In studying the population disparities in mineral metabolism,41,160 African-American patients with CKD demonstrate marked deficiencies in serum 25-hydroxyvitamin D (25-OH vitamin D) and higher PTH levels than Caucasians.161–163 As these patients progress toward the need for dialysis, they show even more severe secondary hyperparathyroidism and 25-OH vitamin D deficiencies.164–166 This result was also shown by the multicenter Study to Evaluate Early Kidney Disease (SEEK) in 1,860 patients with early CKD, of whom 12% were African-American. This evidence concerns the gene PTH and chronic kidney disease.