Optimal vs. "normal": why most lab ranges are too late

When you get a lab back, the result is usually flagged green or red based on a reference range, the band of values considered “normal.” Anything inside that band is fine. Anything outside is a problem.

But here’s the catch: most reference ranges are built around the population average, not what’s healthy.

How ranges are actually built

A reference range usually represents the middle 95% of people tested at that lab. Two people get cut off at each tail. The middle 95% is “normal.”

That sounds reasonable until you remember the population getting tested isn’t healthy. They have type 2 diabetes, fatty liver disease, chronic inflammation, sleep deprivation, and the metabolic damage of a Western diet. The “normal” range is normal for that group, not for someone optimizing health.

A concrete example: fasting glucose

The conventional range for fasting glucose is roughly 70–99 mg/dL. Anything in that window is fine.

Functional medicine optimal range: 75–86 mg/dL.

Studies of metabolic and cardiovascular outcomes find risk starts climbing well below the conventional cutoff. Someone with a 95 fasting glucose is “normal” by conventional standards, but already showing signs of insulin resistance. By the time they hit 100 and get flagged, the damage has been compounding for years.

What this looks like in practice

Functional medicine ranges are typically tighter than conventional ones. A few examples:

Marker	Conventional “normal”	Functional optimal
Vitamin D	30–100 ng/mL	50–80 ng/mL
TSH	0.4–4.5 mIU/L	1.0–2.0 mIU/L
Ferritin (men)	24–336 ng/mL	50–150 ng/mL
hs-CRP	< 3.0 mg/L	< 0.5 mg/L

When you score against the tighter ranges, you start spotting drift years before a conventional lab would flag a problem.

Why this matters

Conventional medicine waits for breakage. Functional medicine watches for drift. That’s the whole game.

In the My Health Optimized dashboard, every marker is scored against the functional range automatically. Greens, yellows, and reds show you at a glance what’s optimal, what’s drifting, and what needs attention. No more squinting at the printout.