Another study shows vitamin D supplementation to provide no benefit. OR DOES IT REALLY? Post 2OK, this post is about
a new study in D vs bone health. Conclusions were that "Supplemental vitamin D3 versus placebo had no effect on 2-year changes in aBMD at the spine..........." and other areas of the body. At the end of the abstract, it gets a little more specific by saying "Supplemental vitamin D3 versus placebo for 2 years in general healthy adults not selected for vitamin D insufficiency did not improve BMD or structure.". Notice the caveat there, NO benefits for those not deficient in vitamin D. However, many, many studies have shown that most folks who don't either supplement or get plenty of sunshine are either insufficient or deficient. Starting with folks who already have plenty of D is likely to dilute any supposed benefits, no?
Also, before I go into more details of the problems I have with their conclusions, I would like to remind about
my recent cautions about
how D is known to do it's thing in conjunction with other nutrients such as A, K2, magnesium, and others. Supplementing with D without adequate A in the diet could lead to some problems, rather than benefits, in some areas. Hopefully most get adequate A, but some probably don't, and the higher the D supplemented, the more likely that might be a problem. Of course this study, like most, did not consider any of that. They simply gave some D vs placebo and looked at several measures of bone health, and found NO benefit.
However, even though they did not have help from A, K2 or magnesium, not only did they find no harm, but in every single area they looked at, they found a benefit! What, you say, how can it be that ""Supplemental vitamin D3 versus placebo had no effect on 2-year changes in aBMD at the spine..........." and other areas of the body., and yet there was an improvement in all areas? Lack of statistical significance! If you lack that, it is almost always declared a "no benefit" conclusion. But they did indeed have benefit.
1: Supplemental vitamin D3 versus placebo no effect on 2-year changes in aBMD at the spine (0.33% versus 0.17%; p = 0.55)
2: femoral neck (-0.27% versus -0.68%; p = 0.16)
3: total hip (-0.76% versus -0.95%; p = 0.23)
4: whole body (-0.22% versus -0.15%; p = 0.60)
Notice that in every single parameter measured, D does between between 1.5 and 2.5 times better, or that much less worse than, placebo. And in zero areas it does worse than placebo. Now, it might be that no single area is statistically significant, but which group would you rather be in?
Finally, what about those in the group who started out deficient, as so many non-supplementing, non-sunbating folks are? "Among participants with baseline FVD(free vitamin D) levels below the median (<14.2 pmol/L), there was a slight increase in spine aBMD (0.75% versus 0%; p = 0.043) and attenuation in loss of total hip aBMD (-0.42% versus -0.98%; p = 0.044) with vitamin D3 . Whether baseline FVD levels help to identify those more likely to benefit from supplementation warrants further study. " Boy, it sure does warrant further study, that seems to be the never ending conclusion to all of these studies. But, question: is not even that last parameter, a .75% increase in bone vs ZERO % increase at the spine, (p=.43) or in the hip only 42%(p-.044) as much bone loss as placebo,
still not count as statistically significant? Actually, I think both are, just barely, but they don't seem to point that out for some reason.
But even if not, which group would you rather be in? They conclude ""Supplemental vitamin D3 versus placebo had no effect on 2-year changes in aBMD...........Supplemental vitamin D3 versus placebo for 2 years in general healthy adults not selected for vitamin D insufficiency did not improve BMD or structure."". But, as for me, I call BS. I think a far more accurate conclusion would be "Supplemental vitamin D3 versus placebo had SLIGHT BUT NOT QUITE STATISTICALLY SIGNIFICANT IMPROVMENT on 2-year changes in aBMD............" and "Supplemental vitamin D3 versus placebo for 2 years in general healthy adults SELECTED for vitamin D insufficiency DID improve BMD or structure compared to placebo."
Going by the official conclusion and abstract only of a study can really lead one down the wrong path, if you don't dig into the details of the study.
I ask again: If you do not supplement and thus most likely are insufficient in D, would you rather be in the group who saw an actual, if small(.75%), increase in spinal bone mass, or in the group that had zero improvement? Or in the group that saw a further decrease in the hip of 0.42%, or 0.98%, over twice as much decrease?
I know dang well which group I would pick. But these researchers apparently think there is no difference. "Supplemental vitamin D3 versus placebo had no effect on 2-year changes.............Supplemental vitamin D3 versus placebo for 2 years in general healthy adults not selected for vitamin D insufficiency did not improve BMD or structure...........". Yeah, right.
EDIT: Sorry, I forgot the link. https://pubmed.ncbi.nlm.nih.gov/31923341/Post Edited (BillyBob@388) : 9/21/2020 7:04:30 AM (GMT-6)