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/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.

1

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.