Dr. Michael Ruscio, DC is a clinician, Naturopathic Practitioner, clinical researcher, author, and adjunct professor at the University of Bridgeport. His work has been published in peer-reviewed medical journals and he speaks at conferences around the globe.
What You Need to Know Before You Order Micronutrient Testing
Micronutrient testing looks at the levels of essential vitamins and minerals in the body, usually through blood/serum testing.
It’s tempting to take these tests at face value, but the truth is that they don’t always give an accurate picture of your micronutrient status.
It is often better to assess potential micronutrient deficiencies via symptom evaluation, and then address them using diet intervention first and supplementation second.
Most people should be getting enough micronutrients through their diet and using a high-quality multivitamin as insurance if desired. However, there are exceptions with age, chronic illness, and stress where extra supplementation might be useful and warranted.
Micronutrient tests (blood tests that analyze your levels of specific vitamins and minerals) seem to be an appealing diagnostic tool — they suggest the ability to showcase exactly what’s going on inside your body and what nutrients you might be missing. Certain micronutrient tests, like those for iron, or vitamin D, are simple, inexpensive, and accurate.
However, other types of micronutrient testing(such as organic acid tests)can be distracting, sometimes expensive, and generally not as helpful as we wish they were. For example, when it comes to many important nutrients — like zinc — blood levels don’t actually correlate well with clinical presentation. This is in part because blood tests can’t tell you about the levels of a nutrient throughout the rest of your body, or how your cells and tissues are using it.
While test results may be more accurate and helpful for certain micronutrients, including magnesium and B vitamins, the best overall approach to prevent nutritional deficiencies is to balance your diet — including a multivitamin supplement for “insurance” if desired. Next, it’s important to ensure that your gut is healthy, as gastrointestinal issues can lead to impaired absorption of nutrients.
Once this healthy foundation has been established, any ongoing symptoms can be used by your health care provider to help identify and treat nutrient deficiencies as needed. In most cases, micronutrients can be supplemented without the need to run a blood test.
What Are Micronutrients?
Micronutrients are the vitamins and minerals your body needs to function chemically and electrically on an intracellular level. Micronutrients contribute to your immune system, nervous system, hormones, gut health, and just about every aspect of your overall wellness.
Micronutrients are needed on a comparatively small scale to macronutrients, which include carbohydrates, protein and amino acids, fatty acids, and water. Your body needs these in much larger amounts for energy production, muscle and tissue maintenance, and systems operation.
B vitamins (Folate, vitamin B12, etc.)
Micronutrient tests are essentially any tests that look at levels of micronutrients in the body, usually via a serum/blood test. You can also look at minerals using a hair mineral analysis test or a urine test, for example, though this is less common.
The most common micronutrient tests used in functional medicine include: vitamin D, iron, organic acid tests, magnesium, zinc, and copper. You may have a:
Comprehensive metabolic panel
Complete Blood Count (CBC)
Organic acids test
Some micronutrient tests (including CBC, ferritin/iron, and vitamin D) are basic, inexpensive, and accurate. Others (like organic acid tests) can be quite expensive and are arguably not accurate.
Micronutrient Testing May Be Misleading
Examining individual micronutrients may not offer the concrete answers doctors and patients are looking for. This isn’t to say that your micronutrient status isn’t important; micronutrients are critical for overall health and wellbeing. But there are several reasons that micronutrient testing often doesn’t hit the diagnostic mark when evaluating a patient’s symptoms.
Reason #1: Missing the Big Picture
This is a common pitfall of testing in general — getting too granular on details like individual micronutrient levels may miss the big picture issue at play. For example, maybe a micronutrient test shows that a patient has low magnesium and potassium levels, but the larger issue is that they are not prioritizing a whole foods diet that would include these nutrients.
For most people, a balanced, whole foods diet and maybe a multivitamin is enough to get all of the micronutrients you need. If this is not the case, it’s important to consider factors like dietary balance, gut health, and possible absorption issues.
Symptoms, signs, and risk factors are generally better clinical tools when it comes to determining where micronutrient deficiencies may lie. Remember that lab testing is only about 25% of the information needed to make informed treatment decisions to improve your health.
Reason #2: Blood Tests Don’t Account for Absorption and Utilization by Your Cells
Blood tests can only detect the micronutrients floating around in your blood. In some cases, this may be misleadingly reassuring or may be a false alarm of a problem that doesn’t exist. And in most cases, there doesn’t seem to be a one-to-one relationship between dietary intake and serum levels of micronutrients.
Zinc is a good example of this issue. Zinc is an extremely important micronutrient for immunity, helping to create white blood cells that fight off illness. Deficiency is thought to be quite common, and it’s linked to numerous health conditions.
But, serum zinc testing is not very closely linked with health outcomes . It’s likely more beneficial to just supplement with zinc if you have symptoms of a deficiency, monitor for improvements, and investigate dietary and other reasons why you might have a deficiency in the first place.
Gut health is another important aspect to consider with absorption and utilization of micronutrients. Blood tests can not see whether you are low in a certain micronutrient because there is inflammation in the gut that is preventing good digestion and absorption of nutrients through the gut lining. Looking at and addressing any gut issues first is probably a better strategy to increase the absorption of micronutrients in the body.
Reason #3: Symptoms May Be More Indicative of Micronutrient Deficiencies
A skilled practitioner can identify potential micronutrient imbalances based on a thorough symptom evaluation and knowledge of clinical disease presentation. For example, if a patient presents with low energy, arrhythmia, and headaches or migraines, that’s enough of an indication that the patient may be low in magnesium.
To correct this, the practitioner can recommend foods that are higher in magnesium as well as magnesium supplements if needed. Then it’s just a matter of monitoring for improvements and reevaluating symptoms later on, no expensive testing required.
Reason #4: Micronutrient Requirements Vary Depending on Age, Sex, Medical History, Etc.
Often, doctors evaluate micronutrient levels based on standardized ranges for an “average” person. These ranges themselves can vary based on how the testing is processed and by what lab. But beyond that, micronutrient requirements vary greatly from, say, a teenage boy to a woman in her first trimester of pregnancy to a man in his 70’s. They can also change depending on the presence of chronic disease, stress levels, and environmental factors.
This can make testing very frustrating for those patients who show “normal” lab values, yet they still have symptoms of a micronutrient deficiency. In these cases, it makes more sense to evaluate micronutrient deficiencies based on symptoms rather than lab values.
Evaluating Micronutrient Tests
Let’s take a closer look at the research behind some of the common individual micronutrient tests that shows how easily they can be misinterpreted (and a few times where some of them can be diagnostically useful).
Only a small part of total body zinc levels are found in the serum (blood). Blood tests may be useful at a population level to study effects on a large scale, but they are an unreliable measure of zinc levels on an individual basis. Serum zinc levels can also vary slightly depending on the time of day and whether the person has eaten anything .
A meta-analysis (the highest quality of research available) of patients with acne found that these patients also had lower serum zinc levels. When they were treated with zinc, the acne improved. However, the baseline zinc levels of those with acne were not even considered marginally deficient according to other studies (96 μg/dL vs 102 μg/dL) .
Another trial of 200 pre-diabetics taking zinc supplements found that a lower percentage of participants developed Type 2 diabetes (11% vs 25%) at a 12-month follow-up even though they had normal zinc levels at baseline . This may be due to zinc’s antioxidant properties combating the oxidative stress associated with developing diabetes regardless of baseline levels .
We can see from these studies that supplementing zinc based on clinical outcomes rather than serum levels is recommended, safe, and beneficial.
Serum copper levels are one of the markers that really varies depending on sex, ethnicity, and age, making it difficult to interpret. One study found that serum copper concentrations in women were significantly higher than in men, and there were significant differences in serum zinc and copper levels with age .
It remains unclear whether low or high copper levels are associated with poor health effects. For example, a meta-analysis of eight studies with 2,188 subjects found that low copper levels were associated with osteoporosis . However, another study found the opposite result in regards to copper and fracture risk: Higher serum copper levels were significantly associated with increased total fracture, especially in men .
Basically, copper levels are inconsistent in their relation to certain health outcomes, and there isn’t strong enough evidence to suggest testing is useful. Most people should be getting enough copper through a balanced, whole foods diet.
One measurement that may be useful is a zinc:copper ratio, which has been linked to colorectal cancer and poor sleep quality [9, 10]. However, this ratio has not been studied enough to help make clinical decisions for patients.
Magnesium is one of the few micronutrients for which testing may have useful implications.
Still, only 0.8% of magnesium is found in the blood, and researchers concluded that serum magnesium could remain within the normal range in patients with chronic magnesium deficiency and should not be used to exclude deficiency .
Given that magnesium deficiency is relatively common compared to other micronutrient deficiencies, it is linked to so many negative health outcomes, and the symptoms are easily recognizable, it makes sense to recommend supplementation without needing to test blood levels.
Testing for B vitamins may be helpful. The B vitamins, including folate, B12, and B6, are linked to a marker called homocysteine, which is an amino acid that can become toxic in high amounts. High levels of homocysteine are a risk factor for cardiovascular disease [29, 30].
We know that high levels of homocysteine are a strong predictor of folate and B12 deficiency.
In a group of over 1,000 adults, two-thirds of those with high homocysteine had a deficiency of folate, B12, or B6 . Several other studies have also reinforced this finding [32, 33, 34, 35]. Knowing serum B vitamin and homocysteine levels can also be helpful in diagnosing pernicious anemia [36, 37, 38].
However, it’s unclear whether simply correcting these levels (through folic acid supplementation, for example) also results in clinical improvement in patients. In a meta-analysis of 15 randomized controlled trials and 71,000 participants, interventions to lower homocysteine did not result in a reduction in cardiovascular events or all-cause mortality .
This suggests that, instead of simply correcting the homocysteine level, more significant diet and lifestyle interventions are probably needed to reverse negative cardiovascular outcomes. In that sense, B vitamin/homocysteine tests are not an end-all-be-all indicator of heart and metabolic health.
The Bottom Line on Micronutrient Testing
Micronutrient testing is, unfortunately, less reliable than we might like it to be. It can also be very expensive and even become a distraction from evaluating and addressing your symptoms.
There are a few times when certain markers can be clinically useful, such as homocysteine and magnesium levels. But overall, there is not a clear one-to-one relationship between dietary intake and serum levels of micronutrients in most cases. Factors like absorption, utilization in tissues and organs, and excretion also need to be taken into account when assessing nutritional status.
When considering supplementation of any particular micronutrient, it’s much more clinically relevant to consider a person’s age, sex, health history, stress level, and environment, rather than rely solely on micronutrient testing. For someone in relatively good health, a whole foods diet and an optional good-quality multivitamin should be enough to ensure good micronutrient status.
Reach out to us at the Ruscio Institute for Functional Medicine and schedule a consultation to explore your diet and lifestyle options to increase your micronutrient intake.
The Ruscio Institute has developed a range of high quality formulations to help our patients and audience. If you’re interested in learning more about these products, please click here. Note that there are many other options available, and we encourage you to research which products may be right for you.
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