Vitamin D

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Fred99

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#208714 24-Feb-2017 12:44

https://www.sciencedaily.com/releases/2017/02/170216110002.htm

That's what (based on poor science) Vitamin C was supposed to do.

Note that the study found extremely strong effect of daily or weekly Vitamin D supplementation for people considered to have deficient levels, that defined as < 25 nmol/L blood.
A NZ (2012 - source) study showed that around 5% of adults were below that threshold, but that seasonally (late winter - spring) and in the SI region (excl Nelson Marlborough) 18% were deficient.
27% nationwide had "low" levels between 25 and 50 nmol/L. I don't see a figure in that data for the % with low level (but not formally "deficient") in the same seasonal / regional group, but guess it must be much higher than 18%.

Protective effect of supplementation - reduction in acute respiratory infection - was still seen in people with above deficient levels (10% reduction), not as dramatic as a halving of those diseases in people who were deficient.

The "flu/cold season" correlates with seasonal low in Vitamin D blood serum levels.

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#1725699 24-Feb-2017 15:06

Examine.com https://examine.com/supplements/vitamin-d/

MikeAqua

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#1725709 24-Feb-2017 15:31

An issue with vitamins is the supplement market may be limited to a maximum daily dose that is well below the dose required for any helpful effect.

For example Vitamin C seems to have benefits at 500mg per day. But most multi-vitamins only contain 100 - 150mg.

Mike

jarledb

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#1725710 24-Feb-2017 15:33

MikeAqua:

An issue with vitamins is the supplement market may be limited to a maximum daily dose that is well below the dose required for any helpful effect.

For example Vitamin C seems to have benefits at 500mg per day. But most multi-vitamins only contain 100 - 150mg.

Any references?

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Fred99

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#1725743 24-Feb-2017 16:28

No references to OTC "multivitamins" but when I've looked, most have absolute piddling amounts of Vitamin D - typically 20 or 50 IU, typical supplement may be 500 or 1000 IU daily or in cases of deficiency / osteoporosis treatment/prevention then monthly bolus dose of 100,000 IU.

I shouldn't have mentioned vitamin C in my original post - opens a can of worms, I'm not a "believer" myself that taking large doses achieves anything useful.

There are some cautions with vitamin D though - overdose can kill you. There would be problems if people thought the same way about it as vitamin C - that 100x "enough" would be "better" than just enough.

With a balanced diet incl fruit veges, IMO vitamin C supplementation is not needed. Not so with Vitamin D - a balanced diet doesn't necessarily provide enough, and then if you don't get enough sunlight exposure, you're at risk of deficiency.

Kids too - especially with risk-averse sun-avoidance and often crappy diets. We used to be given cod liver oil - was quite common to do that when rickets was "a thing". Rickets is "a thing" again in NZ. But there's more to Vitamin D inadequacy than risk of rickets from deficiency.

HcoNmeM

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#1732980 8-Mar-2017 12:24

I've been told the best time to take vitamins is before going to bed.. when the body rests is when vitamins are being absorbed the best..

Is this true? I've usually taken them at the start of the day..

jnimmo

1097 posts

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#1733059 8-Mar-2017 14:35

Yes! Didn't think of posting a thread about this earlier.

Unfortunately my doctor was not impressed at me asking to be prescribed a 50,000 IU monthly supplement, dispite some local research suggesting this as a blanket rule and not even bothering with blood tests to confirm deficiency.

This is a good read:

Seasonal variation in vitamin D levels in the Canterbury, New Zealand population in relation to available UV radiation (September 2007 NZ Medical Journal)

MikeAqua

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#1733563 9-Mar-2017 11:03

jnimmo:

Yes! Didn't think of posting a thread about this earlier.

Unfortunately my doctor was not impressed at me asking to be prescribed a 50,000 IU monthly supplement, dispite some local research suggesting this as a blanket rule and not even bothering with blood tests to confirm deficiency.

This is a good read:

Seasonal variation in vitamin D levels in the Canterbury, New Zealand population in relation to available UV radiation (September 2007 NZ Medical Journal)

On my read the resrach recommend between 1450 and 2600 IU

When I look at my daily multi it contains 100 IU of D [Edit and this amount (25mcg) is the maximum allowable by law in a supplement

http://www.legislation.govt.nz/regulation/public/1985/0208/latest/whole.html?search=sw_096be8ed812954be_ascorbic_25_se&p=1#DLM102135 ]

My daily multi also contains 100mg of C.

Research (numerous studies) have found 200mg (0.2g) of C to marginally reduce the duration of colds if taking as a daily preventative.

e.g. https://www.ncbi.nlm.nih.gov/pubmed/23440782

Mike

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MikeAqua

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#1733565 9-Mar-2017 11:08

jarledb:

MikeAqua:

An issue with vitamins is the supplement market may be limited to a maximum daily dose that is well below the dose required for any helpful effect.

For example Vitamin C seems to have benefits at 500mg per day. But most multi-vitamins only contain 100 - 150mg.

Any references?

Just noting I made a typo and 500mg should be 200mg (too late to edit). I've provided a link to meta-analysis in another post.

Mike

jnimmo

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#1733571 9-Mar-2017 11:28

MikeAqua:

jnimmo:

Yes! Didn't think of posting a thread about this earlier.

Unfortunately my doctor was not impressed at me asking to be prescribed a 50,000 IU monthly supplement, dispite some local research suggesting this as a blanket rule and not even bothering with blood tests to confirm deficiency.

This is a good read:

Seasonal variation in vitamin D levels in the Canterbury, New Zealand population in relation to available UV radiation (September 2007 NZ Medical Journal)

On my read the resrach recommend between 1450 and 2600 IU

When I look at my daily multi it contains 100 IU of D [Edit and this amount (25mcg) is the maximum allowable by law in a supplement

http://www.legislation.govt.nz/regulation/public/1985/0208/latest/whole.html?search=sw_096be8ed812954be_ascorbic_25_se&p=1#DLM102135 ]

My daily multi also contains 100mg of C.

Research (numerous studies) have found 200mg (0.2g) of C to marginally reduce the duration of colds if taking as a daily preventative.

e.g. https://www.ncbi.nlm.nih.gov/pubmed/23440782

Yeah - 50,000 IU is to be taken once every 1.3 months or something like that, just the only high dosage ones able to be prescribed in NZ. I've read a few books - perhaps the ones linked to here https://www.grc.com/health/vitamin-d.htm I can't remember

When I got the blood test I came back as deficient - even by the very low levels they class as deficient (i.e. for maintaining general health, no where near the higher levels which can be beneficial to health)

Fred99

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#1733593 9-Mar-2017 12:04

MikeAqua:

On my read the resrach recommend between 1450 and 2600 IU

When I look at my daily multi it contains 100 IU of D [Edit and this amount (25mcg) is the maximum allowable by law in a supplement

A decimal point error there somewhere,. 25 mcg Vitamin D is 1,000 IU (not 100 - 1 mcg = 40IU). Most daily "multis" I've seen have much less - so little it's IMO a waste of money - but that's not to say that you aren't getting multis with 1,000IU, from the legislation linked to, that seems perfectly legal.

Some 2016 data from the UK here

I haven't read it (no time ATM) but looks like their recommended safe upper limit for adults with monitoring is 4,000 IU/day, so 2600IU is getting quite high and probably excessive/risky for children or even adults especially if they're also getting sufficient through other combined sources (sunlight exposure, dietary, or other supplementation).

Not sure where you get the 1,450-2,600 IU recommended dose, it seems excessive as a "guideline" - except in case of known deficiency perhaps or for example elderly people or others at specific risk of osteoporosis etc (ie bone density loss can be a side effect from other medications). In those cases they may be given a monthly bolus dose of say 100,000IU (or sometimes more) rather than daily supplements.

The stuff (cholecalciferol / Vit D3) is used as rat poison - it's quite effective for that, and the same mechanism will kill people if they overdose, you could slowly accumulate a potentially fatal overdose by gradual daily overdosing.

dipkiwi

51 posts

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#1735728 13-Mar-2017 13:42

Fred99:Kids too - especially with risk-averse sun-avoidance and often crappy diets.

Yes, a mother's D level during pregnancy and the child's development to the age of around 16 is critical for immune function development. The rise of autoimmune disorders/diseases may be the result of our sun phobia.

Ivor Cummins gives a good talk on vitamin D. I'll start it here halfway through at a particular interesting point.

MikeB4

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#1735797 13-Mar-2017 14:44

With all supplements it is best to consult ones Doctor before taking them. A blood screen can be done to determine if in fact the supplements are required. There are very real risks associated with vitamin D overdose and vitamin over dose in general.

dipkiwi

51 posts

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#1735842 13-Mar-2017 16:09

MikeB4:

With all supplements it is best to consult ones Doctor before taking them. A blood screen can be done to determine if in fact the supplements are required. There are very real risks associated with vitamin D overdose and vitamin over dose in general.

The best way to get D is to expose your skin to some midday sun. Say sitting outside to eat your lunch.

This page is useful to see UV strength and burn times in your hometown...

www.niwa.co.nz

Supplements may be needed in the winter months particularly if you live further south.

Hammerer

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#1735888 13-Mar-2017 17:23

The health risks are real with an actual overdose of Vitamin D but you have to go crazy to overdose on over the counter products which are usually about 1000IU a dose.

Taking 50,000 international units (IU) a day of vitamin D for several months has been shown to cause toxicity. This level is many times higher than the Recommended Dietary Allowance (RDA) for most adults of 600 IU of vitamin D a day.

http://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/expert-answers/vitamin-d-toxicity/faq-20058108

cadman

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#1736267 14-Mar-2017 11:59

A mate of mine used to pop all sorts of OTC pills in an effort to be "healthy". He was perfectly fit. But anyway they screwed with his liver function so the Doctor told him to stop and the problem went away.

Just eat properly and your body will derive all it needs from that.

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