I'm an indoor person. Perhaps you are, too. When we moved to Costa Rica, my exposure to sun dropped to nearly zero. San Jose is often rainy or cloudy; it's a busy city, where it's not as pleasant to go out; and my sleep schedule rotates, so I'm often asleep during the day.
I knew all this. I knew I wasn't getting enough sun, so I got vitamin D pills. I took one a day, 400 IU, the then FDA-recommended dietary allowance. I didn't know that this wasn't nearly enough. I even asked a doctor if I'm taking an appropriate amount. He dismissed the question. He had no knowledge of vitamin D-3, or its importance.
A year into our life in Costa Rica, I felt a palpable sense of ennui. I objectively have everything; I am blessed with a high income, no work stress, rent and mortgage-free life, a beautiful and supportive wife with whom we have a wonderful relationship. By all accounts, I should be happy with my life. And I was. Except... I felt less and less enthusiasm. I reasoned that I'm satisfied, but no longer felt it.
In April 2013, a person walked into my life. Suddenly, there was passion, and interest, and meaning. Then shortly after, she left. By September, I was in a relentless depression. I wanted to enjoy life, but I couldn't. I lacked enthusiasm. Everything felt mundane and grey. Our son was born, bringing excitement and love, and also challenge. (He's screaming on top of my head as I post this.) I enjoyed spending time with Jana and Aaron, but depressed thoughts set in as soon as I was alone. I enjoyed games, in particular WoW battlegrounds, but I was depressed again as soon as the match was over. I tried to work, I pushed myself, but it was hard to find motivation. Hundreds of days, I got up from bed only because I had to, and spent the day wishing I didn't exist. I couldn't enjoy a good life as it was. And I had no solution.
To illustrate the depth of my abyss, here's a diary entry I wrote a month ago, on October 5:
11:43I hope you understand: it takes a certain misery to write this.
I genuinely smile at the thought of Ebola killing us all. I mean all humans. Entire planet. If only I die - or if any number of people die, short of a vast majority - I'm not achieving anything. I'll still be reincarnated back into this crap.
But if we all died... If we all died, maybe I wouldn't have to come back.
So I wish we all died. I wish life on Earth would be over.
It's a hormone!
The evening of October 6, I found this presentation by Dr. Stasha Gominak, who also maintains this informative vitamin D-3 page. The next day, I wrote a blog post about it. I started taking much larger doses of vitamin D-3. I got a blood test: on October 8, my level of D25OH was 27.15 ng/mL. Based on established guidelines, that's slightly below normal - and no big deal. It's just a vitamin; it's optional. But if Dr. Gominak is right, it isn't optional. It's not even a vitamin, it's a hormone - and I'm way below the healthy range, 60 - 80 ng/mL.
For the past month, I've been taking 7,000 IU of vitamin D-3 per day. During this time, my frequency of depressed moods has much decreased; they have become absent most days. I have more energy. Things are now interesting! I feel an esprit similar to what I felt in the Caribbean, where I could bask in the sun any day.
It is estimated that a light skinned person, naked and without sunscreen under the sun in the summer, produces between 10,000 and 20,000 IU of vitamin D-3 in thirty minutes. Using sunscreen, synthesis is reduced to negligible levels. It's also reduced if you're dark-skinned. At higher latitudes, you can't synthesize vitamin D-3 during winter. You can't get it in meaningful amounts from food, except if you take drops or pills. Synthesis requires Ultraviolet B, which is absorbed in the ozone layer. It only hits the Earth's surface when the sun is at a high angle. In mainland US and Europe, this is from April to October, between 10 am and 4 pm. Even if you're outside at such a time - sunscreen blocks it.
Evolution made depression for a reason, and we know its seasonality is tied to vitamin D. When days are short, and food is scarce, depression improves survival. It makes you want to find a comfortable place, and lie down, and just sleep. It makes everything dull and gray; it makes you not interested in things, because that helps to conserve energy. You can't be running around, expending scarce fat reserves, when food is many months away.
In the ancestral environment, this state would only last a season. In our environment, it can last indefinitely because we're ignorant. It becomes chronic, and gets much worse. Other than its effects on bone health, we don't know much about vitamin D at all. It's named a "vitamin", so that sounds like snake oil. At best, it's "science" for "nutritional doctors" - you know, the kind that are mostly female. Most of us spend hours from 9 to 5 inside, so we have to supplement it - yet we don't even know what the dose is.
So that's how I spent a year depressed.
I'm not saying all depression is for this reason. But if you're dark skinned; or if you're rarely out in mid-day, without sunscreen, in summer sun; get your D25OH level tested. If it's not between 60 to 80 - make sure it gets there. Don't be deluded into thinking it's fine, just because you're taking 400 or 1,000 IU per day.