In colorectal carcinoma patients, serum vitamin D levels vary according tostage of the carcinoma

BACKGROUND. Epidemiologic studies have demonstrated an inverse correlation between dietary calcium and vitamin D intake and the incidence of colorecta l carcinoma. Elevated serum levels of 25-hydroxyvitamin D-3 (25-OH-D-3) are associated with a major reduction in the incidence of this neoplasm. The r eduction in tumor size and number induced by calcium supplements in an expe rimental carcinogenesis model was neutralized by vitamin D-3 deficiency. To the authors' knowledge, vitamin D serum levels have never been determined previously in colorectal carcinoma patients. They compared serum 1,25-dihyd roxyvitamin D-3 (1,25(OH)(2)D-3), 25-OH-D-3, and parathyroid hormone (PTH) levels of colorectal carcinoma patients with those of healthy controls. METHODS. Serum 1,25(OH)(2)D-3, 25-OH-D-3, and PTH levels were determined in 84 colorectal carcinoma patients (10 with Stage I, 29 with Stage II, 25 wi th Stage III, and 20 With Stage IV) and 30 healthy controls, all of whom we re normocalcemic and not taking calcium or vitamin D supplements. RESULTS, 25-OH-D-3 serum levels were higher in cancer patients than control s, irrespective of stage. Serum 1,25(OH)(2)D-3 decreased with advancing sta ge: 73+/-18, 48+/-16, 39+/-12, 34+/-13, and 75+/-20 pg/mL in Stages I, II, III, IV and controls, respectively. There was a corresponding increase in s erum PTH levels: 58.0 +/- 9.4, 73.7 +/- 14.4, 79.0 +/- 21.3, 100.4 +/- 30.9 , and 51.2 +/- 3.9 pg/mL in Stages I, II, III, TV, and controls, respective ly. Serum vitamin D metabolite levels did not correlate with gender, age, t umor localization, or histologic grade. CONCLUSIONS. An inverse correlation between serum levels of the active meta bolite of vitamin D and colorectal carcinoma stage has been demonstrated fo r the first time, to the authors' knowledge, in colorectal carcinoma patien ts. Because 1,25(OH)(2)D-3 has been shown to inhibit proliferation of colon ic epithelial cells, decreased serum levels may facilitate the growth of co lorectal carcinoma and influence its biologic behavior. (C) 1999 American C ancer Society.