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Over the past few years, I’ve become increasingly skeptical about the benefits of taking vitamin C (and other antioxidant) supplements. On the other hand, vitamin D research has looked increasingly promising. So here’s a study from Montreal’s Jewish General Hospital that suggests I should keep my mind open:
In a double-blind clinical trial, patients admitted to the JGH were randomly assigned to receive either vitamin C or vitamin D supplements for seven to ten days. Patients administered vitamin C had a rapid and statistically and clinically significant improvement in mood state, but no significant change in mood occurred with vitamin D, the researchers discovered.
Now, this is a fairly specific population being studied, so the results aren’t generalizable. Apparently about 20% of the acute-care patients in that hospital “have vitamin C levels so low as to be compatible with scurvy,” so it’s not surprising that vitamin C helped. Ultimately, this is simply more evidence that supplements are useful for treating deficiencies; it doesn’t say anything about whether supplements provide any benefits for healthy people.
Hm yeah, but to normalize 25(OH)D levels and see substantial effects takes alot longer than 1 week; perhaps up to 6 months in some cases. The short-term effects may be faster and more noticable with Vitamin C.
Good point, Brian. To be fair to the researchers, they seemed to be primarily interested in vitamin C — I’m not sure why they chose vitamin D as the “control” rather than a simple placebo. (In the paper, they write “Vitamin D was selected as a plausible alternative treatment because, as with vitamin C, biochemical vitamin D deficiency is highly prevalent in acutely hospitalized patients and has been linked to abnormal mood.”) In the end, they managed to increase 25(OH)D levels by 20%, though since it only rose from 51.0 to 61.8 nmol/L you could argue that they were still deficient. But you certainly can’t conclude from this paper that raising vitamin D levels can’t affect mood.
I think many people make the mistake of thinking of vitamin D as just another vitamin. The name is a little unfortunate, since it’s not only a vitamin but also a prohormone that has a profound effect on the human body and genes. It’s also difficult to get enough of it just by eating healthy; you need sun exposure aswell since that is the natural source for vitamin D. It’s just such an enourmous powerful “vitamin” that has been around since the beginning of life and is essential in many ways.