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Vitamin D deficiency worsens Respiratory Tract Infections: Meta-analysis (ncbi.nlm.nih.gov)
118 points by HaukeHi 2287 days ago
9 comments

Absolutely, not only respiratory but all the illnesses. It affects your immune system. But with cavaets:

- It won't make any effect for around month once you start taking it

- it only has effect if you have serious deficiency.

I used to be sick really easily for years, always tired. Finally got doctor to make blood tests and if normal level 100, min is 60, then my vitamin D levels were 12. Ofcourse my body immune system struggled. After started with suppliments got more energy, got less often sick. Felt like a normal person.

There is also other extreme, taking too many will have negative effect. I've experienced them myself.

I do live in a northern climate (imagine Finland) with long dark winters and only sun time is spend in the office.

The negative effects only happens if incorrectly supplemented.

75% of the population is suboptimal in Magnesium, without Mg - our ability to absorb D diminishes, even with supplementation.

Vitamin D must be supplemented with Vitamin K2 MK7 to ensure the extra calcium generated is deposited in the bones and not in the soft tissues (hypercalcemia)

Subclinical magnesium deficiency: a principal driver of cardiovascular disease and a public health crisis https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5786912/

Magnesium Supplementation in Vitamin D Deficiency. https://www.ncbi.nlm.nih.gov/pubmed/28471760

Low magnesium levels make vitamin D ineffective https://www.sciencedaily.com/releases/2018/02/180226122548.h...

Vitamin K: Double Bonds beyond Coagulation Insights into Differences between Vitamin K1 and K2 in Health and Disease https://www.mdpi.com/1422-0067/20/4/896/htm

Vitamin K2: A Vitamin that Works like a Hormone, Impinging on Gene Expression https://www.intechopen.com/books/cell-signalling-thermodynam...

If you take a lot of vitamin D, you have to make sure that you are getting enough magnesium.

Also, vitamin D really shouldn't be taken any other time than before noon.

(Not sharing this for you in particular, just for anyone reading who decides to try vitamin D supplementation for the first time. Doctors aren't always sharing she vital info about how to take vitamin D)

> Also, vitamin D really shouldn't be taken any other time than before noon.

I'm sure I could go find sources, but it might be helpful if you link them here. It's hard to believe comments that give medical information and disparage doctors.

The theory is that vitamin D intake helps set the circadian clock because it has been correlated with exposure to sunlight for hundreds of millenia. I think Gwern did a single blind experiment on himself and found some correlation to lower sleep quality if it's taken at night.
I'm actually just completing a high-strength vitamin D tablet course and the advice for taking it in the instructions is to take it with your evening meal, so sounds like a load of hogwash.

Here, for example, are the instructions that came with my tablets:

https://www.sunvitd3.co.uk/site/wp-content/uploads/2019/01/S...

Note the:

"Please Note: SunVit-D3® tablets should be swallowed whole with water and taken in the evening with a main meal."

The reason for that recommendation is that Vitamin D absorbs better in a meal with fat, and dinner is the biggest meal for most people.

See my other comment in reply to parent. There might be lower quality sleep because of the timing.

https://www.gwern.net/zeo/Vitamin-D

Why magnesium? Any references?
> vitamin D really shouldn't be taken any other time than before noon

Does this advice apply to people that work night shifts?

I believe the actual science (rather than than that it's somehow sensitive to the time of day) is that it requires sunlight (UV) exposure to absorb, rather than just be excreted.

So if you work a nightshift, hopefully there's some opportunity still to get some sunlight either side, and you should take it before that.

(IANA healthcare professional)

Specimen 1) - A thorough meta analysis on a sizable amount of data

Specimen 2) - The first comment on hackernews: Unfounded anecdata

What a disappointment.

While one supplement is in trend, as now with vitamin D, when you search and try to make a decision if you should supplement it, you always end up deciding it is beneficial, or at least doesn't hurt to. But as the trend fades, you may find that it is not that important or even harmful to overdose in specific situations.

So I am skeptical of supplements as a rule. Of course there are a couple of odds, like iodine, which is so beneficial to supplement in general community, that it is added to table salt as default, you only skip if you have specific conditions like thyroid problems.

I wish there were more research or comments on possible harms and disadvantages of excessive use of vitamin D, than I think I could more easily decide to use.

I really don't see the issue. All vitamin d sales come with daily dosage information. There's (always going to be) some issues with literacy to understand this information, but that's it.

If you follow the daily dosage information, you won't even get near harmful levels of vitamin d. Recommended is about 600 IU daily. If you take 60.000 on a daily basis for months, you build up toxicity.

For that you typically need to take 30 pretty strong 2000 UI pills on a daily basis for months, while ignoring the label that states each pill is typically 250% of the daily recommended amount, and the instruction which notes the tolerable levels max out at just two daily pills.

Toxicity is extremely uncommon. Whereas deficiency is extremely common. Up to a billion people are expected to have some form of vitamin d deficiency.

That's not to say it's not a problem, but rather that it's very rare, nothing like say an opioid overdose problem. As with all things, balance is key. You can overdose on 5 cents of water in the span of 5 minutes. Acute vitamin d overdose is known to happen if you take something like 300-1000 pills of 2000 UI over a period of days, which is pretty insane.

You reminded me of a paper that suggested that there was an error made in developing the RDA of Vitamin D; the 600IU RDA may be wildly wrong.

“ It also estimated that 8895 IU of vitamin D per day may be needed to accomplish that 97.5% of individuals achieve serum 25(OH)D values of 50 nmol/L or more.”

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4210929/

It's important when megadosing vitamin D to be getting enough magnesium, and to make sure you're taking it earlier in the day, so as not to disrupt your circadian rhythm.
But from the same article:

Hypervitaminosis D symptoms appear several months after excessive doses of vitamin D are administered.

A similar article was discussed previously here https://news.ycombinator.com/item?id=22463713
This is a more recent meta-analysis, but thanks it's helpful that you're linking to the discussion.
From the first sentence in the abstract:

"however, findings are inconsistent"

Agreed - I believe the meta-analysis and the underlying studies are likely of poor quality.

I think it might be worth for people here to reanalyze everything.

The effect sizes seem large and clinically significant.

So this is big if true.

I fear that the second this hits major mainstream media, all vitamin D capsules still left in stores will immediately be hoarded by the same people who hoard toilet paper...
You're two steps behind. Who do you think pushed all these "nutritional recommendations" ?
It already is here in The Netherlands. Vit-D and Vit-D supplements are pretty much all gone.

Luckily we have a large supply in house thanks to being forgetful and needing it for the baby. My wife has a large supply of girly multivits and I managed to score a months supply of multivits.

Vit D deficiency is omnipresent in today's society. Literally almost everyone I know has it. Supplementing Vit D drastically changed my mood. Too bad public healthcare in Europe, especially the NHS in the UK, doesnt recognize Vit D deficiency as a problem.
"...the NHS in the UK, doesn't recognize Vit D deficiency as a problem."

The NHS does recognise vitamin D deficiency as an issue.

In the UK, a science advisory body (Scientific Advisory Committee on Nutrition) published a 300 page report of the evidence on vitamin D and health in 2016. Their conclusion: adults and children over one in the UK should have at least 10 micrograms of vitamin D every day. For some people this may mean taking a vitamin D supplement. People who have a higher risk of vitamin D deficiency are advised to take a supplement all year round.

Here is an overview of the guidelines on the NHS website which includes a link to the 300 page scientific review.

https://www.nhs.uk/news/food-and-diet/the-new-guidelines-on-...

Yeah, these guidelines are on point not gonna deny that, but the doctors are actually far behind reading these. My hypogonadism wasn't diagnosed for years despite being in the guidelines. NHS docs just dont care, no skin in the game. My friends dad is a NHS doc and he just admits he tries to process patients faster as it gives him more money, and diagnoses them faster since they get paid per diagnosis not per visit.
I'm highly sceptical of it being anything but a placebo for most people. I live in the UK so I'm a good candidate for deficiency but I don't actually feel anything is wrong with me. Everyone thinks they are tired all the time and their sex drive isn't as high as it could be. If I supplement vitamin D the only thing it does is give me constipation. I'm sure there are some people with actual deficiency, but if you're white and go outside sometimes you're probably fine.
There's a difference between sickness-causing deficiency and optimal level. Most people are somewhere in between. If you tried and it didn't make a difference, then you're probably around the optimal level.

However, the specifics do matter; see e.g. https://www.gwern.net/zeo/Vitamin-D - this is n=1 but consistent with many other n=1 self-experiments I'm familiar with; personally, my sleep is improved with increased protein consumption AND 10,000 IU D3 before 10AM (Both contribute; I've not gone about 10,000 IU, but 5,000 UI has a much lesser effect)

I have not find a peer reviewed time-of-taking-D3 paper when I looked, but D3 is recognized as a timing mechanism ("Zeitgebber") in many papers I've found.

Maybe you're not actually deficient, even though in theory you could be. I used to get regular seasonal depression, to the point that I'd struggle to get out of bed at times. And I'd crave sunshine. Of ot was sunny. I'd obviously tried a lot of things. Changing diet, exercising, and also SAD lights which helped a tiny bit, but not really. Regular supplementation with vitamin D has made this almost entirely go away. I'm a completely different person.

So while you not everyone who is feeling tired or depressed will have a vitamin D deficiency, I'd say that it absolutely can cause those symtoms.

Literally everyone you know got tested for vitamin D levels?
Interesting, vit D deficiency and TB immunity both run in my family.
Sunshine has always been helpful for people with TB, I wonder if that is why people get more chest ailments in winter, ie colds and flu?
(2019)
Vitamin D went out of fashion in 2020?
Also consider combining w/ K2 (as MK-7) for better absorption.