The 10 Most Important Blood Biomarkers to Track

Why These 10 Biomarkers Matter Most

Your blood contains hundreds of measurable markers, but not all are equally important for long-term health. After reviewing the medical literature and consulting with longevity researchers, we've identified the 10 biomarkers that provide the most actionable insights into your health trajectory.

These markers collectively cover cardiovascular risk, metabolic health, inflammation, immune function, thyroid health, and nutritional status. Tracking them consistently gives you an early warning system for the diseases that kill most people: heart disease, diabetes, cancer, and neurodegenerative conditions.

You can track all of these on your VitaDash biomarker dashboard with a single blood test upload.

1. Vitamin D (25-Hydroxyvitamin D)

Optimal range: 40–60 ng/mL

Vitamin D is far more than a bone-health nutrient. It functions as a hormone that influences immune regulation, mood, cardiovascular health, and cancer risk. Nearly 42% of American adults are deficient (below 20 ng/mL), and many more are suboptimal.

Low Vitamin D is associated with increased risk of autoimmune disease, depression, cardiovascular events, and certain cancers. Most people need 2,000–5,000 IU of Vitamin D3 daily to maintain optimal levels, especially if they live above the 37th parallel or have darker skin. For a deep dive, read our complete Vitamin D guide.

2. LDL Cholesterol

Optimal range: Below 100 mg/dL (below 70 if high cardiovascular risk)

LDL cholesterol is the primary driver of atherosclerosis — the buildup of plaque in artery walls that causes heart attacks and strokes. The relationship between LDL and cardiovascular disease is one of the most well-established in all of medicine, supported by genetic studies, randomized trials, and epidemiological data spanning decades.

What matters most is not a single reading but your cumulative lifetime exposure to LDL. Every year spent with elevated LDL adds to arterial plaque burden. This is why early detection and intervention matter so much.

3. HDL Cholesterol

Optimal range: Above 50 mg/dL (women), above 40 mg/dL (men)

HDL cholesterol performs "reverse cholesterol transport" — it picks up excess cholesterol from artery walls and returns it to the liver for disposal. Higher HDL levels are consistently associated with lower cardiovascular risk.

The best ways to raise HDL include regular aerobic exercise, moderate alcohol consumption (if you already drink), consuming healthy fats (olive oil, avocados, nuts), and losing excess body fat. Importantly, HDL raised artificially by drugs has not shown benefit in clinical trials — the HDL you build through lifestyle is what counts.

4. HbA1c (Glycated Hemoglobin)

Optimal range: Below 5.5%

While fasting glucose gives you a snapshot of blood sugar at a single moment, HbA1c reveals your average blood sugar over the past 2–3 months. It measures the percentage of hemoglobin proteins that have been glycated (coated with sugar).

• Below 5.7% — Normal
• 5.7–6.4% — Prediabetes
• 6.5% or above — Diabetes

HbA1c is crucial because chronically elevated blood sugar damages blood vessels, nerves, kidneys, and eyes — often silently for years before symptoms appear. Catching an upward trend at 5.5% gives you years to intervene before prediabetes develops.

5. High-Sensitivity C-Reactive Protein (hs-CRP)

Optimal range: Below 1.0 mg/L

CRP is produced by the liver in response to inflammation. The high-sensitivity version of this test detects the low-grade chronic inflammation that drives aging, cardiovascular disease, and cancer.

• Below 1.0 mg/L — Low cardiovascular risk
• 1.0–3.0 mg/L — Moderate risk
• Above 3.0 mg/L — High risk (rule out acute infection first)

Elevated hs-CRP is one of the strongest independent predictors of heart attack and stroke, even in people with normal cholesterol. Anti-inflammatory strategies — omega-3 fatty acids, Mediterranean diet, exercise, adequate sleep, and stress reduction — can meaningfully lower CRP.

6. TSH (Thyroid-Stimulating Hormone)

Optimal range: 0.5–2.5 mIU/L

Your thyroid controls metabolic rate, energy production, body temperature, mood, and weight regulation. TSH is the primary screening test — when the thyroid underperforms, the pituitary gland raises TSH to stimulate more hormone production.

The standard lab range goes up to 4.0 or even 5.0 mIU/L, but many endocrinologists and functional medicine practitioners consider values above 2.5 as suboptimal. If your TSH is trending upward over time — even within "normal" range — it may warrant further investigation with Free T4, Free T3, and thyroid antibody testing.

7. Ferritin

Optimal range: 40–150 ng/mL (women), 40–300 ng/mL (men)

Ferritin reflects your body's iron stores. It's the most sensitive early marker of iron deficiency — ferritin drops long before hemoglobin falls and anemia develops.

Low ferritin causes fatigue, brain fog, hair loss, restless legs, and exercise intolerance, even when hemoglobin is still technically "normal." This is an incredibly common issue in premenopausal women, with some studies suggesting up to 30% have suboptimal ferritin.

On the flip side, very high ferritin (above 300–500) can indicate iron overload, chronic inflammation, liver disease, or hemochromatosis — a genetic condition affecting 1 in 200 people of Northern European descent.

8. Creatinine and eGFR

Optimal range: Creatinine 0.7–1.2 mg/dL; eGFR above 90 mL/min

Your kidneys filter 200 liters of blood every day, and creatinine is the key marker of how well they're doing it. eGFR (estimated glomerular filtration rate), calculated from creatinine, provides a more intuitive measure of kidney function as a percentage of normal capacity.

Kidney disease is called the "silent killer" because it can progress to advanced stages without any symptoms. By the time symptoms appear, significant irreversible damage has occurred. Regular monitoring is especially important for people with diabetes, hypertension, or a family history of kidney disease.

9. Liver Enzymes (ALT and AST)

Optimal range: ALT below 25 U/L (men), below 22 U/L (women); AST similar

Standard lab ranges for liver enzymes go up to 40–55 U/L, but research suggests that even mildly elevated values within the "normal" range are associated with increased cardiovascular and liver disease risk. Some experts advocate for tighter optimal ranges.

ALT is more specific to the liver, while AST can also come from muscle damage (including after intense exercise). The most common cause of mildly elevated liver enzymes today is non-alcoholic fatty liver disease (NAFLD), which affects roughly 25% of adults globally and is strongly linked to metabolic syndrome.

10. Complete Blood Count (CBC) — White Blood Cells and Red Blood Cells

Optimal ranges: WBC 4,000–7,000/μL; RBC, hemoglobin, and hematocrit within sex-specific ranges

The CBC is the most comprehensive single blood test. White blood cell counts that are consistently elevated (even in the upper normal range of 7,000–10,000) are associated with higher cardiovascular risk and all-cause mortality. Meanwhile, red blood cell parameters reveal anemia, nutritional deficiencies (iron, B12, folate), and bone marrow health.

Pay attention to red cell distribution width (RDW) — this often-overlooked marker measures variation in red blood cell size. Elevated RDW is independently associated with increased mortality and accelerated biological aging, and it's one of the nine biomarkers used in the PhenoAge biological age algorithm.

How Often Should You Test?

For most healthy adults, testing these biomarkers every 6–12 months is sufficient. If you're actively working to improve a specific marker (lowering LDL, optimizing Vitamin D, etc.), testing every 3 months lets you see whether your interventions are working.

The key is consistency: test at the same time of day, with the same fasting status, and track your trends over time. That's exactly what VitaDash is built for — check our pricing plans to find the right option for you.

Ready to understand your blood work? Upload your blood test for free and get AI-powered insights in under 2 minutes.

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This article is for informational purposes only and does not constitute medical advice. Always consult your healthcare provider before making health decisions.