I have two general states to my life lately:
One is where I regularly take vitamin D supplements and everything ticks along smoothly.
The other (like today) is when I forget to take my supplements.
It takes a few days (I think I last remembered to take my D on Friday.) My mornings are usually still pretty good, but sometime around noon I get depressed. (I probably shouldn’t use the term ‘depressed,’ which means something specific in the therapeutic world. I guess the proper phrase would be ‘seriously blue.’)
The shift is subtle. My mood starts to drift over the last few hours of morning. I start feeling overwhelmed. I start thinking no one likes me. I start doubting all my work.
If I eat, things get a little better (thank you, delicious bowl of Bibimbap,) but generally it’ll take two or three days of consistently taking 4000 UI of D before I’ll feel totally okay again.
I guess another sign that I’m not seriously depressed is that there’s a part of my brain always analyzing these moods. I can sort of step back and go, “Oh, crap, right. Ah well, keep your head down and get through the day … and then go take your damn vitamins.”
I think it's possible to "think" one's way through the early stages of even a clinical depression if one is self-aware. I have struggled with depression off and on, and in the early stages I can often go, "Oh, I'm getting depressed, I should take my vitamins/exercise/get some sun/etc." It's only if I don't do those things immediately that things get to the "why bother getting out of bed" phase.
Vitamin D is really very important for our health. I think the information about Vitamin D Intake Guidelines you have shared through your post is functional. I admire your work. Wish you best of luck.