What evidence is there to suggest that dietary supplementation can reduce BP in CKD patients?
The effects of potassium supplementation on BP have been assessed in a number of studies, however these have produced conflicting results, with some but not all indicating a benefit. In the absence of specific studies demonstrating a benefit in CKD patients, potassium supplementation cannot be recommended to reduce BP in patients with CKD. The evidence base for magnesium supplementation is similar, with some but not all studies suggesting a benefit with respect to BP. Fish-oil supplementation has been shown to produce small but significant reductions in BP in a number of RCTs and systematic reviews. However, the mechanisms of these effects remain uncertain, and the safety of fish oil has not been clearly demonstrated in CKD patients. Therefore, it is premature to recommend this treatment for BP lowering in the CKD population.