In Part 1 of this series, I broke down my immune system results and what they meant through a functional medicine lens. Today, we’re diving into my kidney function — a system that showed up as needing attention in my report.

So, Should I Be Worried About My Kidneys?

According to the functional blood work algorithm, I scored a 77% probability of kidney dysfunction.

Now, that might sound dramatic — but let’s take a breath and look at what’s really going on.

Functional medicine analysis uses algorithms to identify patterns across multiple blood markers, not just single values in isolation. These patterns can suggest early dysfunction or areas of stress in the body — well before they show up as disease in conventional testing.

What Do the Kidneys Actually Do?

The kidneys are like your body’s internal filtration system. They:

Filter waste and toxins
Balance minerals and fluids
Help regulate blood pressure
Maintain acid-alkaline balance
Support bone health and red blood cell production

The kidney score in this report is based on markers that give clues about how well your kidneys are keeping up with these jobs.

Key Markers in My Kidney Function Panel

Three markers stood out in particular:

BUN: High
Creatinine: High
eGFR: Slightly Low

Let’s break those down one by one.

Why Is My BUN High?

BUN (Blood Urea Nitrogen) is a marker of how well your kidneys are clearing nitrogen waste — mostly from protein breakdown.

I eat a high-protein diet (meat 3 times a day, plus eggs and dairy), so this result makes total sense. When you eat more protein, your body produces more urea — and that shows up in your BUN score.

✅ Healthy kidneys can handle a high-protein load
✅ Research shows no harm from high protein in people with normal kidney function
✅ My BUN is elevated because I'm fuelling my body well — not because my kidneys are failing

Why Is My Creatinine a Bit High?

Creatinine is a waste product from muscle metabolism, and it’s filtered out by the kidneys. So higher levels can suggest reduced kidney function — unless you lift weights, eat meat, or take creatine… which I do.

I take 5g of creatine most days for its mental health and cognitive benefits. Combine that with muscle mass and a high-protein diet, and of course my creatinine will be a bit higher.

So in context:

✅ This is an expected result
✅ It reflects muscle and supplement use — not dysfunction
✅ My kidneys are doing their job just fine

What About My eGFR?

eGFR (estimated glomerular filtration rate) came in at 71 mL/min. That’s technically “normal” by conventional standards (anything >60 is acceptable), but functional medicine likes to see 90+.

However, eGFR is calculated using creatinine — so if creatinine is elevated from training or creatine, eGFR gets pushed down artificially.

Add in age, muscle mass, and hydration levels, and this number starts to make more sense.

Bottom line:

✅ Not a red flag
✅ Worth monitoring over time
✅ Makes sense given my lifestyle

My Magnesium Levels: A Friendly Nudge

Magnesium came back at 0.79 mmol/L — within the conventional range, but below the functional sweet spot (0.85–0.95 mmol/L).

To be fair, I’ve been lazy with my magnesium for the last 12 months — inconsistent with supplements, even though I know better. This test was a reminder that consistency matters.

Why Magnesium Matters for Men

Magnesium is involved in over 300 biochemical processes, including:

Muscle function and recovery
Nervous system and brain health
Sleep quality
Energy production
Blood sugar control
Testosterone regulation

Most modern diets don’t supply enough magnesium — and stress, training, caffeine, and alcohol all increase your need for it. That’s why active men should supplement regularly.

✅ I’m back on the magnesium train
✅ Prioritising forms like glycinate and malate
✅ Lesson learned

My Takeaways: Context is Everything

Looking at this report, you might think my kidneys are struggling — but lab numbers without context can be misleading.

Here's why I'm not panicking:

I eat a high-protein diet — and my BUN reflects that
I supplement with creatine — so my creatinine and eGFR will naturally shift
I train regularly and carry more muscle than the average man my age
I’m aware of my hydration, sleep, and recovery — and I’m working with a practitioner who knows the full picture

The algorithm flagged kidney dysfunction based on patterns, but it doesn’t know my lifestyle, goals, or health history. That’s why working with a practitioner who asks questions — not just reads numbers — is so important.

In the next post, I’ll be diving into GI Function, what the numbers say, and what they don’t. If you're in midlife and want to stay on top of your health without spiraling into fear or confusion — stick with me. This series is for you.

My 2025 Functional Blood Work – Part 2: Kidneys, Creatine & Context