I suppose if you let some direct sunlight hit the fruits (right before harvest), without the lid on for a couple minutes.. that should be enough to boost the vitamin D levels by 100% almost instantly, according to those studies anyway, right? They pulsed them for a very short time, and was all it took so yeah..
I don't think any UV will make it through the clear plastic totes that is worthwhile from the outside. You would probably have to install the lights under the lid somehow, so you get direct contact.
If mushrooms synthesize vitamin D just like humans, I wonder if they can be deficient too then? The real question is; do psilocybes that aren't deficient in vitamin D produce different psychoactive compounds that otherwise wouldn't be in the dried product, besides the extra vitamins? Would it alter the affects?