I don't feel this is a very good article.<p>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).<p>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.<p>This article covers the differences well enough: <a href="http://www.medicinenet.com/script/main/art.asp?articlekey=10736" rel="nofollow">http://www.medicinenet.com/script/main/art.asp?articlekey=10...</a><p>I think what drives vitamin taking is a combination of<p>i) people not fully trusting doctors<p>ii) knowing that today's food is factory-produced and may be deficient in micro-nutrients like vitamins and minerals<p>iii) being willing to spend a few dollars per day as an insurance policy; after all, how many drop $5 a day at Starbucks?
Sometimes visualisations are useless overillustrations. Other times, they are enough to put a complex argument to rest. One of the latter ones:<p><a href="http://www.informationisbeautiful.net/play/snake-oil-supplements/" rel="nofollow">http://www.informationisbeautiful.net/play/snake-oil-supplem...</a>
Everything I've read about this in recent years seems to boil down to one simple rule of thumb: Supplement vitamin D and forget about everything else.
I used to eat the gummy vitamins like candy, I got Hypervitaminosis, and my hair started to fall out. I thought I had a horrible disease. Then we figured it out. It wasn't much fun.
I hope everyone understands that there is NO reliable evidence that any dietary supplements, including vitamins, provide any health benefits whatsoever to healthy people.[1] Occasionally individual studies will find an association between a particular positive outcome and a particular supplement, say breast cancer survival and vitamin D.[2] But it is just as likely to find an association with a negative outcome, say higher breast cancer risk in regular vitamin takers.[3] However none of these results has ever been found to be reproducible AFAIK.<p>For example a 2009 thorough review of all research on vitamin D and calcium supplements by US DHHS concluded:<p>The majority of the findings concerning vitamin D, calcium, or a combination of both nutrients on the different health outcomes were inconsistent.[4]<p>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.<p>FYI - Peter Norvig has a nice writeup of what to look out for when considering the results of a study.[5]<p>[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.<p>[2] <a href="http://www.medpagetoday.com/HematologyOncology/BreastCancer/42208" rel="nofollow">http://www.medpagetoday.com/HematologyOncology/BreastCancer/...</a><p>[3] <a href="http://www.medicalnewstoday.com/articles/183880.php" rel="nofollow">http://www.medicalnewstoday.com/articles/183880.php</a><p>[4] <a href="http://www.ahrq.gov/research/findings/evidence-based-reports/vitadcal.pdf" rel="nofollow">http://www.ahrq.gov/research/findings/evidence-based-reports...</a><p>[5] <a href="http://norvig.com/experiment-design.html" rel="nofollow">http://norvig.com/experiment-design.html</a>
What I'm interested in with all the recent talk (/hype) about gut health and gut bacteria transplants: Are there studies into whether the nutrients we can supplement actually don't enter our own metabolism, but instead benefit our gut bacteria which in turn benefit us?
Well, then don't take too many vitamins - problem solved.<p>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...