After full adjustments for age, sex, season, BMI, hemoglobin, eGFR, hypertension, diabetes, use of vitamin D supplements and RAS blockers, serum albumin, calcium, phosphorus, HDL cholesterol, triglycerides, and hs-CRP, the predicted probability of high-normal UAE increased non-linearly with decreasing serum 25(OH)D levels, particularly at approximately the threshold levels of serum 25(OH)D. The gene discussed is CRP; the disease is Hypertension.