Vitamin D Supplementation in CKD: A Systemic Review and Meta-Analysis of Observational Studies and Randomized Controlled Trials - Article Review - Dr. Paul Barre
This article appraisal is part of the EMiNEM Bone and Mineral Metabolism Series. Click here to reach the EMiNEM homepage on UKidney
To study the benefits and harms of vitamin D supplementation (ergocalciferol or cholecalciferol) in CKD, dialysis and renal transplant patients.
Study Design and Study Population
Meta-analysis of 22 studies (17 observational and 5 RCTs) with respect to biochemical endpoints.
Intervention or Observation
Heterogeneous group of studies from Europe and North America between 1998 and 2009 with a study duration from 1-15 months. Intervention included variable but pharmacological doses of ergocalciferol or cholecalciferol and reported outcomes varied but include calcium, phosphorus, PTH, 25(OH)D, 1,25 (OH) 2D and EPO.
The considered outcomes included biochemical endpoints (changes in calcium, phosphorus, PTH, 25(OH)D and 1,25(OH)2D), patient-centered endpoints (cardiovascular events, bone disease and mortality), adverse effects (hypercalcemia or hyperphosphatemia) or miscellaneous outcomes.
The Newcastle-Ottawa scale was used to assess study quality for observational studies. Quality of RTCs was assessed by allocation concealment, intention to treat, completeness of followup and blinding.
There was a significant increase in 25(OH)D studies in both observational studies and RTCs in CKD, dialysis and transplant patients. There was a significant decrease in PTH levels with the highest benefit in dialysis patients. There was a significant increase in 1,25(OH)2D levels in observational studies but a variable response in RCTs. There was no significant change in serum calcium or serum phosphate in any group and a low incidence of hypercalcemia and hyperphosphatemia. Other outcomes largely revealed no change with intervention and no study reported outcomes related to cardiovascular disease, bone disease or mortality.
This systemic review and meta-analysis of observational studies and limited randomized clinical trials fills a void in the absence of large, long-term RTCs and provides a general consensus with respect to improved biochemical results in all groups studies over a relatively short period of time. There is no data with respect to cardiovascular events, outcomes related to bone disease or mortality. There are limited miscellaneous outcomes.
This study supports the administration of vitamin D (ergocalciferol or cholecalciferol) in CKD as recommended by KDIGO 2009 in vitamin D deficient or insufficient patients with CKD, dialysis or renal transplantation.
However, there is no outcome data and no data relating to areas beyond mineral metabolism.
Reviewed by Reviewed by Dr. Paul Barre