Top comment it pertinent.

Aurornis 1 hour ago | next [–]

Study was in an elderly cohort with cognitive impairment. This is a cohort more likely to have nutrition and diet problems and spend all of their time indoors. I haven’t found the full study but the results look marginal for a narrow group. Then there’s this important note in the highlights:

Higher daily Vitamin D intake may impact cognition in persons with sleep disturbance and MCI.

More is not better with Vitamin D. Correcting deficiencies is good but the mega dosing trend is not.