Q: I read that the BUN level should be around 20. I have 30 (normal scale 15-30 mg/dL according to my laboratory). I started the Zone Diet seven months ago, and four months ago my BUN was 49. It's going down. How do I read these results? Do I have to lower my protein intake?
A: BUN stands for Blood Urea Nitrogen. One of the first breakdown products of protein is ammonia, which is quickly converted into urea. The urea is then filtered out of the body by the kidney. A high BUN is indicative of too much protein consumption or inefficient kidney function. I would recommend spreading your protein content over a larger number of small meals so that the BUN stays about 20.