Association Between Elevated Serum Uric Acid and Vitamin D Insufficiency Among the Middle-Aged and Elderly Population

OBJECTIVE: Vitamin D insufficiency might have a role in numerous diseases including autoimmune disease, cancer, diabetes mellitus, hypertension and heart diseases. The relationship between vitamin D insufficiency and hyperuricemia has been shown previously but there are conflicting results in studies. MATERIAL and METHODS: A total of 1562 patients who had serum uric acid and vitamin D levels measured at the same time were enrolled. Patients who were on vitamin D replacement therapy, receiving calcium and/or allopurinol, or had gout and chronic kidney disease were excluded. RESULTS: Hyperuricemic patients had significantly lower levels of serum vitamin D level compared with normouricemic patients (p<0.001) whereas there was no difference between the groups in terms of serum calcium, phosphorus, parathormone and alkaline phosphatase. Severe deficiency (25(OH) vitamin D <10) was significantly more common among patients with hyperuricemia (p<0.001). When vitamin D levels were analyzed according to age, a significant inverse correlation between vitamin D and serum uric acid level was found in decades 7 and 8. Age, eGFR and vitamin D level below 20 appeared as independent associates of serum uric acid levels. CONCLUSION: These data suggest that hyperuricemia associates with vitamin D deficiency. Further studies are needed to understand the mechanism underlying this association and its potential clinical implications.