What is Vit D?
Vit D sources
What can Vit D do?
How much Vit D ?
Vit D deficiency
Vit D & Flu
Vit D & Cancer
Vit D for Depression
Vit D Blood test
Test explanation
Vit D News
Vit D videos
Vitamin D Books
Vitamin D Articles
Vit D Links e-mail me

Vitamin D sources


Our richest source of vitamin D comes from exposure of bare skin to the UVB rays of the sun.

Small amounts can be found in food, but not enough to maintain healthy levels.

Do not rely on diet alone for vitamin D.

Only 10% of our daily requirements can be had from food.

It is nearly impossible to attain healthy levels from food alone.

Fatty fish like wild salmon (not farmed salmon) and mackerel contain some vitamin D

but you would have to consume huge amounts daily.

There are only 2 reliable sources of vitamin D; The sun and vitamin D3 supplements.

The best is from the sun, as the sun also regulates how much cholecalciferol the body can make.

So there is absolutely no risk of overdosing from sun exposure. 

Sunbeds provide vitamin D - something to consider in the winter months.

Vitamin D3 supplements are by far the best way to keep vitamin D levels up all year round,

especially in the winter, but also in the summer months, if you do not go out in  the sun.


Absorption levels vary from person to person.  Two people taking the same amount in supplements may

have completely different levels.

The only way to be sure of how much you need to take is by getting your vitamin D blood levels tested. 

There is no other way to find out what your levels are and whether you are deficient or not.

Most of us are deficient, so there is little need to wait before taking supplements.

It has been recommended by many of the experts that a safe dose to start with is between 2,000 -5,000 iu.

This is a perfectly safe level to start with.

The chart below is from Dr. Mercolas website

Below 535 units per pound per day
Age 5 - 102500 units
5000 units
Pregnant Women5000 units
There is no way to know if the above recommendations are correct. The ONLY way to know is to test your blood. You might need 4-5 times the amount recommended above. Ideally your blood level of 25 OH D should be 60ng/ml.

After 2-3 months of taking vitamin D3 supplement get a blood test.

This is called a 25 (OH)D or 25 hydroxy vitamin D  test.

Your doctor can order one for you, or you can get one from Birmingham hospital for £25.00.

 Click on the link...

Some people have concerns over toxicity when taking vitamin D supplements.

This should not be a concern unless you are taking dosages higher than 10,000 iu. for several months.

Again, I reiterate the importance of testing for peace of mind, but also to be sure you are taking enough.

See Dr Cannell's article on toxicity. Click on the link...

If we are lucky enough to get daily sun exposure (and this isn't easy in the UK!) we are able to make between 10,000

-20,000 international units naturally in our skin in the space of 15- 30 minutes, if our shadow is shorter than our body.

This seems incongruous in the light of the government's RDA (recommended daily allowance) of 400-1000 iu.

If you are someone who wears sunscreen or avoids the sun, or lives at a high latitude...

or simply finds little time to go out in the sun daily because of lifestyle choices it is likely you will be deficient,

or at least only adequate in the summer months.

A simple blood test will determine whether you are or not.

You can ask your doctor for a test. Be sure to ask for a 25(OH)D test.

If your doctor is resistant to giving you a test (they often are, as many doctors are not yet aware of the new research) 

you can get a test done by Birmingham hospital for £25.00. Click on the link below:

They send you a kit and you simply prick your finger and send the spot test back to them.

They will either email or post the results to you within a week.

It is important to understand the many factors that can lead to deficiency.

Some of which I have listed below.


If you wear sunscreen... sunscreens block production of vitamin D by up to 99%.

If you have dark skin... it takes 6 times more exposure to the sun than fair skin to make vitamin D.

If for religious reasons your skin is never exposed to sunlight.

If you live at high latitudes...

 -Latitudes from 0 degrees to around 35 degrees north or south of the equator allow all year round vitamin D production, 

  the amount produced will decrease as latitude increases. Click on the link below to find the latitude of where you live... 

If you do not go out in the sun between 11am and 3pm in the summer.

If you use soap before and after sun exposure...

-Washing before going out in the sun washes off cholesterol in the skin that is needed to synthesise cholecalciferol.

 Washing immediately after also has drawback, though there is controversy over this. Click on the link...

Q & A with DrCannell | Natural Health News | Natural Health ...

15 Jul 2009 – Does showering after sunbathing wash off the Vitamin D

Getting as much bare skin as possible exposed to the sun will get the best results.

Experts recommend as much as 40-60% of skin exposure.

If you are sensitive to the sun and burn easily, start with a few minutes a day and slowly build up your exposure.
A key to whether you have made any cholecalciferol in the skin is the tingling feeling you get just as your skin

begins to turn a little pink. Then either cover up or use a safe sunscreen.

For a safe sunscreen click on the link...


or check out Dr. Mercolas Natural Sunscreen SPF 30 at