Many people think they’re healthy because their “blood test was ok”. 

The problem, however, is that most blood tests are not ideal tools to fully assess your health. 

Blood tests are often ok to track serious problems, like leukemia, kidney failure, liver problems or infections like pneumonia, appendicitis and pancreatitis. These are serious diseases, and because they are so grave they can show blatant abnormalities in a blood test. 

But to assess overall health, and to track down deficiencies that in the long term can significantly undermine your health, blood tests are not ideal (we explain more about the best supplements for optimal longevity here and here).

Why blood tests are rudimentary

Blood tests have various shortcomings. First of all, they often are not very good in detecting deficiencies of various minerals.

It is often the case that you can be deficient in magnesium, vitamin B12, iodine, calcium and other minerals and vitamins, while still having “normal” levels of these according to your blood test. 

For example, magnesium is measured in the blood serum, but most magnesium is found in the cells and in the fluid between the cells, not in the blood. So you can have “normal” magnesium levels, but still be magnesium deficient. 

In other words, a blood test is not ideal to track down deficiencies. Nonetheless, sometimes a blood test can find a deficiency, which makes it indeed likely that you are deficient.

However, finding no deficiency does not mean everything is ok. 

There are some exceptions, like vitamin D levels. Deficiencies of vitamin D can be tracked relatively accurately with a blood test.

But then there is another problem: the cut-off values most labs use are too low.

They will say your vitamin D levels are “good” because they are higher than 20 or 30 ng/ml. But studies show that ideally vitamin D levels should be much higher for optimal health, like 50 ng/ml, or even 90 to 150 ng/ml. 

Despite their limitations, blood tests can still be interesting

Blood tests can still be interesting to find out other problems than vitamin or mineral deficiencies, such as metabolic issues. Interesting metabolic blood test biomarkers to measure are total cholesterol, LDL, HDL (and their ratios), fasting triglycerides, fasting insulin, fasting glucose and HbA1c. 

However, keep in mind that many people (up to 70 percent) who end up in the hospital with a heart attack have normal cholesterol, LDL or HDL levels, indicating that many other things (which are not measured in a standard blood panel) contribute to heart disease risk, such as low-grade inflammation (e.g. high levels of TNF-alpha, IL-6, IL-1, etc), the size of the cholesterol particles, the amount of glycation, the health of the endothelial cells that line the blood vessel walls, and so on. 

So what are some of the most interesting and practically helpful blood tests you can do? 

14 important blood biomarkers to test for

1. Fasting insulin

A measure of insulin resistance. This is an interesting blood biomarker. The lower the fasting insulin levels, the better.

Increased insulin resistance plays a role in many aging-related diseases, such as cardiovascular disease, Alzheimer’s disease, and type 2 diabetes.

Increased insulin resistance accelerates aging.

“Fasting” means at least a 9 to 12 hour fast before the blood is drawn in the morning – so no breakfast or other food before the blood draw.

2. Fasting glucose

Higher than normal fasting glucose levels could be a sign of an unhealthy metabolism, or even worse: pre-diabetes or diabetes.

3. HOMA-IR (Homeostatic Model Assessment of Insulin Resistance)

Ideally, this value is also calculated. It’s a more accurate measure of insulin resistance and glucose metabolism, taking into account fasting insulin levels and fasting glucose levels.

4. HDL cholesterol, LDL cholesterol and total cholesterol ratios

These are biomarkers to assess cardiovascular risk.

However, people can have normal HDL, LDL or cholesterol levels, but still have an increased risk of heart disease.

Therefore, ideally, also the diameter of cholesterol particles is measured (smaller cholesterol particles are more dangerous given they can get into the blood vessel walls more easily), and how much cholesterol particles are oxidized and glycated (the more oxidized and glycated the cholesterol particles are, the more dangerous), but these tests are not readily available.

Low-grade smoldering inflammation can also increase the risk of heart disease. Therefore, us-CRP, a measure of inflammation, would also need to be measured (see further below).

Keep in mind that when the good cholesterol (HDL) rises, your total cholesterol also rises, so don’t panic if your total cholesterol is too high: look at the ratio of total cholesterol versus HDL cholesterol: the lower, the better.  

5. HbA1c

A measure for glycation. The more glycation, the faster the body ages and the higher the risk of aging-related diseases.

6. Fasting triglycerides

To assess cardiovascular risk. Triglycerides are fats circulating in your blood. Some cardiologists believe that fasting triglycerides are a bigger risk factor for heart disease than increased cholesterol levels.

7. Vitamin B12

Is often measured in the blood. However, often vitamin B12 levels can be normal while one still can be deficient. It’s better to measure the vitamin B12 metabolite methylmalonic acid in the urine to get a view of vitamin B12 status.

Despite this, people can have normal methylmalonic acid levels, but still be deficient.

Also, vitamin B12 levels can be “normal” but one can still be deficient in many other B vitamins, like vitamin B1, vitamin B2, vitamin B5, folic acid, vitamin B6 and so on.

8. Thyroid-stimulating hormone (TSH)

This biomarker is used to detect thyroid abnormalities, including the most common manifestation, hypothyroidism (a slow thyroid gland).

Most labs use a cutoff value of 4 mU/L (above 4 mU/L is indicative of hypothyroidism). With that said, many endocrinologists believe that TSH levels should be at least below 2.5 mU/L.

However, still be skeptical: TSH can often be normal in people, but they can still be iodine deficient (as happens a lot in people who consume a Western diet). It’s better to do an iodine challenge test and collect the amount of iodine in the urine during 24 hours, but most MDs have no experience with this test. 

9. Homocysteine

Deficiencies in vitamin B12 and other B vitamins can lead to increased homocysteine, which leads to insufficient methylation in the body, which can be negative for health and increase risk of heart attacks and stroke, among other diseases.

10. High sensitivity or ultra-sensitive C reactive protein (hs-CRP)

A measure of inflammation. Low-grade inflammation accelerates aging and increases the risk of aging-related diseases.

11. The levels of tumor markers like prostate-specific antigen (PSA), CEA, CA13, CA125

These can vary a lot among people. However, keeping track of whether they increase or not (instead of focusing on just a one-time measurement/baseline level) could be more interesting to see if there is a tumor growing. This can be especially useful for PSA in males, given prostate cancer is very prevalent. In the future, more advanced methods will be developed to diagnose cancer much earlier via a simple blood test.  

12. Cortisol

Cortisol levels are often measured in the blood. However, it’s better to measure cortisol levels in the urine, collected over a period of 24 hour, to have a better idea of the total daily cortisol production.

13. Magnesium and other mineral and vitamin levels

The levels of these minerals are often measured in the blood. However, these are often inaccurate measurements. People can have normal magnesium levels (and other normal levels of vitamins and minerals) and can still be deficient in these substances. The best way/test to see if you are deficient in specific vitamins and minerals is by taking them in appropriate dosages for at least 90 days and seeing if you notice an improvement.

14. Iron levels

Iron deficiency can be measured in multiple ways, like looking at iron levels, proteins involved in iron metabolism and transport (transferrin, ferritin), and the size and amount of red blood cells, as defined by for example MCV (mean corpuscular volume), RDW (red cell distribution width), or HCT (hematocrit – the amount of red blood cells).

However, it is possible to have “normal” iron biomarkers, but to still be iron deficient.

Also, when the size and amount of red blood cells decreases (they need iron to be produced), the iron deficiency is often already (very) severe and long-standing.

Be skeptical of blood test values

The cut-off values that labs use are not the ideal cut-offs values: they are often based on population averages.

In other words, if many people are deficient in a specific biomarker, often such levels will be considered as “normal”.

Additionally, the cut-off values are often based on disease outcomes: if they are below or above a specific cut-off value, you can become (very) ill.

But these cut-offs are often not based on optimal values for a long, healthy life. Learn more here about optimal levels and doses of the most important health supplements here. 

We believe that there are other, innovative tests to holistically assess your overall aging process and health, like for example epigenetic tests, skin aging tests, and comprehensive health questionnaires, the latter two which you can already try out here.

NOVOS will make various tests available to its subscribers soon!

Learn more about the anti-aging supplement NOVOS Core