•A lower serum vitamin D3 concentration has been associated with an increased risk of cardiovascular disease. However, the associations between serum vitamin D3 levels and heart failure with preserved ejection fraction (HFpEF) have not been well-characterized.•Lower serum vitamin D3 levels were associated with left ventricular concentric remodeling and incident HF, mainly HFpEF in Black Americans.•Further investigation is required to examine whether supplementation of vitamin D3 can prevent left ventricular concentric remodeling and incident HFpEF in Black Americans. In observational studies, a lower serum vitamin D3 concentration has been associated with an increased risk of cardiovascular disease. However, the associations between serum vitamin D3 levels and left ventricular (LV) structure and heart failure with preserved ejection fraction (HFpEF) have not been well-characterized among Black Americans. The prevalence of vitamin D3 deficiency is higher among Black Americans than in other race/ethnicity groups. We hypothesized that serum vitamin D3 levels are associated with LV concentric remodeling and incident HFpEF in Black Americans. Among 5306 Black Americans in the Jackson Heart Study cohort, we investigated the relationships between serum vitamin D3 levels and LV structure and function, evaluated with echocardiography, and incident HF hospitalization, categorized as either HF with reduced EF (HFrEF; an EF of <50%) or HFpEF (an EF of ≥50%). After adjustment for possible confounding factors, lower vitamin D3 levels were associated with greater relative wall thickness (β for 1 standard deviation SD increase –0.003, 95% confidence interval –0.005 to –0.000). Over a median follow-up period of 11 years (range 10.2–11.0 years), 340 participants developed incident HF (7.88 cases per 1000 person-years), including 146 (43%) HFrEF and 194 (57%) HFpEF cases. After adjustment, higher serum vitamin D3 levels were associated with decreased hazard for HF overall (hazard ratio for 1 SD increase 0.88, 95% confidence interval 0.78–0.99) driven by a significant association with HFpEF (hazard ratio for 1 SD increase 0.84, 95% confidence interval 0.71–0.99). In this community-based Black American cohort, lower serum vitamin D3 levels were associated with LV concentric remodeling and an increased hazard for HF, mainly HFpEF. Further investigation is required to examine whether supplementation with vitamin D3 can prevent LV concentric remodeling and incident HFpEF in Black Americans. Display omitted