vitamin D

[Martha]

As I was cleaning the kitchen People's Pharmacy was on public radio. They had a guest who has done research on the utility of vitamin D supplements for cancer prevention. Oddly, I talked to a friend of my minutes before and she had just read an article in Scientific American about evidence supporting use of vitamin D to reduce cancer risk. My friend takes 2000 milligram a day, far above the current recommended dose, but consistent with the Scientific American article.

We live where there is not much sun in the winter and when the sun shines it is fairly low on the horizon. Apparenly, cancer rates are lower in southern areas with more sun (skin cancer aside).

So, Rich or any other medical people or nutritionists have any thoughts on this? I have never been one for supplements but when I remember I do take a multivitamin.

 

[jay-pee]

Hi Martha: As a man fighting prostate cancer, I can state that my oncologist"s(I ve seen more than one over the years) have all reccomended up to 10,000 Iu per day of Vt D3(cholecalciferol), which I have been taking for a few years now. This high of a dosage would not normally be reccomended to a person with good health, and requires constant monitoring of calcium levels in the blood. I would suspect that dosages in the 2000 Iu per day range would be safe, but still should only be used under a doctors advice. There is evidence published that optimal Vit D levels help protect against Diabetes, Heart Disease, Hypertenson, Osteoporosis, as well as some cancers. Hopefully Rich will way in and correct any inaccuracies that I might have stated (if any).

 

[Nords]

Hi Martha: As a man fighting prostate cancer, I can state that my oncologist"s(I ve seen more than one over the years) have all reccomended up to 10,000 Iu per day of Vt D3(cholecalciferol), which I have been taking for a few years now. This high of a dosage would not normally be reccomended to a person with good health, and requires constant monitoring of calcium levels in the blood.

The Nov 2007 Scientific American article claims that the average adult woman with white skin wearing a bikini outdoors in sunshine generates ~10,000 IU of D3 within 15-20 minutes. That's an equilibrium; beyond that the UVB destroys the vitamin D as fast as the body makes it.

Toxicity wasn't observed until ~40,000 IU over a prolonged time.

I'll continue doing additional research at the beach...

 

[Moemg]

We pre -menopausal women or just plain menopausal need Vitamin D to help absorb the Calcium

Vitamin D plays a major role in calcium absorption and bone health. The relationship between calcium absorption and vitamin D is similar to that of a locked door and a key. Vitamin D is the key that unlocks the door and allows calcium to leave the intestine and enter the bloodstream. Vitamin D also works in the kidneys to help resorb calcium that otherwise would be excreted.

 

[Khan]

The Nov 2007 Scientific American article claims that the average adult woman with white skin wearing a bikini outdoors in sunshine generates ~10,000 IU of D3 within 15-20 minutes. That's an equilibrium; beyond that the UVB destroys the vitamin D as fast as the body makes it.

Toxicity wasn't observed until ~40,000 IU over a prolonged time.

I'll continue doing additional research at the beach...

I assume not in the winter.
How far from the equator?

 

[Nords]

Vitamin D plays a major role in calcium absorption and bone health. The relationship between calcium absorption and vitamin D is similar to that of a locked door and a key. Vitamin D is the key that unlocks the door and allows calcium to leave the intestine and enter the bloodstream. Vitamin D also works in the kidneys to help resorb calcium that otherwise would be excreted.

This is how submariners get kidney stones. Especially caffeine-swilling submariners (I know, redundant).

I assume not in the winter.
How far from the equator?

I think the article's world map specified latitudes smaller than 30 degrees, so the "winter" part may be irrelevant... the two authors mentioned that they both take Vitamin D supplements during their winters.

 

[Rich_by_the_Bay]

Here is a somewhat techy by current synopsis:

Effectiveness and Safety of Vitamin D in Relation to Bone Health: Structured Abstract

It says that vitamin D supplements probably have beneficial bone outcomes but the current state of the art is only fair.

A 2003 Veterans study showed some reduction in colon polyps with supplements. It was not a definitive study. This article is not technical and seems fair and balanced. We have not proven that vitamin D decreases colon cancer, but the hypotheses are credible.

Population-based studies about diet are notorious for "break-throughs" which a year later become "break-downs."

My personal opinion: dietary supplements are wise for most people, in the 400u range. Low-sun northern area dwellers and shut-ins are the highest potential beneficiaries. I take a general multivitamin each day.

 

[FinallyRetired]

The Nov 2007 Scientific American article claims that the average adult woman with white skin wearing a bikini outdoors in sunshine generates ~10,000 IU of D3 within 15-20 minutes

And that's just in the men around her. The woman herself generates much more.

 

[merlyn]

Here is something you might find to be of interest

http://www.medicalnewstoday.com/articles/51913.php

 

[FinanceGeek]

I have heard that the US RDA for D3 (presently 200 to 400 IU) is considered by many Docs and researchers to be "way low".

My family Dr told me that upping to 1000 IU a day was a no-brainer, and higher levels were OK with annual blood tests to make sure its not too much.