>I learned of this study from my local newspaper.
This same article appeared in my local newspaper.
>The article pointed out that with all the "super megadosage" vitamin
>pills selling so well it's important to know not just about the
>recommended dose, but how much can cause a harmful overdose.
True. This was the exact situation that lead me to compile my
_Nutrients_Catalog_
<http://harveynewstrom.com/nutrition/nutrientscatalog/index.html>. I
turned vegetarian, but could not find good sources of toxic symptoms.
Most books gave symptoms that suggested taking more, but almost none
gave symptoms that would suggest taking less. I did my own research
at a biochemistry library and quickly discovered that popular books
are mostly wrong and are decades behind recent research. Eventually
my research database became so large that I decided to publish it as
a reference volume through McFarland & Company.
>Vitamin A -a dose of 3,000 micrograms can risk birth defects in the
>unborn and cause liver damage for people.
The article confused the beta-carotene form of vitamin A (found in
carrots) with the retinol form of vitamin A (found in liver). The
article references carrots as a source of vitamin A, which would be
the beta-carotene form, but then calculates the dangerous dosage and
gives the toxicity symptoms of the retinol form.
Micrograms are useless to measure vitamin A because different forms
have different potency. 3000 micrograms of beta-carotene (found in
carrots) would be 2500iu which is only half of the RDA. 3000
micrograms of retinol (found in liver) would be 15000iu which is
three times the RDA.
The toxicity symptoms given above only occur with high dosages of the
retinol form, but is not a danger with the beta-carotene form.
Linking this dosage and these symptoms with vitamin A from carrots is
just wrong.
>Vitamin E -more then 1,000 milligrams can risk uncontrolled bleeding.
Milligrams of vitamin E is also a useless measurement. Different
forms of vitamin E have different potencies. Measuring 1000
milligrams of alpha-, beta-, gamma-, delta-, and other tocopherols
will yield different dosages. The article is obviously referencing
the most common form of vitamin E, dl-alpha-tocopherol, and is
calculating a commonly cited limit of 3000iu.
The uncontrolled bleeding is due to the blood thinning effect of
vitamin E. People taking vitamin E to reduce their risk of heart
attacks may bleed more easily, as do people taking aspirin every day.
Most people taking these high doses consider this to be a health
enhancing property rather than a detracting one. One must have
specific health goals in mind before deciding what effects are good
or bad, or how much is appropriate.
>Folic acid -more then 1 milligram a day can result in nerve damage.
This seems low, but close enough. They either have more recent
information or are adding a safety margin.
>The institute warns that consumers are sometimes confused by
>vitamins sold in "international units" because they do not know how
>to convert them into micrograms and milligrams which can differ
>based on the nutrient. So be careful...
This is bizarre. Nobody should be converting milligrams to
international units (iu) unless you are weighing or measuring your
own. All nutrients sold in pill form are dosed in iu. All
scientific information about nutrients in measured in iu. Once you
determine how many iu is desired, the pills are labeled the same way.
This implies that milligrams are normal measurements and that iu are
confusing. Actually, it is the other way around. Wieghts in
milligrams are only useful if you have a pharmaceutical scale and are
mixing/packing your own capsules.
-- Harvey Newstrom <HarveyNewstrom.com>
This archive was generated by hypermail 2b30 : Mon May 28 2001 - 09:56:24 MDT