[thewebguyd]

> which is worse due to cloud cover.

Not just cloud cover. Most areas in the PNW, the sun is so low in the sky between October and March that you can't synthesize vitamin D through the skin at all during those months, even on a bright sunny day.

Even during the summer up here, you really only get a window of roughly 10am to 3pm where enough UV-B rays can penetrate the atmosphere, in July. It's estimated that >80% of the PNW population are deficient (compared with 40% nationwide in the US).

[hinkley]

That same podcast I mentioned pointed out that if a white person nude sunbathed in the winter in full sun, you’d get 2nd degree burns long before you made enough vitamin d.

The body stores it though. So how much of a deficit you’re running for how long matters.