Anees MA, et al. - Among participants (n=5,894, 58.12 ± 12.9 years; 54.7% women; 49.8% non-Hispanic Whites) from NHANES III, who had no clinical cardiovascular disease (CVD), researchers assessed if there was a link between vitamin D deficiency and electrocardiographic markers of left atrial (LA) abnormalities (ie, prolonged P wave duration and PR interval), given the link between electrocardiographic markers of LA abnormalities and increased risk of CVD. Across vitamin D categories, the prevalence of prolonged P wave duration and PR interval showed an incremental increase. Participants with vitamin D levels <20 ng/ml showed the highest prevalence, followed by 20–29 ng/ml and then >30 ng/ml. In this study, an increased risk of LA abnormalities was observed in relation to vitamin D deficiency, and these links were seen consistently across age, sex, and race. An alternate pathway by which vitamin D deficiency may increase CVD risk is clarified by this link.