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Vitamin D reduces incidence and duration of colds in those with low levels

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Re: Vitamin D reduces incidence and duration of colds in those with low levels

#21

Post by snozolli »

thrusong wrote: post #4

I live in Winnipeg, Manitoba where it is quite cold for a big majority of the year. I have dabbled with supplements because I get a couple of major colds every year. I've heard things like you only need 15 minutes of sunshine per day to get your recommended dose of Vitamin D, but I've also heard it can be quite bad for you if you have too much in your system (and it's hard for your body to flush excess amounts). If t…

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!

Re: Vitamin D reduces incidence and duration of colds in those with low levels

#22

Post by scythe »

ErikCorry wrote: post #14
mwigdahl wrote: post #10

Earlier quoted context omitted.

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/

That sounds like a lot: To help prevent vitamin D toxicity, don't take more than 4,000 international units (IU) a day of vitamin D unless your healthcare professional tells you to. Most adults need only 600 IU of vitamin D a day https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-h...

Part of the issue with vitamin supplements is that the bioavailability can be unpredictable. The actual amount absorbed can vary between 10% and 100% depending on the time of day, supplement formulation, what foods if any are taken together, as well as the particular characteristics of the individual's intestines, which are difficult to assess. Because supplements are not regulated as pharmaceuticals in the United States, this variability can be severe; in the worst cases, supplements do not even contain the active principle.

So, I am not surprised that someone needs to take 5000 IU to get 600 IU worth of effect. Institutional medical authorities are (rationally) quite defensive when cautioning readers about supplement consumption; they must consider the worst case (100% bioavailability) when assessing the risk of overdose.

As an alternative to vitamin supplements, exposing common dietary mushrooms to ultraviolet light converts (by an uncatalysed photochemical reaction) the ergosterol therein to calciferol. How best to achieve this in a home setting is unclear.

Re: Vitamin D reduces incidence and duration of colds in those with low levels

#23

Post by morley »

ErikCorry wrote: post #14
mwigdahl wrote: post #10

Earlier quoted context omitted.

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/

That sounds like a lot: To help prevent vitamin D toxicity, don't take more than 4,000 international units (IU) a day of vitamin D unless your healthcare professional tells you to. Most adults need only 600 IU of vitamin D a day https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-h...

One number is not going to work for everyone. The only way to be sure is to get a blood test for Vitamin D levels. I get tested with my yearly physical, but if someone really cares they can get more frequent blood tests.

Re: Vitamin D reduces incidence and duration of colds in those with low levels

#24

Post by btilly »

kacesensitive wrote: post #13
pif wrote: post #6

Earlier quoted context omitted.

> 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?

Very well could be a placebo

Reminds me of the old, with treatment, most colds will be cured in just 7 days! Without treatment they generally last about a week.

That said, do not underestimate the health benefits of the placebo effect. It can help a lot. Particularly with anything to do with stress.

Re: Vitamin D reduces incidence and duration of colds in those with low levels

#25

Post by mwigdahl »

ErikCorry wrote: post #14
mwigdahl wrote: post #10

Earlier quoted context omitted.

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/

That sounds like a lot: To help prevent vitamin D toxicity, don't take more than 4,000 international units (IU) a day of vitamin D unless your healthcare professional tells you to. Most adults need only 600 IU of vitamin D a day https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-h...

The advice on this is all over the map and that's a big problem in the space. Reputable medical sources have recommendations almost two orders of magnitude off from each other at times.

This article, for example:

https://www.ccjm.org/content/89/3/154

...cites several cases where daily supplementation of 50K IU was required to restore normal D levels, although also a case where that same dose caused toxicity. As one of the other commenters in the thread noted, working with your doctor to establish the right level is probably the right move. If nothing else, they have the capability to test your serum levels to see where you're at.

Re: Vitamin D reduces incidence and duration of colds in those with low levels

#26

Post by jerf »

thrusong wrote: post #4

I live in Winnipeg, Manitoba where it is quite cold for a big majority of the year. I have dabbled with supplements because I get a couple of major colds every year. I've heard things like you only need 15 minutes of sunshine per day to get your recommended dose of Vitamin D, but I've also heard it can be quite bad for you if you have too much in your system (and it's hard for your body to flush excess amounts). If t…

"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

Re: Vitamin D reduces incidence and duration of colds in those with low levels

#27

Post by gilfoy »

efsavage wrote: post #16
thrusong wrote: post #4

I live in Winnipeg, Manitoba where it is quite cold for a big majority of the year. I have dabbled with supplements because I get a couple of major colds every year. I've heard things like you only need 15 minutes of sunshine per day to get your recommended dose of Vitamin D, but I've also heard it can be quite bad for you if you have too much in your system (and it's hard for your body to flush excess amounts). If t…

You probably have to really try to take too much Vitamin D with any over the counter supplement ( 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.

I’ve had a prescription twice and it was 50,000IU of D2 once weekly. Usually the OTC one people buy is D3.

Re: Vitamin D reduces incidence and duration of colds in those with low levels

#28

Post by derbOac »

Glad to see this study, seems decent, but for a different perspective there was a relatively recent meta-analysis on the effectiveness of Vitamin D for RIs that suggested no effect:

https://www.thelancet.com/journals/landia/article/PIIS2213-8...

Re: Vitamin D reduces incidence and duration of colds in those with low levels

#29

Post by shmel »

ErikCorry wrote: post #14
mwigdahl wrote: post #10

Earlier quoted context omitted.

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/

That sounds like a lot: To help prevent vitamin D toxicity, don't take more than 4,000 international units (IU) a day of vitamin D unless your healthcare professional tells you to. Most adults need only 600 IU of vitamin D a day https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-h...

You can't possibly have the same recommendation for all geographies. Florida and Scotland have somewhat different level of UVB especially throughout the winter, come on.

Re: Vitamin D reduces incidence and duration of colds in those with low levels

#30

Post by layer8 »

ErikCorry wrote: post #7

Most vitamins are a waste of time and money, some are even harmful[1], but there are a lot of people with D deficiency, especially in winter[2]. 1 https://www.mdpi.com/2072-6643/17/17/2744#:~:text=highest%20... 2 https://www.abs.gov.au/articles/vitamin-d#edit-group-image--...

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).
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