Post by Vanny"We need to do a better job as a society in ensuring that the messages
people get about value versus risk is accurate for nutritional
supplements," Byers says. "My conclusion is that taking high doses of
any particular nutrient is more likely to be a bad thing than a good thing."
http://www.eurekalert.org/pub_releases/2012-05/uocd-dsi051512.php
Tips For The Savvy Supplement User: Making Informed Decisions And
Evaluating Information
http://www.fda.gov/Food/DietarySupplements/ConsumerInformation/ucm110567.htm
Tips for Older Dietary Supplement Users
http://www.fda.gov/Food/DietarySupplements/ConsumerInformation/ucm110493.htm
Dietary supplement fact sheets
http://ods.od.nih.gov/factsheets/list-all/
give me a
Post by Vanny"We need to do a better job as a society in ensuring that the messages
people get about value versus risk is accurate for nutritional
supplements," Byers says. "My conclusion is that taking high doses of
any particular nutrient is more likely to be a bad thing than a good thing."
http://www.eurekalert.org/pub_releases/2012-05/uocd-dsi051512.php
Tips For The Savvy Supplement User: Making Informed Decisions And
Evaluating Information
http://Vitamin E from natural (food) sources is listed as "d-alpha-tocopherol" on food packaging and supplement labels. Synthetic (laboratory-made) vitamin E is listed as "dl-alpha-tocopherol." The natural form is more potent. For example, 100 IU of natural vitamin E is equal to about 150 IU of the synthetic form.www.fda.gov/Food/DietarySupplements/ConsumerInformation/ucm110567.htm
Tips for Older Dietary Supplement Users
http://www.fda.gov/Food/DietarySupplements/ConsumerInformation/ucm110493.htm
Dietary supplement fact sheets
http://ods.od.nih.gov/factsheets/list-all/
"fact sheets" LOL BS in the Sheets
Fact sheet quote:
Vitamin E from natural (food) sources is listed as "d-alpha-tocopherol" on food packaging and supplement labels. Synthetic (laboratory-made) vitamin E is listed as "dl-alpha-tocopherol." The natural form is more potent. For example, 100 IU of natural vitamin E is equal to about 150 IU of the synthetic form.
Wrong the natural form is twice as active see below.
1. Vitam Horm. 2007;76:281-308.
Alpha-tocopherol stereoisomers.
Jensen SK, Lauridsen C.
Department of Animal Health, Welfare and Nutrition, Faculty of Agricultural
Sciences, University of Aarhus, DK-8830 Tjele, Denmark.
Vitamin E comprises a group of compounds possessing vitamin E activity.
alpha-Tocopherol is the compound demonstrating the highest vitamin E activity,
which is available both in its natural form as RRR-alpha-tocopherol isolated from
plant sources, but more common as synthetically manufactured
all-rac-alpha-tocopherol. Synthetic all-rac-alpha-tocopherol consists of a
racemic mixture of all eight possible stereoisomers. Assessing the correct
biological activity in form of bioavailability and biopotency has been a great
challenge during many years as it is difficult to measure clinical endpoints in
larger animals than rats and poultry. Thus, the biological effects in focus are
resorption of fetuses, testicular degeneration, muscle dystrophy, anemia,
encephalomalacia, and in recent years the influence of vitamin E on the immune
system are the most important clinical markers of interest. For humans and
animals, only different biomarkers or surrogate markers of bioactivity have been
measured. In studies with rats, a good consistency between the classical
resorption-gestation test and the bioavailability of the individual stereoisomers
in fluids and tissues has been shown. For humans and other animals, only
different biomarkers or surrogate markers of bioactivity have been measured, and
due to the lack of good biological markers for bioactivities, bioavailability is
often used as one of the surrogate markers for bioactivities with those
limitations this must give. Therefore, a relatively simple analytical method,
which allows analysis of the individual stereoisomers of alpha-tocopherol, is an
important tool in order to quantify relative bioavailability of the individual
stereoisomers. The analytical method presented here allows the quantification of
total tocopherol content and composition by normal phase HPLC and subsequent
separation of the stereoisomers of alpha-tocopherol as methyl ethers by chiral
HPLC. Using this method, the alpha-tocopherol stereoisomers are separated into
five peaks. The first peak consists of the four 2S isomers (SSS-, SSR-, SRR-,
SRS-), the second peak consists of RSS-, the third peak consists of RRS-, the
fourth peak consists of RRR-, and the fifth peak consists of
RSR-alpha-tocopherol. The discussion on the bioavailability of RRR- and
all-rac-alpha-tocopheryl acetate has primarily been based on human and animal
studies using deuterium-labeled forms, whereby a higher biopotency of 2:1 (of
RRR: all-rac) has been demonstrated, differing from the accepted biopotency ratio
of 1.36:1. In agreement with previous studies, the 2S-forms exert very little
importance for the vitamin E activity due to their limited bioavailability. We
find notable differences between animal species with regard to the
biodiscrimination between the 2R-forms. Especially, cows preferentially transfer
RRR- alpha-tocopherol into the milk and blood system. The distribution of the
stereoisomer forms varies from tissue to tissue, and in some cases, higher levels
of the synthetic 2R-forms than of the RRR-form are obtained, for example, for
rats. However, the biodiscrimination of the stereoisomers forms is influenced by
other factors such as age, dietary levels, and time after dosage. More focus
should be given on the bioactivity of the individual 2R-forms rather than just
the comparison between RRR- and all-rac-alpha-tocopheryl acetate.
PMID: 17628178 [PubMed - indexed for MEDLINE]
Additional the other natural isoforms have different activities
and functions at practical level.
Trig