It is not uncommon for there to be considerable differences between what you are told is “normal” for a blood test and what is ideal. The differences are big enough to impair health, even increase risk for numerous diseases, even death.
Here is why labs and your doctor often provide grossly misleading interpretations of blood tests and how you can decipher the real answers. Among the examples:
- Vitamin D—The lab says that blood levels of 25-hydroxy vitamin D should be between 10-30 ng/ml. How did they get that value? Easy: They tested the blood levels of many people who live indoors, wear clothes, and don’t consume foods like liver that contain vitamin D. No surprise: Testing a population deficient in vitamin D provides the appearance that low vitamin D blood levels prevail. The problem is that this deficient level is regarded as “normal”—it is not. We therefore aim for the ideal level which is 60-70 ng/ml based on observations such as maximal suppression of parathyroid hormone (PTH) and maximal avoidance of cancers.
- TSH—Lab reports state that a thyroid stimulating hormone, TSH, level should be 0.2-5.5 mIU/L. (Some labs specify 4.5 mIU/L as the upper limit of normal.) But why? Once again, populations were tested who were largely iodine-deficient and exposed to numerous thyroid toxins such as bisphenol A (BPA), perfluorooctanoic acid, and hundreds of others that we know from numerous toxicological studies have potential to disrupt thyroid status. In other words, the “normal” range for TSH was taken by surveying a diseased population. A TSH of 0.2-5.5 mIU/L may be the prevailing level, but that should not be interpreted to mean that it is the ideal level.
- HbA1c—Sometimes, “normal” is regarded as the level of a lab value that suggests that prescription medications are not yet necessary. But the lack of need for medication is far from being ideal. While lab reports tell us that a hemoglobin A1c (HbA1c) should be 5.7% or less, a level associated with increased cardiovascular death and health conditions from cataracts to fatty liver, we aim for a HbA1c level that erases all this excess risk: 5.0% or less.
The divide between what labs and doctors quote as “normal” and what is ideal varies with each and every blood test, as there is no one rule to follow to know what is ideal. For this reason, stay tuned to the conversations we have here, in the Undoctored world, and in my Undoctored Inner Circle.