To investigate the correlation between 25-hydroxyvitamin D and H-type hypertension in elderly patients, and to observe the clinical efficacy of vitamin D supplementation in those patients.This was a retrospective study. One hundred and twenty elderly hypertensive patients treated at The Affiliated Hospital of Hebei University from June 2022 to June 2023 were randomly divided into Group-A (n=60) with hypertension and elevated homocysteine (Hcy) levels (H-type hypertension), and Group-B(n=60) with hypertension and normal Hcy levels. Blood levels of 25-hydroxyvitamin D and 24 hours ambulatory blood pressure were assessed in both groups of patients upon admission, with the correlation analysis performed simultaneously. The therapeutic effects were compared between the two groups.Through Pearson correlation analysis, there were negative correlations of serum 25-hydroxyvitamin D levels with 24 hours SSD, 24 hours DSD, dnSBP, and nDBP(all p<0.05). After 12 weeks of treatment, the treatment group had higher 25-hydroxyvitamin D levels and lower 24 hours SBP, 24h DBP, dSBP, dDBP, nSBP, nDBP levels than those of the control group(p<0.05). After treatment, the treatment group had lower blood Hcy, IMT, TC, TG, and LDL-C levels(p<0.05), and higher HDL-C levels(p<0.05) than those of the control group.Serum 25-hydroxyvitamin D levels in elderly patients with H-type hypertension have negative correlations with 24 hours SSD, 24 hours DSD, dnSBP, and nDBP. Oral vitamin D supplementation for H-type hypertensive patients exhibits significant therapeutic effects, with improvements in 24 hours ambulatory blood pressure monitoring results, blood lipid levels, IMT, and blood Hcy levels after treatment.Copyright: © Pakistan Journal of Medical Sciences.