In the PDF they are all titled as

"Assistant Professor, Department of General Medicine, Arundathi Institute of Medical Sciences, Dundigal, Medchal Malkajgiri, Telangana, India"

The 2nd author is listed here: https://aims.ac.in/general-medicine/ I did not find any trace for the other two authors (do they exist?).

Also, look at the timings: Received: 16-09-2025 Accepted: 29-09-2025 Available online: 14-10-2025

That's relatively fast but also the paper is not super in-depth.

And in general it seems like that the "International Journal of Medical and Pharmaceutical Research" is not quite well known. See the Editors, not even pictures there: https://ijmpr.in/editorial-board/

My bullshit meter redlined as well.

> Incidence of ARIs was documented through monthly follow-up visits and self-reported symptom diaries validated by physician assessment.

This is basically impossible to accomplish for 386 participants who aren't in some form of captivity (e.g. incarcerated, institutionalized, in the military, or a boarding school). Nobody cares enough to maintain a "self-reported symptoms diary" and make monthly visits for some study. If they actually ran the study as designed, they would've have zero usable participants even starting from 400.

Saying nothing of the ethics of giving half the Vitamin D deficient patients presenting at your clinic with a placebo.

While I find your comment enjoyably pithy, in the case of vitamin D, many humans are currently living at latitudes which they are not suited to (skin being too dark to generate enough vitamin D given the insolation), and eating diets which do not provide them with sufficient amounts of it (the carnivore diets of Inuits and similar groups being a good contrast).

Man suffered outdoors very much, for a million years.

Man want both good of indoors and good of out outdoors.

While I’d love to just go for a walk outside, the allergen exposure of the outdoors is too high most of the time. This elements any mental health benefits a walk in a forest might otherwise give.

How do I bring outdoors to the wage slave office? And how do I bring light to the pre-work and afterwork when there is no sun at those times?

The practical man uses technology to offset the prison built for him. The hapless enabler farms “pithy” HN points in his LED-lit room.

The issue I've found with these discussions is it appears there's mixed evidence on if vitamin D *supplementation* actually has a positive impact, regardless of vitamin D deficiency. In other words, is the deficiency causal or correlative.

I have no opinion on the matter, and am inclined to think there is at least some positive benefit. But YMMV

Vitamin D isn’t technically a vitamin in the strict sense, because unlike the other vitamins the human body can produce it itself (by exposure to sunlight).

I don't agree. As with everything, it requires care. Taking a multivitamin and thinking you're good to go is delusional.

People like ErikCorry will get you to suffer greatly and then get you killed with their extremely harmful disinformation. Most doctors are no better in this way, although some are.

How do you feel about vaccines and Tylenol?

One significant difference in this study is that it focused on people with low baseline vitamin D (10-30 ng/mL 25(OH)D), and moderate intervention (2000 IU daily).

The meta-analysis you posted did perform subgroup analysis on people with low baseline vitamin D (<25 ng/mL), but this included a wide range of intervention levels, 90% of which were <2000 IU daily equivalent. They also performed subgroup analysis on high intervention levels, but this included a wide range of baseline vitamin D, 90% of which were >25 ng/mL.

"Winnipeg, Manitoba" ... "only need 15 minutes of sunshine per day to get your recommended dose of Vitamin D"

That doesn't apply to you most of the time, unfortunately. Vitamin D is the result of UVB exposure. For significant portions of the year, you don't get very much [1], compare with, say, [2] Orlando Florida in the US. 10-15 minutes is for a UV index of 7 [3], so that's only 4-6 months out of the year for you. And just based on my couple minutes with Google here, that number may also include the assumption that you're not just "out in the sun" for 15 minutes, but basically sunbathing. Lesser exposure may take longer: [4] Winter times can be effectively impossible because you can't sunbathe at 10 below (regardless of which scale I'm talking about) and you're not going to spend the requisite hours in the sun for what little skin is exposed. Or they can be outright impossible if your skin is dark enough.

[1]: https://winnipeg.weatherstats.ca/charts/forecast_uv-monthly....

[2]: https://nomadseason.com/uv-index/united-states/florida/orlan...

[3]: https://overcomingms.org/program/sunlight-vitamin-d/uv-index...

[4]: https://vitamindwiki.com/dl2105?display

I take 5000 IU per day year round and have not had any issues. Research suggests you can dose 10x that without major problems, although personally I wouldn't go higher than I am already.

https://pubmed.ncbi.nlm.nih.gov/30611908/

You probably have to really try to take too much Vitamin D with any over the counter supplement (<=5,000 IU), especially if you live that far north. For reference, a prescription dose for someone who is low is usually 50,000 daily.

It should be part of your standard blood tests so you should know if you're running high or low and your doctor can recommend or prescribe a good dose.

First know that the body will stop making vitamin D before you reach overdose quantities. This means you should take vitamin D in the morning.m rather than the evening. Second know that vitamin D is fat soluble. So if you are losing weight, you can more easily overdose if you have high levels stored in your fat. Also know the body won’t absorb as much vitamin D if you don’t take it with fat.

This can make dosing tricky. You can be taking an amount that is safe right now, but then is too much later.

You can max out your body’s vitamin D production even on a cloudy day, though the sun’s angle of incidence effects production.

The body typically maxes production at something like 20k iu (pleae verify this number it has been a while since I learned it), so staying below this number should mostly safe.

The USDA has set its recommended daily allowance mostly to avoid rickets. It is largely considered too low a number for general well being.

I live in north western Washington, and previously used to combat seasonal affective disorder, with some pretty dark thoughts come february. Since I started taking 1k D3 some 20 years ago much of the seasonal mental health has gone away. I take 2k D3 consistently currently, and if I run out for more than a week my mood starts to deteriorate quickly. I still haven’t proved causation since there are likely reasons I’ve let myself run out of the supplement that long, but it is so consistent that I treat it as causal at this point. YMMV

Please do research above just asking a forum for dosing advice though. This is a well educated place, and I would very much trust it as a starting point, but there is a lot of good published content on the topic. Though, I admit google is so bad today, I might fail to find any of the content I referenced years ago… if you use chatgpt make sure to require references, and check them. I find that using multiple instances to review research references separately prevents some context based poisoning as well. And pointing out inconsistencies can be a good way to find nuance in a topic. Though sometimes LLM will just waffle, and the context may be done

I've heard the 15 minutes is all you need. I've also heard that in winter the sun is so weak that no amount of sunshine gives you any. (even if you were naked outside in winter - risking frostbite).

I'm not a medical doctor. I cannot evaluate any of the above claims. I wish I could find a source I could trust.

You can get blood tests pretty cheaply. The safe level is the level that, after you take it consistently, has you in the desired range on the test.

You don't need to guess, go to your GP and get yourself tested. It's not expensive, depending on where you're from it might even be free, and usually you get the results back already the next day.

EU considers 600 I.U. per day as safe. Probably not enough if the level is low. Blood sampling is cheap, why don’t you have it checked.

25000 IU weekly during winter is OK, for an adult

I've heard things like you only need 15 minutes of sunshine per day to get your recommended dose of Vitamin D

The figure I read years ago was that it takes 15 minutes in short sleeves to get the necessary light exposure at the 45th parallel in winter. I'm right at the 45th parallel and I don't go out in short sleeves in the winter, so I imagine it's significantly worse for you!

It's possible to overdose on Vitamin D, but you have to eat absurd amounts.

Unless you eat the pills like candy, you're safe.

> typically without a meal

any reason why? it's fat soluble and absorbs much better if taken with a meal.

There can be hundreds of safe, possibly effective, and cheap interventions. Can’t try them all. Higher quality of evidence helps narrow it down.

An even better option is to go to your GP and have them run your bloodwork. It's cheap, depending on where you're from it might even be free, and you don't have to guess or randomly pick supplements you read about online. Most people on HN will live to a very high age, there's no reason to take random gambles on what you do to your body.

And K2.

As for magnesium, I would go with magnesium glycinate or magnesium threonate.

Would do...? Zinc taken the first day of symptoms may reduce the duration of a cold by a day on average. It's probably useful, but not certain.

Be sure to take zinc with meals, or your stomach may hate you.

That's Doctor Roger Seheult, MD, who hosts videos for continuing education provider MedCram (https://www.medcram.com/). They post lots of free videos on their YouTUbe channel (https://www.youtube.com/channel/UCG-iSMVtWbbwDDXgXXypARQ) and several of them cover the research behind heliotherapy.

Yeah, this is a crucial point. This is studying "adults with suboptimal baseline." If you have a vitamin deficiency and get sick, I would expect supplementation with that vitamin to provide some relief, regardless of which vitamin it is.

This does not mean that the same will happen for people who did not have a deficiency.

Having said that, there is good evidence that Vitamin D deficiency is widespread, and supplementation of Vitamin D is relatively safe unless you take excessive amounts.

Take like 2g of Vitamin C. It's a lot stronger. Vitamin D is good too, but if anything you want to take C.

There were a few soft recommendations. Specifically I remember an ER doctor in 2019 saying vitamin D seemed to be a differentiator in the sample of cases he was seeing in the ER (everyone was starting to panic) and the CDC walking it back as unsubstantiated. I mentioned it at work, then 10 days later my boss's boss asked me where I had heard it, because he had heard the same thing.

There have been a number of people on HN who have attributed any measurable COVID benefit of Vitamin D, to a confounding variable, as recently as 3 months ago - https://news.ycombinator.com/item?id=44705486 The Big Vitamin D Mistake

One of the best treatments is interferon. It's something you will also produce yourself, with therapeutic effect, if exposited to sunlight or the infrared light used in red light therapy. Here's a video about it, from a continuing education provider: https://www.youtube.com/watch?v=oRkxH56LqCo

Vitamin D therapy doesn't have such an effect.

Because the right people couldn't make money off of it - same reason that a lot of beneficial treatments were not recommended or flat out defamed.

IANAMD.

It is my general understanding that unless you are severely deficient, Vitamin D supplementation generally takes weeks to bring levels up. It's unlikely that taking it for a few days is going to have any measurable impact on your recovery from illness unless you are severely deficient and/or taking MASSIVE doses, which may or may not be recommended depending on your prior levels and BMI.

See more here: https://www.ccjm.org/content/89/3/154

e: fixed broken URL

Same... In our family we start taking Emergen-C a few days before we travel also.

> which typically helps me.

Uhm, how can you get to that conclusion? I mean: how can you compare the evolution of a cold with and without the vitamin surplus?

If there is any reason for the test, it would be diagnostic and not preventative, and that is generally covered. Just checking cause you want to know your levels generally wouldn't be, but there are any number of symptoms that could be related to that.

As for it being a "scam" - there are enough valid studies that show what this one did, that folks who are deficient that are able to raise their levels tend to be slightly healthier.

There isn't necessarily evidence for supplementation beyond "normal" range, and I do agree that no one should just take high-dose vitamin D supplements without data (tests) that it is necessary.

If it's a scam, who's profiting? The pills are dirt cheap, generic, and over the counter.

It is a double blind study. what else do you want for confirmation ?