Burden and Associated Factors of Vitamin D Deficiency Among Hypertensive and Normotensive Adults: A Hospital-Based Cross-Sectional Study in a Tertiary Care Hospital in Kathmandu, Nepal

Background: Vitamin D deficiency is increasingly recognized 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 burden of vitamin D deficiency and identify associated demographic and clinical risk factors of hypertension among 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, blood pressure, lipid profile and serum 25(OH)D were collected. Vitamin D levels were measured using Chemiluminescence Immunoassay (CLIA), and was categorized 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 done by a Chi-Square test and significant variables were subjected to multivariate logistic regression. Results: Overall, 42.6% were vitamin D deficient, with a higher prevalence among hypertensives; although the difference was not statistically significant (p = 0.05). In multivariate logistic regression abdominal obesity factor (AOR: 2.8; 95% CI: 1.2–6.7; p = 0.01), dyslipidemia (AOR: 2.9; 95% CI: 1.2–7.3; p = 0.02) and family history of hypertension hypertensive (AOR: 2.8; 95% CI: 1.1–6.8; p = 0.02) were independently associated with increased odds of hypertension. Conclusions: Dyslipidemia, abdominal obesity and family history were significantly associated with hypertension in this clinical sample. Although vitamin D deficiency was not independently associated with hypertension in our study, its high prevalence highlights the need for increased public health awareness and the formation of preventive healthcare strategies. Larger population-based studies are required for understand the role of vitamin D in hypertension prevention and control in Nepal.