Vitamin D - how much?

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ANTONISH
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Vitamin D - how much?

Post by ANTONISH »

I've been reading recently that the elderly (that probably includes me :( ) would benefit from vitamin D supplementation.
I also read that intake should not exceed 10 micrograms.

My weekly diet includes items like oily fish and chestnut mushrooms that have added vitamin D - in fact a few of these mushrooms would appear to supply half the recommended daily dose.
Also like most cyclists I get my summer vitamin D from sunlight.

I generally don't take vitamin supplements and I'm aware that too much vitamin D is unhealthy.
How does one diagnose a defficiency?
Jdsk
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Re: Vitamin D - how much?

Post by Jdsk »

I suggest starting with the NHS site:
https://www.nhs.uk/conditions/vitamins-and-minerals/vitamin-d/

Most people in the UK won't get enough in winter without supplementation of some kind.

ANTONISH wrote:How does one diagnose a defficiency?

Clinically symptoms aren't very clear. In many cases deficiency isn't detected until a fracture occurs. Biochemical tests are problematic in several different ways (I used to do this for a living).

At both the individual and population policy level it's much much smarter to supplement than to test.

Jonathan
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Paulatic
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Re: Vitamin D - how much?

Post by Paulatic »

You get a blood test :D
Have been prescribed Vit D for over 10 yrs now.
I was loosing weight and one of the last things they looked at was vit D. Why? Because I worked outside eat oily fish and love mushrooms. It appears living in the northern hemisphere my body can’t get enough. My mother had MS , often linked with vit d, which suggests lack of could be hereditary.
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Jdsk
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Re: Vitamin D - how much?

Post by Jdsk »

Paulatic wrote:You get a blood test

As above, I'm a chemical pathologist and I recommend not.

Jonathan
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al_yrpal
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Re: Vitamin D - how much?

Post by al_yrpal »

I take the recommended dose of 10 micrograms of Vitamen D with calcium every morning. My wife didnt and ended up with osteoporosis and three fractured vertebrae resulting in massive pain and loss of mobility. Its particularly vital for women to get sufficient vitamen D.

I only take it in autumn and winter. In summer sunlight does the trick.

Al
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Paulatic
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Re: Vitamin D - how much?

Post by Paulatic »

Jdsk wrote:
Paulatic wrote:You get a blood test

As above, I'm a chemical pathologist and I recommend not.

Jonathan

I can only say what happened to me when looking for cause of weight loss.
So are you saying medics shouldn’t have tested my D level?
The results are unreliable?
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Jdsk
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Re: Vitamin D - how much?

Post by Jdsk »

No comment on what happened to you personally. And this doesn't apply to people at high risk or with fractures or other relevant conditions.

Hinging the decision on whether to supplement on the result of a laboratory test requires:
1 Measuring the relevant analyte in the right bit of the body at the right time.
2 Knowing appropriate decision limits.
3 Using an assay that gives the same information as the ones used in the studies that established the decision limits.

For "Vitamin D" there are problems with all of those. And that's before cost is brought into it.

For most individuals and as a population policy it's much smarter to supplement without investigation. As in the NHS advice cited above.

Jonathan
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Re: Vitamin D - how much?

Post by fullupandslowingdown »

Various studies I have read suggest that when we're not getting tanned in the spanish sun, we should supplement at least 10ug a day, and more if you have dark skin because of the melanin blocks more of the sun's UV which causes D to be synthesised. Some studies suggest that this is a contributory factor to the differing rates of type diabetes as low levels of vitamin D are implicated in a range of health conditions. But as always, it's knowing who is talking sense and who is trying to sell something... Science says that we can overdose on D as it is a fat soluble vitamin which means it's stored in the body unlike vitamin C which is water soluble. But supplement levels needed to overdose on D are estimated to exceed 25ug daily. I've not seen any study that says a dose of 10ug even throughout the year is harmful.
Last edited by fullupandslowingdown on 18 Feb 2020, 6:59pm, edited 1 time in total.
softlips
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Re: Vitamin D - how much?

Post by softlips »

Very few British people get enough vitamin D. Blood tests in my company showed 86% had levels classed as deficient- (almost 600 people tested in Summer). I read Team Sky found similar and now give vit D supplements to all riders.

I take a daily dose and my levels are now good.
ANTONISH
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Re: Vitamin D - how much?

Post by ANTONISH »

Thank you all for the advice - I'll try the 10 microgram dose.
Why the calcium with it al- yrpal ?
Jdsk
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Re: Vitamin D - how much?

Post by Jdsk »

A major action of Vitamin D is enabling calcium absorption from the gut. So deficiency of the vitamin can interact with deficiency of calcium in the diet. Or with the presence of other substances that get in the way: the most notorious being phytates. And some flours contain a lot of those.
https://en.wikipedia.org/wiki/Phytic_acid#Dietary_mineral_absorption

Jonathan
ANTONISH
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Re: Vitamin D - how much?

Post by ANTONISH »

Jdsk wrote:A major action of Vitamin D is enabling calcium absorption from the gut. So deficiency of the vitamin can interact with deficiency of calcium in the diet. Or with the presence of other substances that get in the way: the most notorious being phytates. And some flours contain a lot of those.
https://en.wikipedia.org/wiki/Phytic_acid#Dietary_mineral_absorption

Jonathan


Thank you for that. Life is complicated isn't it?
At least I have some idea why I may need to supplement now.
BTW I don't have any unexplained weight loss, my weight is pretty constant.
windmiller
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Re: Vitamin D - how much?

Post by windmiller »

I took 50,000 iu of vitamin D3, combined with K2 and magnesium over 3 days to fight off a chest infection. It worked after the second night. Vitamin C in huge amounts is also quite effective in powdered pharmaceutical grade quality, the only down side being that you have to take it to bowel tolerance. Wise to check with your doc if taking massive doses of supplements to ensure that they reconcile with any medications taken.
Jdsk
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Re: Vitamin D - how much?

Post by Jdsk »

I would strongly advise against taking "huge" or "massive" or any amount of substances for which there is no evidence of efficacy.

Jonathan
richardfm
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Re: Vitamin D - how much?

Post by richardfm »

windmiller wrote:I took 50,000 iu of vitamin D3, combined with K2 and magnesium over 3 days to fight off a chest infection. It worked after the second night. Vitamin C in huge amounts is also quite effective in powdered pharmaceutical grade quality, the only down side being that you have to take it to bowel tolerance. Wise to check with your doc if taking massive doses of supplements to ensure that they reconcile with any medications taken.

How do you know it worked? The chest infection could well have cleared up without taking all those chemicals.
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