Pediatr Nephrol (2008) 23:195–207 8. 9. A 9-year-old boy on dialysis has a serum calcium level of 10.2 mg/dl and serum phosphorus of 7 mg/dl. He currently receives two tablets of calcium carbonate (500 mg) with each meal and snack (a total of eight tablets per day). Optimal control of his serum phos- phorus could best be obtained by: a. dietary protein restriction to 0.8 mg/kg per day b. increasing his calcium carbonate to three tablets with meals and snacks c. adding sevelamer to his phosphate binder regimen d. increasing vitamin D sterol therapy e. starting him on a calcimimetic A 14-year-old boy with stage 4 CKD has the following serum biochemical determinations: phosphorus 5.8 mg/ dl, calcium 9 mg/dl, and PTH 160 pg/ml. The following intervention is not recommended at this stage of his treatment: a. calcium carbonate with meals b. lanthanum carbonate with meals c. low-dose calcitriol, nightly d. dietary phosphate restriction References 1. Moe S, Drueke T, Cunningham J, Goodman W, Martin K, Olgaard K, Ott S, Sprague S, Lameire N, Eknoyan G (2006) Definition, evaluation, and classification of renal osteodys- trophy: a position statement from Kidney Disease: Improving Global Outcomes (KDIGO). Kidney Int 69:1945–1953 2. Martinez I, Saracho R, Montenegro J, Llach F (1996) A deficit of calcitriol synthesis may not be the initial factor in the pathogenesis of secondary hyperparathyroidism. Nephrol Dial Transplant 11 [Suppl 3]:22–28 3. Levin A, Bakris GL, Molitch M, Smulders M, Tian J, Williams LA, Andress DL (2007) Prevalence of abnormal serum vitamin D, PTH, calcium, and phosphorus in patients with chronic kidney disease: results of the study to evaluate early kidney disease. Kidney Int 71:31–38 4. Fraser DR, Kodicek E (1970) Unique biosynthesis by kidney of a biological active vitamin D metabolite. Nature 228:764–766 5. Gray R, Boyle I, DeLuca HF (1971) Vitamin D metabolism: the role of kidney tissue. Science 172:1232–1234 6. Norman AW (1971) Evidence for a new kidney-produced hormone, 1,25-dihydroxycholecalciferol, the proposed biologi- cally active form of vitamin D. Am J Clin Nutr 24:1346–1351 7. Svensson O, Wernerson A, Reinholt FP (1988) Effect of calcium depletion on the rat parathyroids. Bone Miner 3:259–269 8. Wernerson A, Widholm SM, Svensson O, Reinholt FP (1991) Parathyroid cell number and size in hypocalcemic young rats. APMIS 99:1096–1102 9. Martinez I, Saracho R, Montenegro J, Llach F (1997) The importance of dietary calcium and phosphorous in the secondary hyperparathyroidism of patients with early renal failure. Am J Kidney Dis 29:496–502 10. Portale AA, Booth BE, Halloran BP, Morris RC Jr (1984) Effect of dietary phosphorus on circulating concentrations of 1,25- 203 dihydroxyvitamin D and immunoreactive parathyroid hormone in children with moderate renal insufficiency. J Clin Invest 73:1580–1589 11. Almaden Y, Canalejo A, Ballesteros E, Anon G, Canadillas S, Rodriguez M (2002) Regulation of arachidonic acid production by intracellular calcium in parathyroid cells: effect of extracel- lular phosphate. J Am Soc Nephrol 13:693–698 12. Naveh-Many T, Bell O, Silver J, Kilav R (2002) Cis and trans acting factors in the regulation of parathyroid hormone (PTH) mRNA stability by calcium and phosphate. FEBS Lett 529:60–64 13. Massry SG, Coburn JW, Lee DB, Jowsey J, Kleeman CR (1973) Skeletal resistance to parathyroid hormone in renal failure. Studies in 105 human subjects. Ann Intern Med 78:357–364 14. Naveh-Many T, Rahamimov R, Livni N, Silver J (1995) Parathyroid cell proliferation in normal and chronic renal failure rats. The effects of calcium, phosphate, and vitamin D. J Clin Invest 96:1786–1793 15. Lloyd HM, Parfitt AM, Jacobi JM, Willgoss DA, Craswell PW, Petrie JJ, Boyle PD (1989) The parathyroid glands in chronic renal failure: a study of their growth and other properties made on the basis of findings in patients with hypercalcemia. J Lab Clin Med 114:358–367 16. Larsson T, Nisbeth U, Ljunggren O, Juppner H, Jonsson KB (2003) Circulating concentration of FGF-23 increases as renal function declines in patients with chronic kidney disease, but does not change in response to variation in phosphate intake in healthy volunteers. Kidney Int 64:2272–2279 17. Gutierrez O, Isakova T, Rhee E, Shah A, Holmes J, Collerone G, Jüppner H, Wolf M (2005) Fibroblast growth factor-23 mitigates hyperphosphatemia but accentuates calcitriol deficiency in chronic kidney disease. J Am Soc Nephrol 16:2205–2215 18. National Kidney Foundation (2005) K/DOQI clinical practice guidelines for bone metabolism and disease in children with chronic kidney disease. Am J Kidney Dis 46 [4 Suppl 1]:S1–121 19. Norris KC, Goodman WG, Howard N, Nugent ME, Coburn JW (1986) Iliac crest bone biopsy for diagnosis of aluminum toxicity and a guide to the use of deferoxamine. Semin Nephrol 6 [4 Suppl 1]:27–34 20. Salusky IB, Coburn JW, Brill J, Foley J, Slatopolsky E, Fine RN, Goodman WG (1988) Bone disease in pediatric patients undergoing dialysis with CAPD or CCPD. Kidney Int 33:975– 982 21. Atkins D, Peacock M (1975) A comparison of the effects of the calcitonins, steroid hormones and thyroid hormones on the response of bone to parathyroid hormone in tissue culture. J Endocrinol 64:573–583 22. Lee K, Deeds JD, Bond AT, Juppner H, Abou-Samra AB, Segre GV (1993) In situ localization of PTH/PTHrP receptor mRNA in the bone of fetal and young rats. Bone 14:341–345 23. Sherrard DJ (1986) Renal osteodystrophy. Semin Nephrol 6: 56–67 24. Groothoff JW, Offringa M, Van Eck-Smit BL, Gruppen MP, Van De Kar NJ, Wolff ED, Lilien MR, Davin JC, Heymans HS, Dekker FW (2003) Severe bone disease and low bone mineral density after juvenile renal failure. Kidney Int 63:266–275 25. Malluche H, Faugere MC (1990) Renal bone disease 1990: an unmet challenge for the nephrologist. Kidney Int 8:193–211 26. Hamdy NA, Kanis JA, Beneton MN, Brown CB, Juttmann JR, Jordans JG, Josse S, Meyrier A, Lins RL, Fairey IT (1995) Effect of alfacalcidol on natural course of renal bone disease in mild to moderate renal failure. BMJ 310:358–363 27. Salusky IB, Coburn JW, Foley J, Nelson P, Fine RN (1986) Effects of oral calcium carbonate on control of serum phospho- rus and changes in plasma aluminum levels after discontinuation of aluminum-containing gels in children receiving dialysis. J Pediatr 108:767–770