Vitamin D is a fat-soluble vitamin that is naturally present in
very few foods, added to others, and available as a dietary
supplement. It is also produced when ultraviolet rays from
sunlight strike the skin and trigger vitamin D synthesis.

What is generally not known is
that the vitamin D that is added
to foods is usually the synthetic
vitamin D2 and that vitamin
D3 is the only form that the body
can effectively use.

Fat-soluble means that vitamin D requires some dietary fat
in the gut for absorption. The fact that so many are attempting
fat-free or low fat eating may be one of the reasons for
the fact that so many Americans are deficient in vitamin D.

Vitamin D is essential for promoting calcium absorption from
the gut to the blood and for maintaining adequate blood calcium
and phosphate concentrations to afford normal mineralization
of bone and to prevent low-calcium tremors.  It is also needed
for bone growth and bone remodeling.  Without sufficient
vitamin D, bones can become thin, brittle, or misshapen.

Vitamin D sufficiency prevents rickets in children and
osteomalacia (painful softening and weakening of the bones)
in adults.  Together with calcium, vitamin D also helps protect
adults from osteopenia and osteoporosis.

Vitamin D has other roles in human health, including
aiding nerve, muscle and immune function and reducing
inflammation.

In 2008, the American Academy of Pediatrics (AAP) issued
new recommended intakes for vitamin D that exceed those of
the Food and Nutrition Board. The AAP recommendations are
based on evidence from more recent clinical trials and the
history of safe use of 400 IU/day of vitamin D in pediatric and
adolescent populations.

In the 1930s, a milk fortification program was begun in the
United States to combat rickets, then a major public health
problem. This program virtually eliminated the problem at
that time .  Other dairy products made from milk, such as
cheese and ice cream, are generally not fortified. And due
to the fact that many children arenow drinking fat-free milk,
rickets has been resurfacing in our country ( you maynotice
more bow-legged children – one of the symptoms of rickets).

Ready-to-eat breakfast cereals often contain added vitamin D,
as do some brands of orange juice, yogurt, and margarine. In
the United States, foods allowed to be fortified with vitamin D
include cereal flours and related products, milk and products
made from milk, and calcium-fortified fruit juices and drinks .
Maximum levels of added vitamin D are specified by law.

Tomorrow I will share some of the amazing discoveries from
new research.  You may also find some of this information at
Reverse Osteoporosis.

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