Association Between Vitamin D and Serum Uric Acid in a Large Chinese Cohort of Middle-Aged and Elderly Chinese Men and Women

Rong Cao¹Bingchao Xu²Yubao Wang³Xinzheng Lu⁴Xianhui Qin⁵Xiaoshu Cheng⁶Guifan Sun⁷Jingang Yang⁸Ningling Sun⁹Gang sun¹⁰Hui Shi²Han-Ping Shi¹¹Liangdi Xie^12*

• ¹First Affiliated Hospital of Fujian Medical University, Fuzhou, China
• ²Lianyungang No 1 People's Hospital, Lianyungang, China
• ³Lianyungang Oriental Hospital, Lianyungang, China
• ⁴The First Affiliated Hospital With Nanjing Medical University, Nanjing, China
• ⁵Southern Medical University Nanfang Hospital, Guangzhou, China
• ⁶Nanchang University Second Affiliated Hospital, Nanchang, China
• ⁷China Medical University, Shenyang, China
• ⁸Chinese Academy of Medical Sciences and Peking Union Medical College Fuwai Hospital, Beijing, China
• ⁹Peking University People's Hospital, Beijing, China
• ¹⁰Second Affiliated Hospital of Baotou Medical College, Baotou, China
• ¹¹Beijing Shijitan Hospital Capital Medical University, Beijing, China
• ¹²The First Affiliated Hospital of Fujian Medical University, Fuzhou, China

Background: Vitamin D is essential for calcium homeostasis, bone health, and immune function, yet its association with serum uric acid (UA) remains uncertain. This study evaluates vitamin D status in Chinese adults and explores its sex- and age-specific relationships with UA and hyperuricemia (HUA). Methods: We conducted a cross-sectional analysis of 15,116 males and 25,895 females from The China Precision Nutrition and Health KAP Real World Study (CPNAS). Restricted cubic spline (RCS) visualized dose-response relationships, while multivariate regression assessed associations between vitamin D and UA/HUA. Subgroup analyses (age <70 vs. ≥70, male vs. female) explored potential variations. Results: The study revealed a high prevalence of vitamin D deficiency (33.5%) and insufficiency (53%) in Chinese adults. Among males under 70 years, we observed an inverse J-shaped relationship between vitamin D and serum UA levels (p-nonlinear =0.046). Compared to those with vitamin D <22 ng/mL, participants with moderate levels (22-30 ng/mL) showed significantly lower UA (β=-5.40 to -4.36, all p <0.05), while no significant reduction occurred at higher concentrations (≥25.8-30 ng/mL, p>0.05). Notably, this association was absent in males ≥70 years. In contrast, females exhibited a consistent positive linear relationship between vitamin D and UA. These patterns were similarly observed for hyperuricemia risk in both sexes. Conclusion: Vitamin D levels are differentially associated with UA and HUA based on sex and age, highlighting the need for personalized approaches in managing vitamin D and UA metabolism. Keywords: vitamin D, vitamin D deficiency, serum uric acid, hyperuricemia, Chinese cohort