[rossdavidh]

There is a long history of taking pills of vitamins and minerals not being as good as getting it the way we evolved for. We evolved to produce vitamin D by getting sunlight. We are NOT evolved from nocturnal animals. A vitamin D supplement might help, but a better idea is to take a walk in the park every day, while the sun is up.

[bird_monster]

Sure, and that's great, but what about the scenarios in which I cannot walk to the park (during 600+ AQI wildfires, as an example), is the reason I'd like the data on supplementation.

[undersuit]

You can buy or make a SAD/Sun Lamp.

[bird_monster]

Sure, and that's great, but I'm asking about the efficacy of a supplement

[DanBC]

You're never going to get sensible dietary advice on HN.

Get sun. If you can't get sun you should eat a variety of food that contains vitamin D. If you can't do that, you should take a supplement. Take the supplement at the same time as you eat a meal, preferably a meal that has some fat.

Here's the advice for England:

https://www.nhs.uk/live-well/healthy-body/how-to-get-vitamin...

https://www.nhs.uk/conditions/vitamins-and-minerals/vitamin-...

[gerdesj]

Freely available advice from the UK's NHS would seem to be a good idea. We fund the NHS mostly out of taxation, so advice provided there has to be as close to non partisan as is reasonably possible.

I personally don't give a shit if you are a foreigner. If the NHS website can provide good advice and help someone - anyone, then my tax squids are being put to good use.

There are bound to be other good sources of health related advice around the place but why not start with the NHS and work out from there?

[gridlockd]

If you pay close attention, health authorities always play it safe, for example by saying "there's not enough evidence". That's why they didn't recommend masks in the beginning.

Then, if some sort of expert consensus comes up, the authorities adopt that. When that consensus is challenged by new evidence, authorities are slow to change, because that would be implicit admission that they were giving the wrong advice, which is not something that the human egos involved there can easily stomach.

A good example for this is the food pyramid[1]. It was never supported by good evidence, it was adopted through expert consensus (one might also call it lobbying), and it was later removed from the guidelines. You can still see posters of it hanging in doctor's offices, of course.

[1] https://en.wikipedia.org/wiki/History_of_USDA_nutrition_guid...

[gridlockd]

> You're never going to get sensible dietary advice on HN.

You're never going to get sensible dietary advice, period. Diet is a belief system. Most people, including doctors and health authorities, really just go by clichés, like "eat five a day" or an unspecific "balanced diet". The science on it is poor and forever will be.

> If you can't get sun you should eat a variety of food that contains vitamin D.

Half an hour in the sun, if you are light-skinned, can get your body to produce about 10,000IU of vitamin D. To get that amount in the diet, you would need to eat more than a pound of the right fish.

Diet can get you out of the "severely deficient" range, but almost certainly not into the healthy range.

> Here's the advice for England

They actually advise supplementation, but they err on the low end. The only way to know if you get enough vitamin D is to do blood tests, people react quite different to different doses and forms. One guy here reports 10,000IUs daily gets him to only 55ng/dl (high end of normal), whereas 5000IUs gets others above 70 ng/dl (possibly harmful). Vitamin D builds up over time, so one test is not enough.

[boyakasha]

> You're never going to get sensible dietary advice on HN.

> If you can't get sun you should eat a variety of food that contains vitamin D.

It's admirable that you prove your own point two sentences later.

[stjohnswarts]

It works, I'm not a sunshine person. I work for myself and I usually work after I wake up at noon because I usually stay up til 4 or 5am at night. I get very little outdoors sunshine. I had very low vitamin D. My doc recommended supplementation if I wasn't willing to become a daywalker and my vitamin D levels were perfectly fine after a month of supplementing with 5k IU. I have cut back to 2K IU per day and my vitamin D levels are great since (5 years since I started supplementation).

[undersuit]

Like a supplement for not getting enough sunlight? Supplement your lack of sunlight with appropriate spectrum inside.

[galenlynch]

Most 'sun lamps' do not emit UVB, which is required for your body to make vitamin D.

[undersuit]

Then don't buy those if your looking for that feature?

[xdavidliu]

you're missing the point; he's saying that sun lamps don't have the same effect as the sun. This isn't just a "feature" that some lamps have and others don't; it's a crucial missing ingredient that results in the sun lamps you are suggesting simply _not working_.

[undersuit]

No, I'm not. There are UVB generating light sources and they also fall under the SAD/Sun lamp definition.

[ThePowerOfFuet]

These days those are called Oracle Lamps.

[rxhernandez]

"There are some people (who are typically not dermatologists or experts in the biology of skin cancer) who have advocated for tanning to get vitamin D. But we know that UVB light causes skin cancer and that protecting yourself against it makes sense. As a doctor who treats patients who have melanomas, I want the general public to be advised that under no circumstances can use of a tanning bed or tanning in general be justified on the basis of vitamin D. Take a supplement instead."

https://www.yalemedicine.org/stories/vitamin-d-myths-debunke...

[didibus]

I heard tanning in short doses is actually ideal to prevent melanoma and procure the best vitamin D intake.

By exposing more of the skin, you absorb more vitamin D quicker, and so if you tan only 5 to 20 minutes depending on your skin complexion, you basically avoid skin burns and excess damage which causes melanoma and you get the benefits of the sun.

What do you think of this?

Edit: Maybe not what people think of as tanning, but it's basically skin exposure to the sun where you want to limit how long each part of the skin is exposed, but maximise the surface area for vitamin D absorbtion.

Source: https://www.outsideonline.com/2380751/sunscreen-sun-exposure...

[rxhernandez]

After having my bloodwork show that I had low vitamin D levels a few years ago, I was told by my physician that under no circumstances should I be getting vitamin D from the sun (as risking cancer was not worth it) and to wear sunblock everytime I go outside.

Frankly, I don't have the time to do an extensive literature search to find primary sources but I have seen from plenty of tertiary sources that it is a poor idea to get vitamin D from the sun. Moreover, there are plenty of foods from which you can get vitamin D.

[didibus]

This is the source that first got me curious about this: https://www.outsideonline.com/2380751/sunscreen-sun-exposure...

There's quite a bit of research that seem to coroborate it.

Sun can cause melanoma, but lack of sun also has negative effects albeit harder to track. Some even unrelated to vitamin D, as it seems the Sun does more than just provide us with vitamin D.

But it seems that the research on melanoma actually indicates that it is sunburn that is the prime cause. And sun exposure while under 20 is another leading cause. But after that, exposure that does not result in burn, like short term exposure doesn't seem to cause melanoma and does provide other health benefits.

I recommend a read in any case.

Not saying to go wild sun tanning, but I think if you can avoid burn (even minor ones), you're good.

[TheSpiceIsLife]

Here in Tasmania, and given the tone of my skin, in order to get enough sun exposure to provide for my vitamin D requirements...

I will spend enough time in the sun to damage my skin and significantly increase the risk of melanoma.

[stjohnswarts]

Some of us don't want to do that so we take vitamin D supplements and we're just fine. "Nature is always better" cult is really just magical thinking. I'm not saying that one shouldn't go for walks in the sun or that it's not healthy, but that's an individual's choice.

[nerfhammer]

Being that we are extant mammals we are evolved from nocturnal animals, just that not recently. Primates diverged to be more diurnal.

https://en.wikipedia.org/wiki/Nocturnal_bottleneck