

1 medium

½ C

0

6

7

Sub-total Breakfast 6 – 7
Lunch
Canned beef stew 1 C 3 – 10
Salad with

Romaine Lettuce raw

Red bell pepper, raw

Olive oil and vinegar

1 C

¼ of a pepper

13

38

Sub-total Lunch 54 – 61
Snack
Grapefruit juice, canned

1 oz. cheese

½ Cup or 4 oz. 37
Sub-total Snack 37
Dinner
Clams, canned
with garlic and butter, over…
Spaghetti Squash, boiled
Sprinkled with Lemon juice, raw
Romano Cheese
3 oz

1 C

2 tsp.

2 Tbsp.

19

0

5

5

0

Broccoli, fzn, boiled, drained 1 C (91gms) 74
Sub-total Dinner 103
DAY TOTAL   200 – 208

= 270% of RDA for females

= 267% of RDA for males

Table 2: A vitamin C deficient diet …is a diet without fresh fruits and vegetables.

Food Amount Vit C Content in mg
Breakfast
Sausage and Egg McMuffin 1 McMuffin 0
Sub-total Breakfast 0
Lunch
Pizza Any amount 0
Bread sticks 0
Sub-total Lunch 0
Snack
Crackers or chips or almonds Any amount. 0
Sub-total Snack 0
Dinner
6”Subway Sub Cold Cut combo
(has lettuce and tomato)
6” 21
Sub-total Dinner 21
Snack
Beer 12 oz 0
Sub-total Snack 0
DAY TOTAL   21

=28%RDA for females

=23% RDA for males

More about Vitamin C, Oxalates and Health:DSCN5963

Alkhunaizi, A. M., & Chan, L. (1996). Secondary oxalosis: a cause of delayed recovery of renal function in the setting of acute renal failure. Journal of the American Society of Nephrology: JASN, 7(11), 2320–2326.

Baxmann, A. C., Mendonça, C. D. O. G., & Heilberg, I. P. (2003). Effect of vitamin C supplements on urinary oxalate and pH in calcium stone-forming patients. Kidney International, 63(3), 1066–1071. http://doi.org/10.1046/j.1523-1755.2003.00815.x

Canavese, C., Petrarulo, M., Massarenti, P., Berutti, S., Fenoglio, R., Pauletto, D., … Marangella, M. (2005). Long-term, low-dose, intravenous vitamin C leads to plasma calcium oxalate supersaturation in hemodialysis patients. American Journal of Kidney Diseases: The Official Journal of the National Kidney Foundation, 45(3), 540–549. http://doi.org/10.1053/j.ajkd.2004.10.025

Chai, W., Liebman, M., Kynast-Gales, S., & Massey, L. (2004). Oxalate absorption and endogenous oxalate synthesis from ascorbate in calcium oxalate stone formers and non-stone formers. American Journal of Kidney Diseases: The Official Journal of the National Kidney Foundation, 44(6), 1060–1069.

Curhan, G. C., Willett, W. C., Speizer, F. E., & Stampfer, M. J. (1999). Intake of Vitamins B6 and C and the Risk of Kidney Stones in Women. Journal of the American Society of Nephrology, 10(4), 840–845.

Flagg, L. R. (2007). Dietary and holistic treatment of recurrent calcium oxalate kidney stones: review of literature to guide patient education. Urologic Nursing, 27(2), 113–122, 143; quiz 123.

Gabardi, S., Munz, K., & Ulbricht, C. (2007). A review of dietary supplement-induced renal dysfunction. Clinical Journal of the American Society of Nephrology, 2(4), 757–765. http://doi.org/10.2215/CJN.00500107

Garner, A. (1974). Retinal oxalosis. The British Journal of Ophthalmology, 58(6), 613–619.

Hodgkinson, A., & Zarembski, P. M. (1968). Oxalic acid metabolism in man: a review. Calcified Tissue Research, 2(2), 115–132.

Holmes, R. P. (2000). Oxalate synthesis in humans: assumptions, problems, and unresolved issues. Molecular Urology, 4(4), 329–332.

Holmes, R. P., Knight, J., & Assimos, D. G. (2009). Intravenous ascorbic acid infusions and oxalate production. Metabolism – Clinical and Experimental, 58(6), 888. http://doi.org/10.1016/j.metabol.2009.02.006

Kostman, T. A., Tarlyn, N. M., Loewus, F. A., & Franceschi, V. R. (2001). Biosynthesis of L-ascorbic acid and conversion of carbons 1 and 2 of L-ascorbic acid to oxalic acid occurs within individual calcium oxalate crystal idioblasts. Plant Physiology, 125(2), 634–640.

Mandl, J., Szarka, A., & Bánhegyi, G. (2009). Vitamin C: update on physiology and pharmacology. British Journal of Pharmacology, 157(7), 1097–1110. http://doi.org/10.1111/j.1476-5381.2009.00282.x

Mashour, S., Turner, J. F., & Merrell, R. (2000). Acute renal failure, oxalosis, and vitamin C supplementation – A case report and review of the literature. Chest, 118(2), 561–563. http://doi.org/10.1378/chest.118.2.561

Mchugh, G. J., Graber, M. L., & Freebairn, R. C. (2008). Fatal vitamin C-associated acute renal failure. Anaesthesia and Intensive Care, 36(4), 585–588.

Morgan, S. H., Maher, E. R., Purkiss, P., Watts, R. W., & Curtis, J. R. (1988). Oxalate metabolism in end-stage renal disease: the effect of ascorbic acid and pyridoxine. Nephrology, Dialysis, Transplantation: Official Publication of the European Dialysis and Transplant Association – European Renal Association, 3(1), 28–32.

Ott, S. M., Andress, D. L., & Sherrard, D. J. (1986). Bone oxalate in a long-term hemodialysis patient who ingested high doses of vitamin C. American Journal of Kidney Diseases: The Official Journal of the National Kidney Foundation, 8(6), 450–454.

Padayatty, S. J., Sun, A. Y., Chen, Q., Espey, M. G., Drisko, J., & Levine, M. (2010). Vitamin C: intravenous use by complementary and alternative medicine practitioners and adverse effects. PloS One, 5(7), e11414. http://doi.org/10.1371/journal.pone.0011414

Parasuraman, R., & Venkat, K. K. (2010). Crystal-Induced Kidney Disease in 2 Kidney Transplant Recipients. American Journal of Kidney Diseases, 55(1), 192–197. http://doi.org/10.1053/j.ajkd.2009.08.012

Robitaille, L., Mamer, O. A., Miller, W. H., Jr, Levine, M., Assouline, S., Melnychuk, D., … Hoffer, L. J. (2009). Oxalic acid excretion after intravenous ascorbic acid administration. Metabolism: Clinical and Experimental, 58(2), 263–269. http://doi.org/10.1016/j.metabol.2008.09.023

Rosenthal, A., Ryan, L. M., & McCarty, D. J. (1988). Arthritis associated with calcium oxalate crystals in an anephric patient treated with peritoneal dialysis. JAMA, 260(9), 1280–1282.

Sanadgol, H., Bayani, M., Mohammadi, M., Bayani, B., & Mashhadi, M. A. (2011). Effect of Vitamin C on Parathyroid Hormone in Hemodialysis Patients With Mild to Moderate Secondary Hyperparathyroidism. Iranian Journal of Kidney Diseases, 5(6), 410–415.

Schumacher, H. R., Reginato, A. J., & Pullman, S. (1987). Synovial fluid oxalate deposition complicating rheumatoid arthritis with amyloidosis and renal failure. Demonstration of intracellular oxalate crystals. The Journal of Rheumatology, 14(2), 361–366.

Schwille, P. O., Schmiedl, A., Herrmann, U., Manoharan, M., Fan, J., Sharma, V., & Gottlieb, D. (2000). Ascorbic acid in idiopathic recurrent calcium urolithiasis in humans–does it have an abettor role in oxalate, and calcium oxalate crystallization? Urological Research, 28(3), 167–177.

Taylor, E. N., & Curhan, G. C. (2008). Determinants of 24-hour urinary oxalate excretion. Clinical Journal of the American Society of Nephrology: CJASN, 3(5), 1453–1460. http://doi.org/10.2215/CJN.01410308

Urivetzky, M., Kessaris, D., & Smith, A. D. (1992). Ascorbic acid overdosing: a risk factor for calcium oxalate nephrolithiasis. The Journal of Urology, 147(5), 1215–1218.

Yaich, S., Chaabouni, Y., Charfeddine, K., Zaghdane, S., Kharrat, M., Kammoun, K., … Hachicha, J. (2014). Secondary oxalosis due to excess vitamin C intake: a cause of graft loss in a renal transplant recipient. Saudi Journal of Kidney Diseases and Transplantation: An Official Publication of the Saudi Center for Organ Transplantation, Saudi Arabia, 25(1), 113–116.

Zhang, K., Li, Y., Cheng, X., Liu, L., Bai, W., Guo, W., … Zuo, L. (2013). Cross-over study of influence of oral vitamin C supplementation on inflammatory status in maintenance hemodialysis patients. Bmc Nephrology, 14, 252. http://doi.org/10.1186/1471-2369-14-252

Share this:

  • Click to share on Facebook (Opens in new window) Facebook
  • Click to share on LinkedIn (Opens in new window) LinkedIn
  • Click to share on X (Opens in new window) X
  • Click to print (Opens in new window) Print
  • Click to email a link to a friend (Opens in new window) Email

Related

❮❮ Previous Post
Next Post ❯ ❯

Comments

  1. Chelsey says

    August 25, 2015 at 5:48 pm

    Sally, this is really interesting. My mind is sort of “blown” right now!!! But every bit of this makes sense. I guess I’ll back off of the 3-4k MG of vitamin C I take a day!!

    Reply
    • Sally K. Norton says

      August 26, 2015 at 2:07 am

      Chelsey, It is best to come down on your Vitamin C gradually. A sudden drop can potentially trigger a brief bit of scurvy symptoms. You can cut it in half for 3 days, and keep working down from there.

      Reply
  2. Christopher John Walden says

    November 17, 2019 at 3:19 am

    Hi Sally

    Each morning Inhave a heaped teaspoonful of Turmeric
    Ginger and a pinch of cinnamon with Manukka honey in half a cup of boiled water.
    This definitely helps with my arthritic hip and dodgy knee
    I also have 3500mg of vitamin c tablets spread throughout the day

    I’m gathering from my brief encounter with your website that this is not good?

    Can you offer any alternative suggestions for a busy entrepreneur of 67?

    Kind regards

    Chris J Walden (UK)

    Reply
    • Sally K Norton says

      November 26, 2019 at 12:14 pm

      You can look up Catherine Nelson’s article “The Essential Medicinal Chemistry of Curcumin“, which suggests that curcumin/turmeric is not especially effective in the body at doing any of the things that lab testing suggests it might. I have a blog post on Vitamin C – I’d recommend working down gradually to no more than 500mg per day by cutting your dose in half for a week or so, then cutting in half again. It will take a month or more given where you’re starting.

      Check out my blog post on spices. Ginger is fine in moderation, and honey generally seems quite low.

      Reply
  3. Fiona Aedgar says

    June 6, 2022 at 10:30 am

    Hi Sally, thanks so much for this. I just wanted to ask you – I seem to have a vitamin C deficiency, maybe because I’m auto-immune (type 1 diabetes). Vit C supplements have helped me a lot but now I’m scared to take them. Would Vit C from fresh lemon juice be ok, or does the Vit C content still cause the oxalate issues?

    Fiona

    Reply
    • Sally K Norton says

      September 4, 2022 at 8:34 pm

      Hi Fiona, Good question. Lemon juice is an ideal way to get needed Vit C, because it is hard to over-dose on C that way – even if you juice 6 or 7 lemons everyday. Supplements are altogether too high in C to be safe. I highly recommend that you do juice fresh lemons and drink at least 3/4 cup of juice over the course of a day. Not only do you get the needed Vit C, but the citric acid lemons provide is great for your kidneys and helps the body breakdown oxalate deposits. Lettuce and red peppers also have Vit C.

      Reply
  4. Joanna says

    November 13, 2024 at 5:36 am

    Hi, is Ester-C a safe option?

    Reply
  5. Sharon H says

    January 17, 2025 at 6:35 am

    Sally, this brings a question to my mind. I freeze dry a lot of foods, including fresh lemons and lime. I cut them into either wedges or slices, package them in glass canning jars, adding an oxygen absorber and vacuum seal the jar. (stored in relatively dark area)
    My question: I usually take the thin sliced ends and freeze them in containers to use in my water. Is this method providing ANY benefit to me, besides just flavor?

    Reply

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

CAPTCHA
Refresh

*

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Search on SallyKNorton.com

Shopping Cart

Number of items in cart: 0

  • Your cart is empty.
  • Total: $0.00
  • Checkout
Click to sign up for email list
Click to sign up for email list

Upcoming Events

  • MeatStock 2015: Oxalate Toxicity Talk

    May 18, 2025 @ 11:00 am - 11:40 am
    US Eastern Time
    See more details

  • Group Meeting and Presentation

    May 22, 2025 @ 2:00 pm - 4:00 pm
    US Eastern Time
    See more details

  • Group Meeting and Presentation

    June 5, 2025 @ 1:00 pm - 3:00 pm
    US Eastern Time
    See more details

Connect

  • Home
  • About
  • Table of Contents
  • Shop
  • Recipes
  • Support
  • Blog
  • Contact

Visit Sally’s Other Sites

  • YouTube
  • LinkedIn
  • Facebook
  • X
  • Instagram

Copyright © 2025 — Sally K. Norton • All rights reserved.

 

Loading Comments...