The Miracle Vitamin: Vitamin D
For years most people took vitamin D for granted. We got it from the sun,
and there was no doubt that we got enough. Besides, it didn’t seem to be a
particularly important vitamin. It may surprise you how much that has
changed in the last few years. Vitamin D now appears to give more
protection from cancer than any other vitamin. And that’s not all. It also
protects us from various autoimmune diseases, including MS, Crohn’s
disease, and autoimmune diabetes. It has also been shown to control the
amount of inflammation produces by various cells, and as you likely know,
excess inflammation can be a problem.
The evidence for protection from cancer is quite dramatic. Some of the
forms of cancer it has been shown to protect us from are: bladder, breastm
colon, ovary, and rectal. Northern states get considerably less sunlight ( and
therefore less vitamin D) than southern states and studies have shown that
they have twice as much cancer.
There are actually two forms of vitamin D referred to as D2 and D3. We
will be concerned with D3 as it is the most common; it is created in the skin
by UVB light from the sun, and it is the main type we get from food. D2
comes mainly from mushrooms. The vitamin D we take in is in an inactive
form. It is “preactivated” in the liver and the final activation takes place in
the kidneys. The form from the liver is the main type that circulates in the
blood; it is called 25D.
The major reason that vitamin D is so important is that it is capable of
regulating genes – in other words, turning them on and off. This means that
it sends a message to our genes to start or stop producing protein, and at
least 1000 different genes are regulated and therefore under the control of
Why is this important? One reason (and perhaps the most important one)
is that cancer is caused by cells where the “turn off” switch has been
compromised, and as a result, rapid and uncontrolled growth is occurring.
And since vitamin D contols this growth in many types of cells it obviously
is important. We therefore need to keep appropriate levels of Vitamin D in
our blood. Studies have shown, however, that a large fraction of the
population does not. A recent study in Europe of adolescent girls showed
that 97% had low levels of vitamin D with 35% “severely deficient.”
How much vitamin D do we need? The RDI for adults is 200 – 600 IU,
depending on age, but many researchers believe this is far too low. They
recommend 1000 IU/day, and some even suggest as much as 2000/day. But
it’s important to remember that vitamin D is fat soluble so it is possible to
overdose. Studies have shown, however, that toxicity doesn’t occur until
about 40,000 IU and you could never overdose from food or sunlight. This
would only be possible by taking high doses of pills.
What is the best source of vitamin D? The UVB light from the sun is, of
course, at the top of the list. You can get all you need in a day from about 15
to 20 minutes of sun. I should mention, however, that sun screen blocks
about 98% of UVB. And as you no doubt know: the sun causes sunburn,
which in turn can cause skin cancer so you have to be careful.
What about foods? Cod liver oil is the best, but I know it doesn’t appeal
to most people. Other good sources are: tuna, sardines, salmon, eggs (a small
amount) and fortified milk and orange juice. Shiitake mushrooms are also a