Thursday, December 2, 2010

Triple That Vitamin D Intake, Panel Prescribes



That's far lower than many doctors and major medical groups have been advocating—and it could dampen some of the enthusiasm that's been building for the sunshine vitamin in recent years.

Many doctors have added blood tests of vitamin D levels to annual physicals, and sales of vitamin D supplements have soared to $425 million last year from $40 million in 2001, according to the Nutrition Business Journal.

It's long been known that vitamin D is essential to maintaining strong bones. But hundreds of new studies have also linked low vitamin D levels to a higher risk of a slew of chronic health problems—heart disease, stroke, diabetes, prostate, breast and colon cancers, auto-immune diseases, infections, depression and cognitive decline. Studies have also suggested that many Americans are vitamin D deficient due to working and playing indoors and slathering on sunscreen.

The Institute of Medicine, an arm of the National Academy of Sciences that sets governmental nutrient levels, said there wasn't enough evidence to prove that low vitamin D causes such chronic diseases; it based its new recommendations on the levels needed to maintain strong bones alone. ...

The panel also raised the acceptable upper limit of daily intake to 4,000 IUs for adults, from 2,000 previously. ...

The panel was also concerned about what she called "emerging evidence of concern" about possible ill effects of too much vitamin D. Besides a risk of kidney and heart damage noted with vitamin D levels of 10,000 IUs per day, Dr. Brannon said the panel had seen higher death rates from pancreatic cancer, prostate cancer and other causes in men whose blood levels were above 50 ng/ml. The link is still tentative and may never be proven, she noted: "The difficulty is, you can't design a trial to look at adverse effects." ...

He said that despite the paucity of randomized-controlled trials, the long list of chronic diseases associated with vitamin D does make sense, given that it is actually a hormone that affects virtually every organ in the human body and regulates as many as 2,000 genes.

For his part, Dr. Holick recommends that adults take 2,000 to 3,000 IUs per day—and notes that he had done studies giving subjects 50,000 IUs twice a month for six years and seen no harmful effects. "There is no downside to increasing your vitamin D intake, and there are more studies coming out almost on a weekly basis," he said.  ...

via Triple That Vitamin D Intake, Panel Prescribes - WSJ.com.

I've been sick for the past few days and yesterday I started taking 2,500 IUs/day of Vitamin D3 from a non-fish liver source.

1 comment:

gareth said...

you can see good summaries of all the vitamin D data at www.vitaminD3world.com