Well, my blood work came back and I have an elevated BUN. Naturally, my wife the nurse is telling me that my increased protein intake is to blame and that I'm damaging my kidneys by giving them more than they can handle. Thing is, I'm taking in less than 3/4 gram per pound or less most days. I'm not even meeting myFitnessPal's pre-workout requirements. What the heck do I do now? Kinda hard to build muscle on no protein.

Jeff,

My BUN has been elevated for 31 years and my kidneys are fine. At age 51, my doctor said I have the health, blood profile, and organ health of someone in their 20s. When you get blood work done, they also run a full panel on your liver and kidneys. Unless there is indication your kidneys are being damaged and your doctor has raised concern, your wife is being an alarmist without cause regardless of whether she is a nurse or not :-)

The issue with many of the "normal" ranges that all these lab tests use is they encompass EVERYONE - of all ages, health conditions, etc. It is like testosterone levels. The "normal" range is 250 - 1100. This takes into account men from age 18-90. So if a 30 YO man presents with testosterone of 275, a doctor will say he is fine. However, the healthy testosterone level for a 30 YO man based on data for all 30 year olds is 550-750. 275 is the level a man in his 80s would have. It is the same issue here. Your BUN levels are elevated or may be above the "norm" because your protein consumption is higher than the average male who does not weight train and need increased protein intake. BUN ranges take all people into account not just weight lifters on higher protein diets.

John

A follow-up, if I may?

Is this for any weight lifter or someone who lifts heavy? I only have two lifts that go over 200 lbs and those are legs (I've only been lifting regularly for a few months).

Jeff,

Anyone who eats larger amounts of protein in their diet will have "elevated" BUN. It is not a function of how much weight you lift and what types of lifts. BUN is the urea metabolite of nitrogen processing by the liver of protein thus it is protein intake related not weightlifting related. As I said earlier, unless your doctor is concerned especially in light of your past health challenges I wouldn't worry about it :-)

John

Your Creatinine, BUN and Creatinine ratio, 24-Hour Urine Creatinine Clearance, and GFR is what you want to be more concerned about. If it is elevated then you need to have a renal panel ordered and other diagnostic analysis to determine renal disease or other related ailments.

BUN can be elevated by medications you may be on and even over-the-counter NSAIDS ingested over a period of time can be the culprit.

Your intake isn't even considered "high." BUN can be elevated from a high protein intake yes, but it can be high from poor renal clearance or renal failure. What was your urine creatinine? If that is low too that can help elucidate if kidney problems are present.

100% agree. Elevated Creatinine with elevated BUN is indicative of kidney clearance issues. I have had elevated BUN for years due to my high protein diet but creatinine and other kidney metrics have been fine.

John

My creatinine was on the high end of normal but still normal. The BUN/Creatinine ratio wasn also normal but on the high end. It may just be I don't take in enough water. I only take in about 80-100 oz./day and I tend not to drink a lot when I work out (I'm not the guy who carries a gallon jug with me). My sodium levels already pretty low - don't want to push that too far down.

Ah, I see now... Yes, a low water intake can contribute to high BUN. You're basically taking in 3 liters tops, and with exercise, that total water volume losses are greater. I would increase your water intake ASAP and retest BUN and then see if it normalizes. A low water intake and low sodium is not a great combo.. I would increase sodium intake as well. Don't be afraid of sodium.