Vitamin D (25 hydroxyl) testing

[Leo40]

This may be of interest to Canadian forum members.
During a routine visit to the doctor I requested to add the above
to the usual blood tests. My doctor informed me that this test (for vitamin D level)
has no diagnostic value! He called it a fad, but put it on the requistion sheet anyway.
Interestingly there is no charge for it, yet for the PSA test they want $25.00!
I politely declined. This test was shown to be quite useless for early detection.
It seems to me that the post-war generation (birth years 1940 to 1950) has greater
resistance than later generations, perhaps due to the fact that we had no junk food.
There is a definite link between affluence and health in a given population.

 

[Elly Kay]

Hi Leo40,

Your post piqued my interest because I would like to try Vitamin D supplements and diet changes over the winter here in Canada since sunlight hours are starting to wane. I understand the part about the testing being done and the doctor’s ambivalence towards performing it, but I am unclear on one point you made:

I politely declined. This test was shown to be quite useless for early detection.

Early detection of what exactly?

 

[Leo40]

Hi, Elly Kay:

I was referring to the PSA test which I declined to have done.
Re.: vitamin D you can find more at www.naturalnews.com,
also it is important to look for Vitamin D3 (Cholecalciferol).

 

[Voyageur]

Hi Leo40,

As a member from your area I was interested on your doctor’s take on Vitamin–D levels which was surprising. I know the local naturopaths don’t feel this way about D. Have had many old school Doc’s - and some of them are very good at many things, but for some, when it comes to analysis that looks to levels and contraindications, they might fumble through the Merck Manual and mutter something incomprehensible, but in the end they tell you similarly to what you said “it’s a Fad” or basically “I know best, don’t ask, I’m the Doctor”. Based on this I have always looked for a physician who values untraditional medicine and has some balance.

You mentioned;

… also it is important to look for Vitamin D3 (Cholecalciferol).

Checking Cholecalcifero reveals; http://en.wikipedia.org/wiki/Cholecalciferol

Cholecalciferol is a form of Vitamin D, also called vitamin D3 or calciol.[1]
It is structurally similar to steroids such as testosterone, cholesterol, and cortisol (though vitamin D3 itself is a secosteroid).
Regulation of metabolism
• Cholecalciferol is synthesized in the skin from 7-dehydrocholesterol under the action of ultraviolet B light. It reaches an equilibrium after several minutes depending on several factors including conditions of sunlight (latitude, season, cloud cover, altitude), age of skin, and color of skin.
• Hepatic hydroxylation of cholecalciferol to calcidiol (25-hydroxycholecalciferol) is loosely regulated, if at all, and blood levels of this molecule largely reflect the amount of vitamin D3 produced in the skin or the vitamin D2 or D3 ingested.
• Renal hydroxylation of calcidiol to calcitriol by 1-alpha-hydroxylase is tightly regulated (stimulated by either parathyroid hormone or hypophosphatemia) and serves as the major control point in production of the most active circulating hormone calcitriol (1,25-dihydroxyvitamin D3).
As food fortification
Although cholecalciferol can be synthesized in the skin (see Metabolism), it is also a form of vitamin D added to fortify foods. Cholecalciferol is produced industrially by the irradiation of 7-dehydrocholesterol extracted from lanolin found in sheep's wool. In foods where animal products are not desired, an alternative compound is ergocalciferol (also known as vitamin D2) derived from the fungal sterol ergosterol.

If you or anyone else can extrapolate further that would be appreciated as I will soon check my bottle for contents. Not exactly sure what is meant by “Irradiating” but assume it to mean exposure to radiation?

Thanks

 

[Leo40]

Sorry for the delay. I did some more searching.
Parallax: radiation refers to UV light, nothing nuclear!

I have now the test results. My D3 level is still a little on the low side although I have
been supplementing at 4000 IU per day for about 3 months.

Here is some more info:

The primary source of vitamin D3 is sunlight, which converts 7-dehydrocholesterol in the skin to vitamin D3 via photochemical reactions using ultraviolet B radiation (UV-B). Numerous factors such as latitude, season, air pollution, pigmentation of skin, and sunscreen affect UV-ray exposure. The US is between 30° and 45° latitude, and six months or more of each year has insufficient UV-B sunlight to produce optimal D levels. People with dark skin produce less vitamin D since melanin, a skin pigment, acts as a natural sunscreen, absorbing UV radiation. Only a few foods naturally contain vitamin D: fatty fish, fish liver oils and eggs from hens that have been fed vitamin D.

The Reference Daily Intake (RDI) for vitamin D is 400 IU. The U.S. National Academy of Sciences has recommended the following adequate intakes for vitamin D: 200 IU for ages 0-50, 400 IU for ages 51-69, and 600 IU for ages greater than 70. They have also defined a tolerable upper limit intake level (UL) that is unlikely to pose risk to the general population: infants 0-12 months, 1000 IU/day; children and adults, including pregnant and lactating women, 2000 IU/day. However, some researchers argue that the RDIs and ULs are too limited. Testing of plasma 25(OH)D concentration is considered the best way to determine the level of vitamin D and to monitor vitamin D supplementation
The principal direct toxic effects of too much vitamin D are excessive absorption of calcium and phosphorus from the intestine and resorption of calcium and phosphorus from bone. The prolonged ingestion of excessive amounts of vitamin D and accompanying hypercalcemia can result in metastatic calcification of soft tissues, including the kidney, blood vessels, heart and lungs. There is a wide variation among individuals in their tolerance to toxicity. In general, chronic ingestion of 50,000 IU to 100,000 IU daily of vitamin D is required to produce hypercalcemia.

 

[StrawMan]

Just to add some information for when you do get some sun inspired D3...

I would highly recommend Dr. Mercola's site for any other health related information.
http://articles.mercola.com/sites/articles/archive/2009/05/12/shocking-update-sunshine-can-actually-decrease-your-vitamin-d-levels.aspx

First, it’s important to understand that vitamin D3 is an oil soluble steroid hormone. It’s formed when your skin is exposed to ultraviolet B (UVB) radiation from the sun (or a safe tanning bed). When UVB strikes the surface of your skin, your skin converts a cholesterol derivative in your skin into vitamin D3.

However, the vitamin D3 that is formed is on the surface of your skin does not immediately penetrate into your bloodstream. It actually needs to be absorbed from the surface of your skin into your bloodstream.

The critical question then is: how long does it take the vitamin D3 to penetrate your skin and reach your bloodstream?

If you’re thinking about an hour or two, like I did until recently, you’re wrong. Because new evidence shows it takes up to 48 hours before you absorb the majority of the vitamin D that was generated by exposing your skin to the sun!

Therefore, if you shower with soap, you will simply wash away much of the vitamin D3 your skin generated, and decrease the benefits of your sun exposure. So to optimize your vitamin D level, you need to delay washing your body with soap for about two full days after sun exposure.

Now not many people are not going to bathe for two full days.

However you really only need to use soap underneath your arms and your groin area. , so this is not a major hygiene issue. You’ll just want to avoid soaping up the larger areas of your body that were exposed to the sun.

 

[Leo40]

Here is an interview of Gabriele Staehler on YouTube. She is a German Naturopath.
_http://www.youtube.com/watch?v=HH1rB-Ya2UQ
It's in English.