The New Normal: How A Naturopath Looks at Laboratory Testing for Optimal Health

Have you ever gone to your doctor feeling that something was off, but testing revealed that ‘nothing’ was wrong? At least nothing according to conventional medical diagnosis of disease and interpretation of laboratory test results… In naturopathic and functional medicine, however, we are taught to use laboratory testing (along with an in-depth physical exam and history) to detect subtle and early imbalances that precede what conventional medical providers deem abnormal.

Take for example, the case of iron deficiency, conventional medicine typically uses Hemoglobin and Hematocrit (and some other indices on a Complete Blood Count or CBC) to determine deficiency. However abnormalities in these tests do not typically appear until the fourth and final stage of low iron status and can take months (or in some cases, years) to develop. But what if by testing iron stores early on (ferritin and some allied testing) could catch a deficiency in the first stage and prevent its progression and the array of symptoms and health risks that accompany it? (And contrary to the widely held belief in conventional medicine, low iron stores do negatively impact well-being; patients report poor exercise tolerance, low motivation, apathy/dysthymia or depression, difficulty getting out of bed in the morning despite a full night’s sleep… and more.)

Another example, thyroid function is typically evaluated in conventional medicine with the TSH (or Thyroid Stimulating Hormone). But this test does little to evaluate how effective thyroid hormone conversion to its active form is and the impact of other health imbalances on thyroid function (including the impact of nutrient deficiencies (such as iodine, selenium, zinc and iron) thereupon). Further, conventional medicine’s normal range for TSH (typically 0.4- 5.0 mIU/mL) may be far from optimal (1.5-2.0 mIU/mL ). And with low thyroid negatively impacting fasting lipids (serum cholesterol and triglycerides), cardiovascular function and blood pressure, mood (it can lead to depression) and overall metabolic function (metabolic reactions depend on the stimulus to the metabolic rate that the thyroid imparts), having optimal thyroid function is critical!

We have yet another example with Vitamin B12, an important one in psychiatry and neurology. Conventional medicine deems anyone within a serum B12 level of less than 200 pg/mL as being potentially deficient in B12. However, optimal levels are more widely believed to be in the range of 500-700 pg/mL. There is also a condition termed SCCD, or Symptomatic Subclinical Cobalamin Deficiency, which is far more common than clinical deficiency and cannot be detected without evaluating other laboratory parameters and symptoms which are seldom checked by conventional providers. In SCCD, serum B12 is often not low yet, but early signs of Vitamin B12 (or cobalamin) deficiency are nonetheless present. With Vitamin B12’s importance in memory, cognitive function, neurological function, mood, gastrointestinal function, bone health and more, it becomes critical to detect deficiencies accurately and early in their progression. Studies also show that those with Vitamin B12 deficiency are 50-70% more likely to suffer from depression. Vitamin B12 deficiency is more common in those over 60 years of age, in those following a vegan diet, in individuals who have been on proton pump inhibitors long-term and in individuals suffering from malabsorption (Crohn’s disease, Celiac disease).

And for a final example, one that is particularly of interest at this time of year in the Pacific Northwest, is Vitamin D. There is still much to be learned about this vitamin and its many important functions, optimal levels and how to most effectively supplement and assess this nutrient. A standard range that is considered to represent normal vitamin D status in conventional medicine is 20-80 ng/mL, however studies show that optimal levels of calcium absorption (Vitamin D is required for proper absorption of calcium) may not occur until at least 32 ng/mL (80 nmol/L). There is also some evidence to suggest that evaluating Serum 25-hydroxyvitamin D may not be sufficient to evaluate how well an individual can convert less active forms of vitamin D to an active form that the body needs. (Those with a decreased capacity to detoxify, for example, may not convert vitamin D as effectively) so naturopaths and functional medical doctors often evaluate additional Vitamin D forms to ensure adequate conversion of this vitamin in the body.) With Vitamin D being important in immune function, cancer prevention, blood pressure regulation, bone health, muscle function and strength, gene transcription, and mood (according to some studies- perhaps for Seasonal Affective Disorder, in particular), maintaining optimal Vitamin D status becomes highly important for optimal health and disease prevention!

There are numerous examples akin to those above in the realm of both testing for nutrient status and for various medical imbalances and genetic polymorphisms that impact nutrient status and physiologic function. Why not work toward optimal physiologic functioning and nutrient status as you move forward on your path to health?


Gaby, A. (2011). Nutritional Medicine. Concord, NH: Fritz Perlberg Publishing.

Gropper, S., Smith, J. (2013). Advanced Nutrition and Human Metabolism. (6th ed.). Indepenence, KS: Wadsworth Publishing, Cengage Learning.

Higdon, J. & Drake, V.J. (2012). An Evidence-based Approach to Vitamins and Minerals. Health Benefits and Intake Recommendations. (2nd ed.). New York, NY: Thieme.

Ross, A. C., Caballero, B. , Cousins, R. J., Tucker, K.L. & Ziegler, T. R. (2014). Modern Nutrition in Health and Disease. (11th ed.). Baltimore, MD: Lippincott, Williams & Wilkins.

Zimmerman, M. (2001). Burgerstein’s Handbook of Nutrition. Micronutrients in the Prevention and Therapy of Disease. New York, NY: Thieme.


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