# Association between vitamin D and serum uric acid in a large Chinese cohort of middle-aged and elderly Chinese men and women

## TL;DR

This study finds that vitamin D levels are linked to uric acid in Chinese adults, with different patterns in men and women and across age groups.

## Contribution

The study reveals sex- and age-specific nonlinear associations between vitamin D and uric acid in a large Chinese cohort.

## Key findings

- Vitamin D deficiency and insufficiency were common in the study population.
- Younger men showed an inverse J-shaped relationship between vitamin D and uric acid.
- Women showed a consistent positive linear relationship between vitamin D and uric acid.

## Abstract

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).

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.

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-non-linear = 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.

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.

This trial was registered at https://www.chictr.org.cn/hvshowproject.html?id=178499&v=2.2, as ChiCTR2100051983.