Is vitamin D a real vitamin?
Vitamin D is synthesized by the human body, but not always
in sufficient quantities. The level of synthesis depends on
exposure to sunlight, so in winter and in polar areas there
is a greater need to take it, whereas in summer and in equatorial
areas it is less necessary. It is generally considered a vitamin,
but one that isn't required in some areas and seasons.
Vitamins A and K
Neither vitamin A nor vitamin K is a single chemical substance,
but all derivatives fulfill the same functions in organisms
(or are converted into the active form by the organism), so
taking just one of the derivatives is sufficient for good
health. The derivatives differ in chemical structure and level
of activity.
Names
Some vitamin names have become obsolete:
· Vitamin B – actually a complex of several vitamins:
B-number, H, and M.
· Vitamin G – another name for riboflavin (vitamin
B2 )
The usage of names in the format "vitamin
letter" and "vitamin letter number" is diminishing.
This is especially true for vitamins H, M, B1, B2, B3, and
B5, which are usually called by their proper chemical names.
On the other hand, vitamins D and E are still usually called
by their symbolic names, and A and K don't even have proper
chemical names (since they are mixtures of chemicals).
The names ascorbic acid and vitamin C are used with similar
frequency.
Whatever Happened to Vitamin F?
Vitamin F was the designation originally given to essential
fatty acids that the body cannot manufacture. They were "de-vitaminized"
because they are fatty acids. Fatty acids are a major component
of fats.
New vitamin discoveries
On April 24, 2003 a research team led by Takafumi Kato of
the Japanese Institute of Physical and Chemical Research confirmed
that pyrroloquinoline quinone (PQQ), a substance originally
discovered in 1979, can be categorised as a vitamin in mice.
Some authorities say that Ubiquinone, also called Coenzyme
Q, is a vitamin (See ref.) Ubiquinone is manufactured by the
body, so other authorities dispute this. However most humans
need about 500mg/day, but manufacture less as they age. Ubiquinone's
primary action is as an antioxidant many times more powerful
than Vitamin E, and one of its most important roles is to
prevent oxidative damage to mitochondria, the cellular organelles
that power human metabolism. Many authorities say that Ubiquinone
supplementation has value to treat or prevent some symptoms
and diseases of aging.
