[ebg13]

> Headline is not imprecise according to above-cited Conclusions and Relevance.

No, aladoc99 is right, because the study doesn't compare against 0. So you don't know if 4000 and 10000 improve strength compared to 0, only that they don't compared to 400. It's not a hill that someone should die on, though.

[fc_barnes]

Nobody has 0 intake, that is a useless control; nor would any IRB sign off on such a study, because it would be harmful to the subjects.

[ebg13]

> Nobody has 0 intake

And thus we have ourselves a quandary, but truth isn't diminished by the practical limits of safe experimentation. We don't have to lie just because.

> it would be harmful to the subjects.

That doesn't make the title precise or the observation inapt.

[scottlocklin]

The experiment itself may be useless control; most people get D vitamins from the sun. How do we know the cohorts got the same D from sun exposure?

[AstralStorm]

Should use a blood tests for vitamin D status, probably calcium, phosphate and K too instead of relying on self reported diet.

[slothtrop]

If you avoid animal foods the only dietary vitamin D really is from fortified products. However we also synthesize it, albeit poorly as adults, particularly with lower exposure to the sun.

[kibibu]

Plenty of people have 0 supplementation though.