Mainstream medication has lengthy had a healthy skepticism of dietary dietary supplements, extending to the present day with commentaries like “Enough is enough.” In an essay entitled “Battling quackery,” nevertheless, printed in the Archives of Internal Medicine, it’s argued that we could have gone too far in our complement bashing, as evidenced by our “uncritical acceptance” of supposed toxicities; the surprisingly “angry, scornful tone” present in medical texts utilizing phrases like “careless,” “useless,” “indefensible,” “wasteful,” and “insidious”; and ignoring proof of potential profit.
“To illustrate the uncritical acceptance of bad news” about dietary supplements, the authors mentioned the “well-known” idea that high-dose vitamin C could cause kidney stones, as I spotlight in my video Do Vitamin C Supplements Prevent Colds however Cause Kidney Stones? Just as a result of one thing is well-known in medication, nevertheless, doesn’t imply it’s essentially true. In truth, the authors couldn’t discover a single, reported case.
We’ve recognized that vitamin C is become oxalates in the physique, and, if the stage of oxalates in the urine will get too excessive, stones can kind, however, even at 4,000 mg of vitamin C a day, which is sort of a couple gallons’ value of orange juice, urinary oxalates could not get very excessive, as you possibly can see at 1:10 in my video. Of course, there could also be the uncommon people who’ve an elevated capability for this conversion into oxalates, so a theoretical threat of kidney stones with high-dose vitamin C dietary supplements was raised in a letter printed in a medical journal again in 1973.
When the theoretical threat was mentioned in the medical literature, nevertheless, the researchers made it sound as if it had been a longtime phenomenon: “Excessive intake of vitamin C may also be associated with the formation of oxalate stones.” Sounds much less like a theoretical threat and extra like a longtime phenomenon, proper? That assertion had seven citations supposedly suggesting an affiliation between extreme vitamin-C consumption and the formation of oxalate kidney stones. Let’s have a look at the cited sources, which you’ll be able to see from 1:47 in my video. One reference is the letter about the theoretical threat, which is reliable, however one other listed quotation, titled “Jaundice following the administration of niacin,” has nothing to do with both vitamin C or kidney stones. What’s extra, the different 5 citations are simply references to books. That could also be acceptable if the books cited main analysis themselves, however, as a substitute, there was a sort of round logic, the place the books simply cite different books citing that theoretical threat letter once more. So, whereas it appears to be like as if there’s lots of proof, they’re all simply expressing this opinion with no new information.
By that point, there really had been research that adopted populations of individuals taking vitamin C dietary supplements and discovered no elevated kidney stone threat amongst males, then later, the similar was proven in girls. So, you possibly can perceive the frustration of the authors of “Battling quackery” commentary that vitamin-C dietary supplements gave the impression to be unfairly villainized.
The irony is that we now know that vitamin-C dietary supplements do certainly seem to extend kidney stone threat. The similar inhabitants of males referenced above was adopted additional out, and males taking vitamin-C dietary supplements did actually find yourself with increased threat. This has since been confirmed in a second research, although additionally of males. We don’t but know if girls are equally in danger, although there has now additionally been a case reported of a baby working into issues.
What does doubling of threat imply precisely on this context? Those taking a thousand milligrams or so of vitamin C a day could have a 1-in-300 probability of getting a kidney stone yearly, as a substitute of a 1-in-600 probability. One in 300 “is not an insignificant risk,” as kidney stones could be actually painful, so researchers concluded that since there aren’t any advantages and some threat, it’s higher to remain away.
But there are advantages. Taking vitamin C simply if you get a chilly doesn’t appear to assist, and though common complement customers don’t appear to get fewer colds, after they do get sick, they don’t get as sick and get higher about 10 p.c quicker. And, these underneath excessive bodily stress could reduce their chilly threat in half. So, it’s actually as much as every particular person to steadiness the potential widespread chilly profit with the potential kidney stone threat.
What about intravenous vitamin C? I’ve obtained a complete video collection on that, together with:
If you’re not taking vitamin C dietary supplements for pharmacological results and simply wish to know what number of vitamin C-rich fruits and greens to eat day-after-day, take a look at my video What Is the Optimal Vitamin C Intake?.
Is there something we are able to put into our mouth that actually may assist forestall colds? These movies will level you in the proper course:
And, when you’re enthusiastic about studying about the most necessary steps you possibly can take to stop and deal with kidney stones, look no additional than my movies How to Prevent Kidney Stones with Diet and How to Treat Kidney Stones with Diet.
What about high-oxalate greens comparable to rhubarb, spinach, beet greens and swiss chard? I’d encourage a moderation in consumption. If you’re going to take my recommendation to ideally eat cups of darkish inexperienced leafy greens a day I’d advocate sticking with different greens comparable to kale or collards.
Michael Greger, M.D.
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