Beta-Carotene dry capsules, as provided by Douglas
Laboratories, contain pure, synthetically-derived
beta-carotene. Each capsule provides 25,000 I.U.
vitamin A activity.
FUNCTIONS
Beta-carotene is a safe precursor of vitamin A.
Human intestinal enzymes convert dietary betacarotene
into active vitamin A. The extent of this
conversion appears to be based on the need for
vitamin A since even very large amounts of betacarotene
do not in...
Beta-Carotene dry capsules, as provided by Douglas
Laboratories, contain pure, synthetically-derived
beta-carotene. Each capsule provides 25,000 I.U.
vitamin A activity.
FUNCTIONS
Beta-carotene is a safe precursor of vitamin A.
Human intestinal enzymes convert dietary betacarotene
into active vitamin A. The extent of this
conversion appears to be based on the need for
vitamin A since even very large amounts of betacarotene
do not increase plasma or liver vitamin A
levels above normal. One milligram of beta-carotene
provides 1,667 I.U. of vitamin A activity. Betacarotene
not converted to vitamin A is absorbed
intact and has other functions in the body.
Beta-carotene is an important antioxidant nutrient
that protects healthy cells from oxidative and free
radical damage. Free radicals are unstable chemicals
formed in the body during metabolism and from
exposure to environmental sources such as pollution
and cigarette smoke. Free radicals are necessary for
energy metabolism and immune function, but when
an excessive number of free radicals are formed, they
can attack healthy cells, especially their membrane
lipids and proteins. This, in turn, is thought to
contribute to a number of degenerative diseases.
Beta-carotene efficiently quenches a chemically
reactive species of oxygen called singlet oxygen.
Singlet oxygen participates in oxidative reactions
which can impair or destroy important cellular
components, such as membranes, nucleic acids
(DNA), and enzymes. In addition, singlet oxygen
reactions can generate free radicals which lead to
further damage. Beta-carotene’s long, conjugated
molecule can absorb the energy of singlet oxygen and
release it safely as heat. In the process, singlet
oxygen is converted to less dangerous, regular
oxygen. One molecule of beta-carotene can quench
about a thousand molecules of singlet oxygen.
Numerous studies have demonstrated the importance
of beta-carotene for normal immune function. The
immune benefits of beta-carotene are due to its
vitamin A precursor role and its antioxidant
functions.
Beta-carotene is present in selected fruits and
vegetables such as carrots, sweet potatoes, and green
leafy vegetables. The U.S. Department of
Agriculture and the National Cancer Institute
recommend an intake of 5 mg (8,335 I.U.) or more of
beta-carotene. Unfortunately, most diets provide
only 1-2 mg (1,667 - 3,334 I.U.) per day.
