Reference Biomarker Education Cardiovascular Health Metabolic Health Thyroid Health Vitamins & Minerals

Normal Blood Test Ranges by Age and Sex

Standard lab reference ranges tell you the minimum threshold. These tables show what is actually optimal — and where the two differ significantly.

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Lab reference range — the "not flagged" threshold
Clariti optimal — associated with best health outcomes

Why "normal" and "optimal" are different

Lab reference ranges are calculated statistically — they represent the middle 95% of a large population sample. Being "normal" means you're not an outlier, not that you're thriving. The tables below show both ranges side by side so you can see exactly where the gap lies.

Why Age-Adjusted Reference Ranges Matter

Standard lab reference ranges are derived from mixed adult populations. But several key markers change systematically with age: testosterone declines by 1–2% per year from age 30; eGFR naturally falls by ~1 mL/min/year from age 40; ferritin typically rises in women after menopause; and TSH upper limits are slightly more generous in older adults. Interpreting results against age-appropriate benchmarks prevents both over- and under-treatment.

Metabolic markers

Biomarker Lab Reference Clariti Optimal Unit
Fasting Glucose70–9975–90mg/dL
HbA1c<5.7%<5.4%%
Fasting Insulin2–252–8µIU/mL

Cardiovascular markers

Biomarker Lab Reference Clariti Optimal Unit
LDL Cholesterol<130<100mg/dL
HDL (Male)>40>60mg/dL
HDL (Female)>50>70mg/dL
Triglycerides<150<100mg/dL
hs-CRP<3.0<1.0mg/L

Thyroid markers

Biomarker Lab Reference Clariti Optimal Unit
TSH0.4–4.51.0–2.0mIU/L
Free T40.8–1.81.0–1.5ng/dL
Free T32.3–4.23.0–4.0pg/mL

Vitamins and minerals

Biomarker Lab Reference Clariti Optimal Unit
Vitamin D (25-OH)20–5040–60ng/mL
Ferritin (Male)24–33670–150ng/mL
Ferritin (Female)11–30750–100ng/mL
Vitamin B12200–900500–900pg/mL
Magnesium1.7–2.22.0–2.2mg/dL

The Difference Between Normal-for-Age and Optimal

Age-adjusted ranges tell you what is statistically typical for your age group — not what is ideal. A testosterone of 320 ng/dL is within range for a 65-year-old, but the man may have significant symptoms of deficiency that would respond to treatment. Optimal values represent what is associated with best health outcomes in research — not just what the average person has.

Kidney markers

Biomarker Lab Reference Clariti Optimal Unit
Creatinine (Male)0.74–1.350.8–1.1mg/dL
Creatinine (Female)0.59–1.040.6–0.9mg/dL
eGFR>60>90mL/min/1.73m²
BUN7–2510–18mg/dL
Uric Acid (Male)3.4–7.03.5–5.5mg/dL

Optimal ranges are based on functional medicine research and may differ from your lab's reference ranges. This table is for educational purposes only. Always consult your doctor for medical advice.

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Medical Disclaimer

This article is for educational purposes only and does not constitute medical advice. Reference ranges, supplement dosages, and nutritional information mentioned are general educational guidance from published research—not personalised recommendations. Do not use this content to self-diagnose or self-treat any condition. Always consult a qualified healthcare provider before making any changes to your health regimen, medications, or supplements.

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