UNMC study may have implications for ag workers

A study led by UNMC found evidence that may contribute to the growing knowledge of benefits of vitamin D.

Researchers found that mice exposed to hog barn dust over three weeks had statistically significant bone loss — 5 percent to 20 percent. But they had no bone loss if they received a high dose supplementation of vitamin D.

It’s well known that agriculture workers have high rates of airway inflammatory diseases and high rates of musculoskeletal diseases.

One of the study goals was to see if high-dose supplementation of vitamin D would help protect against the adverse outcomes of inhaling dusts in the agricultural environment. Though they did find a slight effect on reducing inflammation in the lungs of mice, they found a statistically significant effect on protecting the bones.

“We found if we gave vitamin D, the mice didn’t get bone loss,” said Jill Poole, M.D., associate professor in the UNMC Department of Internal Medicine and principal investigator of the study published in the scientific journal Immunology Research. “There was some benefit of reducing inflammation in their lungs, but it completely protected their bones. This is important because emerging data in humans suggests that generalized chronic lung inflammation is a risk factor for osteoporosis and fractures.”

Dr. Poole said she was surprised to see that lung inflammation can cause such profound bone changes.

“In the study we controlled for diet in the mice,” she said. “We know vitamin D helps bones, but it also appears to help bones in the presence of inflammation, and it had a direct effect on the bones.

“Vitamin D changes molecules that respond to the dust, and through this response, we think vitamin D may be helpful in lessening bone loss brought on by agricultural dust. My goal is to find therapies that farmers can use to reduce the consequences of agricultural dust exposure and improve their health. Musculoskeletal problems are huge.”

Dr. Poole’s message to those who work in agricultural dust environments is to wear protective respiratory equipment.

Although the study is limited because it involved mice and didn’t measure exposure over a long period of time, Dr. Poole also suggests taking vitamin D.

“As a bone protective strategy, people, particularly those with underlying respiratory disorders and symptoms, might want to consider taking over-the-counter supplemental vitamin D3 – 2,000 to 4,000 IUs daily as long as they don’t have any other health problems,” she said. “If they do have health problems, they should first talk to their doctor before taking the vitamin.”