top of page

Why you need True (optimal) Lab range ? (Why Normal Lab Test Ranges are not helpful ?)

Updated: Apr 24, 2022

If your blood test results are coming in the range or called normal range , does it confirm that you are your health is ok ?

As we go into deeper insights the answer is No, but why ?

Because your lab test results are coming within the normal range but they may not optimal for your general wellbeing, your performance indicators, your mental health indicators, your ageing progression etc. It has seen in many tests, when values falling within the normal biological reference range but has increased risk of particular diseases and even mortality. This is the reason why its is very prime and necessary to know and establish Optimal / True ranges of blood tests.

Now know why we are saying like this ? that why Normal blood tests ranges does not mean everything is ok nothing wrong , and here we let you know that which particular lab test marker have misleading normal ranges ?

Why normal test ranges can be misleading and not helpful ?

As per the data normal ranges are the values , where almost 95% of healthy populations falls, which help clinicians to make diagnosis, monitoring & treatment protocols but it does not tell that what is your True Range ( optimal range ) to stay healthy.

In various cases normal biological reference ranges are generated or created on the basis of significant unhealthy population numbers, and it does not reflect a healthy population.

Additionally , we can say that, Normal ranges usually established without taking in consideration of large population based research that links the close relation of certain diseases & mortality with Certain Ranges.

Its because , that there is not sufficient evidence based research for causative link between true / optimal level and health to guide way forward in decision making.

Also you need not to look lab test results value in isolation , your clinician look at it as whole & derive from your lab test value, your clinical symptoms, medical history, imaging studies, other tests, clinical acumen & may prescribe further tests if required.

Lab Test Marker which has Misleading Normal Biological Reference Ranges


Folic Acid / Folate blood test which has unhelpful biological reference range. This vitamin is required for DNA synthesis, RBC maturation, cell growth & proper brain development. Additionally it also helps to decrease the level of Homocysteine , as Homocysteine increased the risk for heart disease.

Most diagnostic labs has lower limit of 03 ng/mL to diagnose folate deficiency, but Researcher have suggested to raised this lower limit to 13 ng/mL. (1)

Research suggests true (optimal) levels are much higher than the established normal range. In one such study on 28800 individuals, levels below 17ng/mL has increased mortality rate . (2)

Another study on 1921 individuals reveal that level above 9.6 ng/mL has lowest risk of heart disease. (3)

39% reduced risk of lung cancer seen in individuals with levels above 11.3 ng/mL compare to levels below 7ng/mL (4)

Now , all this tells us that , the true (optimal) lower limit for folate is very much higher than the current normal lower limit, that the reason why shouldn’t rely on the established normal range to determine if your lab test levels are truly healthy.

Thus, vegetables & fruit intake is directly linked to folate levels & its not astonishing that, lower folate levels have linked with adverse health conditions.


Hormone T3 & T4 is produced in Thyroid gland by TSH which is released by Pituitary Gland. The Normal biological reference range of TSH is quite debated by researchers and most diagnostic labs follows Normal reference range between 0.4 and 6 mIU/L but many scientists recommends that upper limit must be brought down to between 2.5 and 3 mIU/L and they sited reason for this is that, levels above 2.5 mIU/L increases the risk of sub clinical thyroid (Hypothyroidism) and even mortality, (5, 6, 7, 8, 9)

Another reason is that the population used to create the original normal range contained a significant number of people with undiagnosed autoimmune thyroid disease. This led to higher TSH levels that don’t represent a truly healthy population. Indeed, recent studies have found that carefully-screened groups without thyroid dysfunction suggest an upper normal limit between 2.1 and 3.7 mIU/L [10, 11, 12, 13, 14 ).

Now you know that, a TSH value within the normal range does not always mean your thyroid is functioning optimally. Consult to your clinician if your TSH levels are on the high end of the range. Your clinician will interpret this test, taking into account your medical history and other test results.


Published with prior permission and approval from LabAnalyst (originally published in About the Author

Sk Sharad Mishra

Bsc, B. Pharmacy, Advance Diploma in Nutrition, Diploma in Sports Nutrition, Certificate course in Competitive Edge in Management by ICMS, Sydney.

More than 18 years of experience in Medical Lab Diagnostic, Lab Diagnostic Expert, Lab Franchise Consultant, Clinical Pharmacist, Author of “Diagnostic Predicament”, Chief Educator at Labaxy Diagnocademy. Believe in Simplicity & on a Mission to Improve Lives.

Disclaimer :

Our team have produced this piece of public information in form of this article is based on various research and we have tried to interpret all these studies best in public interest and tried to provide the link of these research. We followed strictest norms to avoid any science based error even if you find that it has some error , please do report to us at

44 views3 comments

3 comentários

Avaliado com 0 de 5 estrelas.
Ainda sem avaliações

Adicione uma avaliação
starindia electricals
starindia electricals
25 de jan. de 2022

starindia electricals
starindia electricals
25 de jan. de 2022
Respondendo a


starindia electricals
starindia electricals
25 de jan. de 2022

<a href="">Module Box Suppliers</a>

<a href="">Starindia Electricals</a>