Do Vitamin C Supplements Prevent Colds but Cause Kidney Stones?

Do Vitamin C Supplements Prevent Colds but Cause Kidney Stones?

[Music] mainstream medicine has long had a healthy skepticism of dietary supplements extending to the present day enough is enough but this commentary in the archives Internal Medicine argued we may have gone too far as evidenced by our uncritical acceptance of supposed to cities the surprisingly angry scornful tone found in medical texts with words like careless useless indefensible wasteful and insidious as well as ignoring evidence of possible benefit to illustrate the uncritical acceptance of bad news about supplements they discuss the well-known concept that high dose vitamin C can cause kidney stones but just because something is well known in medicine doesn’t mean it’s necessarily true they couldn’t find a single reported case we’ve known that vitamin C is turned into oxalates in the body and if the level of oxidized in the urine gets too high stones can form but even at 4,000 milligrams of vitamin C a day that’s like a couple gallons of orange juice worth urinary oxalates may not get very high but you know there may be rare individuals that have increased capacity for this conversion into oxalates and so a theoretical risk of kidney stones with high-dose vitamin C supplements was raised in a letter printed in a medical journal back in 1973 okay but when it’s talked about in the medical literature that make it sound like it’s an established phenomenon here’s a reference to seven citations supposedly suggesting an association between excessive vitamin C intake and the formation of oxalate kidney stones let’s look at these cited sources ok there is the letter about the theoretical risk that’s legit but this other citation has nothing to do with either vitamin C or kidney stones and the other five citations are just references to books which can sometimes be okay if books cite primary research themselves but instead there’s like this circular logic where the books just cite other books that like cite that theoretical risk letter again so it looks like there’s a lot of evidence but there just expressing this opinion with no new data now by that time there were actually studies that followed populations of people taking vitamin C supplements and found no increase kidney stone risk among men then later women same thing so you can understand this authors frustration the vitamin C supplements appear to be unfairly villainized the irony is that now we know that vitamin C supplements do indeed appear to increase kidney stone risk this population of men was followed further out and men taking vitamin C supplements did indeed end up with higher risk confirm now in a second study though also of men we don’t know if women are similarly at risk though there’s now also been a case report of a child also running into problems what does doubling of risk mean exactly in this context on that means those taking like a thousand milligrams a day a vitamin C may have a 1 in 300 chance of getting a kidney stone every year instead of a 1 in 600 chance which is not an insignificant risk 1 in 300 kidney stones can be really painful so they conclude that look since there’s no benefit than some risk better to stay away but there are benefits taking vitamin C just when you get a cold doesn’t seem to help and regular supplement users don’t seem to get fewer colds but when they do get sick they don’t get as sick and get better about 10 percent faster and those under extreme physical stress may cut their cold risk in half so it’s really up to each individual to balance the potential common cold benefit with a potential kidney stone risk you [Music] you



  • cookletsdothis

    I got a stone when I took high dose C. I stopped the supplements, and instead now eat an orange most every day.

  • CrazyPTV

    So do vitamin C supplements cause kidney stones?:P if so please tell me to stop taking them:P

  • Andre Bundy

    So don't take vitamin c supplements, only when you are sick or feeling a cold coming on?
    Or just get it from food..

  • Ronnie & Minh

    Colds are viruses, viruses thrive on vitamin C. It should be obvious that if you have a cold or think you are about to get one that VITAMIN C IS NOT EFFECTIVE AGAINST COLDS.

  • Lichtblick

    This video was what i needed, thx!

  • aovint63

    "Rare individuals with high capacity to convert ascorbic acid to stones"…Did someone call me?

    I had two incidents of stones, separated by about 7 years. The first one was traumatically excruciating and made me transition my nutrition into vegan. The last one was about 2 months and I did indeed take vitamin C. The pain wasn't as bad as the first one but still made me suffer until it came out after I made sure to drink plenty water and tea infused with corn beard (I don't have a proof that it works but based on my two incidents, it looks like it did).

    I added Wim Hof's breathing method about twice a day or more, which helped me resist cold so I don't feel like I need any nutritional help.

  • GoustiFruit φ

    But, why take supplements when it's so easy to get natural vitamin C by eating plant-based ???

  • D Master

    unfortunately you didn't mention dose which is very very significant I would have thought. if you give a very low dose of a drug say 1/20 of an antibiotic and it doesn't do anything can you conclude the drug is useless? No you can't. at low dose say 500 milligrams of vitamin C doesn't reduce the duration of a cold that much. but at 1 to 2 grams every 4 hours you will smash that cold virus into oblivion.

  • Vegetable Police

    Vitamin C is a myth.

  • Nikolay Nikolov

    Well, it is not like vit C helps only to fight colds. It helps with a hundred things. And those tested, did they drink enough water? Did they eat fruits? Maybe it only is bad with a SAD diet 😉

  • IW Nunn

    did Linus Pauling know this? I take 4000 every morning. have been for the past couple of years. my frequency of cold have lessened and when I do get one the duration is shortened. (I used to get a summer cold that would last close to a month). no signs of kidney stones thus far, but this report is giving me cause for pause. definitely don't want them.

  • BM32

    Vitamin C is asorbic acid. Just eat or juice fruits

  • Jake And Sarah Health Nuts

    but were the supplements synthetic? makes all the difference

  • michaelcustos

    Man… It isn't the vitamin C that causes the kidney stones it is the additives in the supplements. I really wish I could quote the studies I read awhile ago on taking Vitamin C intravenously where they were taking doses 50g (yes grams) throughout the studies had no side effects but I read and follow these things so as to educate myself not to be quotable or teach others and when I am into something I fact check the hell out of it but I really think ya gotta dig deeper on this one.

  • Eelke Aptroot

    Yet I've read somewhere that kidney stones could be dissolved by consuming fresh lemon juice…

  • Leonardo Da Vinci

    Dr Greger has a very biased opinion of Vitamin C. A while back he made a negative video about vitamin c and I provided links to people in the comments section providing evidence that was contrary to what Dr Greger was saying. As a result of that my comment was deleted.

  • Robb's Homemade Life

    I have afib. I read of a study where patients who had a cardiac ablation had less re occurrences of afib if they took 2 grams of vitamin c a day. I now take 2 grams a day.

  • D Master

    Dr Gregor how many studies have been carried out where people take high quality vitamin C to bowel tolerance when they first start to get a cold?

  • MrChrisMoo

    Most people do not take near enough vit c when they get sick. You should take 1000mg every hour till you feel better.

  • overlogg

    If I could take 10-50 grams a day of IV vitamin C, I would cycle that stuff once a year or more for a week or two.

    Vitamin C is not something we should be scared of.

    Not drinking enough water and supplement adjuvants is way scarier.

  • zpoedog

    I have been taking vitamin C since 1975. starting out with massive doses of 10 grams and and tapered down to 2 grams for the last 30 years. Have had one cold in the last 8 years and generally don't get sick. Long story short, at 79 I am in good health and don't take any prescription drugs and feel great.

  • Timothy Perry

    I'd much rather take the vit C!

  • Lysander Dusseljee

    It's refreshing to see a more balanced review on a supplement. He didn't even mention getting it from whole foods. That is not to say, however, that I disagree with whole foods. Rather, eating whole foods that are deficient in vitamin C is probably fine if supplementing. Someone who reviews as much literature as Greger is bound to stumble progressively closer to the truth. Greger is one of the least biased sources I know of, but still not unbiased.

  • Eat Veg

    High dose vitamin C helped me heal after getting a tooth removed. I won't take them indefinitely.

  • MrHardCash

    How about garlic then, for common cold and/or flu? I've never depended on vitamin C. Actually, the only thing I do when I feel I'm about to catch a cold or mild fever (or even after catching one), is indulging in garlic consumption. What usually takes 2 to 3 days recovery time, ends up being around only 24 hrs or so. So, anything against consuming 10 cloves of garlic per day (separated into two sessions… 5 cloves per session), for preventing and/or combating cold/mild fever?

  • Aaron Verran

    or people could eat DLGs and oranges? 😧

  • RTSSven

    Just a question out of curiousity. So if certain supplements supposedly have a negative effect on health, like for example Dr. Greger states here that Vitamin C supplements might have negative effects, and in another video that protein supplements might be damaging to health, because of relative high dosis of heavy metals were found in them, how come certain other supplements like B12 and D3 are recommended? How are we to know that these do not damage our health in some way?

  • Michelle’s Endo Journey A

    Is there a link to the studies that prove vit c increases kidney stone risk in men? I'd like to read it. Thanks

  • Steven Hurdle

    What about the additional concern that some (all?) vitamin C supplements might not only not be anti-oxidant, they may have a mildly pro-oxidant effect? As for colds and flus, it can happen to anyone but if you eat a lot of whole plant foods that contain vitamin C, and a lot of whole plant foods that contain beta glucans (nutritional yeast, mushrooms, etc.), then your odds of getting a cold or flu is vastly reduced. Anecdotal, but I haven't been sick since 2015, and I think it's in part because in early 2016 I switched to a whole foods plant-based diet rich in vitamin C and beta glucans.

  • Patricia Linder

    Fantastic video, fantastic chanel! You got me Dr. Greger😜

  • Jeff Lebowski

    Study after study has proven that Vitamin C supplements don't help and in some cases cause harm. Citric acid has been proven to help prevent kidney stones, citric acid is found naturally in citrus fruits. Nature gives us a perfect mix of natural vitamin C and citric acid.

  • Johan Smith

    Were all the studies done using vitamin C tablets containing silica? Are kidney stones related to silica additives? For that matter, is high blood pressure related to silica?


    Prevention of kidney stones?

  • scoop245

    The "doubled the risk" study is flawed:

    -The number of kidney stones in the study participants who took ascorbate was very low (31 stones in over a decade), so the odds for statistical error in the study are fairly high.

    -The study was observational. It simply tabulated the intake of vitamin C and the number of kidney stones to try to find an association between them.

    -This method does not imply a causative factor because it was not a randomized controlled study, that is, vitamin C was not given to a group selected at random.

    -This type of observational study is fraught with limitations that make its conclusion unreliable.

    -It contradicts previous studies that have clearly shown that high dose ascorbate does not cause kidney stones.[2-6]

    -The study authors' conclusion that ascorbate caused the low rate of stones is likely due to a correlation between the choice of taking a vitamin C supplement with some other aspect of the participants' diet.

    -The study could not determine the nature of this type of correlation, because it lacked a detailed study of each patient's diet and a chemical analysis of each stone to provide a hint about the probable cause.

  • Justus Stern

    Well, we have to make something clear: "Natural-Vitamin-C" is NOT "Ascorbic-Acid" ! For the kidneystone Problem we have the great potassium-citrat , and we can take ascobic-acid with "Natron" . Problem solved.

  • Katie Pecotich

    this is why the vit c i take isnt from absorbic acid, as the study sites its only from absorbic acid. vit c is one of the most important vitamins. good vid Dr Greger!

  • Wak Job

    Someone seriously needs to do more research on Kratom.
    I haven't had the cold or flu in over two years since taking it daily.

  • alex buck

    does anyone know how can I view the medical papers like the ones he has used for this video?

  • Allen Cohen

    I am a 74 year old white male, whom has been taking 30 GM (30,000 MG) of vitamin C per day, for in the last 30+ years, I have had one cold, and I do volunteer work at nursing homes, where people are very sick from prescribed medications, and I do not get ill !  Not only do I never get sick, almost, my food allergies, and other pollen allergies have completely gone away.  My skin is without wrinkles and my muscle tone on my body is beyond belief for my age.  Take large amounts of vitamin C and you will not get ill, nor get cancer !  Never mind all of the prescribed medications, which are nothing but chemicals designed to make us sick and stay that way.  Don't believe me, just read the side effects of any of the prescribed medications, and you will never take them !  Eat organic foods and at the very least not GM foods, and you will lead a long healthy life !

  • aMTBer

    Personally, I keep Vitamin C supplements to 500mg or under, in addition to balanced diet containing plenty of Vitamin C in natural food sources like berries, potatoes, broccoli, kale, red bell peppers, and citrus. The only reason i need a supplement occasionally is it helps glucosamine/chondroiton work better for joint repair from overuse or injuries.

  • balderdashery G

    I don't supplement vit. C I just eat bags of oranges.

  • Relaxananda

    Love your channel it's so informative. Although I don't really see the point in taking vitamine C supplements when their are so many delicious alternatives to choose from. Just eat your fruits and you not only cover your vitamine C intake but also enjoy the wonderfull flavours.

  • itay mitra

    great video,,,thank u,,,

  • Micca Correia-Cahill

    i love your videos and books. im wondering if one day you could touch upon diet and virus (specifically herpes simplex 1) ive noticed simce going vegan constant cold sores!.. lysine vs arginine? tha ks so much love your work

  • Nick Heasley

    I know this is a nutrition based Youtube channel but what are your thoughts on chiropractic care?

  • FillUmUpp

    ive done 6 or 7 1000 mg emergen-c packets in a day and nothing happens. you just get the shits lol (helps when youre catching a cold)

  • Rohnny5

    that's just for ascorbic acid though

  • dtadeo2006

    So just take it when you get sick. That's what I do. 250 mg every 2 hours until I get better. Works awesome~!

  • SomeStuff

    Is this risk due to taking Ascorbic Acid only? Or are vit C sources like fruit powders (camu camu powder, for example) also contributing to the risk?

  • D Master

    perhaps there's something wrong with your search engine. did you not come across this trial which shows that high dose vitamin C make some massive difference reducing symptoms by 85%. the thing with vitamin C you need to use enough of it to work. it also has a synergy with bioflavonoids. you may need to have adequate zinc as well.

  • PoweredbyPlants

    Eat an orange

  • J Platinum

    Who in the world is taking 1000mg a day!?! How many fresh squeezed lemons in your tea would account for 1000mg? That's over 50 LEMONS SQUEEZED!

    Moral of the story: Kidney stones may occur if you're mega-dosing daily. So stay away from vitamin c in concentrated doses of unnatural tablet-form such as in supplements and stay away from an enormous amount of lemon juice equivalent to 50 lemons. 2-5 squeezed lemons is enough for an average human to prevent scurvy and provide optimal immunity from the long term effects of a cold.

  • kam wolf

    How about taking large amounts until you reach bowel tolerance limit? I thought that's the way to know how much you need.

  • Earmuff Hugger

    I have extreme gas and severe pain everywhere.
    I'm in bed and I can't move.
    I think I'm going to pass away.

  • I Am Not A Robot

    I got stoned while on C. Now I do only acid.

  • Zekerias Varg

    Study Dr Robert Cathcart and vitamin C and his bowel tolerance method. Its on the tube and its also on When feeling the symtoms of a cold you take pure ascorbic acid on your tung and than water to get it down . Take 5 grams and wait 30 minutes and repeat until the symtoms are away. A typical cold takes 20-60 grams a day.

  • Quantum Chang

    Take enough magnesium to lower formation of calcium oxalate and keep urine pH on the alkaline side. Calcium oxalate precipitate in acidic urine pH. So eat your veggies, and because lemon/lime being alkalizing, the vitamin C from it is perfect.

  • Bas X

    Oxalates in the urine can also mean that you get rid of oxalates faster, which means less risk of oxalate stones… So oxalates in the urine doesn't show a thing. It is by the way well known that vitamin C reduces the uric acids in the body. So it may prevent uric acid stones.

  • Joshua A

    Dr Klenner said no. And also said “methylene blue” will get rid of kidney stones. You can order that online

  • zinturis

    NutritionFacts, better tell people about all these successful therapeutic evidences from MDs that apply IV and oral vit. C for seriously ill people on a daily basis. There's documented material decades lod. There are clinics like Riordan and others. So, plenty of material to start with. I'd recommend to start with searching on youtube name Dr. Thomas E. Levy.

  • Mark Ancheta

    Narator is drunk?

  • jesseval1

    Dr. Gregor are liposomal vitamin C better since they go direct to the cells?


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