Folks keep citing this BMJ analysis to push for #vitaminD supps right now. It's not unreasonable to think about VitD but there's very imprecise language going around that "Vitamin D deficiency" is very widespread. This is hotly debated .bmj.com/content/356/bm…
Most folks are citing that many individuals are below 30ng/mL which is the threshold that @TheEndoSociety rec'd in 2011 following the 2010 @NASEM_Health report. There aren't trials treating folks with low -> 30+ng/mL to support the rec,it's mostly epi work and basic bio rationale
The BMJ paper comes in cause folks are saying that it supports a role for VitaminD suppvto reduce respiratory tract infections and may be useful against corona, and there's a high prevalence of VitD deficiency in the population. Makes sense?
But when you read the BMJ analysis, they looked at treatment effects by baseline vitD status to explain the large heterogeneity and find that it's those individuals with <10ng/mL at baseline , actual D def as determined by NASEM/ION cutoffs driving the effect.
TL;DR - reasonable to be concerned about vitD deficiency at this time. But know what deficiency actually means. <30ng/mL is a lofty "optimal" cutoff set with highly uncertain evidence. It is not clear, true deficiency that repletion of nutrient status clearly shows protection.
Also a good time to remind folks that infection/inflammation tend to redistribute many nutrients from the plasma compartment& make serum levels look ⬇️. In most cases, we have limited knowledge as to whether this is pathological or adaptive and if there's benefit to repleting.
Also see - support clinical research and the development of more MS/PhD RDs who can lead studies to answer these questions since much of clinical management is a best guess xoxo #RDchat #RDresearch
Link above looks broken bmj.com/content/356/bm…
