Today’s article summarizes the findings from the September 2024 issue of the Journal of Renal Nutrition, which examines the impact of niacinamide on serum phosphate levels among adults on hemodialysis.
What is niacinamide? Why would it lower phosphorus?
Niacinamide is a form of Vitamin B3, niacin. Vitamin B3 in either format (niacin or niacinamide) inhibits intestinal transport of dietary phosphate. Niacinamide causes fewer side effects than traditional niacin supplements. The most common side effect of niacin is flushing, though for some this side effect can be so extreme it prevents them from continuing to use it.
The benefits of niacin compared to classic phosphate binders are:
- You don’t need to take it with meals
- Lower pill count than traditional binders
What did the researchers do?
- Design: This was a double-blind, randomized, cross-over design, placebo controlled trial.
- Treatment Length: Each treatment arm lasted for 12 weeks
- Dose: Participants took 250 mg of niacinamide once daily for 4 weeks, followed by 500 mg for 8 weeks, or received a placebo. The dosing frequency (once or twice per day) is unclear based on the author’s description).
- Participants: Stable HD patients already on phosphate binders
- Primary outcome: Reduction of serum phosphate by 10% or 0.46mg/dL (0.15mmol/L).
- Measurements: Serum phosphate was measured every 4 weeks as part of routine clinical care yielding a total of 7 measurements during the intervention periods.
What did the researchers find?
35 participants were randomized, 26 participants completed the study. There were two drop outs on placebo and 7 total drop outs during the niacinamide treatment. The causes of dropout on the niacinamide were diarrhea, pruritis, medical unsuitability (unrelated acute illness), unwilling to continue and kidney transplant.
During niacinamide treatment the serum phosphate level was an average of 0.77mg/dL (0.25mmol/L) lower than when on placebo. This result was statistically significant.
What did the researchers conclude?
For those who tolerated niacinamide, it may be an effective add-on to classic phosphate binders therapy. The benefits are lower pill burden and once daily dosing. However, future studies are needed to better assess the optimal dose and long-term safety.
Take Aways
It can be incredibly difficult to get phosphate levels to target, especially for those with advanced CKD or on dialysis. The dosing of phosphate binders can be really high (>9 tablets per day) and onerous (take with EVERY meal or snack) for our patients.
While I am not sure that I am ready to start recommending Niacinamide in my practice, I am excited to think of possibility of being able to offer more strategies for lowering phosphate levels in the future.
New phosphate cheat sheet
With phosphate being on my mind recently, I have developed a new one-page phosphate cheat sheet. Let me tell you – phosphate metabolism is COMPLEX so trying to get all the keys points on one-page wasn’t easy, but I think its a start.
You can find it in my new section just for email-list subscribers here.
