Blood Work Drama, or The “Reference Range” Dilemma

When you have certain lab tests drawn, your provider wants to see your result within the reference range, aka reference interval or pathological range.

An interval shows the statistical norm, or expected values, within a population. “Normal” is often capturing between the fifth and ninety-fifth percentiles of the population within that range, and the remaining ends, the “out of range,” are the outliers. Those outliers usually experience clinical diagnoses that then lead to a medical treatment plan. Each lab company will provide their own reference ranges because they are have data from different people, so sometimes the ranges will vary slightly.

So who’s getting their lab work drawn often? The healthy people that go for a physical every few years? Or the people that are feeling unwell and are trying to find the answers, or the people that are following health conditions? For sure, the latter. So this skews the reference ranges. Our “normal” is being based on unwell populations. Yet we were told that the reference ranges cats are all normal ranges.

If I had a dollar for every time I heard, “But my doctor drew my labs and told me everything was normal, so why do I still feel like crap,” I could retire early

This is why we have general reference ranges, and optimal/functional references ranges.

The optional/functional ranges are based on healthy people, objective and subjective data that supports who feels the best, who isn’t suffering from a state of unwellness. I’m looking at where within the bell curve your unique lab value falls, in combination with where your symptoms suggest it should fall. And I’m also using common sense. For instance, for a marker that is measuring inflammation, a destructive process in the body, we would want that to be as low as possible. Not at the top of the reference range but still considered “normal.” Similarly, for a nutrient that’s very important to our health, such as magnesium, we would want this to be towards the top of the reference range to show that our body is adequate in it. Not at the bottom of the reference range where we are struggling to keep up with our own demand and all of our tissues may not be sufficient with it; yet it is still considered “normal.” When I look at lab work, I am looking at functional ranges.

Take my client, B, for example. She was struggling with tingling feet, cold feet and hands, a history of mercury fillings, and poor response to being sick. These all scream B12 deficiency to me!! When I suggested she draw her vitamin B12, she was at 256. The reference range for B12 is 232-1245, so clearly inside “normal.” But those symptoms were here. Meanwhile the functional range is >600, suggesting to me that this was a case of deficiency. We began supporting her vitamin B12 and, low-and-behold, her fingers and toes stopped getting cold, her feet no longer tingled, and she recovered from colds a bit faster. After 6 months, we pulled her lab again, and she was at 760. Still within range, closer to the top of the bell curve. But more importantly, her position within the reference range gave us an additional clue of what to focus in on, and that allowed us to support her in feeling better.

I love walking through labs with clients and finding all the connections to their symptoms that have been previously missed! Feel free to book a session to review your labs and get you back on track to feeling happier, calmer, and more energetic! Feel free to schedule a free session to find out more.


American Association for Clinical Chemistry. (2020). Reference ranges and what they mean. Retrieved from (2021). Sample Report. Retrieved from

Oczkowski, T. (2021). Why I look at functional lab ranges not just pathological ranges. Retrieved from

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