Aug 27. A new line of journal links has been added at the top of the page. Also the news links at the top of the page were revised.
Aug 4. New post on Vitamin D summarizing conclusions in a recent review.
Aug 2. We added to Bradford Hill Criteria of Causation: In a 2008 study of Finnish smokers Ahn et al (2008) [PMID: 18505967] [Full text] found that the 20% of patients with the lowest blood levels of vitamin D has also had the lowest risk of prostate cancer. There are several reasons to be suspicious of this. Firstly, the dose response criterion is not satisfied. That prostate cancer risk did not always increase with vitamin D level as one proceeds from one quintile to the next. (The quintiles refer to the 5 groups such that the first quintile is the 20% of patients with the lowest vitamin D in their blood, the second quintile is the 20% with the next lowest, etc.) There is also a worry here about temporality and the associated reverse causation. In particular, perhaps those who had the highest vitamin D levels were sicker and were trying actively to prevent further disease through intake of vitamin D?
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