Effect of vitamin D2 supplementation on bone mineral metabolism in patients with chronic kidney disease

• Grant number: 06/03811-6
• Support Opportunities: Regular Research Grants
• Start date: January 01, 2007
• End date: December 31, 2009
• Field of knowledge: Health Sciences - Nutrition
• Principal Investigator: Lilian Cuppari
• Grantee: Lilian Cuppari
• Host Institution: Escola Paulista de Medicina (EPM). Universidade Federal de São Paulo (UNIFESP). Campus São Paulo. São Paulo , SP, Brazil

Abstract

Disorders in calcium and phosphate metabolism are common in chronic kidney disease (CKD). Although some other factors are related to these disturbances, the reduction of the 1,25(OH)2D synthesis, the active form of vitamin D, associated to the loss of kidney function contributes for development of the secondary hyperparathyroidism in these patients. In situations of deficiency or insufficiency of 25(OH)D, the 1,25(OH)2D synthesis can be impaired not only due to the reduction of the renal function, but also due to the lack of substrate for its synthesis. The clinical practice guideline, Kidney Disease Outcomes Quality Initiative (NKF-DOQI), suggests the use of vitamin D2 (ergocalciferol) supplementation for patients on stages 3 and 4 of CKD (glomerular filtration rate of 59 and 15mL/min). However, this recommendation is based on opinion, thus not yet supported by scientific evidence. Therefore, the aim of this study is to evaluate the effect of vitamin D2 (ergocalciferol) supplementation on bone mineral metabolism in CKD patients not yet on dialysis with deficiency or insufficiency of this vitamin. This is a prospective, randomized and controlled study with duration of 6 months. The sample will include 90 adult patients on stages 3 and 4 of CKD (glomerular filtration rate of 59 to 15 ml/min), with deficiency or insufficiency of vitamin D (serum 25(OH)D < 30 ng/mL). The patients will be randomized for 2 groups. The study group will receive the supplementation with vitaminD2 and the control group will follow the standard protocol applied in our the renal outpatient clinic which does not include the use of Vitamin D. All patients will be followed in monthly clinical assessments. The following laboratorial parameters will be measured: total and ionic calcium, phosphorus, PTH intact, serum creatinina, serum urea, 25(OH)D, 1,25(OH)2D, alkaline phosphatase, hemoglobin, hematocrit, serum albumin, serum bicarbonate and 24 h urine collection for measurement of protein, urea, creatinine, phosphorus, calcium and sodium. Anthropometric parameters (body weight, height), subjective global assessment (SGA), handgrip strength (dynamometer) will be used to evaluate the nutritional status. Body composition will be determined by dual-energy X-ray absortiometry (DEXA). (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

GARCIA-LOPES, MIRIAM G.; PILLAR, ROBERTA; KAMIMURA, MARIA AYAKO; ROCHA, LILLIAN A.; CANZIANI, MARIA EUGENIA F.; CARVALHO, ALUIZIO B.; CUPPARI, LILIAN. Cholecalciferol Supplementation in Chronic Kidney Disease: Restoration of Vitamin D Status and Impact on Parathyroid Hormone. ANNALS OF NUTRITION AND METABOLISM, v. 61, n. 1, p. 74-82, 2012. (06/03811-6)