March 24, 2009

Americans Need More Vitamin D

On Monday, U.S. researchers announced that Americans are not getting enough vitamin D.

Researchers from the University of Colorado Denver School of Medicine analyzed data from government health surveys, and found that three out of four Americans suffer from "insufficient" levels of vitamin D.

Clinicians say insufficient vitamin D levels have been associated with cancer, heart disease, infection and poor health overall.

"Vitamin D supplementation appears to mitigate the incidence and adverse outcomes of these diseases and may reduce all-cause mortality," the authors wrote.

A simple blood test can determine whether someone has an ideal level of vitamin D between 30 and 40 nanograms per milliliter of blood.

However, getting enough of the so called sunshine vitamin can be simple; by spending 10 minutes in the sun with legs and arms exposed, or taking vitamin supplements in pill form.

"But people's habits have changed ... they are less active and outdoors less, and also protecting their skin from the sun because of skin cancer risk," said Dr. Adit Ginde.

The new findings were published in the Archives of Internal Medicine.

Wearing both sunscreen and protective clothing halts production of vitamin D in the skin.

Clinicians previously believed the major health problems associated with vitamin D deficiency were rickets in children and reduced bone mineral content in adults, problems believed to be made better by eating fortifying foods with vitamin D.

However, recent discoveries show many types of cells in the body contain vitamin D receptors, which indicates they use vitamin D in some way, Ginde said.

The vitamin regulates 1,000 genes, he said, and is believed to have a role in preventing cardiovascular disease and cancer, and regulating the immune system.

Ginde compared data on 18,000 Americans from 1988 to 1994 and 13,000 from 2001 to 2004.

He found the percentage of Americans who had less than 10 nanograms per milliliter of blood tripled to 6 percent from 2 percent, putting them at risk of developing rickets and bone problems.

"Given the guidelines currently existing, most Americans could use more vitamin D," Ginde said.

"In the last few years, vitamin D has gained more attention both in the media and the scientific literature. I think people are paying a lot more attention to it, people are taking more supplements, or having small amounts of sun exposure, so I think we'll see a leveling of the downward trend," he said.


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