Primary Causes & Action Plans

Iron and Ferritin

Iron deficiency causes brittle nails
Iron-deficient nails are pale and brittle. Iron repletion strengthens nails in 2-3 months.
Target Ferritin 50-150 ng/mL
Suggested Action Plan

Supplement iron glycinate 25-50 mg daily. Nails strengthen within 2-3 months as iron levels rise.

Biotin

Vitamin B7; deficiency causes brittle nails
Biotin supplementation strengthens nails. Most research uses 2.5 mg daily.
Target > 200 pg/mL
Suggested Action Plan

Supplement biotin 2.5-5 mg daily. Nails harden within 2-3 months in deficient individuals.

Zinc

Essential for keratin production; deficiency causes brittle nails
Zinc deficiency impairs nail growth. Supplementation strengthens nails.
Target > 70 mcg/dL
Suggested Action Plan

Supplement zinc 15-30 mg daily. Nails improve within 3 months.

Thyroid Panel (TSH, Free T4)

Thyroid dysfunction can cause brittle nails
Hypothyroidism slows nail growth and causes brittleness. Thyroid replacement strengthens nails.
Target TSH 1.0-2.5
Suggested Action Plan

If thyroid is low, replacement therapy strengthens nails. Retest 6-8 weeks after starting.

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Getting Started

1
Test Your Nail Health Biomarkers

Test iron, ferritin, biotin, zinc, thyroid. Identify which nutrient deficiency is causing brittleness.

2
Supplement Deficient Nutrients

If iron is low, supplement iron. If biotin is low, biotin 2.5-5 mg daily. Nails harden within 2-3 months.

3
Ensure Adequate Protein Intake

Nails are made of keratin (protein). Ensure 1.0-1.2 g protein per kg body weight daily.

4
Avoid Damage and Keep Hydrated

Protect nails from chemical exposure (wear gloves). Keep nails and cuticles hydrated with moisturizer.

5
Retest in 3 Months

Nails grow slowly (6 months for full nail renewal). Retest biomarkers in 3 months; nails should be visibly stronger by month 3-4.

Why I built this guide.

"Healthy nails reflect healthy metabolism. Nails strengthen as you correct underlying deficiencies."

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