I get asked a lot about supplements.
With all my harping about supplementation of vitamin D, K2 (MK-4: menaquinone-4 or menatetrenone), and omega-3 essential fatty acids EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) it may surprise you to learn that I have for some long time been generally opposed to vitamin supplementation. And here's a pretty decent synopsis of why, by Drucilla Dyess in Health News. I'm not going to quote it at length because, frankly, it's far too much to quote here and there's far too much gold-standard (randomized, controlled, intervention, double-blind) research to quote anyway. Just read it. It's not that long.
Since I began to really understand evolution and its underlying mathematical logic of natural selection, I have understood one thing about biology above all else: biological systems are chemically complex. Really complex. Really interdependently and interrelatedly complex. Chaotically complex (plausibly the underlying reason that, even though we all have the same chemical composition, we nonetheless all respond differently to identical chemical inputs). With that in mind, I'll quote the third to last paragraph of the article I cited.
According to one expert, a vitamin's benefit may become apparent only if people aren't getting enough of it, which could explain why vitamin D has been linked to a reduction in rates of heart disease, cancer and diabetes. Another school of thought is that randomized clinical trials are designed to test only one factor at a time, although vitamins and minerals work together when consumed as part of a healthy diet.
Now, on the first point, this is one expert's view that makes perfect sense. In any hugely complex system, it's far easier to tell that something is wrong and to identify what it is (at least in part) than it is to explain how any single element works in total. And, this goes hand-in-hand with the second point, which is that if you don't control for variables, you can't say for certain what's cause and what's effect, associated with, or ancillary. On the other hand, when you do control for variables (as in: "controlled study") in a hugely complex system, you essentially have the same problem. That doesn't mean that all supplementation, or even drug therapy is automatically guilty or suspect. Rather, it ought to be regarded as a tradeoff. In some cases, it would clearly be better to supplement or drug — potentially making one or more things worse off — if you have good evidence that what's objectively made better is worth the risk. Chemotherapy is a good example. It wreaks havoc to your whole body; but that's often preferable to allowing a cancer to ravish it uncontrollably until you're dead.
However, with regard to chronic prophylactic vitamin supplementation, we may have gotten to the point with so many controlled studies that don't seem to point to any clear benefit to it (there are studies, however, that suggest a detriment), that you can begin to "tease" out some level of confidence. That's where I am on the issue. I'm confident it's unnecessary and potentially a bad tradeoff, with qualifications I'l develop in part three of this series.
In part two I'm going to take a detour to cover some of the background that I believe it at the root of this issue.