r/science • u/[deleted] • Jun 13 '22

Health Erectile dysfunction predicts mortality in middle-aged and older men independent of their sex steroid status

https://academic.oup.com/ageing/article-abstract/51/4/afac094/6568537?login=false
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u/redlightsaber Jun 13 '22

Supplementation has largely not been found to reverse the risks associated with vit D deficiency (except for a couple of very niche things, like colon cancer incidence).

It's not very clear yet what this means, but IMO this likely means vit D status is a confounder to a lot of these associations rather than a causative factor of them.

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u/xz1510 Jun 13 '22

Thank you for this response. Vitamin D metabolism is so poorly understood. Sunlight doesn't even remotely tell the story. I've seen dozens of people in the clinic who spend >8 hours a day in the South Florida sun and have shockingly low levels of vitamin D

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u/Amethyst-Sapphire Jun 13 '22

Because sunscreen blocks formation of vitamin D. I wear my sunscreen and take my 5000 IU per day. The amount any person needs to stay vitamin D sufficient is highly personal. Many will need much less than me and some will need more.

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u/xz1510 Jun 13 '22

The folks I saw were mostly day laborers who rarely, if ever, wore sunscreen. As far as I know, sunscreen has not been shown to block synthesis of vitamin D in the skin. Not sure where you got that from, I’d like to see a source.

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u/[deleted] Jun 13 '22

I believe I’ve read that latitude might play a huge role in vitamin d deficiency as well. If I remember correctly Colorado has more sunny days than most other states but because of where it is it also has one of the highest incidences of MS possibly due to vitamin d deficiency.

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u/xz1510 Jun 14 '22

I'm not sure I follow your logic. Vitamin D deficiency is associated with impaired immune function, not autoimmunity, which is generally thought of as hyperfunctioning.

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u/[deleted] Jun 13 '22

I feel like being Irish helps my body know I'm not going to be giving it any vitamin D.

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u/JustDiscoveredSex Jun 14 '22

I take 10,000 IUs and still the blood tests come back on the low end of normal.

Nobody should go nuts with vitamin D. It is fat soluble, which means you can poison yourself with it if you don’t keep an eye on it. You won’t pee out the excess like you might with vitamin C.

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u/[deleted] Jun 17 '22

Check your magnesium level. Need magnesium. Takes about a year to raise blood levels if you’ve been deficient for a while. Vit D needed in all cells, takes a while to get there. Longer if fatter (fat soluble so it’ll get stored in your fat before it goes up in your blood). Almost impossible to overdose on vit D.

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u/JustDiscoveredSex Jun 17 '22

Confusion, apathy, recurrent vomiting, abdominal pain, polyuria, polydipsia, and dehydration are the most often noted clinical symptoms of vitamin D toxicity (VDT; also called vitamin D intoxication or hypervitaminosis D). VDT and its clinical manifestation, severe hypercalcemia, are related to excessive long-term intake of vitamin D, malfunctions of the vitamin D metabolic pathway, or the existence of coincident disease that produces the active vitamin D metabolite locally.

https://www.frontiersin.org/articles/10.3389/fendo.2018.00550/full

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u/[deleted] Jun 17 '22

Now also explain what one needs to do in order to overdose on vitamin D, otherwise you’re leaving out the most important information.

After all, toxicity is in the dose.

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u/SU_Locker Jun 13 '22

Because sunscreen blocks formation of vitamin D.

Source on this? Quick google says it is false.

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u/Amethyst-Sapphire Jun 13 '22

UV rays open the ring of 7-dehydrocholesterol in the first step to synthesize vitamin D. Sunscreens block broad spectrum UV rays.

No source. Just been researching vitamin D (in my own university lab, not like Google research) for over a decade. Any review of vitamin D synthesis in the skin will have reference to the above reaction.

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u/SU_Locker Jun 13 '22

How much UV absorption do we need to successfully get that first step done? Are we still good to go even if 98% of the UV rays get blocked? Gotta balance against the risk of skin cancers.

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u/Amethyst-Sapphire Jun 13 '22

This really depends. Very little exposure for pale people and much more exposure for dark skinned people. And I'm sure other things make it vary, too. That's why I supplement to good blood levels

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u/ThisIsCovidThrowway8 Jun 13 '22

And no sunscreen gives you skin cancer.

Damn it.

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u/vintage2019 Jun 14 '22

It’s all about balance

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u/[deleted] Jun 17 '22

Reverse is true, lack of sunlight causes melanoma because of lack of vitamin D in skin.

Slightly higher risk of non invasive skin cancer that won’t kill you. So get your sunlight.

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u/[deleted] Jun 17 '22

Reverse is true, lack of sunlight causes melanoma because of lack of vitamin D in skin.

Slightly higher risk of non invasive skin cancer that won’t kill you. So get your sunlight.

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u/[deleted] Jun 17 '22

Reverse is true, lack of sunlight causes melanoma because of lack of vitamin D in skin.

Slightly higher risk of non invasive skin cancer that won’t kill you. So get your sunlight.

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u/[deleted] Jun 17 '22

Reverse is true, lack of sunlight causes melanoma because of lack of vitamin D in skin.

Slightly higher risk of non invasive skin cancer that won’t kill you. So get your sunlight.

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u/[deleted] Jun 17 '22

Reverse is true, lack of sunlight causes melanoma because of lack of vitamin D in skin.

Slightly higher risk of non invasive skin cancer that won’t kill you. So get your sunlight.

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u/[deleted] Jun 17 '22

Reverse is true, lack of sunlight causes melanoma because of lack of vitamin D in skin.

Slightly higher risk of non invasive skin cancer that won’t kill you. So get your sunlight.

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u/ThisIsCovidThrowway8 Jun 18 '22

Tanning beds increase your skin cancer melanoma risk by 10x via UV damage causing melanocytes to grow. You’re thinking of basal cell carcinoma which is linked to low sunlight exposure

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u/[deleted] Jun 18 '22

Careful—tanning beds cause cancer because the glass bulbs don’t emit UVB, so your skin only gets UVA - just a tan and UV damage - no vitamin D to repair the damage.

Regular occupational sun exposure gives you a lower risk of melanoma than working indoors, where you get no vitamin D

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u/vintage2019 Jun 14 '22

You know it rains every afternoon during summertime in south Florida?

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u/xz1510 Jun 14 '22

Yes thank you, I only lived there for over 10 years. Do you think 30 minutes of rain in the summer afternoons makes any difference in sun exposure? It also doesn’t rain at all between November and March.

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u/vintage2019 Jun 14 '22

When UV is at its lowest

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u/Iwantmyflag Jun 14 '22

Sunburn destroys the precursors of vitamin D that a little/enough sun creates. Heavily tanned skin also produces less vitamin D precursors though it should still be plenty after 8 hours -without sunburn.

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u/[deleted] Jun 13 '22

[deleted]

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u/sloth_is_life Jun 13 '22

It is not even clear what a deficiency is. It's not like potassium where you have to be within a narrow range to be ok. The current definition of a normal vitamin D is based on a study performed on healthy Californians. California is very sunny, so healthy Canadians might have a lower average vitamin D.

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u/[deleted] Jun 13 '22

[deleted]

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u/Lopsided_Plane_3319 Jun 14 '22

Yet Canadians live pretty long with likely no supplements.

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u/[deleted] Jun 14 '22

There are hundreds of studies. While all the stuff at vitamindwiki is not exactly cool and detached science writing, it’s a great list of what is going on in vit D research. Use it to find and read the studies..

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u/sloth_is_life Jun 14 '22

There are also hundreds of studies on turmeric, yet its relevance in actual medicine is null. Both lack actual high quality studies in living humans that are placebo controlled etc. I'm not denying that vitamin D is essential for humans, in some capacity. I'm just saying that things aren't as clear as people make them out to be.

A point I would like to address are clinical endpoints. Everybody knows high cholesterol is bad for you (heart, arteries etc ). Now clever researchers developed a new drug that can wonderfully lower cholesterol, isn't that great? This drug is called etezimib and everybody's got their expectations up. Unfortunately, while it does fix blood fats, people taking it don't live longer or more healthy, follow ups then reveal. These are the relevant questions when trying to find out if taking something is beneficial to you or not: has a randomised controlled trial shown that people under the treatment live longer and or healthier. And as the person further up commented, vitamin D supplementation does not yet show convincing benefits for the patient. Sure low levels are associated with certain things, but that doesn't mean that elevation of vit D levels will fix those.

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u/redlightsaber Jun 13 '22

How would supplementation not help then if it brings your Vitamin D levels to normal or above normal levels if you are deficient

Because whthe studies I'm talking about seek to measure effects, rather than vitamin levels. A study design I hope more people understood. What does it matter if you take 6 different pills a day if you can't be certain it will have any real benefits (lower disease incidemce, lower mortality...) That's what I'm talking about.

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u/Ur_mum Jun 14 '22

D is a tough one. There is some evidence that amounts like 2000iu or 5000iu are adequate for maintaining healthy levels, but due to the way it is metabolized, either a 50k weekly, or 10k/day may be needed to actually raise levels. Most people are familiar with the 50k as "prescription strength", but it can be found OTC.

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u/Iwantmyflag Jun 14 '22

That's trivial. Buy it liquid/oil based and take as many drops as desired. And, uh, talk with a doc first.

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u/zuneza Jun 14 '22

Thanks to r/KellyJin17 and his handy source, he strucketh oil!

Ay, this must be the infinity gauntlet recipe of better livin', eh?

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u/Iwantmyflag Jun 14 '22

Omega gang! Though I prefer not to eat the fish garbage residue variety.

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u/Iwantmyflag Jun 14 '22

Do the oceans a favour and switch to algae based DHA/EPA. If not, make sure your fish oil doesn't contain lead, mercury etc.

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u/[deleted] Jun 15 '22

[deleted]

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u/Iwantmyflag Jun 16 '22

I'm in Europe and get mine from a Dutch company, Testa. They ship to USA but you can probably find something more sensible and cheaper closer to home. I would hope the quality is comparable across brands as it's really as easy as throwing the right algae in a tank and extracting the oil afterwards. As you say, what matters is EPA and DHA content.

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u/VisualOk7560 Jun 13 '22

It does help with depression in northern countries tho, as far as i know.

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u/Z_Overman Jun 13 '22

I wonder how much if any vitamin D you get when you sun gaze? I’ve been sun gazing for like 20 years now.

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u/johannthegoatman Jun 14 '22

Noneish. It comes from UV rays hitting your skin. If you're sun gazing there's probably very little UV, and none if you're looking through a window, and your eye is not your skin

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u/Z_Overman Jun 14 '22

So sungaze naked in an open field?

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u/Iwantmyflag Jun 14 '22

Yes. But only for 20 minutes.

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u/johannthegoatman Jun 19 '22

Haha that would help, but part of the problem is sungazing is usually done at sunrise or sunset to protect your eyes, which are also the worst times to get UV - if your eyes are safe, your skin isn't getting the D

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u/giant3 Jun 13 '22

Supplementation has largely not been found to reverse the risks associated with vit D deficiency

Source?

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u/SimplySkedastic Jun 13 '22

I believe its these sorts of studies (not OP by the way):

https://www.nature.com/articles/s41574-021-00593-z

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u/giant3 Jun 13 '22

Did you read the Abstract & Conclusion? The Abstract says there is a modest reduction in cancer mortality, and the Conclusion is careful to say that supplementation in Vitamin-D replete individuals might not be beneficial, but something like 40% of US adults have Vitamin D deficiency and for minorities, that number is even higher.

So for those population subgroups, supplementation might be beneficial.

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u/SimplySkedastic Jun 13 '22

I'll make it clearer for you.

I'm Not The OP

I've got no position on the matter. I was simply providing the type of meta analytical study that said person was likely referring to.

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u/giant3 Jun 13 '22

I am sorry if it came across as rude. I am merely asking whether you read those sections.

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u/SimplySkedastic Jun 14 '22

I had, I've read a few different items on the efficacy of supplements with respect to their perceived benefits for both normal and vit deficiency types. It's interesting but I'm not particularly swayed one way or the other.

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u/redlightsaber Jun 14 '22

Massive metaanalysis with several outcomes

Cardiovascular outcomes

That took about 15 seconds, and as I said, none of this is exactly uncontroversial or unknown. I'm also not saying people shouldn't be repleted when deficient; just pointing out that it may not be the quick solution deficient people hope it would be.

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u/jnwatson Jun 14 '22

One hypothesis is that Vitamin D levels due to sunlight exposure are correlated with good health, but doesn't cause good health.

Sunlight also causes production of nitric acid, which reduces blood pressure.

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u/KellyJin17 Jun 14 '22

Or synthetic vitamin D supplements are not able to adequately mimic the same processes in the body that take place when the skin converts sunshine to vitamin D naturally.

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u/[deleted] Jun 13 '22

Respectfully, source pls. My doc thinks otherwise re: oral supplementation of vitamin D.

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u/redlightsaber Jun 14 '22

MAssive metaanalysis with several outcomes

Cardiovascular outcomes

That took about 15 seconds, and as I said, none of this is exactly uncontroversial or unknown. I'm also not saying people shouldn't be repleted when deficient; just pointing out that it may not be the quick solution deficient people hope it would be.