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- Hacker News
- I have HIV and am under treatment using medication, I have found D3 and K2 helps alleviate some of the side effects of the medication; largely my mood. Which makes a lot of sense because my immunity system is in constant daily activity.
However, I need to get more sunlight; I just don't think supplementation is the same as being in the sun. When I was homeless I never had these mood issues, but that's complicated, living day-to-day & meal-by-meal puts you survival mode so nothing is really past the hour.
All anecdotal, duh.
by lonelyrock42 - Vitamin D is a biomarker of a process that happens in the body that is beneficial for longevity. This biomarker is created in response to receiving sunlight. The synthetic vitamin itself, does little, if anything, for your health. The process of receiving the sunlight is what benefits your health. This applies to a lot of other vitamin supplements as well.
So whilst you may be able to take a supplement to boost your vitamin D levels, the negative health effects of lack of sunlight are still going to occur.
by nullbio - Do you have any sources for this? Genuinely interested in reading more.by redrove
- All I know is I used to have full on colds during winter in my 20s to early 30s, like every winter I would get two weeks of runny nose till the skin became red and irritated, sore and painful throat, coughing, etc. Since I take 25000 IU (D-Cure in Belgium) like 2-3 times a month during winter for the past 15+ years my cold last 2-3 days and symptoms are much more mild. For me the data is there.
- The problem is that you don't know what your situation would be like if you'd not taken Vitamin D. There are too many variables, generally -- e.g. in your early 20s and 30s you're likely socialising with many more people (so, more exposure chances), and you may also have young children (even worse disease vectors).
I'm similar to you in experience, btw, except that I don't believe correlation is causation. But as it won't do any harm, most of us don't regularly monitor our Vitamin D levels, and Vitamin D supplements are cheap -- it becomes a harmless form of Pascal's wager that I'm happy to keep making. Nothing to lose except a very, very tiny amount of money.
by epihelix - I suspect that blood vitamin D is mainly a marker for how much outdoor exercise people are getting, and that it is the exercise rather than the D which is causal.
- Ding ding ding.
People who are drawing blood and trying to find some correlation between vitamin presence and health at this point are just practicing divination. The fact that it can be published in a scientific journal without any sort of RCT to back it up is palpably unscientific.
The customers of these studies are the supplement companies looking for another product to sell.
by legitster - It depends on one’s whereabouts and kind of exercise. Exercising in a gym or outside with all your skin covered won’t make much vitamin D.by mantas
- But then why do we see improvements in people that get vitamin D + K2 supplements and not exercise?by fragmede
- I also suspect that the frequency of outdoor exercise matters even if the total duration of outdoor exercise remains the same. Subjectively, I feel much healthier when doing thirty minutes of outdoor exercise six times a week, than when doing one hour of outdoor exercise three times a week. But then of course, all the causal effects could have been caused by a different factor (say dopamine release) than vitamin D.by kccqzy
- Maybe this is true if you’re only considering white people. Brown people can spend a lot of time outdoors and still be deficient, especially if their ancestry is from much a much sunnier region or lifestyle than the one they’re currently living in.by smt88
- Bingo. Obviously being deficient is bad, but the reason supplementation seems unimpressive is this is one of those proxies for healthy lifestyle. Kinda like how grip strength is correlated with longevity but banging out tons of hand gripper sets isn’t going to do much for you health.by ChimpWithHat
- Keep in mind vitamin D is really, among other things, an immune signaling molecule.
So, we know the mechanism, and it's quite plausible that supplementation works.
In other words, as an skeptic, I don't think it's just an epidemiological correlation.
by nextos - My life changed after I got tested for vit D and started talking supplements. I was severely deficient. I am now sufficient and everything changed for me.
- > For a while there, many people thought vitamin D was magical
I never heard that in Germany. I only heard that if you use certain medications like cortisone that vitamin d could be problematic. Most doctors will give vitamin d supplements when prescribing cortisone, at least in Germany.
by merb - Just two borders away, in Hungary, I've heard plenty of "magical vitamin D" tales. Tired? Take some D. Depressed? Take some D. Leg hurts? Take some D.
I do take it in the winter, but I'm quite skeptical regarding the panacea hype.
by holistio - Even so, it still seems to be a small effect. The author mentions some studies looking at sunlight vs all cause mortality. These, and more recent studies [1] found much higher reductions in all cause mortality from sunlight exposure, of about 30%. It's thought that other factors may be behind this, such as NO production in the skin in response to UV [2].
[1] https://pubmed.ncbi.nlm.nih.gov/32918215/
[2] https://karger.com/bpu/article-abstract/41/1-3/130/328295/Su...
by cpncrunch - Sunlight would likely get you all the "red light therapy" effects too.by Aerroon
- It's arguable whether Vitamin D is really a vitamin or a hormone, see
https://pubmed.ncbi.nlm.nih.gov/33549285/
Look at the molecular structure
https://en.wikipedia.org/wiki/Vitamin_D
that's a freakin' steroid with one of the bonds in the rings deleted
by PaulHoule - It's pretty well-established science now that vitamin D is a hormone, not a true vitamin. Vitamin D binds a nuclear receptor that regulates roughly 1,000 to 2,000 genes (5-10% of the human genome).
The "Vitamin D" moniker has just stuck around since it was named in 1922.
by brandonb - Has anyone done a RCT of D3+K2? K2 seems to be important in the absorption of D3. Another aspect that bothers me with these studies is that we’re simply supplementing the vitamin D, seemingly without measuring the change in blood levels. I took 2000IU (+K2) a day for many years in between testing my blood levels and still had <30ng/ml and had to go up to 5000IU/day. I’d like to see some further study.by rzz3
- What I found was that I had to dissolve vit D under the tongue, not immediately swallow it.by amelius
- When I did my master's thesis on Vitamin D supplementation the conclusion was that vitamin D testing is wildly inaccurate, and we needed to have studies based on a target level - ideally one based around sub-saharan African community levels.
As for supplementation, sunlight has been estimated at providing up to 20,000IU per day, which I think (not medical advice due to the lack of study), from a mechanistic point of view, suggests an upper limit to daily supplementation.
by trevorkoob - Were you taking hard tablets? And were you taking them with a fatty meal?
Those are both very important. I take a Vitamin D + K2 softgel with a meal that has some fat in it.
by odie5533 - TARGET-D is an in-progress study that supplements vitamin D based on blood levels (your idea).by brandonb
- > I took 2000IU (+K2) a day for many years in between testing my blood levels and still had <30ng/ml and had to go up to 5000IU/day.
Likewise, 23ng/ml while taking 2000iu/day of dry vitamin-d.
Switched to 5000iu +K2 in MCT oil, -- 8 months later I'm at 64ng/ml.
by nullc - K2 is also known to prevent problems with calcium build up which can happen if Vitamin D is dosed too high. I personally would never take Viramin D without K2 alongside it.by cj
- Not in the field, but every time vitamin D studies come up I am reminded of the one that called out how current recommendations are based on faulty math (confusion on how to combine different sized studies confidence ranges ) and miss the mark significantly (and a lot of studies are based on those recommendations...)by persedes
- This has come up several times before. It's not well cited. I read through it myself and even if the math is right, the application of the math seems incorrect.
The original data was a small number of studies with a small amount of old (1980s?) data that found a slope with so-so correlation.
The revised math finds a much smaller slope with what appears to be much worse fit to the same old data. The data was nearly horizontal before, but after the math changes it's much further away from 0.
The original study was making predictions near the data. The revision is doing massive extrapolation, far away from the range of what any of the studies tested.
I'm not a statistician, but it's not surprising to me that it's being ignored.
by rendaw - To save people the click: the study says that the recommended vitamin D intake is much too low.by nostromo