Nutrient Deficiencies in Heart Failure: A Micro Problem With Macro Effects?

D ietary micronutrient deficiency is common in adults with heart failure (HF), with >20% having low intake of vitamin A, calcium, magnesium, selenium, and iodine and up to 75% having low intake of vitamin D. 1 Micronutrients are necessary cofactors for normal cardiac metabolism, and deficiencies have been implicated in the development and progression of HF. 2,3 There is increasing interest in nutrition among patients with HF, two thirds of whom report taking vitamins or supplements, despite limited evidence of impact on outcomes. 4,5Acknowledging this disconnect, the National Heart, Lung, and Blood Institute and the National Institutes of Health Office of Dietary Supplements convened a Working Group in 2013 to address the impact of nutrition on HF, which recognized substantial knowledge gaps and a need to improve the quality of evidence. 6n this issue of the Journal of the American Heart Association (JAHA), Lennie and colleagues present a multicenter prospective cohort study evaluating the impact of dietary micronutrient deficiencies on clinical outcomes in ambulatory patients with HF. 7 The study enrolled 274 patients recruited from 3 HF clinics affiliated with academic medical centers in Georgia, Indiana, and Kentucky, with 1-year followup.Patients were eligible if they had documented HF with either reduced or preserved ejection fraction with clinical stability for 3 months.Primary exclusion criteria included urgent listing for cardiac transplantation or presence of a left ventricular assist device, end-stage illness that would considerably shorten life expectancy, or conditions other than HF or diabetes mellitus that required dietary restrictions.Four-day food diaries were collected from 246 patients to estimate the intake of 17 micronutrients, including 11 vitamins and 6