L carnitine is derived from the lysine and methionine
amino acids. It is mainly synthesized in the liver
and the kidneys, and must be transported for use to
other tissues in the body. It is found in highest
concentration in tissues that use fatty acids as the
main dietary fuel, such as the skeletal and cardiac
muscles.
One of the key uses of Acetyl L-Carnitine supplement
is for fatty acid oxidation - helping users burn unwanted
body fat. Fatty acids are one the key energy sources
the body uses, and oxidation is the process by which
they're broken down to create energy. The fatty acids
cannot penetrate the inner mitochondia membrane (where
they are burned for energy), and the key role for
L-Carnitine is to transport fatty acids accross the
mitochondra membrane to allow for oxidation of the
fats.
Sources Of L Carnitine From Foods
Carnitine plays a fundamental role in energy production,
and it is used to support all bodily functions that
require high levels of energy. It is present in many
of the foods we eat, such as meats, vegetables, and
grains. Typically, it comes in higher concentration
in red meats such as beef and lamb, and in lower concentration
(or none) in foods such as white meats and vegetables.
For example, beef has about 145mg of l-carnitine
per every 100 grams, compared to only 2.6mg per every
100grams of mushroom. It's even less for other vegetables
such as carrots with only 0.4mg. Obviously, if you're
a vegetarian, you're at a disadvantage for carnitine
sources compared to someone who eats meat in their
regular diet - making it a very good reason to supplement
with acetyl l carnitine supplements. (see below for
deficiency).
Carnitine Deficiency
Your body can produce a very small amount of L-Carnitine
on a daily basis, with the highest concentrations
in the heart and skeletal muscles. In certain conditions,
the demand for carnitine may exceed a person's ability
to synthesize it, thus making it a conditionally essential
nutrient.
As said above, individuals who eat little to no meats
(vegetarians) will benefit from supplementation of
L-Carnitine. Although deficiencies are uncommon, muscle
fatigue, cramping are some signs of possible deficiency.
Generally, deficiency is categorized as primary and
secondary carnitine deficiencies.
Primary Carnitine Deficiency
These are relatively rare hereditary disorders, such
as:
Systemic deficiency
Myopathic deficiency
These deficiencies are generally characterized by
low carnitine levels, poor absorption of l-carnitine
from diet, muscle pain, progressive muscle weakness,
etc. The myopathic deficiency is less severe than
the systemic form.
Secondary L Carnitine Deficiency
This form can be hereditary, or acquired, and generally,
there's is low levels of available l-carnitine. This
can be characterized by:
Increased loss of carnitine
Insufficient synthesis of carnitine
Malabsorption from diet
These forms of deficiency are generally rare, and
although vegetable sources contain much less (close
to none) L-Carnitine, vegetarians can usually synthesize
enough carnitine to prevent deficiency. However, among
pre-mature infants, children, and breast-feeding women,
vegetarians are more likely to be deficient.
Some symptoms of deficiency include:
Kidneys not functioning properly after exercise
Weak muscle
Muscle fatigue and muscle cramping
Heart irregularities
(keep in mind: L-Carnitine is found in highest
concentrations in the heart and skeletal muscles.)
Acetyl L Carnitine Benefits and
Side Effects
There are very few documented side effects, and they
include:
Increase in blood pressure
Faster heartbeats
Fever
Large amounts may cause diarrhea
That's about it, and their occurances are quite rare.
As for benefits of L-Carnitine, there are quite a
few:
L-carnitine plays an important role in energy
production
It helps in weightloss and fat burner (see next
point)
It transports long-chain fatty acids into the
mitochondra to metablize to generate energy
Enhance cellular energy in the brain
Improve mental performance
Helps slow the effects of aging
Decerases symptoms of depression
Helps prevent cataracts
Used to support all bodily functions that have
a high energy demand
How much should you take?
Generally, about 2 grams should be taken, and L-carnitine
supplements usually come in 250mg and 500mg caps.
If you're looking for Acetyl L Carnitine supplements,
follow the links below.
Am J Clin Nutr 1980 Jul;33(7):1489-92
-- Guarnieri GF, Ranieri F, Toigo G, Vasile A, Ciman
M, Rizzoli V, Moracchiello M, Campanacci L.
Rebouche CJ. Carnitine. In: Shils
ME, Olson JA, Shike M, Ross AC, eds. Nutrition in
Health and Disease. 9th ed. Baltimore: Williams &
Wilkins; 1999:505-512
Brass EP, Hiatt WR. The role of
carnitine and carnitine supplementation during exercise
in man and in individuals with special needs. J Am
Coll Nutr. 1998;17(3):207-215
