Effect of High-Dose Vitamin D on Volumetric Bone Density and Bone Strength • Hacker News Board

Re: Effect of High-Dose Vitamin D on Volumetric Bone Density and Bone Strength

#51

Post by epmaybe » Tue, Sep 10, 2019, 4:14 AM UTC

fractal618 wrote: post #47

Isn't that a pretty narrow age group? "mean [SD] age, 62.2 [4.2] years"

It's actually good for the purposes of the study, as the highest risk populations for decreased bone mineral density are elderly populations. We know from multiple studies that women are at highest risk due to decreasing estrogen levels post-menopause, and around peak risk around age 65 (hence why it's recommended to get osteoporosis screening done at age 65). Men aren't quite as susceptible as our testosterone levels are relatively stable, and maybe including them isn't the best of ideas. However, proportion of gender is nearly equal in all treatment arms of the study, so it shouldn't skew the results.

Re: Effect of High-Dose Vitamin D on Volumetric Bone Density and Bone Strength

#52

Post by arto » Tue, Sep 10, 2019, 4:41 AM UTC

01100011 wrote: post #6

I thought you needed both vitamin D and vitamin K2 - D to mobilize the calcium and K2 to put it into the right place. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5613455/

This.

Re: Effect of High-Dose Vitamin D on Volumetric Bone Density and Bone Strength

#53

Post by AstralStorm » Tue, Sep 10, 2019, 5:04 AM UTC

aladoc99 wrote: post #5

Headline is imprecise. The study is saying that higher doses of vit D do not strengthen bone more than lower doses, not that they don't strengthen bone at all, which is suggested by this headline.

I'd trust EPIC series more, even though it's not RCD. They showed J-curve for all cause mortality and morbidity with best inflection point around 1500-2000 IU. The curve is somewhat flat above this.

One of the findings (there's a summary somewhere): https://epic.iarc.fr/highlights/vitamindcolorectal.php

Re: Effect of High-Dose Vitamin D on Volumetric Bone Density and Bone Strength

#54

Post by AstralStorm » Tue, Sep 10, 2019, 5:10 AM UTC

mrfusion wrote: post #40

01100011 wrote: post #6

I thought you needed both vitamin D and vitamin K2 - D to mobilize the calcium and K2 to put it into the right place. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5613455/

In my mind that’s what makes this kind of a garbage study.

Alongside focus on just osteoporosis, lack of control for calcium levels (other than blind supplementing with low dietary intake), phosphate levels.

Some people may be responding poorly to the supplement, especially at high doses and low calcium. Direct blood test for status would help.

Re: Effect of High-Dose Vitamin D on Volumetric Bone Density and Bone Strength

#55

Post by AstralStorm » Tue, Sep 10, 2019, 5:36 AM UTC

scottlocklin wrote: post #36

fc_barnes wrote: post #33

Earlier quoted context omitted.

Nobody has 0 intake, that is a useless control; nor would any IRB sign off on such a study, because it would be harmful to the subjects.

The experiment itself may be useless control; most people get D vitamins from the sun. How do we know the cohorts got the same D from sun exposure?

Should use a blood tests for vitamin D status, probably calcium, phosphate and K too instead of relying on self reported diet.

Re: Effect of High-Dose Vitamin D on Volumetric Bone Density and Bone Strength

#56

Post by nradov » Tue, Sep 10, 2019, 5:38 AM UTC

Tryptaminded wrote: post #26

AlexanderNull wrote: post #20

Why are there so many studies looking at vitamin D and bone health? Vitamin D levels affect expression of over 400 genes in the human body, make a difference in cancer survival and are strongly inversely correlated with all cause mortality ( https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4103214/ https://www.mdedge.com/psychiatry/article/66349/depression/v... https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6201256/ ). Doe…

Time to start taking vitamin D

You would probably benefit more from being out in the sun than from taking vitamin D supplements.

Re: Effect of High-Dose Vitamin D on Volumetric Bone Density and Bone Strength

#57

Post by amelius » Tue, Sep 10, 2019, 9:15 AM UTC

01100011 wrote: post #6

I thought you needed both vitamin D and vitamin K2 - D to mobilize the calcium and K2 to put it into the right place. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5613455/

I wonder if taking mega-doses of vitamin D without K2 would drain the subject's stored supply of K2, leaving none for other processes in which K2 plays a role (?)

Re: Effect of High-Dose Vitamin D on Volumetric Bone Density and Bone Strength

#58

Post by tomhoward » Tue, Sep 10, 2019, 9:20 AM UTC

chrisco255 wrote: post #2

I thought calcium had a bigger impact on bone density than Vitamin D?

Well yes, but Vitamin D is needed to absorb calcium. So both are needed in adequate quantities. One without the other will be ineffective.

Re: Effect of High-Dose Vitamin D on Volumetric Bone Density and Bone Strength

#59

Post by blurbleblurble » Tue, Sep 10, 2019, 9:38 AM UTC

01100011 wrote: post #6

I thought you needed both vitamin D and vitamin K2 - D to mobilize the calcium and K2 to put it into the right place. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5613455/

Also... Magnesium!

Re: Effect of High-Dose Vitamin D on Volumetric Bone Density and Bone Strength

#60

Post by PavlikPaja » Tue, Sep 10, 2019, 10:12 AM UTC

dogmatism wrote: post #18

D3 is converted to 1,25(OH)2-D3 which is the active form. The transformation is limited by 1α(OH)-ase which in turn is regulated by levels of calcium and PTH and degraded by renal 24-OH-ase, which previous work has shown is upregulated by high 1,25(OH)2-D3, and 25(OH)D (formed in the liver from the oral cholecalciferol), thereby providing a brake on the system. It has also been shown that the upregulation of 24(OH)as…

It isn't counterintuitive. Too much calcium (especially in the absence of mangesium) hurts your bones (and many other things)