Abstract
BACKGROUND: Vitamin D deficiency is increasingly recognised as a risk factor for non-communicable diseases, including hypertension. However, evidence on their relationship remains inconsistent, particularly in middle and low-income countries like Nepal. This study aimed to assess the prevalence of vitamin D deficiency among hypertensive and normotensive adults, and identify the demographic, anthropometric and clinical risk factors among hypertensive adults attending a tertiary care hospital in Kathmandu, Nepal. METHODS: A hospital-based cross-sectional study was conducted among 108 adults (54 hypertensive and 54 normotensive) at Nepal Medical College and Teaching Hospital from September 2024 to March 2025. Data on sociodemographic factors, anthropometric variables and clinical parameters were collected. Serum 25(OH)D was measured using Chemiluminescence Immunoassay (CLIA), and was categorised as sufficient (≥ 30 ng/ml), insufficient (20-29 ng/ml) and deficient (< 20 ng/ml). Blood pressure was classified according to the 7th Joint National Committee on the Prevention, Detection, Evaluation and Treatment of High Blood Pressure. Group comparisons were performed using the Chi-Square test, and significant variables were subjected to multiple logistic regression. RESULTS: Overall, 42.6% were vitamin D deficient. Although deficiency was more prevalent in hypertensive than normotensive, the association was only borderline significant (p = 0.05) and did not remain significant after post-hoc correction. In multiple logistic regression, abdominal obesity (AOR: 2.8; 95% CI: 1.2-6.7; p = 0.019), dyslipidemia (AOR: 2.8; 95% CI: 1.2-7.2; p = 0.024) and having a family history of hypertension (AOR: 2.7; 95% CI: 1.1-6.8; p = 0.028) were independently associated with increased odds of hypertension. The overall model explained 24% of variance in hypertensive status (Nagelkerke R(2) = 0.24). CONCLUSIONS: Dyslipidemia, abdominal obesity and family history were significant predictors of hypertension in this cohort, while vitamin D deficiency showed a non-significant association with hypertension. Nonetheless, the high prevalence of vitamin D deficiency highlights the need for increased public health awareness and preventive healthcare strategies. Larger population-based studies are needed to understand the role of vitamin D in the prevention and control of hypertension in Nepal.