MCV – Early Clue to Brewing Disease Dynamics?

This Clinical Tip encourages practitioners to look for often unexplored evidence in typical “everyday” labwork – cues’n’clues – that commonly point to brewing disease dynamics.

The markers in the ubiquitous Complete Blood Count (CBC) often hold more value beyond what is typically considered. Today, we explore MCV – Mean Corpuscular Volume – and what it can tell us beyond the size and volume of the Red Blood Cells.

Check out this short video to learn more about how this common marker can give us critical insight to brewing disease dynamics, including the impact of  excessive alcohol use and inadequate nutrients – especially folate (B9) and cobalamin (B12). 

Much too often, primary care providers still rely on out-of-normal-range lab markers as prompts for further investigation. This practice doesn’t serve their patients – especially when considering longer term consequences to health.

Contrary to common belief, normal ranges are typically not intended to be “healthy” ranges. They are statistical norms (two standard deviations around a norm). Normal ranges capture what 95% of the population without a formal medical diagnosis within a given sample set presents upon testing. When considering the overall, large level of functional imbalance and loss of optimal vitality in our communities, we must acknowledge a key truth: there’s a huge amount of subclinical disease biasing these “normal” ranges. 

B12 and Folate inadequacy (again, not necessarily overt deficiency with outside normal range low values) have long been known contributors (and often causative factors) of macrocytosis – large RBCs. Explore here for the etiology of this dynamic and to learn more about how these two B vitamins can be involved. And here for more nuance assessing macrocytosis (reported to be widely underestimated using normal lab guides).

B12 deficiency is quite common in our patient populations – and, unfortunately, a serum B12 marker is a better indicator of recent intake and digestion than of intracellular sufficiency.  You may want to review this and this on general considerations on B12 deficiency, metabolism, and clinical management. For your patients using metformin, a resulting B12 deficiency is quite common – see here for more on this. 

In the realm of cardiovascular health, here is a good review on borderline-high MCV and arterial stiffness. In addition to MCV, Homocysteine is well-known to be a predictive marker for cardiovascular health; it turns out that  it can also give us more information on the status of both B12 and B9. And another marker, Methylmalonic Acid (available in both serum and urine),  turns out to be a valuable surrogate of general B12 status.

Your takeaway? Look at historical CBC trends for progressive, subclinical increases in MCV (we teach a level of 91 fL or higher) to explore possible macrocytic dynamics. Cast a broad net as you consider contributors or “puzzle pieces” in creating this dynamic… Regular alcohol use (even if not objectively “excessive”)? Suboptimal B9 or B12 status? Is your patient vegan?  Do they eat a normal “crap food” diet? Do they have impaired digestion? High stress levels impairing HCl secretion? Are they on a PPI or another drug that could affect these key nutrients? Is there a hypothyroid dynamic in play? 

These brewing imbalances can affect so much in the body – from the ubiquitous need to properly methylate DNA, to glutathione synthesis, neurotransmitter balance, hormone metabolism, peripheral nervous system dysfunction, and so much more. 

Learn to use this simple, everyday blood marker – and so many more that we teach at SAFM – to get in front of symptoms and suffering so common in our practices today. If we want health care to be truly effective and affordable, we must move beyond waiting for a disease dynamic to become severe enough to merit a diagnosis. 

We must proactively find and resolve the dysfunction within the norms to prevent worsening symptoms and suffering and increase the vitality of the people we serve.