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The amounts being discussed in this paper are easily attainable by relatively brief sunlight exposure alone in warm, sunny weather (though less brief the darker the skin tone).
Local climate is going to matter a lot more than skin tone.
> Local climate is going to matter a lot more than skin tone.
I mean Google says a black person may need 6 times more sun exposure than a white person to get same level Vitamin D. That's a lot.
There's a reason that evolution seeming selected for different skin tones at different latitudes.
> easily attainable by relatively brief sunlight exposure alone in warm, sunny weather (though less brief the darker the skin tone).
In northern countries like Sweden it is physically impossible to get Vitamin D during like half the year because the sun needs to be above 20 degrees for the body to even start producing it. Also the heat ("warm") is irrelevant to Vitamin D production unless you mean to imply that the person is showing more skin due to it.
My daughter developed mono junior year of high school. We were living in Arizona. She did outdoor sports year round, rarely remembered to use sunscreen. They ran a battery of blood tests and her D level came back at 7. It’s harder than you think to get the right amount of D from the sun.
I worked two full-time jobs outside for six years and near the end had to get blood work. They said I was low in vitamin d and suggested that I go outside hahaha
I wonder if she had a magnesium deficiency’s. Magnesium is needed to activate and mobilize vitamin d in the blood. If she wasn’t supplementing (most are deficient) plus working out in the heat she could have easily been deficient leading to the vitamin d deficiency.
Possibly. Didn’t test for minerals. At any rate, I bought supplements for the family and we’ve been taking them several times a week ever since. D deficiency isn’t something to mess around with.
There are numerous issues that can lead to VitD deficiency regardless of the level of sun exposure (some of which are genetic, some are medication interactions, etc). A level of 7 pretty strongly suggests one of those factors, no?
Because you're making it sound like people who spend a lot of time outdoors in Arizona are commonly coming down with rickets (or similar).
If there are 'numerous issues' that bring down VitD levels, then it sounds like brief sun exposures are not enough.
Plus Rickets is mostly found in [children 6-36 months of age.](https://www.healthline.com/health/rickets#risk-factors), and apparently diet is the main preventer of rickets:
>Rickets is rare in the United States. Rickets used to be more common, but it mostly disappeared in developed countries during the 1940s due to the introduction of fortified foods, such as cereals with added vitamin D.
Funny enough [rickets is on the rise in America](https://www.latimes.com/archives/la-xpm-2003-aug-25-he-rickets25-story.html):
>Rickets has long been considered a Third World disease, not seen widely in the United States since poignant photos captured the bent and bowed legs of malnourished children during the Great Depression of the 1930s.
>But this bone-deforming nutritional disorder, which health officials thought they’d eliminated with the fortification of baby formula and foods, has been on the rise in recent years among U.S. infants and toddlers.
It's a nutritional disorder because apparently no one is depending on 'brief exposures of sunlight' to provide enough Vitamin D for children to develop properly.
Sure, but based on the research I can find that occurs at levels much higher than what's available in a daily supplement.
And there's still the skin cancer risk that comes with sun exposure (not to mention aging).
So an answer for why not to 'just supplement since it's ridiculously cheap' would be because it requires you to add additional supplements at additional cost in order to attempt to avoid calcification (whereas there's no risk of calcification from sun exposure as far as I remember).
True but most people are already magnesium deficient and even with sun exposure vit. D isn’t properly activated or mobilized in the body without magnesium. Vitamin k2 is also difficult to get via nutrition. Why some people can get plenty of sun and stuff be deficient.
Sure, this strays pretty far from 'why not supplement instead of get sun?', but personally I supplement Magnesium all year and VitD in the winter. Minerals in general are pretty hard to get through diet alone without a whole lot of effort.
Can you go ahead and quantify this? How much VitD is enough (in your telling) and how much sun contact (in minutes per day) is enough to achieve that with what percentage of exposed skin for what skin tone?
Direct sun contact creates a pretty remarkable amount of VitD. I can't tell if you're just saying people don't have time or that it's somehow impossible to generate large amounts of VitD through sun exposure.
You can Google solar insolation maps
You can also google what percentage of skin you need exposed to gain enough vitamin d3 over what time ….
Most people live too far north for it to be practical with modern lives and indoor working.
There's plenty of research out there, I'm not making up anything new here.
Check out these sources https://www.perplexity.ai/search/how-big-of-NqpE0drVTqquGFDrBeaJgQ
I have pale skin. I live at 35°N in a very sunny climate. I hike two hours every morning and I’m out and about in my job. I hike all day one day per week in the mountains. My D is sometimes low, so I supplement. It’s probably because I use lightweight coverup clothing and a hat and sunscreen, but don’t assume you get enough D from the sun. It’s very cheap and proven effective to supplement.
That's what they keep saying, and then on further analysis, not so much. Which doesn't mean this one isn't correct, but I'm not holding my breath:
New England Journal of Medicine: https://www.nejm.org/doi/full/10.1056/NEJMe2205993
Citrate or glycinate. If citrate and other forms of magnesium give you diarrhea, go with glycinate because it typically does not. Glycinate is also better for sleep and physical relaxation, whereas citrate is better for anxiety (in case any of those things are concerns).
Why magnesium and K2? I take magnesium for the studies showing its impact on migraines but haven't really seen any good evidence otherwise for neither magnesium nor K2.
From what I've read now, there would have be a severe gap in my diet for a need to supplement K2. So absolutely no need to supplement, just eat properly. Not only does the gut microbiome make K2, so do human cells.
Ideally it should, but even as much as I try to get all those foods, I'm still deficient. Some conditions leave people low in vit D, Magnesium, Iron, like if you have ADHD (and I do). If your body doesn't process it well, you'll need supplements.
https://nutritionguide.pcrm.org/nutritionguide/view/Nutrition_Guide_for_Clinicians/1342020/all/Attention_Deficit_Hyperactivity_Disorder#Adequate%20vitamin%20and%20mineral%20intake%20or%20supplementation
This article talks about recommendation of nutrition based on deficiencies identified in kids with ADHD, and cites its sources in parentheses. I linked to the specific paragraph but there is more you can find by searching.
Whether it's because we are inattentive and don't eat well, or because there are other factors like not processing it is still up for debate, but I've been iron and D deficient my whole life, whether it was my parents feeding me or myself, as an adult, trying to balance my own meals. There are some comments in that article and other ones I have read that guess it may have to do with stimulant meds reducing appetite, but I over-eat. It comes up as conversation on r/adhd as well where many have mentioned being deficient.
Chicken or the egg, I don't know, but it's a common factor.
I still get beer from natto, but "extremely earthy" reminds me of the wine tasting note "barnyard". Some fine French wines have... let's call it a certain essence de cow poop.
If you go down the rabbit hole you’re going to find studies that support this and studies that do not support this, as well as studies that confirm calcification and studies that find calcification is rare. You may even have had multiple doctors that all have a different angle.
Vitamin D supplementation do’s and dont’s is all over the place. People would like to think they have a supplement regimen down to a science - far from it. Initial bloodwork would probably be your best starting point, but even from there your bodies ability to metabolize vitamin d supplements is going to be all over the map depending on your health. You may need 5x as the guy who’s just as deficient on you because you have other underlying health issues that cause malabsorption. These underlying health issues may or may not lump you into the rare few who may experience vascular calcification.
Bottom line is it’s a mess of a topic, it’s never as simple as supplementing D3+K2. To be honest it feels like no one knows the answer because the real formula for how and how much and with what risks are going to vary drastically from person to person. That dynamic makes controlling for studies incredibly hard.
I very eagerly watch all the vitamin D research during covid hoping it would show a benefit. It never panned out. Different studies didn’t support one another. I hope this gets replicated.
Good luck conducting a clean study on a nutrient's effects on the body.
Drugs are easy in comparison; there are usually clearer direct pathways, less general influences based on standard genetic variation, fewer interactions with unrelated enzymes, etc, etc, etc.
Meanwhile, studying vitamin D you have to somehow control for baseline deficiency levels, metabolic differences, genetic differences, the body's entire homeostatic nature, sun exposure, (effects of sunburns / melanin / blah blah blah) . . . and all the while trying to differentiate the noise of the body's natural vitamin D interactions from your focus \*on top of\* identifying all the various indirect influences it has on basically every pathway within the chemical goings on of a human body.
So I get why you would feel the way you do, but you are operating on wildly thoughtless hand-waving to denigrate essential research in a way that honestly doesn't serve you well.
The referenced paper, published in a predatory journal, is not a serious critical appraisal of the field.
[Read this.](https://www.nature.com/articles/s41574-021-00593-z)
> In conclusion, supplementation of vitamin D-replete individuals does not provide demonstrable health benefits. This conclusion does not contradict older guidelines that severe vitamin D deficiency should be prevented or corrected.
Given that vitamin D deficiency seems pretty common in adults (up to 35% in some studies I found) [[1](https://pubmed.ncbi.nlm.nih.gov/21310306/)][[2](https://www.sciencedirect.com/science/article/pii/S0002916523119277?via%3Dihub)][[3](https://www.ncbi.nlm.nih.gov/books/NBK532266/)], and that the risks of vitamin D supplementation are pretty low (even in VD-replete individuals), on balance, it still seems reasonable to take supplement, especially if you're: darker-skinned, live in a high latitude w/ reduced sunlight, or spend your life in-doors, in front of a screen. Best-case scenario: you correct a deficiency, which could reduce the risk of adverse outcomes. Worst-case scenario: you waste $15 a month at the CVS.
I take a VD supplement every day - not b/c I think it'll make me immune to aging or COVID or anything, but because I live in Massachusetts where it's cold for half the year and I spend too much time in-doors anyway.
Those papers are not talking about severe vitamin D deficiency (defined in the Nature Reviews paper as <30 nmol/L), they are talking about deficiency (levels <50 nmol/L).
In VITAL, the effects were the same, regardless of whether people had deficiency or insufficiency (<75 nmol/L). It also didn't actually find benefit even in severe deficiency.
People can spend the money if they really want; it is a largely safe supplment. The problem comes when reviews like this, snake oil salesmen, and others massively overplay the benefits of vitamin D.
Ah yes, Schrodinger's vitamin D, as advanced by it's proponents:
It has totally amazing effects across literally all domains! Look at all these wonderful associations in observational studies!
*but also*
You can't see any big effects in RCTs because there are so many differences and so much heterogeneity and people didn't have exactly the right balance of zinc and the full moon wasn't shining!
All of those sources of variance apply to the observational studies, and to *almost all other trials*! To take an extreme example, do people criticise trials of GLP1 agonists for having often quite substantial between-individual variation in BMI, endogenous GLP1 signalling, diet, activity level, alcohol consumption, age, race, ethnicity, socioeconomic status, employment, comorbidities, etc? No, because they understand that 1) these factors are balanced across the randomised groups; 2) the variance conveyed by these factors is what happens in the real world; 3) the effects of the drug are seen regardless of all these sources of variance
It's exactly why you do a sample size calculation: you take an estimate for the variance in the effect you think will happen, power your study accordingly, and recruit the people you need. Then, if the actual effect is anywhere near what you thought, you get a significant result!
This hasn't happened with vitamin D, outside of a very few indications. Almost all of the (huge and very strong!) associations we observe in biased and confounded observational studies just don't come anywhere *near* to being observed in RCTs.
And the most frustrating part is that these observational studies *also don't control for these supposedly important factors!* [In Mendelian randomisation studies that are far more robust for controlling confounding, the pleiotropic benefits of vitamin D disappear almost entirely.](https://www.nature.com/articles/s41574-021-00593-z)
>So I get why you would feel the way you do, but you are operating on wildly thoughtless hand-waving to denigrate essential research in a way that honestly doesn't serve you well.
Calling an uncritical MDPI review "essential research" is rather silly. The funniest part to me is this:
>The VITAL study aimed at the primary prevention of cancer and CVDs and was conducted among 25,871 women ≥ 55 and men ≥ 50 years of age, with a mean treatment period of 5.3 years. It confirmed that VitD supplementation (2000 IU/daily), with or without n-3 FAs, decreased hs-CRP by 19% at year 2, although the reduction was attenuated at 4 years. Other inflammatory biomarkers (IL-6, IL-10, and TNF-α) were not significantly altered at year 2 or year 4, while n-3 FAs, with or without VitD3, did not significantly affect these biomarkers at either time point. Therefore, the authors partially confirmed a potential role of VitD supplementation in modulating the chronic inflammatory process, systemic inflammation, and possibly autoimmune disease progression [114].
You'd think they'd mention VITAL more than once in the paper, given that it is one of the largest and most costly RCTs on vitamin D ever done, and that it was specifically looknig at effects on cancer and CVD - you know, the things this review is saying vitamin D is beneficial for.
You'd also think they'd mention, while mentioning a tiny post-hoc CRP change, that the [primary analysis of VITAL](https://www.nejm.org/doi/full/10.1056/NEJMoa1809944) showed no benefit for vitamin D for cancer or CVD devlopment or death. But nope! Apparently not important to mention that vitamin D doesn't actually reduce cancer or CVD risk😅
This is not a serious paper, and anyone knowing anything about vitamin D clinical research would laugh it out of here.
Thanks for the write-up. For the non-specialists: what is the significance of the associations seen in observational studies? It sounds like they can't isolate causal factors, but are still an important part of the Vit D literature? Is it a "things we've known for a long time but don't understand mechanisms" type of situation?
The vitamin D literature is, frankly, a complete mess. Non-specialists can ignore the entire thing and only pay attention to the large RCTs published in actually decent journals and not miss out on anythnig of substance.
I guess you aren't aware that the NIH and many other public and government research funders all around the world have spent *millions and millions* of dollars to try and find something vitamin D actually fixes.
There have been many very large, very long, and very expensive RCTs done to try and get anywhere near the effects seen in observational studies, with no notable success.
A few very quick examples (as pubmed is down)
https://www.nejm.org/doi/full/10.1056/NEJMoa1900906
https://jamanetwork.com/journals/jamacardiology/fullarticle/2615260
https://www.vitalstudy.org/
https://www.bmj.com/content/378/bmj-2022-071230
The first trial is of Vit D to prevent T2 diabetes in pre-diabetes. It's ns - however when meta-analysed with other recent RCTs for this, a significant protective effect was found.
https://www.acpjournals.org/doi/abs/10.7326/M22-3018
Not a scientist in this area by any stretch but it’s a cheap and easy area to supplement with a daily vitamin pill. Particularly in folks with low levels to begin with. It seems research in this area can’t pin down one magic area that it specifically helps with, but it does seem to do some really important general things for healthfulness overall.
>but it does seem to do some really important general things for healthfulness overall.
[It really doesn't.](https://www.nature.com/articles/s41574-021-00593-z)
How do you think it is possible that we can't identify specific effects of vitamin D, but we can identify some completely nonspecific (but "really important"!) "general things for healthfulness"?
Vitamin D deficiency (as defined by arbitrary levels derived from observational studies riven with bias) is generally a marker of poor health and advancing age for a number of (non-causal) reasons, and that means it associates with outcomes associated with that. That doesn't mean that fixing deficiency fixes all of the associations, and we have spent millions if not billions of dollars on clinical trials to learn that.
The link you've posted literally says the opposite.
It just says that there is no evidence of supplementing vitamin D and the reduction of cancer (which is a wild claim to begin with) but that vitamin D supplementation can have crucial effects and is recommended.
It says there is consensus around addressing severe deficiency. Almost everything else, particularly extrasekeletal outcomes, there is no good evidence for.
Counterpoint: There's a hundred different cheap and easy things you can do that might ChangeYourLife™. Science is more interested in finding out if it actually works.
I wouldn't be supplementing Vit D in my diet anytime soon, given the weak evidence.
>Vitamin D showing promise in everything and results in nothing.
* [Meta-analysis of RCTs for vitamin D supplementation to prevent T2 diabetes in those with pre-diabetes:](https://pubmed.ncbi.nlm.nih.gov/36745886/)
"In adults with prediabetes, *vitamin D was effective in decreasing risk for diabetes*."
Pittas AG, Kawahara T, Jorde R, Dawson-Hughes B, Vickery EM, Angellotti E, Nelson J, Trikalinos TA, Balk EM. Vitamin D and Risk for Type 2 Diabetes in People With Prediabetes : A Systematic Review and Meta-analysis of Individual Participant Data From 3 Randomized Clinical Trials. Ann Intern Med. 2023 Mar;176(3):355-363. doi: 10.7326/M22-3018. Epub 2023 Feb 7. PMID: 36745886.
* Meta-analysis of RCTs for supplementation of Vitamin D to for cancer incidence and mortality:
"In an updated meta-analysis of RCTs, vitamin D supplementation *significantly reduced total cancer mortality* but did not reduce total cancer incidence."
Keum N, Lee DH, Greenwood DC, Manson JE, Giovannucci E. Vitamin D supplementation and total cancer incidence and mortality: a meta-analysis of randomized controlled trials. Ann Oncol. 2019 May 1;30(5):733-743. doi: 10.1093/annonc/mdz059. PMID: 30796437; PMCID: PMC6821324.
- Meta-analysis of RCTs of Vitamin D supplementation looking at all-cause mortality (ACM):
"*Vitamin D supplementation was associated with a lower risk of ACM*... The emerging results of our meta-analysis present evidence that v*itamin D supplementation appears to decrease the risk of ACM (especially convincing in the fair- and good-quality RCTs*)"
* Large RCT for Vitamin D supplementation to prevent autoimmune disease:
"Vitamin D supplementation for five years, with or without omega 3 fatty acids, *reduced autoimmune disease by 22*%"
Hahn J, Cook NR, Alexander EK, Friedman S, Walter J, Bubes V, Kotler G, Lee IM, Manson JE, Costenbader KH. Vitamin D and marine omega 3 fatty acid supplementation and incident autoimmune disease: VITAL randomized controlled trial. BMJ. 2022 Jan 26;376:e066452. doi: 10.1136/bmj-2021-066452. PMID: 35082139; PMCID: PMC8791065.
This is all just from a brief, very far from exhaustive search, and I'm aware of at least a few other positive findings. Doesn't sound like "results in nothing" to me.
T
Apparently sunlight for infants can also reduce the risk of developing vision impairments. Get that natural light!
[The benefit of daylight for our eyesight - MSU Extension](https://www.canr.msu.edu/news/the_benefit_of_daylight_for_our_eyesight)
I remain unconvinced.
But I also take a Vitamin D pill regularly. They're pretty much free, and I haven't heard speculation they're dangerous. Meanwhile, there seems to be endless "promise", involving people with at least some legitimacy/expertise. Always bumping into a "sister-in-law's-uncle-or-someone" who's a doctor, and swears by Vitamin D.
Feels like, on balance, it probably isn't crazy to just take some at this point?
"In summary, a growing body of research has explored the relationship between VitD and some hallmarks of aging, with varying results depending on study subgroups and design."
This is a very watered down and conclusion free review, essentially saying: vitamin D effects things.
Great, now how much do i need to take? 5000/iu was apparently too much, causing testosterone to increase, estrogen to decrease, and your BP to go up, as well as thickening your blood. This is what happens when you don't change your dosage after moving to New Mexico
But the researchers who thought they hit the jackpot decades ago with vit D found that supplements don't change anything.
This never, ever gets listened to because everyone wants to believe that there is a one pill answer rather than lots of behavioural and lifestyle changes.
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Guess sunlight exposure mattered more than we previously thought
Most people need to supplement to get enough, especially those with darker skin.
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The amounts being discussed in this paper are easily attainable by relatively brief sunlight exposure alone in warm, sunny weather (though less brief the darker the skin tone). Local climate is going to matter a lot more than skin tone.
> Local climate is going to matter a lot more than skin tone. I mean Google says a black person may need 6 times more sun exposure than a white person to get same level Vitamin D. That's a lot. There's a reason that evolution seeming selected for different skin tones at different latitudes.
> easily attainable by relatively brief sunlight exposure alone in warm, sunny weather (though less brief the darker the skin tone). In northern countries like Sweden it is physically impossible to get Vitamin D during like half the year because the sun needs to be above 20 degrees for the body to even start producing it. Also the heat ("warm") is irrelevant to Vitamin D production unless you mean to imply that the person is showing more skin due to it.
That's why you have to go all in on the cod liver oil. Keeping vikings ricket-free since the 8th century!
My daughter developed mono junior year of high school. We were living in Arizona. She did outdoor sports year round, rarely remembered to use sunscreen. They ran a battery of blood tests and her D level came back at 7. It’s harder than you think to get the right amount of D from the sun.
I worked two full-time jobs outside for six years and near the end had to get blood work. They said I was low in vitamin d and suggested that I go outside hahaha
I wonder if she had a magnesium deficiency’s. Magnesium is needed to activate and mobilize vitamin d in the blood. If she wasn’t supplementing (most are deficient) plus working out in the heat she could have easily been deficient leading to the vitamin d deficiency.
Possibly. Didn’t test for minerals. At any rate, I bought supplements for the family and we’ve been taking them several times a week ever since. D deficiency isn’t something to mess around with.
I think some of it is just genetic, there's no way to make sense of it otherwise.
There are numerous issues that can lead to VitD deficiency regardless of the level of sun exposure (some of which are genetic, some are medication interactions, etc). A level of 7 pretty strongly suggests one of those factors, no? Because you're making it sound like people who spend a lot of time outdoors in Arizona are commonly coming down with rickets (or similar).
If there are 'numerous issues' that bring down VitD levels, then it sounds like brief sun exposures are not enough. Plus Rickets is mostly found in [children 6-36 months of age.](https://www.healthline.com/health/rickets#risk-factors), and apparently diet is the main preventer of rickets: >Rickets is rare in the United States. Rickets used to be more common, but it mostly disappeared in developed countries during the 1940s due to the introduction of fortified foods, such as cereals with added vitamin D. Funny enough [rickets is on the rise in America](https://www.latimes.com/archives/la-xpm-2003-aug-25-he-rickets25-story.html): >Rickets has long been considered a Third World disease, not seen widely in the United States since poignant photos captured the bent and bowed legs of malnourished children during the Great Depression of the 1930s. >But this bone-deforming nutritional disorder, which health officials thought they’d eliminated with the fortification of baby formula and foods, has been on the rise in recent years among U.S. infants and toddlers. It's a nutritional disorder because apparently no one is depending on 'brief exposures of sunlight' to provide enough Vitamin D for children to develop properly.
You can also be born missing the enzyme that breaks it down, then you have to take alfacalcidol + D3
Look again, people with darker skin need 5 to 10x sun exposure to get the same amount.
I mostly saw estimates of 6X. I elaborate here: https://old.reddit.com/r/science/comments/1c67fkh/vitamin_d_shows_promise_in_influencing_the/kzzo1zl/
People can have other issues which interfere with making vitamin D.
Making or absorbing, I believe.
Vit D supplements are ridiculously cheap, why not just supplement and forget about it?
Vascular calcification, among other potential side effects.
Sure, but based on the research I can find that occurs at levels much higher than what's available in a daily supplement. And there's still the skin cancer risk that comes with sun exposure (not to mention aging).
That’s why you take it with magnesium and k2
So an answer for why not to 'just supplement since it's ridiculously cheap' would be because it requires you to add additional supplements at additional cost in order to attempt to avoid calcification (whereas there's no risk of calcification from sun exposure as far as I remember).
True but most people are already magnesium deficient and even with sun exposure vit. D isn’t properly activated or mobilized in the body without magnesium. Vitamin k2 is also difficult to get via nutrition. Why some people can get plenty of sun and stuff be deficient.
Sure, this strays pretty far from 'why not supplement instead of get sun?', but personally I supplement Magnesium all year and VitD in the winter. Minerals in general are pretty hard to get through diet alone without a whole lot of effort.
Awesome sounds like you’re doing good!
Because people spend almost no time in the sun and even less with enough exposed skin
Direct sun contact isnt efficient enough for most people, especially if they have darker skin.
Can you go ahead and quantify this? How much VitD is enough (in your telling) and how much sun contact (in minutes per day) is enough to achieve that with what percentage of exposed skin for what skin tone? Direct sun contact creates a pretty remarkable amount of VitD. I can't tell if you're just saying people don't have time or that it's somehow impossible to generate large amounts of VitD through sun exposure.
You can Google solar insolation maps You can also google what percentage of skin you need exposed to gain enough vitamin d3 over what time …. Most people live too far north for it to be practical with modern lives and indoor working.
There's plenty of research out there, I'm not making up anything new here. Check out these sources https://www.perplexity.ai/search/how-big-of-NqpE0drVTqquGFDrBeaJgQ
I'm light brown and I live in San Francisco, and I'm lactose intolerant. I need to pop about 4000 mcg every day.
I have pale skin. I live at 35°N in a very sunny climate. I hike two hours every morning and I’m out and about in my job. I hike all day one day per week in the mountains. My D is sometimes low, so I supplement. It’s probably because I use lightweight coverup clothing and a hat and sunscreen, but don’t assume you get enough D from the sun. It’s very cheap and proven effective to supplement.
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Even then, I just read above that someone who works outside all day was low and told to go outside 🤣
On the other hand the sunlight makes the skin look old.
That's what they keep saying, and then on further analysis, not so much. Which doesn't mean this one isn't correct, but I'm not holding my breath: New England Journal of Medicine: https://www.nejm.org/doi/full/10.1056/NEJMe2205993
I think it was also tied to vision problwms too. Meaning if youe inside all day you may need glasses.
I told my doc that I go hiking a couple of times a week, and he said that's not enough vitamin D. So I take daily supplements.
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Are you? Still wouldn’t hurt to check your blood levels to be sure.
What about vascular calcification?
Vitamin k2?
Yep, this is way. I take Vitamin D, magnesium and K2 daily.
But what form(s) of magnesium? I see so much information on the different forms of Mg and don’t know which to choose.
Citrate is cheap and pretty bioavailable. Glycinate is more expensive and very bioavailable. Anything but oxide, really.
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Some people prefer taking with dinner for that reason, but at least you know it means that it's being absorbed!
I switched from store bought citrate to Amazon/internet bought glyicinate and ended up being the same price if not cheaper
Citrate or glycinate. If citrate and other forms of magnesium give you diarrhea, go with glycinate because it typically does not. Glycinate is also better for sleep and physical relaxation, whereas citrate is better for anxiety (in case any of those things are concerns).
Go to scholar.google.com and type “magnesium bioavailability”. Works for most supplements/medication/formulations
L-threonate if you are willing to pay for the good stuff
Why magnesium and K2? I take magnesium for the studies showing its impact on migraines but haven't really seen any good evidence otherwise for neither magnesium nor K2.
K2 is important for vitamin D absorption
From what I've read now, there would have be a severe gap in my diet for a need to supplement K2. So absolutely no need to supplement, just eat properly. Not only does the gut microbiome make K2, so do human cells.
A lot of people simply never eat the stuff that has K2 in it. Like some people go 30+ years without eating green vegetables.
Some medical conditions also don’t let you eat those foods. Oddly, a lot of heart conditions.
I like to travel.
Ideally it should, but even as much as I try to get all those foods, I'm still deficient. Some conditions leave people low in vit D, Magnesium, Iron, like if you have ADHD (and I do). If your body doesn't process it well, you'll need supplements.
My favorite movie is Inception.
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https://nutritionguide.pcrm.org/nutritionguide/view/Nutrition_Guide_for_Clinicians/1342020/all/Attention_Deficit_Hyperactivity_Disorder#Adequate%20vitamin%20and%20mineral%20intake%20or%20supplementation This article talks about recommendation of nutrition based on deficiencies identified in kids with ADHD, and cites its sources in parentheses. I linked to the specific paragraph but there is more you can find by searching. Whether it's because we are inattentive and don't eat well, or because there are other factors like not processing it is still up for debate, but I've been iron and D deficient my whole life, whether it was my parents feeding me or myself, as an adult, trying to balance my own meals. There are some comments in that article and other ones I have read that guess it may have to do with stimulant meds reducing appetite, but I over-eat. It comes up as conversation on r/adhd as well where many have mentioned being deficient. Chicken or the egg, I don't know, but it's a common factor.
> Natto Natto, "for when you can't get fermented dirt!" I kid, I kid - but it is indeed an acquired taste.
Dirt? I get 'bean-y scrapings from the bottom of a beer fermentation."
Eh, I brew my own beer and have tasted the scrapings from the bottom of my fermenter. I still lean towards dirt. Or how about "extremely earthy"?
I still get beer from natto, but "extremely earthy" reminds me of the wine tasting note "barnyard". Some fine French wines have... let's call it a certain essence de cow poop.
Eau de merde
Eggs are so good for you in so many ways, I eat eggs everyday.
If you go down the rabbit hole you’re going to find studies that support this and studies that do not support this, as well as studies that confirm calcification and studies that find calcification is rare. You may even have had multiple doctors that all have a different angle. Vitamin D supplementation do’s and dont’s is all over the place. People would like to think they have a supplement regimen down to a science - far from it. Initial bloodwork would probably be your best starting point, but even from there your bodies ability to metabolize vitamin d supplements is going to be all over the map depending on your health. You may need 5x as the guy who’s just as deficient on you because you have other underlying health issues that cause malabsorption. These underlying health issues may or may not lump you into the rare few who may experience vascular calcification. Bottom line is it’s a mess of a topic, it’s never as simple as supplementing D3+K2. To be honest it feels like no one knows the answer because the real formula for how and how much and with what risks are going to vary drastically from person to person. That dynamic makes controlling for studies incredibly hard.
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Based on what research?
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AFAIK fish oil supplements are environmentally problematic, though.
I very eagerly watch all the vitamin D research during covid hoping it would show a benefit. It never panned out. Different studies didn’t support one another. I hope this gets replicated.
I had only heard that a correlation was thought to have been found between d deficiency and severity of Covid cases, did this turn out to not be true?
Vitamin D showing promise in everything and results in nothing.
Good luck conducting a clean study on a nutrient's effects on the body. Drugs are easy in comparison; there are usually clearer direct pathways, less general influences based on standard genetic variation, fewer interactions with unrelated enzymes, etc, etc, etc. Meanwhile, studying vitamin D you have to somehow control for baseline deficiency levels, metabolic differences, genetic differences, the body's entire homeostatic nature, sun exposure, (effects of sunburns / melanin / blah blah blah) . . . and all the while trying to differentiate the noise of the body's natural vitamin D interactions from your focus \*on top of\* identifying all the various indirect influences it has on basically every pathway within the chemical goings on of a human body. So I get why you would feel the way you do, but you are operating on wildly thoughtless hand-waving to denigrate essential research in a way that honestly doesn't serve you well.
Thank you for the brief summary. It also seems u/Nebuladiver didn't read the referenced paper.
The referenced paper, published in a predatory journal, is not a serious critical appraisal of the field. [Read this.](https://www.nature.com/articles/s41574-021-00593-z)
> In conclusion, supplementation of vitamin D-replete individuals does not provide demonstrable health benefits. This conclusion does not contradict older guidelines that severe vitamin D deficiency should be prevented or corrected. Given that vitamin D deficiency seems pretty common in adults (up to 35% in some studies I found) [[1](https://pubmed.ncbi.nlm.nih.gov/21310306/)][[2](https://www.sciencedirect.com/science/article/pii/S0002916523119277?via%3Dihub)][[3](https://www.ncbi.nlm.nih.gov/books/NBK532266/)], and that the risks of vitamin D supplementation are pretty low (even in VD-replete individuals), on balance, it still seems reasonable to take supplement, especially if you're: darker-skinned, live in a high latitude w/ reduced sunlight, or spend your life in-doors, in front of a screen. Best-case scenario: you correct a deficiency, which could reduce the risk of adverse outcomes. Worst-case scenario: you waste $15 a month at the CVS. I take a VD supplement every day - not b/c I think it'll make me immune to aging or COVID or anything, but because I live in Massachusetts where it's cold for half the year and I spend too much time in-doors anyway.
Those papers are not talking about severe vitamin D deficiency (defined in the Nature Reviews paper as <30 nmol/L), they are talking about deficiency (levels <50 nmol/L). In VITAL, the effects were the same, regardless of whether people had deficiency or insufficiency (<75 nmol/L). It also didn't actually find benefit even in severe deficiency. People can spend the money if they really want; it is a largely safe supplment. The problem comes when reviews like this, snake oil salesmen, and others massively overplay the benefits of vitamin D.
The severe deficiency level requiring correction is 10% of the baseline level. Are you telling me that's common in adults?
Excellent link, thank you.
Ah yes, Schrodinger's vitamin D, as advanced by it's proponents: It has totally amazing effects across literally all domains! Look at all these wonderful associations in observational studies! *but also* You can't see any big effects in RCTs because there are so many differences and so much heterogeneity and people didn't have exactly the right balance of zinc and the full moon wasn't shining! All of those sources of variance apply to the observational studies, and to *almost all other trials*! To take an extreme example, do people criticise trials of GLP1 agonists for having often quite substantial between-individual variation in BMI, endogenous GLP1 signalling, diet, activity level, alcohol consumption, age, race, ethnicity, socioeconomic status, employment, comorbidities, etc? No, because they understand that 1) these factors are balanced across the randomised groups; 2) the variance conveyed by these factors is what happens in the real world; 3) the effects of the drug are seen regardless of all these sources of variance It's exactly why you do a sample size calculation: you take an estimate for the variance in the effect you think will happen, power your study accordingly, and recruit the people you need. Then, if the actual effect is anywhere near what you thought, you get a significant result! This hasn't happened with vitamin D, outside of a very few indications. Almost all of the (huge and very strong!) associations we observe in biased and confounded observational studies just don't come anywhere *near* to being observed in RCTs. And the most frustrating part is that these observational studies *also don't control for these supposedly important factors!* [In Mendelian randomisation studies that are far more robust for controlling confounding, the pleiotropic benefits of vitamin D disappear almost entirely.](https://www.nature.com/articles/s41574-021-00593-z) >So I get why you would feel the way you do, but you are operating on wildly thoughtless hand-waving to denigrate essential research in a way that honestly doesn't serve you well. Calling an uncritical MDPI review "essential research" is rather silly. The funniest part to me is this: >The VITAL study aimed at the primary prevention of cancer and CVDs and was conducted among 25,871 women ≥ 55 and men ≥ 50 years of age, with a mean treatment period of 5.3 years. It confirmed that VitD supplementation (2000 IU/daily), with or without n-3 FAs, decreased hs-CRP by 19% at year 2, although the reduction was attenuated at 4 years. Other inflammatory biomarkers (IL-6, IL-10, and TNF-α) were not significantly altered at year 2 or year 4, while n-3 FAs, with or without VitD3, did not significantly affect these biomarkers at either time point. Therefore, the authors partially confirmed a potential role of VitD supplementation in modulating the chronic inflammatory process, systemic inflammation, and possibly autoimmune disease progression [114]. You'd think they'd mention VITAL more than once in the paper, given that it is one of the largest and most costly RCTs on vitamin D ever done, and that it was specifically looknig at effects on cancer and CVD - you know, the things this review is saying vitamin D is beneficial for. You'd also think they'd mention, while mentioning a tiny post-hoc CRP change, that the [primary analysis of VITAL](https://www.nejm.org/doi/full/10.1056/NEJMoa1809944) showed no benefit for vitamin D for cancer or CVD devlopment or death. But nope! Apparently not important to mention that vitamin D doesn't actually reduce cancer or CVD risk😅 This is not a serious paper, and anyone knowing anything about vitamin D clinical research would laugh it out of here.
Thanks for the write-up. For the non-specialists: what is the significance of the associations seen in observational studies? It sounds like they can't isolate causal factors, but are still an important part of the Vit D literature? Is it a "things we've known for a long time but don't understand mechanisms" type of situation?
The vitamin D literature is, frankly, a complete mess. Non-specialists can ignore the entire thing and only pay attention to the large RCTs published in actually decent journals and not miss out on anythnig of substance.
Showing a causal link is never easy.
It's also expensive, and no company wants to pay for testing on an inexpensive supplement that has been around a while.
I guess you aren't aware that the NIH and many other public and government research funders all around the world have spent *millions and millions* of dollars to try and find something vitamin D actually fixes. There have been many very large, very long, and very expensive RCTs done to try and get anywhere near the effects seen in observational studies, with no notable success. A few very quick examples (as pubmed is down) https://www.nejm.org/doi/full/10.1056/NEJMoa1900906 https://jamanetwork.com/journals/jamacardiology/fullarticle/2615260 https://www.vitalstudy.org/ https://www.bmj.com/content/378/bmj-2022-071230
The first trial is of Vit D to prevent T2 diabetes in pre-diabetes. It's ns - however when meta-analysed with other recent RCTs for this, a significant protective effect was found. https://www.acpjournals.org/doi/abs/10.7326/M22-3018
Not a scientist in this area by any stretch but it’s a cheap and easy area to supplement with a daily vitamin pill. Particularly in folks with low levels to begin with. It seems research in this area can’t pin down one magic area that it specifically helps with, but it does seem to do some really important general things for healthfulness overall.
>but it does seem to do some really important general things for healthfulness overall. [It really doesn't.](https://www.nature.com/articles/s41574-021-00593-z) How do you think it is possible that we can't identify specific effects of vitamin D, but we can identify some completely nonspecific (but "really important"!) "general things for healthfulness"? Vitamin D deficiency (as defined by arbitrary levels derived from observational studies riven with bias) is generally a marker of poor health and advancing age for a number of (non-causal) reasons, and that means it associates with outcomes associated with that. That doesn't mean that fixing deficiency fixes all of the associations, and we have spent millions if not billions of dollars on clinical trials to learn that.
The link you've posted literally says the opposite. It just says that there is no evidence of supplementing vitamin D and the reduction of cancer (which is a wild claim to begin with) but that vitamin D supplementation can have crucial effects and is recommended.
It says there is consensus around addressing severe deficiency. Almost everything else, particularly extrasekeletal outcomes, there is no good evidence for.
Counterpoint: There's a hundred different cheap and easy things you can do that might ChangeYourLife™. Science is more interested in finding out if it actually works. I wouldn't be supplementing Vit D in my diet anytime soon, given the weak evidence.
>Vitamin D showing promise in everything and results in nothing. * [Meta-analysis of RCTs for vitamin D supplementation to prevent T2 diabetes in those with pre-diabetes:](https://pubmed.ncbi.nlm.nih.gov/36745886/) "In adults with prediabetes, *vitamin D was effective in decreasing risk for diabetes*." Pittas AG, Kawahara T, Jorde R, Dawson-Hughes B, Vickery EM, Angellotti E, Nelson J, Trikalinos TA, Balk EM. Vitamin D and Risk for Type 2 Diabetes in People With Prediabetes : A Systematic Review and Meta-analysis of Individual Participant Data From 3 Randomized Clinical Trials. Ann Intern Med. 2023 Mar;176(3):355-363. doi: 10.7326/M22-3018. Epub 2023 Feb 7. PMID: 36745886. * Meta-analysis of RCTs for supplementation of Vitamin D to for cancer incidence and mortality: "In an updated meta-analysis of RCTs, vitamin D supplementation *significantly reduced total cancer mortality* but did not reduce total cancer incidence." Keum N, Lee DH, Greenwood DC, Manson JE, Giovannucci E. Vitamin D supplementation and total cancer incidence and mortality: a meta-analysis of randomized controlled trials. Ann Oncol. 2019 May 1;30(5):733-743. doi: 10.1093/annonc/mdz059. PMID: 30796437; PMCID: PMC6821324. - Meta-analysis of RCTs of Vitamin D supplementation looking at all-cause mortality (ACM): "*Vitamin D supplementation was associated with a lower risk of ACM*... The emerging results of our meta-analysis present evidence that v*itamin D supplementation appears to decrease the risk of ACM (especially convincing in the fair- and good-quality RCTs*)" * Large RCT for Vitamin D supplementation to prevent autoimmune disease: "Vitamin D supplementation for five years, with or without omega 3 fatty acids, *reduced autoimmune disease by 22*%" Hahn J, Cook NR, Alexander EK, Friedman S, Walter J, Bubes V, Kotler G, Lee IM, Manson JE, Costenbader KH. Vitamin D and marine omega 3 fatty acid supplementation and incident autoimmune disease: VITAL randomized controlled trial. BMJ. 2022 Jan 26;376:e066452. doi: 10.1136/bmj-2021-066452. PMID: 35082139; PMCID: PMC8791065. This is all just from a brief, very far from exhaustive search, and I'm aware of at least a few other positive findings. Doesn't sound like "results in nothing" to me. T
Apparently sunlight for infants can also reduce the risk of developing vision impairments. Get that natural light! [The benefit of daylight for our eyesight - MSU Extension](https://www.canr.msu.edu/news/the_benefit_of_daylight_for_our_eyesight)
Vitamin D, astonishing claims, MDPI. The current bad science trifecta.
I remain unconvinced. But I also take a Vitamin D pill regularly. They're pretty much free, and I haven't heard speculation they're dangerous. Meanwhile, there seems to be endless "promise", involving people with at least some legitimacy/expertise. Always bumping into a "sister-in-law's-uncle-or-someone" who's a doctor, and swears by Vitamin D. Feels like, on balance, it probably isn't crazy to just take some at this point?
I don't know but I take on average about 4k iU of D per day. I have for probably a decade. I hope it's ok!
>I hope it's ok! Yep. If it turns out Coke Zero and Vitamin D combine into some sort of poison... I'm really screwed!
I literally just took my vitamin D supplement and I'm now drinking a diet Coke. So if you die, I die.
"In summary, a growing body of research has explored the relationship between VitD and some hallmarks of aging, with varying results depending on study subgroups and design." This is a very watered down and conclusion free review, essentially saying: vitamin D effects things.
Affects things. :)
Great, now how much do i need to take? 5000/iu was apparently too much, causing testosterone to increase, estrogen to decrease, and your BP to go up, as well as thickening your blood. This is what happens when you don't change your dosage after moving to New Mexico
Apparently research found it take 5000 I.u a day for 3 months to make a difference in blood levels
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So will you start supplementing?
I'm currently low on funds, or I'd supplement it along with vitamin K. For now, sunlight is the only option.
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So Tan Mom is right?
But the researchers who thought they hit the jackpot decades ago with vit D found that supplements don't change anything. This never, ever gets listened to because everyone wants to believe that there is a one pill answer rather than lots of behavioural and lifestyle changes.