Dietary Intake and Plasma Concentration of B Vitamins in Relation to Incident Coronary Artery Disease in African-American Adults: The Jackson Heart Study.

OBJECTIVES

To assess the role of B vitamins in the disproportionately higher burden of coronary artery disease mortality among African Americans.

BACKGROUND

B vitamin inadequacies are common in the United States, particularly among African Americans. B vitamins play a key role in 1-carbon metabolism, and poor status may influence cardiovascular health. We investigated associations of dietary intake of vitamins B-6, B-12, and folate, as well as plasma concentrations of vitamin B-12 and folate, with incident coronary artery disease (CAD).

METHODS

We analyzed data from the Jackson Heart Study (2000-2016), including 4863 participants in the dietary analytic sample (309 CAD cases) and 4906 in the plasma analytic sample (311 CAD cases). Dietary intake of B vitamins was energy-adjusted using the residual method. Cox proportional hazards regression with multiple imputation was used to estimate hazard ratios (HRs) for incident CAD over a median of 13.8 y of follow-up (60,660 and 61,180 person-years in the dietary and plasma samples, respectively). Linearity of associations was evaluated using restricted cubic splines.

RESULTS

In multivariable-adjusted models (per 1 SD), higher energy-adjusted dietary intake of vitamin B-6 [HR = 1.07; 95% confidence interval (CI): 0.93, 1.25], vitamin B-12 (HR = 0.99; 95% CI: 0.87, 1.12), or folate (HR = 0.97; 95% CI: 0.82, 1.15) was not significantly associated with CAD risk. Similarly, plasma vitamin B-12 (HR = 0.99; 95% CI: 0.84, 1.18) and folate (HR = 0.97; 95% CI: 0.80, 1.17) showed no statistically significant associations. Tests for nonlinearity revealed no evidence of threshold or U-shaped relationships.

CONCLUSIONS

In this cohort of African-American adults, neither dietary intake nor plasma concentrations of B vitamins were significantly associated with CAD risk. These findings do not support a strong association between B vitamin status and CAD risk in this cohort.