The June 23, 2008, issue of the Archives of Internal Medicine published an article based on new research that links vitamin D deficiency with an increased risk of death. It is really quite a fancy report, with 10 authors from the Medical University of Graz, Austria, representing a 7-year study of 3,258 patients. Furthermore, when I looked into the original report (as opposed to the screaming newspaper headlines and their accompanying articles), I found all kinds of impressive statistics and great scientific jargon, which I love.

What does this research mean about the benefits of vitamin D? Let me quote the conclusions of the research article: "Low 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D levels are independently associated with all-cause and cardiovascular mortality. A causal relationship has yet to be proved by intervention trials using vitamin D."

What this means is that the study did not show anything about cause and effect. Does vitamin D deficiency cause cardiovascular-related deaths? There is no way to know. Indeed, there is no way to know whether it is just the other way around, that cardiovascular disease causes vitamin D deficiency!

So if you are looking for some science behind how much supplemental vitamin D to take, or what benefits you can expect from supplemental vitamin D, this study provides no clue whatsoever. Ten authors, 7-year study, 3,258 patients, published in an internationally reputable medical journal, headlines in newspapers worldwide. Probably cost more than a million dollars (medical research is expensive!). Nothing useful. Incredible.