Before starting an altitude training block (real or simulated), testing key vitamins and minerals is crucial to ensure optimal physiological adaptations, prevent deficiencies, and maximise performance gains like increased hemoglobin mass (Hbmass) and VO2 max. Altitude exposure triggers hypoxia, boosting red blood cell production but increasing demands on certain nutrients. Deficiencies can lead to suboptimal results, fatigue, or health risks like anemia. Based on sports science recommendations, focus on these priorities, ideally tested 8–10 weeks in advance via blood work (e.g., serum ferritin for iron).

Consult a sports nutritionist or doctor for personalised testing.

1. Iron (Ferritin Levels)

• Why Important: Iron is the top micronutrient for altitude training, as hypoxia stimulates erythropoietin (EPO) and red blood cell production, which requires iron. Low levels can hinder adaptations, cause anemia, or reduce efficiency. Supplement if ferritin <30–100 ng/mL (threshold varies by gender/athlete status), starting 2–3 weeks before.
• How to Test: Blood test for serum ferritin, total iron-binding capacity (TIBC), and transferrin saturation. Aim for ferritin >100 ng/mL for optimal response.

2. Vitamin C (Ascorbic Acid)

• Why Important: Enhances iron absorption, combats oxidative stress from altitude-induced free radicals, and supports immune function during training stress. Pairing with iron supplements can improve efficacy.
• How to Test: Serum vitamin C levels; deficiency is common in athletes under stress.

3. Vitamin D

• Why Important: Vital for bone health, muscle function, and immune support; altitude can exacerbate deficiencies due to reduced sun exposure or increased demands. Low levels may impair recovery and performance.
• How to Test: 25-hydroxyvitamin D blood test; aim for >30–50 ng/mL.

4. Vitamin E and Other Antioxidants (e.g., Beta-Carotene, Selenium, Zinc)

• Why Important: Altitude increases oxidative stress; these protect cells, reduce inflammation, and support adaptation. Vitamin E is highlighted for altitude-specific benefits, while zinc/selenium aid immune and thyroid function.
• How to Test: Serum levels for vitamin E, selenium, zinc; include in a comprehensive micronutrient panel.

5. B Vitamins (Especially B6, B12, Folate)

• Why Important: Essential for energy metabolism, red blood cell formation, and nerve function; deficiencies can worsen fatigue at altitude.
• How to Test: Serum B12, folate, and B6 levels.

6. Magnesium and Calcium

• Why Important: Magnesium supports muscle/nerve function and energy production; calcium for bone health. Altitude stress can deplete them.
• How to Test: Serum magnesium and calcium; consider RBC magnesium for accuracy.