What is Micronutrient Testing? Understanding Its Importance and Benefits

Patients commonly ask, “Is there a way to test my nutrient levels?”… This is a valid question considering approximately one-third of the US population is at risk for at least one vitamin deficiency.  For many Americans, the food on their plates exceeds caloric needs yet falls short of meeting the body’s micronutrient demands. This results in nutrient insufficiency and vulnerability to various nutrient-dependent health concerns. 

Most people are unaware of the significant limitations of serum nutrient testing. This article explores solutions for reliable micronutrient testing through dependable laboratories and reviews the benefits of intracellular and functional micronutrient assessment.

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Understanding Micronutrients

Essential micronutrients are a group of nearly 30 vitamins and minerals that the body cannot produce adequately. They are required in small quantities and are derived from dietary or supplement sources. Micronutrients are involved in various functions throughout biochemistry, including those that support energy production, metabolism, normal growth, development, and health maintenance. 

Due to the substantial food supply available to most Americans, vitamin and mineral deficiency is much less common than in the past. However, consuming less than ideal amounts of critical vitamins and minerals favors nutrient inadequacy and the development of several health concerns and significant illnesses, including type 2 diabetes, heart disease, osteoporosis, and cancer. 

For example, suboptimal D3 levels are correlated with bone loss, zinc deficiency negatively influences immune function, and suboptimal levels of multiple B vitamins are associated with higher rates of heart disease, neuropathies, and chronic fatigue.

Understanding Bioavailability

It is important to note that a plentiful micronutrient supply within the bloodstream does not equate to an ample supply within our cells. Micronutrients must pass through proteins embedded in the cell membrane called carrier proteins or transmembrane transporters to participate in intracellular biochemistry.  

Several factors influence intracellular levels of various nutrients, including ease of transport across the cell membrane and availability of nutrient cofactors required for transport. Malabsorption, the demands placed upon the body, and the level of systemic inflammation all affect micronutrient supply and micronutrient metabolism. When serum levels are at the lower end of the normal reference range, there is a greater likelihood of deficiency within the cell.

Imagine having a well in your yard with thirst-quenching, crystal-clear drinking water.  But the pipes to the house must be malfunctioning because when you turn the faucet on, just a few tiny drops drip into your glass. Your cells are like that house; despite plenty of water in the well, there is no guarantee you will get it into your glass. The biochemistry necessary to reap the benefits of vitamins cannot occur if nutrients do not enter the cell.

What is Micronutrient Testing?

Micronutrient assessment refers to lab testing that measures a patient’s nutritional status by measuring levels of minerals, vitamins, and other essential nutrients. This helps patients achieve better health while working to uncover the cause of their health concerns.

Serum Testing

Most providers measure micronutrients through serum testing, which has significant limitations.  Serum testing:

• Measures extracellular micronutrients in the blood's plasma (the liquid portion). 
• This may be valuable in detecting grave deficiency; however, circulating levels are poor indicators of the body’s nutrient status. 
• Examples of serum tests include:  some text
  • Serum B12 (Access Med Labs)
  • Serum D3 (Boston Heart Diagnostics)
  • Serum Magnesium (Access Lab Corp)

Measuring nutrient levels outside the cell tells us very little about what is happening intracellularly, where micronutrients do most of their work. 

Intracellular testing

Intracellular testing is a more dependable and beneficial way to investigate micronutrient status. 

• Measures nutrients inside the blood cells rather than in the serum. 
• It is a significantly more helpful tool to assess a patient’s nutrition status and design an effective treatment plan to address their health concerns.
• Examples of intracellular tests include:  some text
  • MetabolomX + (Genova Diagnostics)
  • Micronutrient Test (SpectraCell)
  • Cellular Micronutrient Assay (Cell Science Systems)

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Assessment of Functional Micronutrient Deficiency 

In addition to serum nutrient testing and intracellular micronutrient testing, some labs assess for functional micronutrient deficiency. Functional micronutrient testing measures the function or performance of a nutrient within a cell rather than the amount of micronutrients present. The measurements reveal whether the body has ample nutrients to satisfy the biochemistry by assessing markers involved with immune function, antioxidant function, glucose-insulin interactions, and fructose metabolism. 

• Functional micronutrient testing measures metabolites and organic acids (byproducts of various metabolic processes such as drug metabolism or energy production) involved in various systems throughout the body. 
• Functional micronutrient panels use urine and blood for testing.

The most valuable micronutrient test panels combine intracellular and functional testing for the most comprehensive look at the patient’s nutritional status.  A 2022 study found that athletes had significantly lower intracellular selenium levels than extracellular ones. Researchers attributed this to inflammation and oxidative stress from regular training, which impairs selenium transport into cells.

One of our most valued minerals, magnesium, is a cofactor (a molecule required to turn on an enzyme) in more than 300 enzyme reactions within our cells. It is important for energy production, protein synthesis, muscle and nerve function, blood sugar, and blood pressure regulation. Magnesium is another excellent example of a micronutrient that is difficult to assess for deficiency since most magnesium exists inside cells or in the bone, not in our serum. This shows little correlation between serum levels and total body or tissue magnesium status. 

Reputable test panels measure 30 essential micronutrients and function nutrition markers, providing the most comprehensive view of a patient’s nutritional status.  

Benefits and Common Applications of Micronutrient Testing

Micronutrient testing has proven invaluable in clinical practice; for example:

• Combining intracellular and functional markers for each nutrient allows for screening of suboptimal nutrient status.
• Assessing how patients employ micronutrients at the cellular level allows for treatment plan design to optimize nutritional status. 
• Panels are valuable in challenging patient cases, such as patients not responding to treatment as expected.  
• Results aid with treatment plan design for athletes to support optimal performance and for even the healthiest patients to ensure their treatment plan remains effective. 
• Results can provide confidence in reducing a patient’s supplement load following their health recovery to ensure they supplement what is necessary alongside a healthy diet.

Challenges and Considerations

While micronutrient testing is a great tool to better understand where to initiate treatment if a patient is not already on a supplement or nutrition plan, it can also be employed to assess the efficacy of an existing treatment.  

Supplement regimes and nutrition plans should remain consistent for three months before ordering a micronutrient test. Consistency before testing allows for a more accurate assessment of how well a treatment works for the patient and how to adjust their plan going forward. 

It is essential to educate patients on the importance of reading test instructions thoroughly before taking the test to ensure proper planning and completion. Some test panels require morning urine to be sent with a blood sample. By researching the different micronutrient panels available, providers can select a consistent favorite, avoiding the variability in methodology and laboratory standards that come with switching between different companies.

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Key Takeaways

• Serum nutrient levels may be valuable in detecting grave deficiency; however, a plentiful micronutrient supply within the bloodstream does not equate to an ample supply within our cells.
• Intracellular nutrient testing is a more dependable and beneficial way to investigate micronutrient status as it measures nutrients inside the blood cells rather than in the serum. 
• Intracellular and functional micronutrient testing is another excellent tool in our functional medicine toolbox. 
• Access to improved testing techniques that provide more accurate results allows providers to optimize patient outcomes by further individualizing our treatment plans.
• Learning when and how to utilize micronutrient testing best allows providers the information and opportunity to work with our patients to make significant health gains in even the trickiest cases.  
• As functional medicine's invaluable nature and impressive outcomes continue to be better understood, our patient’s curiosity and interest in adopting better lifestyle habits to benefit their health will continue to grow.