Mario Castro, Washington University School of Medicine (image) Washington University School of Medicine Share Print E-Mail Caption Mario Castro, M.D., listens to the lungs of a patient with asthma. Castro led a clinical trial investigating the effects of vitamin D supplements on asthma control. Adding vitamin D to asthma treatment to improve breathing only appears to benefit patients who achieve sufficient levels of the supplement in the blood. Overall, the ability to control asthma did not differ between a study group that received vitamin D supplements and a group that received placebo, according to new research at Washington University School of Medicine in St. Louis. Credit Robert Boston Usage Restrictions None Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.