Re: Dr. Cannell: Unprecedented Warning About Cod Liver Oil

[Guest guest]

On 11/11/08, Tom Jeanne <tjeanne@...> wrote:

> Oh boy, take a look at this! Just got this today from the

> Vitamin D Council mailing list. I got the full paper but haven't read

> it yet.

I got it too. Interesting that Cannell (a psychiatrist who has done

one study on vitamin D) wrote the paper, but big-names like Willett

signed on. Interesting that big-names in vitamin D such as Holick and

Heaney did not sign on (though some D names did). I'll probably write

a response to the paper by next week.

Chris

[Guest guest]

Can someone post the journal this article is published in?

> > Oh boy, take a look at this! Just got this today from the

> > Vitamin D Council mailing list. I got the full paper but haven't read

> > it yet.

>

> I got it too. Interesting that Cannell (a psychiatrist who has done

> one study on vitamin D) wrote the paper, but big-names like Willett

> signed on. Interesting that big-names in vitamin D such as Holick and

> Heaney did not sign on (though some D names did). I'll probably write

> a response to the paper by next week.

>

> Chris

>

[Guest guest]

,

> Can someone post the journal this article is published in?

Sorry, the link didn't get copied. Here it is, but there is no

abstract viewable, at least for the moment.

http://www.annals.com/toc/auto_abstract.php?id=15313

Ann Otol Rhinol Laryngol 2008;117:864-870.

Tom

[Guest guest]

Here are two key paragraphs from the article. Does anyone want to offer a

rebuttal?

" Although activated vitamin D and vitamin A signal through common cofactors,

they

compete for each other's function. Retinoic acid antagonizes the action of

vitamin D and

its active metabolite.33,34 In humans, even the vitamin A in a single serving of

liver

impairs vitamin D's rapid intestinal calcium response.35 In a dietary intake

study, Oh et

al36 found that a high retinol intake completely thwarted vitamin D's otherwise

protective

effect on distal colorectal adenoma, and they found a clear relationship between

vitamin D

and vitamin A intakes, as the women in the highest quintile of vitamin D intake

ingested

around 10,000 IU/d of retinol.

Furthermore, the consumption of preformed retinol — even in amounts consumed by

many Americans in both multivitamins and cod liver oil — may cause bone toxicity

in

individuals with inadequate vitamin D status.37 Women in the highest quintile of

total

vitamin A intake have a 1.5-times elevated risk of hip fracture.38 Indeed, a

recent

Cochrane Review found that vitamin A supplements increased the total mortality

rate by

16%,39 perhaps through antagonism of vitamin D. Another recent Cochrane Review

concluded that although vitamin A significantly reduced the incidence of acute

lower

respiratory tract infections in children with low intake of retinol, as occurs

in the Third

World, it appears to increase the risk and/or worsen the clinical course in

normal

children.40 As early as 1933, Alfred Hess, who discovered that sunlight both

prevented

and cured rickets — writing in JAMA — warned about vitamin A consumption,

concluding,

" ...as to a requirement of thousands of units of vitamin A daily, the

unquestionable answer

is that this constitutes therapeutic absurdity, which, happily, will prove to be

only a

passing fad. " 41(p662) "

>

> ,

>

> > Can someone post the journal this article is published in?

>

> Sorry, the link didn't get copied. Here it is, but there is no

> abstract viewable, at least for the moment.

>

> http://www.annals.com/toc/auto_abstract.php?id=15313

> Ann Otol Rhinol Laryngol 2008;117:864-870.

>

> Tom

>

[Guest guest]

On a related note, the last high-quality mill producing cod liver oil

with natural vitamin A/D is switching to synthetic vitamin A/D. This

means Green Pasture's fermented cod liver oil is the only natural

high-vitamin cod liver oil left on the market. (AFAIK)

I'm not as familiar with the cohort over at the Vitamin D Council as

other posters appear to be. (It would be great if someone could post a

brief description). But it did occur to me that their concern over cod

liver oil may be influenced by the fact that most cod liver oil now

contains synthetic vitamin A which is much more toxic and interacts

differently with vitamin D than natural vitamin D.

It would be nice though if they would explain all these details,

assuming they know or support them.

Also, if someone could please explain a few things about vitamin D in

cod liver oil, I'd be grateful.

1. Most cod liver oil now has calciol added for vitamin D which is

created by irradiating 7-dehydrocholesterol extracted from lanolin.

How is the 7-dehydrocholesterol " extracted " and what contaminants are

involved?

2. Calciol is an inactive (unhydroxylated) form of vitamin D. How is

it metabolized into calcidiol or calcitriol? And what is the typical

efficiency?

3. In natural, fermented high vitamin cod liver oil, what is the

proportions of calciol, calcidiol and calcitriol?

Sincerely,

> >

> > ,

> >

> > > Can someone post the journal this article is published in?

> >

> > Sorry, the link didn't get copied. Here it is, but there is no

> > abstract viewable, at least for the moment.

> >

> > http://www.annals.com/toc/auto_abstract.php?id=15313

> > Ann Otol Rhinol Laryngol 2008;117:864-870.

> >

> > Tom

> >

>

[Guest guest]

How does Green Pastures get cod liver oil without the synthetic vitamin D added?

Green

Pastures is located in Nebraska and seems like a small operation. The Blue Ice

cod liver oil

they sell must be made under contract at some factory overseas.

> > >

> > > ,

> > >

> > > > Can someone post the journal this article is published in?

> > >

> > > Sorry, the link didn't get copied. Here it is, but there is no

> > > abstract viewable, at least for the moment.

> > >

> > > http://www.annals.com/toc/auto_abstract.php?id=15313

> > > Ann Otol Rhinol Laryngol 2008;117:864-870.

> > >

> > > Tom

> > >

> >

>

[Guest guest]

,

> But it did occur to me that their concern over cod

> liver oil may be influenced by the fact that most cod liver oil now

> contains synthetic vitamin A which is much more toxic and interacts

> differently with vitamin D than natural vitamin D.

Do you have any evidence for this?

[snip]

> 1. Most cod liver oil now has calciol added for vitamin D which is

> created by irradiating 7-dehydrocholesterol extracted from lanolin.

> How is the 7-dehydrocholesterol " extracted " and what contaminants are

> involved?

I don't know about the extraction process, but the production of

vitamin D by irradiating 7-dehydocholesterol is the same way we make

it and the same way its made in the rest of the animal kingdom.

> 2. Calciol is an inactive (unhydroxylated) form of vitamin D. How is

> it metabolized into calcidiol or calcitriol? And what is the typical

> efficiency?

Virtually all that is absorbed is hydroxylated in the liver fairly

short-term to calcidiol. This is hydroxylated to the active

calcitriol as needed, in a very, very highly regulated process.

Mostly in the kidney, but in much smaller amounts in many other cell

types.

> 3. In natural, fermented high vitamin cod liver oil, what is the

> proportions of calciol, calcidiol and calcitriol?

No one knows. A major vitamin D researcher, I think Heaney or Holick,

but I forget exactly who, suggested that one could make a career out

of characterizing the vitamin D metabolites in cod liver oil.

Chris

[Guest guest]

Chris-

> No one knows. A major vitamin D researcher, I think Heaney or Holick,

> but I forget exactly who, suggested that one could make a career out

> of characterizing the vitamin D metabolites in cod liver oil.

A whole career? Do different CLOs have different amounts of the

different metabolites? Are there exotic metabolites in CLO?

-

[Guest guest]

They constantly irrigate their pastures so the cows have constant access to

fresh green grass during the growing season.

From their Web page at: http://www.greenpasture.org/about

Green Pastures ProductsT is committed to producing a consistent quality,

nutrient dense, high vitamin butter oil. Our high vitamin butter oil is

produced from cows that graze on irrigated pastures of the Northern Great

Plains.

The combination of the irrigation, pastures rich in a specialized forage mix

and the Northern Great Plains climate ensure optimal levels of Activator X

and an ideal rumen pH for a bacterial digestive function to create high

levels of CLA isomer 9-11 in this unique, raw dairy oil extract.

In addition to our fine butter oil products, we also offer cod liver oil and

have recently added organic, extra virgin coconut oil.

From:

[mailto: ] On Behalf Of jeremyfox

Sent: Friday, November 14, 2008 1:44 AM

Subject: Re: Dr. Cannell: " Unprecedented Warning About Cod Liver Oil "

How does Green Pastures get cod liver oil without the synthetic vitamin D

added? Green

Pastures is located in Nebraska and seems like a small operation. The Blue

Ice cod liver oil

they sell must be made under contract at some factory overseas.

> > >

> > > ,

> > >

> > > > Can someone post the journal this article is published in?

> > >

> > > Sorry, the link didn't get copied. Here it is, but there is no

> > > abstract viewable, at least for the moment.

> > >

> > > http://www.annals.com/toc/auto_abstract.php?id=15313

> > > Ann Otol Rhinol Laryngol 2008;117:864-870.

> > >

> > > Tom

> > >

> >

>

[Guest guest]

,

AFAIK, their Blue Ice product is made in the last mill that still uses

natural vitamins in the process described here:

http://www.westonaprice.org/modernfood/codliver-manufacture.html

However, even this mill is apprently switching to synthetic vitamin A/D.

Their fermented cod liver oil is made from whole livers right in NE so

they have complete control over the process.

> > >

> > > Here are two key paragraphs from the article. Does anyone want to

> > offer a rebuttal?

> > >

> > > " Although activated vitamin D and vitamin A signal through common

> > cofactors, they

> > > compete for each other's function. Retinoic acid antagonizes the

> > action of vitamin D and

> > > its active metabolite.33,34 In humans, even the vitamin A in a

> > single serving of liver

> > > impairs vitamin D's rapid intestinal calcium response.35 In a

> > dietary intake study, Oh et

> > > al36 found that a high retinol intake completely thwarted vitamin

> > D's otherwise protective

> > > effect on distal colorectal adenoma, and they found a clear

> > relationship between vitamin D

> > > and vitamin A intakes, as the women in the highest quintile of

> > vitamin D intake ingested

> > > around 10,000 IU/d of retinol.

> > >

> > > Furthermore, the consumption of preformed retinol — even in amounts

> > consumed by

> > > many Americans in both multivitamins and cod liver oil — may cause

> > bone toxicity in

> > > individuals with inadequate vitamin D status.37 Women in the highest

> > quintile of total

> > > vitamin A intake have a 1.5-times elevated risk of hip fracture.38

> > Indeed, a recent

> > > Cochrane Review found that vitamin A supplements increased the total

> > mortality rate by

> > > 16%,39 perhaps through antagonism of vitamin D. Another recent

> > Cochrane Review

> > > concluded that although vitamin A significantly reduced the

> > incidence of acute lower

> > > respiratory tract infections in children with low intake of retinol,

> > as occurs in the Third

> > > World, it appears to increase the risk and/or worsen the clinical

> > course in normal

> > > children.40 As early as 1933, Alfred Hess, who discovered that

> > sunlight both prevented

> > > and cured rickets — writing in JAMA — warned about vitamin A

> > consumption, concluding,

> > > " ...as to a requirement of thousands of units of vitamin A daily,

> > the unquestionable answer

> > > is that this constitutes therapeutic absurdity, which, happily, will

> > prove to be only a

> > > passing fad. " 41(p662) "

> > >

> > >

> > > --- In , " Tom Jeanne " <tjeanne@>

wrote:

> > > >

> > > > ,

> > > >

> > > > > Can someone post the journal this article is published in?

> > > >

> > > > Sorry, the link didn't get copied. Here it is, but there is no

> > > > abstract viewable, at least for the moment.

> > > >

> > > > http://www.annals.com/toc/auto_abstract.php?id=15313

> > > > Ann Otol Rhinol Laryngol 2008;117:864-870.

> > > >

> > > > Tom

> > > >

> > >

> >

>

[Guest guest]

That's a good point, I don't have any direct evidence with regard to

the difference between irradiated lanolin and natural vitamin D and

it's interaction with any form of vitamin A, natural or synthetic.

Which is why I asked so many questions in this post--just trying to

learn more about the subject.

However, that was only a minor point. The major point is that perhaps

the concern over cod liver oil is partially influenced by the fact the

most of it now contains synthetic vitamin A for which there is

evidence of toxicity at levels lower than natural fat soluble vitamin

A in combination with natural vitamin D. Do Cannel or other

researchers accept the differences between water soluble, solidified

or emulsified vitamin A vs natural fat soluble vitamin A?

I'm surprised that it would be difficult to determine the proportions

of calciol, calcidiol and calcitriol in cod liver oil. There surely

must be tests for these three molecules. I suspect one confounding

factor is that there are 40 species of cod that are viable for use as

oil sources and the levels and ratios of vitamin A and D varies by

species. So certainly any research would have to take all that into

account. I guess as a consumer I'd like to see calciol, calcidiol and

calcitriol levels right on the bottle.

The reason I ask is that calciol is an inactive form of vitamin D

which require enzyme production and processing in the liver which I

assume is more metabolically expensive than assimilating calcidiol or

calcitriol. Although to be honest, I don't know the metabolic pathways

for the later two. Perhaps someone could educate me.

>

> ,

>

> > But it did occur to me that their concern over cod

> > liver oil may be influenced by the fact that most cod liver oil now

> > contains synthetic vitamin A which is much more toxic and interacts

> > differently with vitamin D than natural vitamin D.

>

> Do you have any evidence for this?

>

> [snip]

>

> > 1. Most cod liver oil now has calciol added for vitamin D which is

> > created by irradiating 7-dehydrocholesterol extracted from lanolin.

> > How is the 7-dehydrocholesterol " extracted " and what contaminants are

> > involved?

>

> I don't know about the extraction process, but the production of

> vitamin D by irradiating 7-dehydocholesterol is the same way we make

> it and the same way its made in the rest of the animal kingdom.

>

> > 2. Calciol is an inactive (unhydroxylated) form of vitamin D. How is

> > it metabolized into calcidiol or calcitriol? And what is the typical

> > efficiency?

>

> Virtually all that is absorbed is hydroxylated in the liver fairly

> short-term to calcidiol. This is hydroxylated to the active

> calcitriol as needed, in a very, very highly regulated process.

> Mostly in the kidney, but in much smaller amounts in many other cell

> types.

>

> > 3. In natural, fermented high vitamin cod liver oil, what is the

> > proportions of calciol, calcidiol and calcitriol?

>

> No one knows. A major vitamin D researcher, I think Heaney or Holick,

> but I forget exactly who, suggested that one could make a career out

> of characterizing the vitamin D metabolites in cod liver oil.

>

> Chris

>

[Guest guest]

?

> That's a good point, I don't have any direct evidence with regard to

> the difference between irradiated lanolin and natural vitamin D and

> it's interaction with any form of vitamin A, natural or synthetic.

How is irradiated lanolin unnatural? Seems to me that *is* natural

vitamin D. The sheep is natural, it goes out in the sun, which is

natural, and thus its lanolin gets naturally irradiated, and natural

vitamin D is provided to the sheep.

> Which is why I asked so many questions in this post--just trying to

> learn more about the subject.

>

> However, that was only a minor point. The major point is that perhaps

> the concern over cod liver oil is partially influenced by the fact the

> most of it now contains synthetic vitamin A for which there is

> evidence of toxicity at levels lower than natural fat soluble vitamin

> A in combination with natural vitamin D. Do Cannel or other

> researchers accept the differences between water soluble, solidified

> or emulsified vitamin A vs natural fat soluble vitamin A?

No, nor do they provide evidence that cod liver oil is harmful, so

once we get to the evidence part, the line of inquiry is essentially

moot.

> I'm surprised that it would be difficult to determine the proportions

> of calciol, calcidiol and calcitriol in cod liver oil.

Usually " cholecalciferol " is the word for irradiated

7-dehydrocholesterol, which I think is the component of lanolin that

gets irradiated. Is that wrong?

It wouldn't be difficult. It is just that no one has done it. Most

researchers study isolated nutrients rather than foods, and cod liver

oil is a food.

> There surely

> must be tests for these three molecules. I suspect one confounding

> factor is that there are 40 species of cod that are viable for use as

> oil sources and the levels and ratios of vitamin A and D varies by

> species. So certainly any research would have to take all that into

> account. I guess as a consumer I'd like to see calciol, calcidiol and

> calcitriol levels right on the bottle.

Yes, that would be an issue. A greater issue is finding someone to

bother doing it and someone who wants to pay for it. A CLO

manufacturer or distributor might put up the money, but none of them

are probably sensing a significant demand for this information. You

and I would like to know, but it isn't like there is a substantial

component of the CLO market who would choose to buy based on that

knowledge. That said, it would be useful to argue why CLO is

different from supplemental vitamin D.

> The reason I ask is that calciol is an inactive form of vitamin D

> which require enzyme production and processing in the liver which I

> assume is more metabolically expensive than assimilating calcidiol or

> calcitriol. Although to be honest, I don't know the metabolic pathways

> for the later two. Perhaps someone could educate me.

That is the case for vitamin D provided by sunlight as well.

Calcidiol is also inactive. Calcidiol calcitriol are present in foods

such as butterfat and probably in CLO, but they are present in much

smaller amounts. Calcitriol is generally trace, and calcidiol, though

five times more active than vitamin D, is not present in large

amounts.

Chris

[Guest guest]

,

> A whole career? Do different CLOs have different amounts of the

> different metabolites? Are there exotic metabolites in CLO?

He didn't elaborate. But not only are different CLOs likely to have

different amounts, but there are >60 metabolites of vitamin D in the

body, some of which may have activity if they can be enzymatically

reversed back to vitamin D, calcidiol, or calcitriol, these will have

different activities, and some will not have activity.

Chris

[Guest guest]

" How does Green Pastures get cod liver oil without the synthetic

vitamin D added? "

Because the fermented CLO isn't heated at all in the first place, so

the natural vitamins are still there. IF I'm understanding it right...

[Guest guest]

>

> ?

son (I'm relatively new here)

>

> > That's a good point, I don't have any direct evidence with regard to

> > the difference between irradiated lanolin and natural vitamin D and

> > it's interaction with any form of vitamin A, natural or synthetic.

>

> How is irradiated lanolin unnatural? Seems to me that *is* natural

> vitamin D. The sheep is natural, it goes out in the sun, which is

> natural, and thus its lanolin gets naturally irradiated, and natural

> vitamin D is provided to the sheep.

>

I know nothing about sheep physiology, but I would be surprised if

vitamin D is even produced " on " sheep, let alone if the sheep could

absorb externally produced vitamin D through their heavy coats and

skin. I suspect they probably make vitamin D the same way we do.

Rather, lanolin is a waste or " by product " of the wool industry.

However, synthetic vitamin D3 manufacturers use other raw feed stock

like animal skins. I suspect the use of the term " lanolin " is an

attempt to soften the image of synthetic vitamin D3 production. It

wouldn't sound good to tell people their " natural " vitamin D3 is made

from " hog skin " . In addition, lanolin is produced in much smaller

quantities than animal skins and requires additional processing which

makes it a more expensive feed stock so I doubt it actually gets used

much. Although I've never seen vitamin industry statistics and I doubt

they're available for competitive reasons.

The process of synthetic vitamin D3 manufacture is complex, with many

steps that involve solvent dissolution and purification. These types

of manufacturing processes are never 100% efficient and always

introduce contaminants. Further, the irradiation process may well

produce additional contaminants, although I don't know how well this

process is understood.

Here is brief explanation of the process of synthetic vitamin D

manufacturing:

" The commercial production of vitamin D3 is completely dependent on

the availability of either 7-dehydrocholesterol or cholesterol.

7-Dehydrocholesterol can be obtained via organic solvent extraction of

animal skins (cow, pig or sheep) followed by an extensive

purification. Cholesterol typically is extracted from the lanolin of

sheep wool and after thorough purification and crystallization can be

converted via a laborious chemical synthesis into

7-dehydrocholesterol. It should be appreciated that once chemically

pure, crystalline 7-dehydrocholesterol has been obtained, it is

impossible to use any chemical or biological tests or procedures to

determine the original source (sheep lanolin, pig skin, cow skin,

etc.) of the cholesterol or 7-dehydrocholesterol.

Next the crystalline 7-dehydrocholesterol is dissolved in an

organic solvent and irradiated with ultraviolet light to carry out the

transformation (similar to that which occurs in human and animal skin)

to produce vitamin D3. This vitamin D3 is then purified and

crystallized further before it is formulated for use in dairy milk and

animal feed supplementation. The exact details of the chemical

conversion of cholesterol to 7-dehydrocholesterol and the method of

large-scale ultraviolet light conversion into vitamin D3 and

subsequent purification are closely held topics for which there have

been many patents issued " --http://vitamind.ucr.edu/milk.html

Doesn't sound very " natural " to me.

>

> > Which is why I asked so many questions in this post--just trying to

> > learn more about the subject.

> >

> > However, that was only a minor point. The major point is that perhaps

> > the concern over cod liver oil is partially influenced by the fact the

> > most of it now contains synthetic vitamin A for which there is

> > evidence of toxicity at levels lower than natural fat soluble vitamin

> > A in combination with natural vitamin D. Do Cannel or other

> > researchers accept the differences between water soluble, solidified

> > or emulsified vitamin A vs natural fat soluble vitamin A?

>

> No, nor do they provide evidence that cod liver oil is harmful, so

> once we get to the evidence part, the line of inquiry is essentially

> moot.

>

Well it sounds like they have a superficial understanding of vitamin A

then. Too bad because you'd think something called " The Vitamin D

Council " would be a strong ally.

> > I'm surprised that it would be difficult to determine the proportions

> > of calciol, calcidiol and calcitriol in cod liver oil.

>

> Usually " cholecalciferol " is the word for irradiated

> 7-dehydrocholesterol, which I think is the component of lanolin that

> gets irradiated. Is that wrong?

>

> It wouldn't be difficult. It is just that no one has done it. Most

> researchers study isolated nutrients rather than foods, and cod liver

> oil is a food.

>

> > There surely

> > must be tests for these three molecules. I suspect one confounding

> > factor is that there are 40 species of cod that are viable for use as

> > oil sources and the levels and ratios of vitamin A and D varies by

> > species. So certainly any research would have to take all that into

> > account. I guess as a consumer I'd like to see calciol, calcidiol and

> > calcitriol levels right on the bottle.

>

> Yes, that would be an issue. A greater issue is finding someone to

> bother doing it and someone who wants to pay for it. A CLO

> manufacturer or distributor might put up the money, but none of them

> are probably sensing a significant demand for this information. You

> and I would like to know, but it isn't like there is a substantial

> component of the CLO market who would choose to buy based on that

> knowledge. That said, it would be useful to argue why CLO is

> different from supplemental vitamin D.

>

>

> > The reason I ask is that calciol is an inactive form of vitamin D

> > which require enzyme production and processing in the liver which I

> > assume is more metabolically expensive than assimilating calcidiol or

> > calcitriol. Although to be honest, I don't know the metabolic pathways

> > for the later two. Perhaps someone could educate me.

>

> That is the case for vitamin D provided by sunlight as well.

> Calcidiol is also inactive. Calcidiol calcitriol are present in foods

> such as butterfat and probably in CLO, but they are present in much

> smaller amounts. Calcitriol is generally trace, and calcidiol, though

> five times more active than vitamin D, is not present in large

> amounts.

>

So it sounds like even truly natural cod liver oil will have mostly

calciol in it. Which I guess kinda makes sense. Sunlight and

7-dehydrocholesterol react in the blood to produce calciol which then

must accumulate in the liver where enzymes convert it into calcidiol.

But the calcidiol must not accumulate, but rather is released from the

liver and then to the kindeys where it is converted into calcitriol.

Thus, when you extract a liver and process it, most of what's in the

oil in calciol.

Thanks Chris!

> Chris

>

[Guest guest]

,

> synthetic vitamin A for which there is

> evidence of toxicity at levels lower than natural fat soluble vitamin

> A in combination with natural vitamin D. Do Cannel or other

> researchers accept the differences between water soluble, solidified

> or emulsified vitamin A vs natural fat soluble vitamin A?

You seem to be equating " natural " vitamin A with " synthetic " vitamin

A. Retinol is the fat-soluble form and it can be obtained in the diet

(usually in the esterified form, retinyl esters, which the body

hydrolyzes into retinol) or from synthetic retinol. When the

intestinal epithelial cells absorb retinol they (re)esterify it for

transport on chylomicrons. Do you have evidence that synthetic retinol

acts differents from retinol?

> I know nothing about sheep physiology, but I would be surprised if

> vitamin D is even produced " on " sheep, let alone if the sheep could

> absorb externally produced vitamin D through their heavy coats and

> skin. I suspect they probably make vitamin D the same way we do.

I'm confused by this paragraph. We humans make vitamin D when UVB rays

strike our skin and convert the 7-dehydrocholesterol that is present

into cholecalciferol. Why would you be surprised that sheep make it

the same way we do? Note that sheep don't have heavy coats year-round

and have some skin that is not covered with fleece (e.g. on their

face). Also, where are you getting the idea that any animal would

absorb " externally produced " vitamin D through its skin? I have never

heard of this happening in nature. It is internally produced in the

skin cells.

Here is a reference re sheep from Vitamins in Animal and Human

Nutrition by L. R. McDowell (Blackwell Publishing, 2000)

http://tinyurl.com/5rk8sj

" Vitamin D is synthesized in the skin of many herbivores and

omnivores, including humans, rats, pigs, horses, poultry, sheep, and

cattle. "

Tom

[Guest guest]

Sorry, I made a mistake in my first paragraph. I wrote:

> You seem to be equating " natural " vitamin A with " synthetic " vitamin

> A.

That sentence should read:

> You seem to be equating " natural " vitamin A with " fat-soluble "

> vitamin A.

Tom

[Guest guest]

Tom,

Actually I understand the distinction between natural vitamin A, like

in a cod liver vs. synthetic vitamin A like that manufactured in a

chemical plant. It is the later form which is used extensively in

vitamin pill and food supplements. Natural vitamin A is fat soluble.

Synthetic vitamin A is often water soluble, solidified or emulsified

depending on how it will be used.

The point I'm making is that Dr. Cannel's warning against cod liver

oil may be partly motivated by the fact that almost all commercially

available cod liver oil uses synthetic vitamin A, which is more toxic

than natural vitamin A.

As for " external " vitamin D production, I was responding to Chris's

comment that lanolin " on " sheep is somehow converted into vitamin

D--which seems unlikely since the lanolin is simply a raw feed stock

in the vitamin D3 manufacturing process. Lanolin on a sheep's wool

cannot be converted to vitamin D3. It has to be collected and highly

processed before being put under UVB light to make synthetic vitamin D3.

Like you, I'd expect that all useful vitamin D produced by sheep would

be produced in a process similar, if not identical, to how we produce

it via sunlight.

>

> ,

>

> > synthetic vitamin A for which there is

> > evidence of toxicity at levels lower than natural fat soluble vitamin

> > A in combination with natural vitamin D. Do Cannel or other

> > researchers accept the differences between water soluble, solidified

> > or emulsified vitamin A vs natural fat soluble vitamin A?

>

> You seem to be equating " natural " vitamin A with " synthetic " vitamin

> A. Retinol is the fat-soluble form and it can be obtained in the diet

> (usually in the esterified form, retinyl esters, which the body

> hydrolyzes into retinol) or from synthetic retinol. When the

> intestinal epithelial cells absorb retinol they (re)esterify it for

> transport on chylomicrons. Do you have evidence that synthetic retinol

> acts differents from retinol?

>

>

> > I know nothing about sheep physiology, but I would be surprised if

> > vitamin D is even produced " on " sheep, let alone if the sheep could

> > absorb externally produced vitamin D through their heavy coats and

> > skin. I suspect they probably make vitamin D the same way we do.

>

> I'm confused by this paragraph. We humans make vitamin D when UVB rays

> strike our skin and convert the 7-dehydrocholesterol that is present

> into cholecalciferol. Why would you be surprised that sheep make it

> the same way we do? Note that sheep don't have heavy coats year-round

> and have some skin that is not covered with fleece (e.g. on their

> face). Also, where are you getting the idea that any animal would

> absorb " externally produced " vitamin D through its skin? I have never

> heard of this happening in nature. It is internally produced in the

> skin cells.

>

> Here is a reference re sheep from Vitamins in Animal and Human

> Nutrition by L. R. McDowell (Blackwell Publishing, 2000)

> http://tinyurl.com/5rk8sj

>

> " Vitamin D is synthesized in the skin of many herbivores and

> omnivores, including humans, rats, pigs, horses, poultry, sheep, and

> cattle. "

>

> Tom

>

[Guest guest]

,

> Lanolin on a sheep's wool

> cannot be converted to vitamin D3. It has to be collected and highly

> processed before being put under UVB light to make synthetic vitamin D3.

I don't understand why you think that. If the lanolin has

7-dehydrocholesterol in it, then it just needs to be exposed to UVB

light. Obviously if you want a highly purified supplement, you need

to highly purify it first, but there is no reason that if the sheep

were exposed to UVB light the 7-dehydrocholesterol that is there would

not partially convert to vitamin D.

Animals secrete 7-dehydrocholesterol into their fur that gets

converted and often they eat this by licking their fur.

No 7-dehydrocholesterol gets converted in the blood. It takes place

in the skin. UVB light does not penetrate into the blood and there

isn't much 7-DHC there anyway.

It seems silly to me to call irradiated 7-DHC " synthetic " vitamin D.

Of course, all vitamin D is synthetic. Some is biosynthetic and some

is industrially synthesized, but it is all synthesized. But exposing

purified 7-DHC to UVB just mimics the natural synthesis. It may be

industrially *purified* but it is biologically synthesized.

If you revert cholesterol to 7-DHC than I would be up for calling that

" synthetic, " although it's worth noting that the majority of the

synthesis is still being done biologically.

Chris

[Guest guest]

Whatever happens to lanolin on a sheep's wool is irrelevant to this

discussion.

With the exception of Green Pasture's fermented cod liver oil, all

commercial cod liver oil now, or will soon, contain vitamin D3

manufactured in a chemical plant using multiple dissolution and

purification processes any of this can create or introduce contamination.

The WAPF website has numerous references to " toxic " and " synthetic "

vitamin D3 so it's not like I'm totally off base with this concern. In

fact this is one of the criteria used in recommending for or against

any given brand of cod liver oil.

>

> ,

>

> > Lanolin on a sheep's wool

> > cannot be converted to vitamin D3. It has to be collected and highly

> > processed before being put under UVB light to make synthetic

vitamin D3.

>

> I don't understand why you think that. If the lanolin has

> 7-dehydrocholesterol in it, then it just needs to be exposed to UVB

> light. Obviously if you want a highly purified supplement, you need

> to highly purify it first, but there is no reason that if the sheep

> were exposed to UVB light the 7-dehydrocholesterol that is there would

> not partially convert to vitamin D.

>

> Animals secrete 7-dehydrocholesterol into their fur that gets

> converted and often they eat this by licking their fur.

>

> No 7-dehydrocholesterol gets converted in the blood. It takes place

> in the skin. UVB light does not penetrate into the blood and there

> isn't much 7-DHC there anyway.

>

> It seems silly to me to call irradiated 7-DHC " synthetic " vitamin D.

> Of course, all vitamin D is synthetic. Some is biosynthetic and some

> is industrially synthesized, but it is all synthesized. But exposing

> purified 7-DHC to UVB just mimics the natural synthesis. It may be

> industrially *purified* but it is biologically synthesized.

>

> If you revert cholesterol to 7-DHC than I would be up for calling that

> " synthetic, " although it's worth noting that the majority of the

> synthesis is still being done biologically.

>

> Chris

>

[Guest guest]

-

> Whatever happens to lanolin on a sheep's wool is irrelevant to this

> discussion.

Given that the factory creation of vitamin D3 mimics the natural

process, it's quite relevant. The actual D3 that's produced should be

completely bio-identical.

> With the exception of Green Pasture's fermented cod liver oil, all

> commercial cod liver oil now, or will soon, contain vitamin D3

> manufactured in a chemical plant using multiple dissolution and

> purification processes any of this can create or introduce

> contamination.

I'll grant you that contamination could conceivably be an issue, but

it seems to me it's almost as likely that CLO itself would be

contaminated by the processes required to produce it.

> The WAPF website has numerous references to " toxic " and " synthetic "

> vitamin D3 so it's not like I'm totally off base with this concern. In

> fact this is one of the criteria used in recommending for or against

> any given brand of cod liver oil.

Unfortunately, different parts of the WAPF site meet different

standards of scientific rigor... or fail to meet them. Though it and

the foundation are invaluable resources, I wouldn't rely on them as

the sole and final arbiter of What Is True. At any rate, the

" synthetic " and " toxic " vitamin D the foundation is talking about (at

least in some cases; as I said, their literature is somewhat

heterogenous) is vitamin D2, AKA ergocalciferol, and that too isn't

exactly synthetic, at least not in the sense of being artificial --

just as 7DHC is converted into vitamin D3 in animals, ergosterol (the

fungal analog of cholesterol) is converted to vitamin D2 in fungi.

Unsurprisingly, the physiological effects of D2 in animals aren't

quite the same as those of D3, and there are toxicity dangers

associated with its use.

-

[Guest guest]

,

> Actually I understand the distinction between natural vitamin A, like

> in a cod liver vs. synthetic vitamin A like that manufactured in a

> chemical plant. It is the later form which is used extensively in

> vitamin pill and food supplements. Natural vitamin A is fat soluble.

> Synthetic vitamin A is often water soluble, solidified or emulsified

> depending on how it will be used.

This is precisely the point that I am arguing. Pick up any bottle of

plain old vitamin A. The ingredients or nutrition facts will list the

active compound as either vitamin A or retinol. When the form is not

specified, " vitamin A " = retinol; it is the basic form of the vitamin.

Retinol is fat-soluble, whether or not it is synthesized industrially.

Hence, I don't agree with your distinction. I wouldn't be surprised if

a few manufacturers sell water-soluble forms of vitamin A, but they

are in the minority. Most vitamin A pills are sold in softgel form to

contain the oil in which the vitamin is dissolved.

> The point I'm making is that Dr. Cannel's warning against cod liver

> oil may be partly motivated by the fact that almost all commercially

> available cod liver oil uses synthetic vitamin A, which is more toxic

> than natural vitamin A.

Do you have references to support your claim that synthetic vitamin A

is metabolized differently than natural vitamin A, or harmful in any way?

Tom

[Guest guest]

Well I suppose that's a loaded question. (You probably know the

literature better than me)

I guess I'll have to revert back to common sense. Common sense says

that vitamin A/D in a cod's liver is probably better for me than

vitamin A/D manufactured in a chemical factory. Not to mention the

fact that CLO can also contain synthetic vitamin E made from GMO soy

beans.

Or at least I was under the impression that on this list that kind of

thinking was taken for granted. I believe the root source of many of

our health problems is too much food that is broken apart and

reassembled in giant factories when a natural alternative is readily

available and usually better for us. Or am I accidentally posting on a

synthetic vitamin manufacturing group? (joke)

>

> ,

>

> > Actually I understand the distinction between natural vitamin A, like

> > in a cod liver vs. synthetic vitamin A like that manufactured in a

> > chemical plant. It is the later form which is used extensively in

> > vitamin pill and food supplements. Natural vitamin A is fat soluble.

> > Synthetic vitamin A is often water soluble, solidified or emulsified

> > depending on how it will be used.

>

> This is precisely the point that I am arguing. Pick up any bottle of

> plain old vitamin A. The ingredients or nutrition facts will list the

> active compound as either vitamin A or retinol. When the form is not

> specified, " vitamin A " = retinol; it is the basic form of the vitamin.

> Retinol is fat-soluble, whether or not it is synthesized industrially.

> Hence, I don't agree with your distinction. I wouldn't be surprised if

> a few manufacturers sell water-soluble forms of vitamin A, but they

> are in the minority. Most vitamin A pills are sold in softgel form to

> contain the oil in which the vitamin is dissolved.

>

>

> > The point I'm making is that Dr. Cannel's warning against cod liver

> > oil may be partly motivated by the fact that almost all commercially

> > available cod liver oil uses synthetic vitamin A, which is more toxic

> > than natural vitamin A.

>

> Do you have references to support your claim that synthetic vitamin A

> is metabolized differently than natural vitamin A, or harmful in any

way?

>

> Tom

>

[Guest guest]

So would there be some consensus in this group then that if you are not

using Green Pastures fermented you should not use Cod Liver Oil as a Vitamin

D delivery source?

--

April Streeter

[Guest guest]

I doubt there will be consensus on that point. GP's fermented is the

only brand I know of that does not use vitamin A/D that is

manufactured in a chemical factory (avoiding the whole

" natural " / " synthetic " thing).

I believe their Blue Ice brand will be discontinued because the mill

they use is switching to vitamin A/D that is manufactured in a

chemical factory. However, I don't represent GP, so you'll have to

confirm that with them.

As for other types of CLO, you'll have to make a cost-benefit type

decision. Factors to include are the benefits of proper vitamin A/D

intake vs purchase price, availability/convenience, concern over

" perceived " , but apparently unsubstantiated, risks from vitamin A/D

that is manufactured in a chemical factory, plus synthetic Vitamin E

made from GMO soy beans or " plant sterols " , fear of the unknown since

CLO is a poorly regulated product from the stand point of ingredient

labeling.

I personally would only buy GP's fermented.

If that goes away, I'll have to start making my own from frozen cod

livers. When I first read Wetzel's " Cod Liver Oil -- Notes on

the Manufacture of Our Most Important Dietary Supplement " I laughed

out loud when he brought up the idea that fresh water cod could be

farmed and cod liver oil could be picked up with other produce at the

farm gate, but I suppose that's really the long term solution.

Unfortunately is appears to be easier said than done. I've only been

able to find one researcher working on aqua-culture for fresh water

cod and they appear to be rather difficult fish to farm so there is a

lot of work still to do to get to that point.

Cheers,

>

> So would there be some consensus in this group then that if you are not

> using Green Pastures fermented you should not use Cod Liver Oil as a

Vitamin

> D delivery source?

>

> --

> April Streeter

>

>

>