Vitamin D deficiency is associated with early functional limitation in HFpEF
V Dimitrova, K Dyankov, G Draganov, M Radkova, K KaramfiloffAbstract
Background
Heart failure with preserved ejection fraction (HFpEF) is a heterogeneous syndrome with limited diagnostic biomarkers. Vitamin D deficiency has been linked to myocardial remodelling, endothelial dysfunction, and impaired muscle performance, but its relation to diastolic function and functional capacity in HFpEF is underexplored.
Purpose
To evaluate the prevalence of vitamin D deficiency in HFpEF and its association with diastolic dysfunction and functional capacity.
Methods
We retrospectively analysed 343 consecutive HFpEF patients (age 51–86 years; 143 men, 200 women) from January 2023 to December 2025. All patients had well-controlled arterial hypertension; no other significant co-morbidities were present. Serum 25-hydroxyvitamin D (25[OH]D) was measured by immunochemical assay (reference 80–200 nmol/L). All patients underwent transthoracic echocardiography. Diastolic dysfunction was diagnosed based on echocardiographic parameters including E/e’ ratio, e’ velocity, left atrial volume index, tricuspid regurgitation velocity, and mitral inflow pattern. Functional capacity was assessed with the 6-minute walk test (6MWT).
Results
Vitamin D deficiency (<80 nmol/L) was present in >80% of patients, more pronounced in women aged 60–65 years, possibly related to postmenopausal changes, reduced sunlight exposure, and lower dietary intake. Patients with deficiency more frequently had diastolic dysfunction and reduced functional capacity: symptom onset occurred at 350–400 m on the 6MWT (NYHA II–III), whereas patients without deficiency developed symptoms after >400 m (predominantly NYHA II). The difference in 6MWT distance between groups was statistically significant (p<0.05). Vitamin D deficiency may contribute to early functional limitation through effects on myocardial relaxation, skeletal muscle strength, and endothelial function. These findings indicate that vitamin D deficiency may serve as a marker of early functional limitation in HFpEF, preceding overt symptom progression.
Conclusion(s)
Vitamin D deficiency is highly prevalent in HFpEF and correlates with diastolic dysfunction and impaired functional capacity. Routine assessment of serum 25(OH)D may help identify patients at risk for early functional decline and guide targeted interventions. To our knowledge, this is one of the largest contemporary studies evaluating vitamin D deficiency in HFpEF and its relation to early functional impairment. Prospective studies are warranted to determine whether vitamin D supplementation may improve functional outcomes in HFpEF.