UV Protection and Vitamin D
cientists estimate that
nearly 42% of U.S.
adults1 and 70% of all
children2 suffer from
a vitamin D deficiency,
the effects of which can range
from decreased energy to rickets.
On top of building strong bones
and a healthy immune system, the
hormone vitamin D has been proven
to help people lose weight, manage
the symptoms of depression and
even lower the chances of getting
many forms of cancer, heart disease
and type 2 diabetes.
There are three sources from
which humans can get vitamin
D: sun exposure, supplements
and food. The first of these is
controversial and complex.
Controversial because while sun
exposure can lead to increased
levels of vitamin D, it can also
subject an individual to skin
damage and skin cancer. Complex
because the sun does not supply
the skin with vitamin D, but rather
starts the process for its production.
Skin naturally contains a
precursor to vitamin D, and when
the sun’s UVB rays touch the
skin, they convert the precursor
to vitamin D3 or cholecalciferol,
which then follows a metabolic
pathway through the liver and
finally to the kidneys where
it is converted into calcitriol.
Vitamin D obtained from food
or supplements follows this same
metabolic highway to become that
active form of vitamin D3.
Vitamin D is not a
one-size-fits-all hormone, and an
individual’s vitamin D requirement
depends on their size. Having
the right amount of vitamin D is
a careful balance. As stated, its
deficiency can cause a range of
issues, but excess vitamin D can
lead to calcium in places it should
not be, as well as kidney stones
and other problems.
Before this article discusses
vitamin D-deficient skin
disorders, correct dosage and
the esthetician’s role, it will first
provide context to the complexity
of UVB exposure through key
aspects of human ancestry.
Evolution and Revolution
The amount of pigmentation
in our skin today directly relates
to the UVB levels to which our
ancestors were exposed. The
current understanding of evolution
places the first appearance of
Homo sapiens in Africa, one of
the continents with the highest
concentration of UVB-rich
sunlight due to its proximity to
By Cynthia Malcom
Sun C nundrum:
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