A cross-sectional study appearing in the Journal of the American Dietetic Association (2009; 109(8): 1406-10) compared 100 patients hospitalized with heart failure to healthy controls. More of the heart failure patients (38%) were deficient in vitamin B6 than subjects in the control group (19%). Also more of the patients were riboflavin deficient (27%) than controls (2%). Taking supplements did not seem to ameliorate these differences.