Vitamin D + Frailty = All-Cause Mortality

We're getting pretty good at looking for vitamin D deficiency but we're not so good at looking for frailty in our elderly.  Perhaps that's because it's easier to measure 25OH vitamin D than it is to define frailty.  Like Justice Potter Stewart's famous "I know it when I see it" quote, we haven't arrived at an agreement regarding the research definition of frailty although we know it when we see it.  Last month, we looked at a study using gait speed to define frailty.

Well, in a retrospective cohort study published two months ago, the authors followed 4,731 participants of NHANES III for 12yrs and defined frailty as having 3 or more of the following criteria: low body mass index, slow walking, weakness, exhaustion & low physical activity).  Pre-frailty was defined as having just one or two of those criteria.

The authors noted that vitamin D was lowest in the frail elderly, highest in the non-frail, and intermediate in the pre-frail.  In fact, the risk of frailty in the lowest quartile of vitamin D was twice that of the highest quartile.  More importantly, all-cause mortality was associated w/frailty, especially in conjunction w/low vitamin D.

Remember that when you play Whac-A-Mole, you win by knocking out all the moles.  Likewise, in life, you win by reducing all-cause mortality, rather than just disease-specific mortality.  Since this is just an observational study, the next step is to determine whether there is in fact a direction of causation such that treating one or the other or both can reduce all-cause mortality.  But while we wait for definitive data, it's difficult to imagine any downside to raising vitamin D level and reducing the 5 frailty criteria.

And yes, my modem is still out of order.

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