My guess is it might help to take the vitamin d when you wake up (at night). Would be interested to hear if it helps your night shifts!

It worked on me when I didn't know it was supposed to, and nighttime vitamin d kept me awake when I didn't know it was supposed to, so . . . I dunno, it might be something that only works in some people, so a study might not see the correlation if other factors are accounted for. Or it's placebo and I'm a weirdo. That's an option 😆

Some people (including me) react to vitamin d with wakefulness. It's not quite like caffeine wakefulness, but it sure keeps me from sleeping for like 4 hours after taking it!

I don't actually know why it works, but I and my ex both had improved daytime alertness and better sleep when we started taking vitamin d in the winter (and it wasn't an environmental change, I started it one year and had the effect, he started it another year and had the effect).

Also just in general: hey everybody it's winter in the northern hemisphere, and if life sucks and you hate everything right now (or even worse, you are absolutely indifferent to it all), maybe try some Vitamin D and see if that helps? Even if you've never taken it before, this might be the year that you really need it.

Also they tend to stock stuff with durable, non-fussy finishes like stainless steel and enamel (and some cast iron). Nobody in a restaurant has time to baby the Teflon coating or make sure plastics and silicone don't get too hot (unless you're talking about really fancy desserts, but that's a whole different shop). Restaurants want stuff that'll go from stovetop to oven to dishwasher several thousand times, and they don't have time or money for anything else.