Vitamin D vs Mortality Part 3

In this 3rd and last in a series of studies published early online in the Journal of Clinical Endocrinology & Metabolism, the authors found an inverse relationship between 25OH vitamin D levels and all-cause mortality.  More specifically, they performed a retrospective analysis of a cohort of 182,152 Israelis average 60yo three quarters female followed for 28.5 months.  Those in the lowest two quartiles of 25OH vitamin D had a significantly greater all-cause mortality compared to those in the two highest quartiles with a median cut off of 50nmol/L (or 20ng/mL).

Even after taking into account all the usual suspects (confounders such as age, gender, ethnicity, seasonality, vitamin D supplementation, statins, smoking, socioeconomic status, body mass index, LDL (bad) & HDL (good) cholesterol, calcium & kidney function), those in the lowest quartile (<33.8nmol/L or 13.5ng/mL) still had 25% greater relative all-cause mortality compared to those in the highest quartile (>65.2nmol/L or 26.1ng/mL).

Remember that this was an observational study.  As such, one can only develop hypotheses, but one cannot demonstrate cause & effect.  Still, after taking Monday's, yesterday's & today's recent studies together as a whole along with the others, it's apparent that vitamin D is somehow linked to all-cause mortality, possibly through some association w/calcium.  If you think about it, perhaps it's not so surprising that the US Preventive Services Task Force came up w/such controversial draft recommendations.  After all, the evidence to support their statement is about as clear as mud.

In the end, we can stand frozen in place while we wait for a message from on high.  In doing so, we've essentially made a decision not to supplement.  Given what I've read so far, I'm going to take my chances w/some extra vitamin D and increase my dietary calcium.

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