I have a wealth of experiential data on this, validated as recently as this previous July over a two week period. Like clockwork, if I take my Vit D supplement in the evening (like before bed), I will have almost zero REM sleep and will wake up from 8 hours of sleep exhausted. I have no idea why this happens but it's very repeatable.
Suggests there's other variables involved, like time of day taken, other supplements taken simultaneously, metabolic processes, diet, and maybe even the placebo effect.