# Understanding Blood Values: Which Lab Markers Really Matter for Active People

> Which values are relevant for active people and what to take away from them.

Active people often face the challenge of interpreting their blood values correctly, since standard reference ranges do not always match their specific needs. This can lead to important nutrient gaps or health imbalances being overlooked. It is crucial to know which markers are particularly relevant for an active lifestyle and how to evaluate their values in the context of training and recovery.

## Micronutrients for Performance

Certain micronutrients are of great importance for physically active people. **Vitamin D** (25-OH vitamin D3) is essential for the immune system, muscle strength and mood. While the standard reference value is often set at above 20 ng/ml, active people aim for values between **40-70 ng/ml** to ensure optimal function. Another critical marker is **ferritin**, the body's iron store. Endurance athletes, women and vegetarians in particular have elevated iron needs. A ferritin value below 30 μg/l can already lead to performance losses; a target of **50-120 μg/l** is what to aim for here.

## Hormonal and Inflammatory Indicators

Hormonal and inflammatory markers provide important clues about health status and recovery capacity. **Fasting insulin** and the **HOMA-IR value** are key indicators of insulin sensitivity. A fasting insulin above 8-10 μIU/ml or a HOMA-IR above 2.0 can point to early insulin resistance, even when fasting glucose is within the normal range. **High sensitivity C-reactive protein (hs-CRP)** measures systemic inflammation. A value below 0.5 mg/L is ideal. Elevated values can indicate overtraining, lack of sleep or chronic stress and should be taken seriously.

## Fatty Acids and B Vitamins

The quality of fatty acids and the availability of B vitamins are also essential for the health of active people. The **omega-3 index**, which measures the share of EPA and DHA in red blood cells, should ideally be above **8%** to signal a low cardiovascular risk. Values below 4% are considered critical. Among the B vitamins, **holotranscobalamin** (active B12) is a far more meaningful marker than standard serum B12. A value below 35 pmol/l points to a deficiency, which should be corrected through supplementation, especially in vegans and vegetarians.

For comprehensive micronutrient coverage and recovery support, **[WOO® Vital Plus](/en/shop/woo-vital-plus-box)** can serve as a broad foundation. To optimize performance and support the immune system, **[WOO® Beetroot Powder](/en/shop/woo-beetroot-powder-bag)** is a good addition. Available in our shop.

## Frequently Asked Questions

**Which blood values are especially important for athletes?**
As an athlete, you should have vitamin D, ferritin, holotranscobalamin, magnesium (in red blood cells), fasting insulin, hs-CRP and the omega-3 index tested to get a comprehensive picture of your health.

**How often should I have my blood values checked?**
An annual baseline check is recommended. If you are actively supplementing or have a known deficiency, a follow-up measurement after about three months makes sense to verify effectiveness.

**Why is magnesium in red blood cells more meaningful than serum magnesium?**
The body regulates serum magnesium very tightly, so it often appears within the normal range even when there is an intracellular deficiency. Magnesium in red blood cells better reflects the actual cellular stores.

## Sources

Holick MF (2007), NEJM - Vitamin D Deficiency.
Peeling P et al. (2008), Sports Medicine - Athletic-Induced Iron Deficiency.
Calder PC (2015), Ann Nutr Metab - Omega-3 Fatty Acids and Inflammatory Processes.
Zava TT & Zava DT (2011), Nutr J - The Importance of Vitamin B12.

*WOO® Vital Plus in the NEMAPO shop.*