The problem with taking too many vitamins(bbc.co.uk) |
The problem with taking too many vitamins(bbc.co.uk) |
IMHO the key to understanding vitamin supplementation is first, to know which are fat-soluble (and will be stored by your body) and which are water-soluble (and will be flushed by your body when you urinate).
So, it is almost impossible to over-dose on Vitamin C, since, your body will easily eliminate anything it doesn't need - C is water-soluble.
This article covers the differences well enough: http://www.medicinenet.com/script/main/art.asp?articlekey=10...
I think what drives vitamin taking is a combination of
i) people not fully trusting doctors
ii) knowing that today's food is factory-produced and may be deficient in micro-nutrients like vitamins and minerals
iii) being willing to spend a few dollars per day as an insurance policy; after all, how many drop $5 a day at Starbucks?
[1] it's a play on words and a homonym, "deke" comes from hockey where you dodge or fake out an opponent to get around them. It must be the Canadian school system further injecting hockey into our lives. :)
For those of us who want an insurance policy, have you got any recommendations on what multi-vitamins to aim for (a particular brand, maybe that you take?) Are all brands equal?
Which statement in that article do you believe supports the position that taking too much vitamin C is "quite harmful"?
Wait, are you really arguing that it's impossible to have too much of something that is water-soluble? What about sugar? What about salt?
Macro nutrients are what processed food loses.
We'd be sitting and coding for a few hours, and we're all just internally waiting for somebody to utter the magic words "...coffee run?".
At a moments notice we're all out the door, headphones are smashed, phones are flung, chairs are tipped over, papers are in the air!
http://www.informationisbeautiful.net/play/snake-oil-supplem...
But yes, mostly don't bother with anything apart from D.
For example a 2009 thorough review of all research on vitamin D and calcium supplements by US DHHS concluded:
The majority of the findings concerning vitamin D, calcium, or a combination of both nutrients on the different health outcomes were inconsistent.[4]
Most if not all of the studies initially finding these spurious correlations are large studies looking at lots of factors and outcomes. Unfortunately due to the nature of statistics there is always a small chance of a false positive or negative relationship and if many possible relationships are examined, such as in these large exploratory studies, it is almost a certainty that some false correlations will be found. This is why almost all of these studies say that confirmation in additional studies is required but this warning does not always make it into press reports. Occasionally a new relationship will be found that is confirmed in follow up studies. Unfortunately this confirmation has yet to be found for any supplement for any outcome in healthy people AFAIK.
FYI - Peter Norvig has a nice writeup of what to look out for when considering the results of a study.[5]
[1] Some supplements can help people with specific health issues but ask an expert such as your doctor as there are many false claims about supplements helping with specific conditions.
[2] http://www.medpagetoday.com/HematologyOncology/BreastCancer/...
[3] http://www.medicalnewstoday.com/articles/183880.php
[4] http://www.ahrq.gov/research/findings/evidence-based-reports...
And as Patrickg_zill said, fat soluble vitamins are the dangerous ones, as they accumulate instead of being flushed. Pretty much all of the other vitamins and minerals are well controlled by the body...
Back when I lived in Jakarta (very large urban area, very warm) I used to get mouth ulcers constantly, despite eating more than my fair share of fruits and vegetables. The solution, according to the family GP, was to supplement vitamin C. Yeah yeah, n=1 (well, n=a family of 5, but still), but it worked and seemed to lend some validity to this theory.
I sort of agree with that, but I also know it is kind of a tautology. 'Healthy people' can't become 'healthier people', by definition. Yet, every healthy person can imagine himself, but slightly better: better vision, more willpower, stronger, faster runner, more intelligent, etc.
Because of that, there are no 'Healthiest people'. Even the hypothetical person who wins the decathlon at the Olympics at the age of 40 in the year they won their fifth Nobel will have something to desire (a bald spot? Feeling more tired after exercise than he used to be?). In that sense, nobody is truly healthy.
That is what all the supplement sellers play at.
Here's a report of a tiny old study (http://www.nytimes.com/1998/04/09/us/taking-too-much-vitamin...)
> 'The vitamin C in supplements mobilizes harmless ferric iron stored in the body and converts it to harmful ferrous iron, which induces damage to the heart and other organs,'' Dr. Herbert said in an interview.
> ''Unlike the vitamin C naturally present in foods like orange juice, vitamin C as a supplement is not an antioxidant,'' Dr. Herbert said. ''It's a redox agent -- an antioxidant in some circumstances and a pro-oxidant in others.''
This was for the relatively small amount of 500mg per day.
I haven't read the Wikipedia references, so maybe they're all trash, but (https://en.wikipedia.org/wiki/Vitamin_C_megadosage#Possible_...)
> Although vitamin C can be well tolerated at doses well above the RDA recommendations, adverse effects can occur at doses above 3 grams per day though overload is unlikely. The common 'threshold' side effect of megadoses is diarrhea. Other possible adverse effects include increased oxalate excretion and kidney stones, increased uric-acid excretion, systemic conditioning ("rebound scurvy"), preoxidant effects, iron overload, reduced absorption of vitamin B12 and copper, increased oxygen demand, and acid erosion of the teeth with chewing ascorbic-acid tablets.[25] In addition, one case has been noted of a woman who had received a kidney transplant followed by high-dose vitamin C and died soon afterwards as a result of calcium oxalate deposits that destroyed her new kidney. Her doctors concluded that high-dose vitamin C therapy should be avoided in patients with renal failure.[26]
And there is an LD50 for rats, although that's 11.9 g per kg. (6 ft adult is 85 kg, that's over a kilogram of vitamin C to reach the same level. That would be 1,000 tablets of 1,000 mg vitamin C.
Dietitians in the UK recommend that people are cautious with juices and smoothies because of the amount of sugar, and they recommend that people just eat the fruit and drink water. Especially for children, the high sugar and acid is tricky for teeth.
(I agree that the hunch seems reasonable. But then, those are the things that need research, to combat my biases.)
"Processed food is fiberless food. That's basically what it comes down to. Processed food means that you've got to take the fiber out for shelf-life. And there are two kinds of fiber. There's soluble fiber: which is the kind of stuff that holds jelly together, and pectins, and things like that. And then there's the insoluble fiber: the stringy stuff, like, you know, cellulose, like what you see in celery. You need both. What I describe in the book is like it's kind of like your hair-catcher in your bathtub drain. Um, you have this plastic lattice work with holes in it. So, if you take a shower and the hair is coming down, it blocks up the holes, but only if the hair catcher is there. So, imagine that the cellulose is the hair-catcher, and imagine the hair is the soluble fiber, blocking up the little holes. When they're both there, it forms a barrier on the inside of your intestine.
You actually can see it during electron microscopy, that it's a secondary barrier that reduces the rate of absorption of nutrients from the gut, into the bloodstream. And what that does is that it actually keeps the liver safe, because it reduces the rate at which the liver has to metabolize, the stuff. And if you overload the liver, what it does is it has no choice but to turn extra energy into liver fat. And that's what drives this whole process. Is the process of liver fat accumulation, and the thing that does that the worst is sugar, especially when it's not teamed up with fiber.""