How is Vitamin D Processed By the Body? 
What does it do? 
What is the government recommendation? 
Are we getting enough? 
Should We Try to Get Our Vitamin D From the Sun? 
Severe Deficiency 
Further Reading 

How is Vitamin D Processed By the Body?

As mentioned on the previous page, when the ultraviolet light in sunlight strikes the skin, it creates vitamin D.  The only food that contains significant amounts of vitamin D is fish liver.  Our ancestors were farmers or hunter/gatherers and spent a lot of time in the sun.  They got ten times the amount of vitamin D we get today.  They had about double the amount of vitamin D in their blood as the average person today.

Vitamin D initially enters the body in one form and is then converted to a more active form.  If you start taking vitamin D everyday, it can take about six weeks before the levels of active D peak in your bloodstream.  It can take weeks to see an improvement!

The half life of active vitamin D is about eight weeks.  It can take weeks or months for the active forms to leave the body.  The levels of vitamin D in the blood depend on many factors.

What does it do?

Vitamin D has many functions.  The most important is to help maintain proper levels of calcium in the blood by aiding absorption of calcium.  Remember this function.  It ties in with the function of the parathyroid gland, which you will read about on another page.

What is the government recommendation?

The government has a recommended daily allowance (RDA) for most vitamins.  This is the amount sufficient to meet the requirements of nearly all healthy individuals.  The government does not have sufficient information to make such a recommendation for vitamin D.  Instead the government has what is called an “Adequate Intake” (AI).  The AI for children and adults up to 50 years of age is 200 IU, for adults 50 to 70 it is 400 IU, and for adults older than 70 it is 600 IU.

Note that prior to 1997, the recommendation for everyone was 400 IU.  The recommendation for most people was lowered at that time!  The evidence for doing so is unclear.

How was this determined?  The dose of 400 IU was determined by measuring the amount of vitamin D in a teaspoon of cod liver oil.  This is the amount taken by children in England for many years and was known to be enough to prevent rickets.  But vitamin D does more than protect from rickets.  It affects at least 30 different systems in the body.  Is this amount adequate to support these other systems?  The government admits this is unknown, and it is the reason that vitamin D has an “Adequate Intake” number instead of a “Recommended Daily Allowance”.

Are we getting enough?

In northern areas, there is very little ultraviolet light available in the wintertime.  Significant UV light is only available from the hours of 10AM through 2PM (11-3 daylight savings time).  Of course, sunscreen filters most UV light.  Even untinted windows filter out most UV light. Your commute to work and back in the morning and afternoon doesn't help you get the vitamin D you need!

Many of us simply don't get outside in the middle of the day.  Many adults don't drink milk or eat much fish.  If we don't get outside and don't take vitamins, there is a very high probability that we have insufficient vitamin D.

Most of our ancestors were farmers and spent most of their time in the sun.  Today, we spend more and more time inside.  When I was a child, parents encouraged children to play outside to get fresh air and sunshine.  We had four TV channels.  Today, kids have video games and over 100 channels to keep them inside.  They are more likely to have karate classes or other activities that are held indoors.

People are spending less and less time outside.  The rate of rickets among children is triple what it was a few years ago according to some reports.

Studies on people that spend a lot of time in the sun such as lifeguards and farmers show that they can have twice as much vitamin D in their blood as other people.  Studies show that about 1% of the population has severe deficiency, but 25% to 50% have the lesser condition of vitamin D insufficiency.

In recent years, we’ve been repeatedly advised to stay out of the sun and use sunscreen.  Yet, we’re often told that vitamins pills are a waste of time, and that if we eat a balanced diet we don’t need them.  If we don’t get out in the sun and don’t drink milk or eat fish, there are no other sources of vitamin D.  It is the forgotten vitamin.

Should We Try to Get Our Vitamin D From the Sun?

I've been asked this question several times lately.

I do believe that getting some sun everyday is important.  In addition to creating vitamin D, sunlight affects several hormones.  It suppresses melatonin which causes sleepiness.  

Ultraviolet light which creates vitamin D is only available in the middle of the day.  To get the level of vitamin D our caveman ancestors got from the sun, you would have to spend several hours in the sun in the middle of the day wearing very little clothing.  This is hardly practical.  If you went out in the sun with only your hands and head uncovered you would get about 400 units.

If you get your vitamin D from the sun, it is also very difficult to measure the dose.  I personally need to keep the dose very constant.

In addition, there is the problem of skin cancer.  Did our ancestors have a high rate of skin cancer or were they somehow protected?  We don't know the answer to this question.

When the ultraviolet light in sunlight strikes the skin, it creates vitamin D3.  Studies seem to show that taking vitamin D3 orally has the same effect.

Personally, I try to get 30 minutes of sunlight in the morning and another 40 minutes at noon time in addition to the vitamin D supplements that I take.

Severe Deficiency

In some cases of severe deficiency, large doses of vitamin D have been shown to have amazing results.  One doctor treated five wheelchair bound patients with large doses of vitamin D.  Four completely recovered in a few months.  I urge people to see a doctor to have their vitamin D levels tested before starting, but even if your levels are "normal" you may still benefit greatly by taking vitamin D.  "Normal" today was far below normal for our ancestors.

Further Reading

This is a wonderful article on the relationship between vitamin D, multiple sclerosis and autoimmune illness:

Vitamin D Supplementation In The Fight Against Multiple Sclerosis

I highly recommend this article published by Dr. Reinhold Vieth in 1999 presenting evidence that vitamin D is safe in doses up to 10,000 IU.  It also shows that at least 4,000 units is desirable.

Vitamin D supplementation, 25-hydroxyvitamin D concentrations, and safety

I highly recommend these articles:

Sunlight Gains Favor As Health Key

Sunlight, health, and vitamin D

The Body's Response To Sunlight

Those that have problems with vitamin D, may wish to consider the possibility that they have Sarcoidosis.  This can be treated by mainstream doctors with steroids.

Description of Sarcoidosis

There is an experimental protocol at this site:

Marshall Protocol

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