[pc2g4d]

"scientists prove"

Somebody needs to read some Kuhn :-P

Vitamin D deficiency correlates strongly with time spent sitting around indoors. They control for physical activity, but not for time spent indoors as far as I can tell from the linked article. Separating time indoors from vitamin D levels would seem to be a tricky endeavor, so it's understandable that that's left uncontrolled.

A vitamin D-depression connection would make some sense. Given that humans largely evolved spending much more time outdoors than modern humans, deleterious effects of indoor life would not be surprising. +75% sounds like an extremely strong effect size deserving of some skepticism.

The original source: https://tilda.tcd.ie/news-events/2018/1813-vitd-depression/

[mygo]

I studied vertebrate physiology in college and Vitamin D is a bit of a misnomer, because it’s not really a vitamin, it acts as a hormone. And although Vitamin D is known as the “sunshine vitamin”, you can get it as a supplement. There’s no telling how many people in the study took it as a supplement vs getting it naturally from the sun. But a vitamin D deficiency is a hormonal deficiency. Whether or not they got their hormonal balance from the sun or from a supplement shouldn’t matter so much. And being a hormone, its deficiency can have different symptoms for different people. Depression is a common one.

You can take a vitamin D supplement and stay indoors or otherwise keep your routine and still receive the hormonal benefits if you are deficient.

[ionised]

I thought supplements were generally considered a scam, as our bodies won't/can't absorb vitamins in that form, we need to absorb them from food or sunlight.

[mygo]

It's fat-soluble so you're not as likely to just piss it out like the usual vitamins. D3 gets pretty good absorption. I wouldn't take it as a dry pill, if they even manufacture it like that. Get it in a liquid gel format that has it suspended in lipids. Take it with a meal or after.

If you really want to be anal about it, best move is to get your levels tested and then start supplementing and test levels again after a month, then up or down your dosage accordingly till you know how much you need to be taking daily. Most people depending on ethnicity, lifestyle/occupation, and locale just take like 500 - 5,000 IU D3 daily. If you're a white dude who goes surfing every day on the equator, you're probably good. If you're a black dude with a desk job, there's about a 90% chance you're deficient.

A doctor can diagnose extreme deficiency and might put you on like 50,000+ IU / week for a short while.

[lewispollard]

A lot of vitamins are water-soluble so they get flushed out fairly quickly if not immediately used. Vitamin D isn't such a vitamin and is stored in fat.