March 6, 2000 (San Diego) -- Most people know vitamin D builds strong bones; now there's evidence that it may help subdue an overactive immune system sometimes seen in cancer patients or those with transplanted organs. Asthma patients also frequently take steroids to suppress the inflammation seen in this disease. The findings were presented here at the annual meeting of the American Academy of Asthma, Allergy and Immunology.
Lead author Orathai Jirapongsananuruk, MD, and colleagues studied the effect of vitamin D in combination with the steroid drug dexamethasone. The researchers found that the combination of vitamin D and the immune system suppressing steroid prevented growth of immune cells that sometimes lead to problems in people with conditions such as cancer, asthma, or organ transplants. The researchers were also able to decrease the dose of steroids and, with the addition of vitamin D, obtain as much immune-suppressing effect.
"These findings demonstrate that vitamin D enhances the effect of steroids on suppressing the immune system," says Jirapongsananuruk, of the Denver Children's Hospital in Colorado. She explains that this effect could allow patients to take lower doses of steroids, and might help them avoid some of the side effects of these drugs, such as infection and weight gain.
The double-whammy of vitamin D and steroids may be particularly beneficial for cancer patients, to whom steroids are sometimes given for various complications of the disease, such as cancer spreading to the brain or bones, and for recipients of transplanted organs, whose immune systems must be inhibited to prevent them from rejecting the organs. However, Jirapongsananuruk tells WebMD that she hesitates to recommend the combination for people with asthma or allergies. Even though these conditions are characterized by an overactive or inappropriate immune response, she says, that response is mediated through different substances than the ones that are important for cancer or transplant patients. But for those individuals, she says, the combination of vitamin D and certain steroids could hold potential.
People receive vitamin D from sunlight and milk, which is usually fortified with the vitamin. However, a vitamin D supplement would probably have to be taken to get an immune-suppressing effect.
- A new study shows that vitamin D, taken in combination with steroids, can enhance the effect of these drugs to subdue an overactive immune system.
- The addition of vitamin D may lower the dosage of steroids needed, and avoid some of their side effects, such as infection and weight gain.
- This combination therapy may be most beneficial for cancer patients and recipients of transplanted organs.