Engineered vitamin D may help strengthen bone

[Guest guest]

Engineered vitamin D may help strengthen bone

By 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.

Today's stories

Endowment

Cleft lip, palate

PHS dentists

Oral health services

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 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 percent 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.