Latar Belakang: Hipertensi merupakan masalah kesehatan yang signifikan pada lansia, dengan prevalensi yang cenderung meningkat seiring bertambahnya usia. Di Desa Rowobranten, prevalensi hipertensi pada lansia mencapai 61,3%. Pola makan yang tidak seimbang, khususnya asupan mikronutrien seperti natrium, kalium, magnesium, dan vitamin C, diduga berperan dalam kejadian hipertensi.
Tujuan: Penelitian ini bertujuan untuk mengetahui hubungan antara asupan natrium, kalium, magnesium, dan vitamin C terhadap tekanan darah pada lansia di Desa Rowobranten, kecamatan Ringinarum, kabupaten Kendal.
Metode: Metode penelitian ini menggunakan desain deskriptif kuantitatif korelasi dengan pendekatan cross-sectional. Dengan jumlah responden sebanyak 75 lansia. Data asupan natrium, kalium, magnesium, dan vitamin C dikumpulkan menggunakan Formulir FFQ Semi Kuantitatif, sedangkan tekanan darah diukur langsung dengan tensimeter digital. Data dianalisis secara univariat dan bivariat menggunakan uji Chi square dan uji Cramers V.
Hasil: Berdasarkan hasi uji Chi square dan Cramer’s V terdapat hubungan antara supan natrium dengan tekanan darah lansia dengan perolehan nilai P <0,001 (P<0,05) dan korelasi (r) = 0,640, yang berarti arah positif dan tingkat korelasi kuat. Terdapat hubungan antara asupan kalium terhadap tekanan darah lansia dengan nilai P < 0,001 (P<0,05) dan nilai korelasi (r) = 0,587, yang berarti arah positif dan tingkat korelasi sedang. Serta tidak terdapat hubungan antara magnesium (p=0,168) dan vitamin c (p=0,124) terhadap tekanan darah lansia.
Kesimpulan: Terdapat hubungan antara asupan natrium dan kalium terhadap tekanan darah lansia. Serta tidak terdapat hubungan antara asupan magnesium dan vitamin c terhadap tekanan darah lansia.

ABSTRACT:
Background: Hypertension is a significant health problem in the elderly, with its prevalence tending to increase with age. In Rowobranten Village, the prevalence of hypertension among the elderly reaches 61.3%. Unbalanced dietary patterns, especially the intake of micronutrients such as sodium, potassium, magnesium, and vitamin C, are suspected to play a role in the incidence of hypertension.
Objective: This study aims to determine the relationship between sodium, potassium, magnesium, and vitamin C intake and blood pressure in the elderly in Rowobranten Village, Ringinarum District, Kendal Regency.
Methods: This study used a quantitative correlational descriptive design with a cross-sectional approach, involving 75 elderly respondents. Data on sodium, potassium, magnesium, and vitamin C intake were collected using a Semi-Quantitative FFQ Formulir, while blood pressure was measured directly with a digital tensimeter. Data were analyzed univariately and bivariately using the Chi-square test Chramer’s V test.
Results: Based on the Chi-square and Cramer's V tests, there was a relationship between sodium intake and elderly blood pressure with a P-value of <0.001 (P<0.05) and a correlation (r) of 0.640, which indicates a positive direction and a strong correlation level. There was a relationship between potassium intake and elderly blood pressure with a P-value of <0.001 (P<0.05) and a correlation (r) of 0.587, which indicates a positive direction and a moderate correlation level. However, there was no relationship between magnesium (p=0.168) and vitamin C (p=0.124) intake and elderly blood pressure.
Conclusion: There is a relationship between sodium and potassium intake and elderly blood pressure. However, there is no relationship between magnesium and vitamin C intake and elderly blood pressure.