Background and objectives. Nutritional vitamin D deficiency is an emerging risk factor for acute myocardial infarction (AMI) and heart failure. The association between 25-hydroxyvitamin D levels and N-terminal pro B-type natriuretic peptide (NT-proBNP), a robust prognostic marker for post-MI mortality and heart failure is unknown and could illuminate a potential pathway for adverse outcomes among post-MI patients with 25-hydroxyvitamin D deficiency.

Design, setting, participants and measurements. In a cross sectional analysis, we studied 238 AMI patients from 21 US centers to test the association of nutritional vitamin D (25-hydroxyvitamin D [25(OH)D]) deficiency with NT-proBNP levels. Patients' 25(OH)D levels were categorized as normal (≥30 ng/ml), insufficient (>20 – <30 ng/ml), deficient (>10 – ≤ 20 ng/ml), and severely deficient (≤10 ng/ml) groups.

Results. 96% of AMI patients had low 25(OH)D levels, with 75% having 25(OH)D deficiency and 21% having insufficiency. No significant trends for higher mean log NT-proBNP levels in severely deficient (6.9 ± 1.3 pg/ml), deficient (6.9 ± 1.2 pg/ml) and insufficient (6.9 ± 0.9 pg/ml) groups were observed as compared with patients having normal (6.1 ± 1.7 pg/ml) levels, P = 0.165. In multivariate regression model after adjusting for several covariates, 25(OH)D was not associated with NT-proBNP levels.

Conclusion. Potential associations between nutritional vitamin D deficiency and prognosis in the setting of AMI are unlikely to be mediated through NT-proBNP pathways. Future studies should examine other mechanisms such as inflammation and vascular calcification by which 25(OH)D deficiency could mediate adverse outcomes such as heart failure and mortality post AMI.