Engineered Vitamin D May Help Strengthen Bone

[~MaryO~]

Health - Reuters

 

Engineered Vitamin D May Help Strengthen Bone

Mon Sep 30, 5:35 PM ET

By Linda Carroll

 

NEW YORK (Reuters Health) - Researchers have discovered a modified form of vitamin D that can help stimulate bone growth, a new study shows.

 

 

 

The compound may lead to new treatments for the brittle bone disease osteoporosis, according to the report published in the online early edition of the Proceedings of the National Academy of Sciences.

 

Scientists have long known that vitamin D is needed for healthy bones. But the naturally occurring form of the vitamin does not appear to play a direct role in bone formation, study co-author Hector F. DeLuca, chairman of biochemistry at the University of Wisconsin in Madison, said in an interview with Reuters Health.

 

DeLuca and his colleagues are studying a form of vitamin D called 2MD. "We and other groups have been modifying the molecule to get selective or improved action," he explained. "This compound is modified in three ways from the natural vitamin D hormone."

 

With the modifications, 2MD appears to boost bone growth by stimulating bone-building cells.

 

Like the skin, bone is continuously being destroyed and rebuilt. Bone-destroying cells, called osteoclasts, chew holes in bone. These cavities are then filled in by bone-forming cells, osteoblasts, using calcium as the building blocks. Up to age 30, bone-forming cells continue to work faster than bone-destroying cells. After that, osteoblasts slow down and bones start to thin.

 

In women, the thinning process accelerates at menopause when the ovaries stop producing estrogen.

 

DeLuca and his colleagues looked at the effects of 2MD on a rat model for menopause-related osteoporosis. The female rats in the study had had their ovaries removed. With no ovaries, the rats produced no estrogen.

 

For the new study, the researchers fed some of the rats vegetable oil with 2MD and some vegetable oil alone.

 

DeLuca and his colleagues measured the rats' bone density at the beginning of the study, at 13 weeks and at 23 weeks. At the end of the study, rats fed oil and 2MD had 9% more bone than those fed oil alone, DeLuca said.

 

The researchers also tested 2MD on human bone cells in the test tube. Once again they found that the vitamin led to bone growth.

 

The Wisconsin researchers aren't sure exactly how 2MD works. But DeLuca said the vitamin appears to affect both osteoclasts and osteoblasts. "It just seems to stimulate bone synthesis more," he said. "We're very excited about it as a potential therapy for bone-loss diseases."

 

The study was supported by the Wisconsin Alumni Research Foundation, Deltanoid Pharmaceuticals and the National Institutes of Health.

 

SOURCE: Proceedings of the National Academy of Sciences Early Edition 2002;10.1073/pnas.202471299.