[voidmain]

There's a history of finding really strong correlations between vitamin D levels and (many kinds of) health, and then disappointing results for RCTs of vitamin D supplementation. There are lots of possible explanations of this, but it seems like a plausible one is that there are some good things sunlight does for you other than produce vitamin D. So I'm a little nervous about everyone eliminating all sun exposure and then taking vitamin D geltabs to compensate, even though sunlight carries some risks. (But obviously too much ionizing radiation is also a problem, and it sounds like most users of tanning beds are getting a lot of intense exposure)

[Workaccount2]

I wonder how much correlation this has with exercise. Generally if you are getting good levels of sunlight, there is a good chance you are outside exercising, even if it's just walking.

After all, exercise is the undisputed God tier all-time winning champion of "Studies show that ______ is good for xyz."

[lukeschlather]

I've taken up running because it's a way to get sunlight during the winter, I can run in shorts and a t shirt. I am very active, but I start getting a lot of anxiety if I don't get sunlight on my skin for a week or two.

[james_marks]

I remember a study where they shone light on the back of the knee to control for this.

While I believe there are many benefits of being outside and exercising, there does appear to be specific benefits to sun-like UV exposure.

[jerlam]

Also gives you a brief respite from sitting in a climate-controlled environment and staring at screens.

[jnwatson]

UVA triggers the release of nitric oxide from the skin into the bloodstream. This causes blood vessels to dilate, lowering blood pressure and improving circulation.

[d3Xt3r]

Exposure to sunlight (or lack of it) affects our circadian rhythm and production of melatonin, which affects our sleep quality. Exposure to morning sun in particular is linked with better sleep quality, leading to better health.

https://pmc.ncbi.nlm.nih.gov/articles/PMC12502225/

[scotty79]

> There's a history of finding really strong correlations between vitamin D levels and (many kinds of) health, and then disappointing results for RCTs of vitamin D supplementation.

This might just mean that bodies that are healthier in many other aspects are also better at managing their vitamin D stores which isn't all that surprising.

[koliber]

Some of the positive sunlight exposure benefits are trivial to see.

- running around outside, because physical activity if healthy

- spending an afternoon in the company of good friends or family

- gardening, which can produce veggies that are pesticide free

Not everything is a biochemical direct benefit of the sun’s rays. Some of the positive effects are a few steps removed.

[scoofy]

There are plenty of foods with vitamin D. You don't actually need to supplement it unless you're a vegetarian, you just need to actively include those foods in your diet.

The current argument I've read for why fair-skinned people even evolved near the North Sea and not anywhere else near the arctic is exactly that the Gulf Stream allowed a cereals-based diet rather than a meat based diet, which led to vitamin D deficiencies which caused problems in pregnancy, leading to people with fairer skin being the most likely to avoid those problems.

You definitely don't need to get your vitamin D from the sun.

[reissbaker]

I don't know where you read that fair skin is a diet adaptation and not a sunlight one, but that's wrong: fair skin is an adaptation to northern latitudes due to reduced sunlight. The majority of people of African descent in America are vitamin D deficient, but in Ghana — where there is much poorer nutrition, but more sunlight — they're not. Meanwhile, the majority of white Americans are not vitamin D deficient. [1]

Getting sufficient vitamin D takes 6x longer sun exposure for black people than for white people. [2] In northern latitudes that's pretty difficult.

1: https://pmc.ncbi.nlm.nih.gov/articles/PMC7913332/

2: https://news.feinberg.northwestern.edu/2011/09/20/vitamin-d/

[hirvi74]

> There are plenty of foods with vitamin D.

My favorite one that I read about is mushrooms. If you grow them in the sun, some species allegedly acquire vitamin D. I am not sure how much nor if this is truly effective, but it gives me a good excuse to grow various mushrooms next spring.

[Theodores]

You might be interested in the British history of Vitamin D supplementation. It all started with kids in the cities getting rickets because the pollution (smog) was that bad that they never got to see further than a metre or two during the worst of it. The way to get around was by taking the tram as that had rails to guide it through the 'pea soupers'.

So they put the kids on trains and took them off to the seaside.

But then...

The railway also allowed milk to be brought into the cities. So they added vitamin D to milk. That was how the rickets was solved. In time milk became free at school, usually it was warm by morning break, which was when it would get consumed, from mini-milk bottles, that would get reused.

I am only piecing together this history, no definitive source, unless you include my elderly neighbour. However, food history is fascinating, once you get away from celebrated brands to the unsung heroes of the vegetable aisle.

What I can't work out is why the children were so vulnerable to rickets when the adults weren't. Workers weren't being sent out to the countryside or beach to get some sun, just the kids. Rickets doesn't affect adults with grown bones, in theory, the adults should have had really painful joints and osteoporosis, but maybe this was not understood at the time.

In time the clean air zones were setup and the smog was banished to a certain extent, by which time it became uncommon to fortify milk with vitamin D. Finally we had Margaret Thatcher, famously the 'milk snatcher', for stopping free school milk.

In the UK we do get vitamin D randomly added to processed foods (what else?) and this is a scattergun approach to fortifying the population. If you don't eat processed foods then you are not going to get any of that processed food fortification goodness.

Then there are the animal corpse sources, as in oily fish and whatnot. If you eat any diet except for whole-food-plant-based vegan, then you are going to get vitamin D either through dead animal or fortification. Vegetarians just have to eat maaassivve blocks of cheese, which they will, with a few eggs and some breakfast cereal to get their vitamin D needs roughly covered. Junk-food vegans should get some vitamin D goodness from fortifications too, particularly if they consume things like 'oat milk' (as if oats have mammary glands). Pure junk food, a.k.a. 'Standard American Diet', should also be pretty good for vitamin D.

So this only really leaves the whole-food, plant-based, everything-cooked-from-scratch vegan diet as lacking, at least as far as the winter months is concerned. Was this a problem historically? I don't think so. Since people used to work the fields, they had plenty of vitamin D to carry over for winter.

Before we had 'modern day racism' in the UK, we had a situation where the aristocracy had white skin and everyone else had leathery brown skin, from working outside. White skin was proof that you didn't have to work the fields and therefore, you were higher status. Racism pre-dated racism, if you get my drift, it was mere class-based xenophobia back then. To be 'truly white' you had to have no tan.

Since meat was hard to come by, peasants were 95% vegan by default, yet working the fields, so vitamin D deficiency was not a problem, for the 1% aristocracy (since they had their oily fish, red meat and dairy) or for the 99% that had to spend lots of time outdoors.

I am not sure where you are coming from regarding the Gulf Stream and cereals. The Fertile Crescent was where farming began for Europe, with wheat not actually growing in the UK and other grains (barley) being the chosen grain. It was only with the Norman Conquest that wheat made it to the UK.

When the Romans made it to the UK they were perplexed at what they found. There were two tribes, the nomadic cattle types and the hill fort living grain growers that were not nomadic. The hill forts got in the way of the migration routes between pastures. The Romans were disgusted by the milk drinking since nobody would do that in Rome, where everyone was lactose intolerant, unlike the Celts.

[zdragnar]

> What I can't work out is why the children were so vulnerable to rickets when the adults weren't

Presumably, children need regular and consistent amounts due to bone growth. Once past puberty, less mineralization of calcium and phosphate happens, which is one of the processes in the body that requires vitamin D.

[mr_toad]

> The railway also allowed milk to be brought into the cities. So they added vitamin D to milk.

That and (later) refrigeration allowed dairy products to be transported to the cities, which helped with calcium intake, as well as vitamin D.

[csomar]

There is probably stuff we don’t know. For example, some people sneeze when they look or are exposed to the sun (for me, usually in the morning). There is still no scientific explanation for why it happens.

There are no devices that can produce a full-spectrum light like the one you get from the sun. So my suggestion would be to go outside and breathe instead of sitting in a box.

[cmclaughlin]

Here’s a podcast on this:

https://www.artofmanliness.com/health-fitness/health/podcast...

[manoDev]

There are multiple studies showing infrared enhances mythocondria function, and this is already used therapeutically.

[KeplerBoy]

Today is the first time in December my town gets any sunlight and boy am I excited. Not because we are that far north, it's still the height of the winter after all, it was just shit weather.