Hand Holding Vitamin D Pills (IMAGE) University of Washington Caption Researchers will be studying genetic variations to try to understand why there are racial and ethnic differences in the need and use of vitamin D. Credit Leila Gray Usage Restrictions None License Licensed content 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.