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Vitamin D, part 3 – The Evidence

devaboone.com

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Re: Vitamin D, part 3 – The Evidence

#131

Post by 0-_-0 »

tchaffee wrote: post #127
0-_-0 wrote: post #62

So what's the purpose of vitamin D then? It must be important if it was worth evolving white skin over, so why are studies failing to find that important reason?

> It must be important if it was worth evolving white skin over Where is the evidence that we evolved white skin to produce more vitamin D? Light skin in Europe may have evolved as a widespread thing as recently as 8,000 years ago [1], which doesn't support the idea that it was essential for survival in northern less sunny areas. Are there any studies giving strong evidence as to the causation for evolving white skin…

From the article you linked:

"A sun lower in the sky and shorter day lengths would have favored skin that more easily synthesized vitamin D."

The article also points out a correlation between latitude and light skin, so the evidence is pretty strong (based only what you linked) for why light skin evolved.

Re: Vitamin D, part 3 – The Evidence

#133

Post by devaboone »

oa335 wrote: post #91

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 li…

I wrote the article. It was very hard to write a concise article about all of Vitamin D research, and so I didn't have space to address it, though I really appreciate the feedback. Race and Vitamin D is an interesting area. The VITAL trial, which is the largest study on Vitamin D that we have, with 25,000 participants, tried to enroll more Blacks, and in the end 20% of the participants were Black. They showed the same results, but interestingly it did seem like there might be a trend toward fewer cancers for Blacks who received Vitamin D, but this was not definitive. More research on this is needed.

The other reason I didn't get into race and Vitamin D is that we then start getting into the blood levels, and what really constitutes deficiency. I think we are a little too liberal with our diagnosis of deficiency right now.

Re: Vitamin D, part 3 – The Evidence

#134

Post by raverbashing »

lprd wrote: post #97
baccheion wrote: post #88

Earlier quoted context omitted.

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.

It is fat-soluble so theoretically it should be ok (based on my limited knowledge and the fact that it's a prescription product)

(I'm not sure those are the vials I'm thinking about, I remember ones that were Vit E maybe of a very oily liquid that I had to take once - not bad, but definitely weird)

Re: Vitamin D, part 3 – The Evidence

#136

Post by citruscomputing »

tarsinge wrote: post #129
devaboone wrote: post #19

Earlier quoted context omitted.

That is a reasonable hypothesis. Also, people who are very ill are less likely to get outside and get enough sun, so they will develop low Vitamin D. Vitamin D is likely a marker of poor health. (Once the Vitamin D gets low enough, we do see direct harmful effects from it (think rickets in children), and this may contribute to poor health at that point.)

I’m healthy, fit and relatively active (3-4 hours exercise / week, 30-1h walk everyday), and I just tested relatively low in Vitamin D (before winter even started). What should I do?

Talk to your doctor.

Re: Vitamin D, part 3 – The Evidence

#137

Post by KerryJones »

Thank you for this deep-dive, I definitely agree it's not a panacea, though I do supplement and recommend most people supplement.

The question I have -- you did a deep dive into many of the "larger" claims, but the claim that I have found most substantiated and most relevant is preventative to various viruses (such as influenza): https://www.sciencedaily.com/releases/2017/02/170216110002.h...

Do you have any additional information or findings about this?

Re: Vitamin D, part 3 – The Evidence

#138

Post by baccheion »

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…

400 IU is the RDA. On the other hand, the RDA assumes 20% will come from food and the other 80% from sunlight. That is, 2000 IU/day is actually what's expected from all sources. Enough to get 25(OH)D in range is the more generalizable rule.

Such an approach as you mention may work well enough if growth is finished (ie, plates fused) and there's a movement away from calcium to magnesium. That is, get more magnesium than phosphorus and then 1/3rd-1/2 as much calcium. For example, 1.5g phosphorus + 1.5g magnesium + 500-750 mg calcium.

As much calcium isn't needed after growth and I am assuming all RDAs are being met (with just a variety of whole quality foods before adding supplements). Especially enough potassium to ensure a negative PRAL score to further lessen stress reactions.

At such a low amount, you could try the sun/S.A.D. or red lamp therapy.

Re: Vitamin D, part 3 – The Evidence

#139

Post by solinent »

I think it's related to diet, a deficiency in Vitamin D probably indicates a certain type of diet that leads to obesity. I wonder if metabolic syndrome and vitamin D deficiency are also comorbid.

You need fat to absorb vitamin D and perhaps this fat has additional benefits (satiety, less feeding periods, the integral of insulin over time is smaller). Ketosis probably has some role to play, I should check if they're controlling for this factor. Until they can control for the entire diet it's hard to really tell based purely on vitamin D, the metabolic processes can be so complicated in a human.

Disclaimer: mindless speculation above--I'm no expert, just a mathematician.

Re: Vitamin D, part 3 – The Evidence

#140

Post by meiraleal »

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.

Not really, Europeans alone are capable of the same level of mess, before and after slavery.

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