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Vitamin D, part 3 – The Evidence

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Re: Vitamin D, part 3 – The Evidence

#91

Post by oa335 »

I would have loved to see some of her advice and information dis-aggregated by race.

Low Vitamin D levels of are not evenly distributed among different ethic groups. e.g. "53%–76% of non-Hispanic blacks [ had low vitamin D levels, in the Southern U.S.] compared with 8%–33% of non-Hispanic whites [0]".

Thus the risk-reward considerations of taking vitamin D are likely different for dark-skinned individuals than for light skinned individuals.

I have to assume her advice at the end is targeted at light-skinned people. As a dark-skinned person myself, I'm irritated that she couldn't bother to at least mention the above issues.

[0] https://academic.oup.com/jn/article/136/4/1126/4664238

Re: Vitamin D, part 3 – The Evidence

#92

Post by dcx »

This seems like it might be a little selective.

What about these [1] [2] randomised controlled trials that show vitamin D supplementation has an effect on IBS symptoms?

Or this [3] double-blinded trial showing supplementation improved sleep quality in people with sleep disorders?

Or this [4] one showing improvements in depressive symptoms in overweight and obese subjects? The study cited in TFA is large but only uses participants aged 50 and above, with a relatively low dose of vitamin D.

Also, is it just me or is the line of argument used a little bit weak? You could use the same kind of argument to dismiss the need for dietary vitamin C, as follows: (a) vitamin C deficiency is associated with a bunch of other health conditions (as it's a marker of poor nutrition or socioeconomic status), so (b) let's look at the effects of supplementing vitamin C, which (c) naturally finds that supplementation does nothing for said conditions, and therefore (d) conclude that it is a pretty useless vitamin, while placing minimal focus on the things that it actually does fix, such as scurvy?

I am not an academic, so perhaps I am missing some context though.

[1] https://pubmed.ncbi.nlm.nih.gov/27154424/

[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5900470/

[3] https://tumj.tums.ac.ir/article-1-8272-en.html

[4] https://onlinelibrary.wiley.com/doi/full/10.1111/j.1365-2796...

Re: Vitamin D, part 3 – The Evidence

#93

Post by devaboone »

TacticalCoder wrote: post #83

What about the study in Spain from a few days ago (I'm in Spain atm and it's kinda big news over here), at the Reina Sofia University Hospital in Córdoba, where they just announced the results of the randomized blind controlled trial and the results are incredible: 1 person out of 50 who got huge doses of vitamin D for a few days after arriving at the hospital with Covid-19 symptoms ended up in the ICU, where 13 out…

There is a lot of excitement about this study, but the details in it matter. It was randomized - but when you look at the two groups (treatment vs. control), they had some key differences. The control group (who didn't receive Vitamin D) had more men (69% vs 54%), more people with hypertension (57% vs 24%) and diabetes (19% vs 6%). So the groups were not the same. If you just compare the numbers of those who went into the ICU vs. not, then the results look amazing. But once you correct for hypertension and diabetes, it was not so impressive - it was not statistically significant in the study. (It is in the study but most people breeze right over that.)

Re: Vitamin D, part 3 – The Evidence

#95

Post by inasio »

TacticalCoder wrote: post #83

What about the study in Spain from a few days ago (I'm in Spain atm and it's kinda big news over here), at the Reina Sofia University Hospital in Córdoba, where they just announced the results of the randomized blind controlled trial and the results are incredible: 1 person out of 50 who got huge doses of vitamin D for a few days after arriving at the hospital with Covid-19 symptoms ended up in the ICU, where 13 out…

Not quite a double blind RCT, but at least the data was masked from the statistician that performed the analysis (and some of the medical personnel). The population was not huge, but the results are indeed quite strong [1]

[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7456194/

Re: Vitamin D, part 3 – The Evidence

#96

Post by devaboone »

burgerquizz wrote: post #47

I've seen a well explained video about a study[1] saying vitamin D3 helps in reducing severity of COVID19. What's your argument(s) against it? [1] https://www.youtube.com/watch?v=V8Ks9fUh2k8

I didn't watch the whole video but I read the study. There is a lot of excitement about this study, but the details in it matter. It was randomized - but when you look at the two groups (treatment vs. control), they had some key differences. The control group (who didn't receive Vitamin D) had more men (69% vs 54%), more people with hypertension (57% vs 24%) and diabetes (19% vs 6%). These are all areas that increase the risk of severe disease. So the groups were not the same. If you just compare the numbers of those who went into the ICU vs. not, then the results look amazing. But once you correct for hypertension and diabetes, it was not so impressive - it was not statistically significant in the study. This does not mean that I think Vitamin D has no effect. There is some evidence for Vitamin D in respiratory illnesses. But the effect is not as dramatic as some of the headlines for this study would imply.

Re: Vitamin D, part 3 – The Evidence

#97

Post by lprd »

baccheion wrote: post #88
lprd wrote: post #85

I have a couple questions for any doctors out there. How many times a year should one check his vitamin levels? I live in Paris, and during the winter months we don't get that much sunlight. My doctor gave me a prescription for vitamin D3 (100,000 IU vial, once a month, for three months). Is this a good dose for the year (provided you get adequate sunlight during the summer months)? How long does vitamin D3 stay in t…

Can you get D3 from a store? Prescriptions are usually vitamin D2. 20,000 IU or 50,000 IU D3 1x/week is a great amount. Or you could try taking a lesser/proportional amount each day. You could also get one of those sun/S.A.D. lamps or red light devices to increase topically.

Just checked the box again and it says "cholecalciferol (vitamin D3) 100,000 IU". I believe the prescription is required due to the dosage (100,000 IUs is pretty high).

I could definitely get some D3 from the store, but I am curious if taking a prescription dosage once a month yields the same result as a lower daily dose.

Re: Vitamin D, part 3 – The Evidence

#98

Post by ellyagg »

devaboone wrote: post #93
TacticalCoder wrote: post #83

What about the study in Spain from a few days ago (I'm in Spain atm and it's kinda big news over here), at the Reina Sofia University Hospital in Córdoba, where they just announced the results of the randomized blind controlled trial and the results are incredible: 1 person out of 50 who got huge doses of vitamin D for a few days after arriving at the hospital with Covid-19 symptoms ended up in the ICU, where 13 out…

There is a lot of excitement about this study, but the details in it matter. It was randomized - but when you look at the two groups (treatment vs. control), they had some key differences. The control group (who didn't receive Vitamin D) had more men (69% vs 54%), more people with hypertension (57% vs 24%) and diabetes (19% vs 6%). So the groups were not the same. If you just compare the numbers of those who went int…

Interesting! Can you quote the part of the study where they say the results are not statistically signifcant when you control for diabetes and hypertension?

Re: Vitamin D, part 3 – The Evidence

#99

Post by nradov »

staticassertion wrote: post #71

It seems interesting that Vitamin D may be so much more prone to false correlations due to the fact that it's tied to going out in the sun, and going out in the sun is what healthy people do. Since so many illnesses and conditions, from psychological to physical, can keep you indoors, one could conclude that vitamin D is really a miracle pill. I take 1k iu a day, since I barely go outside anymore, but I'd probably cu…

Why do you barely go outside?

Re: Vitamin D, part 3 – The Evidence

#100

Post by tszymczyszyn »

coldtea wrote: post #51
api wrote: post #25

The most obvious evidence to me has always been that Europeans are not black. A change like the loss of melanin requires selective pressure, which in this case was likely furnished by less vitamin D as we migrated away from the equator. The pressure must have been significant since being white carries a big downside: higher vulnerability to sunburn and skin cancer. When I lived in Cali I always envied my darker skinn…

> I gotta say though... the world would have far less race problems had that odd little quirk of photosynthesis of a key nutrient not existed. It's not so much about the race, but about the exploitation. Blacks and whites co-lived without racism for millenia, back when anybody could become a slave. When around the 16th century the Europeans started to exploit latin americans, indians and blacks as slaves, they spread…

I agree with the general conclusion about exploitation, but racist theories and justifications existed in different cultures long before the 16th century.
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