Re: flavonoids in Vitamin C is goitrogen

[Guest guest]

This is interesting to me, as I have been taking Vit C with

flaconoids for a fortnight or so, I bought them in error, my OH won't

take them, so I have been.

This morning I have had a crash and burn episode over a trivial

matter, I felt like I would have to go home from work, but didn't,

although I couldn't say I " held it together " and indeed, I wouldn't

normally access the forum during work hours, but I need to calm down

and get my head straight. I was thinking it might mean I should up

the dose of NAE, but now I'm thinking ditch those vit C and up the

dose of NAE!

I'm having trouble remembering to take aa lunchtime one as it is a

new routine for me. I normally get lunch asap and sit for half an

hour before going back to work.

Luv,

Kat

> Hi, I know lots of us hypoT take Vitamin C, and many vitamin c

> supplement products contain bioflavonoids to aid the " absorption " .

such

> as Citrus flavonoids. I just read an " official " article that list

all

> kinds of chemical enviromental goitrogens (There are lots of them

on the

> liste) , including flavonoids. it said " Flavonoids not only ihibit

TPO

> but, acting on iodothyronine deiodinase enzymes, also inhibit the

> peripheral metabolism of thyroid hormones. Flavonoids also affect

serum

> thyroid hormone binding and thyrotropin (TSH) regulation.

Flavonoids

> become an important etiologicla determinant of endemic goiter and

> hypothyroidism " .

>

> Any opinions on it? there are some other vitamin Cs which don't

include

> the Flavonoids.

>

> Fragrance

>

[Guest guest]

Can you cite the article?

TY!

Heidi

>

>

> Hi, I know lots of us here take Vitamin C, and many vitamin c supplement

> products contain bioflavonoids to aid the " absorption " . such as Citrus

> flavonoids. I just read an " official " article that list all kinds of

> enviromental goitrogens, including flavonoids. it said " Flavonoids not

> only ihibit TPO but, acting on iodothyronine deiodinase enzymes, also

> inhibit the peripheral metabolism of thyroid hormones. Flavonoids also

> affect serum thyroid hormone binding and thyrotropin (TSH) regulation.

> Flavonoids become an important etiologicla determinant of endemic goiter

> and hypothyroidism " .

>

> Any opinions on it? there are some other vitamin C which don't include

> the Flavonoids.

>

[Guest guest]

Sorry, I read it in the book, not online.

The source is reliable, because the book what I read is the first

published Encyclopedia of Endocrine Diseases written by worldwide Endo

experts. This specific article " Eoitrogens, Environmental " was written

by " Gaitan in University of Mississippi Medical School " And

" Excess Iodine " is listed as " acitve in Gotrogenic /Antithyroid Effects "

with other 20+ kinds of chemicals, too.

Fragrance

> >

> >

> > Hi, I know lots of us here take Vitamin C, and many vitamin c

supplement

> > products contain bioflavonoids to aid the " absorption " . such as

Citrus

> > flavonoids. I just read an " official " article that list all kinds of

> > enviromental goitrogens, including flavonoids. it said " Flavonoids

not

> > only ihibit TPO but, acting on iodothyronine deiodinase enzymes,

also

> > inhibit the peripheral metabolism of thyroid hormones. Flavonoids

also

> > affect serum thyroid hormone binding and thyrotropin (TSH)

regulation.

> > Flavonoids become an important etiologicla determinant of endemic

goiter

> > and hypothyroidism " .

> >

> > Any opinions on it? there are some other vitamin C which don't

include

> > the Flavonoids.

> >

>

[Guest guest]

Fragrance,

Not all flavonoids are goitrogenic. Isoflavone and isothyocyanates both

definitely are. You need to look up the specific additives to know whether your

C is a problem. Vitamin C is quite soluble, so I would not pay extra for the

alleged benefit.

Chuck

You wrote:

>

> Hi, I know lots of us here take Vitamin C, and many vitamin c supplement

> products contain bioflavonoids to aid the " absorption " . such as Citrus

> flavonoids. I just read an " official " article that list all kinds of

> enviromental goitrogens, including flavonoids. it said ...

[Guest guest]

FLAVONOIDS

Flavonoids are important stable organic constituents

of a wide variety of plants. Flavonoids are universally

present in vascular plants and in a large number of

food plants. Because of their widespread occurrence in

edible plants such as fruits, vegetables, and grains,

flavonoids are an integral part of the human diet.

They are present in high concentrations in polymeric

(tannins) and oligomeric (pigments) forms in various

staple foods in the Third World such as millet,

sorghum, beans, and ground nuts.

Flavonoids are polyhydroxyphenolic compounds

with a C6¨CC3¨CC6 structure. Mammalian organisms

are unable to synthesize the flavone nucleus.

Flavonoids are strictly exogenous food components

of exclusively vegetable origin. They have high chemical

reactivity with multiple important biological implications.

Flavonoids are quickly metabolized in

higher organisms, and that is the reason why they

are not found in normal tissue constituents. Most

flavonoids are present as b-glucosides that cannot be

absorbed in tissues. No mammalian enzymes have

been found that deglycosylate these compounds to

their bioactive aglycone species. Following ingestion

by mammals, flavonoid glycosides are hydrolyzed

by intestinal microbial glycosidases to flavonoid

aglycones. These may be absorbed and undergo

metabolism by mammalian tissues, or they may be

further metabolized by intestinal micro-organisms to

undergo B-ring hydroxylation and middle-ring fission,

with production of various metabolic monomeric

compounds, including phenolic acids,

phloroglucinol, resorcinol, and gallic acid. Each metabolic

step is characterized by a marked increase in

antithyroid effects. Flavonoid aglycones, such as apigenin

and luteolin present in Fonio millet (Digitariaexilis), and a variety of

flavonoid metabolites (e.g.,

phloroglucinol, resorcinol, phenolic acids) are several

times more potent than the parent glycosides glucosylvitexin,

glucosylorientin, and vitexin present in

Pearl millet (Pennisetum [L.] leeke, also known as

typhoides or americanum), as inhibitors of TPO, the

enzyme-catalyzing iodide oxidation and hormone

synthesis in the thyroid gland. This greater inhibitory

effect is further enhanced by the additive effects

exerted by mixtures of flavonoid aglycones and flavonoid

metabolites that are formed after ingestion of

mixtures of flavonoid glycosides present in many

plant foodstuffs. In addition, these metabolic products

may produce adverse effects on other parameters of

thyroid function not observed with the glycosides. As

a result, the antithyroid effects of flavonoid glycosides

in foodstuffs may be greatly enhanced by metabolic

alterations after ingestion by mammals, as in the case

of the flavonoids present in the Pearl millet grain, the

staple food of people living in iodine-deficient endemic

goiter areas of western Sudan, which make

a major contribution to and are primarily responsible

for its antithyroid and goitrogenic effects.

Furthermore, antithyroid effects in vivo of vitexin,

one of the three major flavonoids in Pearl millet,

has been demonstrated to provide evidence that

C-glycosylflavones are the goitrogens in this cereal

grain. It is of interest that a significant portion of the

flavonoids isolated from Fonio millet, the staple food

of people living in the severely affected endemic goiter

area of Guinea in Western Africa, are already present

as the aglycones apigenin and luteolin, with more

potent antithyroid activity than their parent glycosides.

Flavonoids not only inhibit TPO but, acting

on iodothyronine deiodinase enzymes, also inhibit

the peripheral metabolism of thyroid hormones.

Flavonoids also affect serum thyroid hormone binding

and thyrotropin (TSH) regulation. Thus, this class of

compounds alters thyroid hormone economy in a

complex manner.

At this point, there is substantial evidence indicating,

first, that various millet species used as staple

food by the populations in the semi-arid tropics

are rich in flavonoids; second, that flavonoids have

potent and diverse antithyroid properties; and third,

that under the appropriate environmental dietary

conditions of low iodine and protein¨Ccalorie intakes,

which are prevalent in most countries of the

Third World, flavonoids become an important

etiological determinant of endemic goiter and

hypothyroidism.

Chuck, I don't know if there is difference bt Flavonoids, but isn't this

article mentioned all kinds of flavonoids?

Fragrance

> >

> > Hi, I know lots of us here take Vitamin C, and many vitamin c

supplement

> > products contain bioflavonoids to aid the " absorption " . such as

Citrus

> > flavonoids. I just read an " official " article that list all kinds of

> > enviromental goitrogens, including flavonoids. it said ...

>