Vitamin D minskar cancerrisk rejält
Vitamin D kan komma från maten eller från solen. Den kanadensiska tidningen jag citerar nedan menar att det är synd om kanadensare som bara kan få nog med sol för Vitamin D-produktion, från april till september. Men de bor ju ändå långt mer söderut än vi.
Om resultaten från undersökningen visar sig hålla, så bör man ju se till att äta mat med mycket vitamin D i. Här är en bra källa för att ta reda på vilken mat det är. Dessutom bir ju solsemestern på vinterhalvåret inte valfri längre...
In June, U.S. researchers will announce the first direct link between cancer prevention and the sunshine vitamin. Their results are nothing short of astounding. A four-year clinical trial involving 1,200 women found those taking the vitamin had about a 60-per-cent reduction in cancer incidence, compared with those who didn't take it, a drop so large — twice the impact on cancer attributed to smoking — it almost looks like a typographical error.
Läs mer: globeandmail.com: Vitamin D casts cancer prevention in new light
Uppdatering 20:06
Här två kritiska röster från slashdot:
http://science.slashdot.org/comments.pl?sid=232675&cid=18917853
http://science.slashdot.org/comments.pl?sid=232675&cid=18919311
En del D-vitaminer aktiveras först av solljus, tydligen.
Uppdatering 2007-04-30
Här några fler intressanta synpunkter från slashdotdiskussionen:
http://science.slashdot.org/comments.pl?sid=232675&cid=18920141
The revolution in Vitamin D research came with the discovery that D is "activated" (25OH-D3 turns into 1,25OH-D3) in a variety of different tissues of the body, not just the kidneys.Which body tissues do we know can "activate" Vitamin D3? Here's some: prostate tissue, colon tissue, breast tissue. Where are some popular places that cancer likes to form? Same list. Hmmm.
...
There is a simple hypothesis (far from proved, but I'll bet my pill taking regimen on it for now) that explains this: local tissue conversion of 25OH-D3 to 1,25OH-D3 shuts down as soon as serum levels of 25OH-D3 start to decline, and doesn't start up again until serum levels stabilize.
If this hypothesis is true, then allowing your vitamin D3 serum levels to drop during the winter may be as bad for you as just having low levels of vitamin D3 all year round.
http://science.slashdot.org/comments.pl?sid=232675&cid=18920401
The reason that be is this: a fair-skinned person sitting naked in the sun at the equator may make as much as 20,000IU of Vitamin D in 20 minutes. Now go to your grocery store and find a multi-vitamin with Vitamin D in it. It will likely have about 200IU in it. Now try taking 100 of those so you will get the same effect as sitting in the equatorial sun for 20 minutes. Ooops -- you just overdosed on a lot of other substances!
This discovery that the body makes huge amounts of Vitamin D via sunlight is part of what led to the revolution in Vitamin D research. It's hard to look at that number and not ask: WHY, did we evolve to make such large amounts of Vitamin D?