Ferritin

Physiological Role

Ferritin is a storage protein found in nearly every cell of the body. The highest concentrations occur in the liver, spleen and bone marrow. It acts as a biological vault: each molecule can sequester up to 4,500 iron atoms in a non-toxic form, ready to be mobilised.

The iron stored in this way fuels several vital functions. It forms part of haemoglobin (the red blood cell protein that carries oxygen to the tissues) and myoglobin (its equivalent in muscle). It also participates in the mitochondrial respiratory chain, the cellular mechanism that produces energy in the form of ATP.

Circulating ferritin, the fraction measured in the blood, represents only a small portion of total stores. A low level signals progressive depletion of reserves. An elevated level may reflect overload or an inflammatory response. This dual reading makes ferritin both a sensitive and nuanced marker.

Reference Ranges

These reference ranges are derived from scientific literature and may differ from your laboratory's reference values.

Source : WHO, Ferritin to assess iron status (2020)

Biological Significance

Ferritin is the first-line parameter for assessing iron status. Low values reflect depleted reserves and often precede a drop in haemoglobin. Tracking this marker over time helps identify a downward trend before it affects oxygen transport and energy production.

Elevated values require contextual interpretation. Ferritin is also an acute-phase protein: it rises in response to inflammation, regardless of actual iron status. Singular measures hs-CRP alongside ferritin to distinguish inflammation-driven elevation from genuine iron overload. The transferrin saturation coefficient (TSAT) completes this picture by assessing circulating iron.

In women of reproductive age, menstrual losses explain typically lower reserves. Singular factors this variable into interpretation and adjusts optimal ranges by biological sex. In men, values above the optimal zone warrant regular monitoring to observe trends.

The value of longitudinal tracking lies in early trend detection. A level that gradually decreases from one assessment to the next tells a more precise story than a single measurement. This sequential approach sits at the heart of the Singular philosophy.

Influencing Factors

Diet. Dietary iron intake directly affects reserves. Haem iron (red meat, offal, seafood) is absorbed two to three times more efficiently than non-haem iron (legumes, whole grains, spinach). Vegetarians and vegans have higher iron requirements due to this absorption difference.

Vitamin C. Vitamin C enhances non-haem iron absorption by converting it to a more assimilable form in the digestive tract. Consuming a vitamin C source at the same meal as an iron-rich food can increase absorption two- to threefold.

Absorption inhibitors. Tannins (tea, coffee), phytates (whole grains, legumes) and calcium consumed at the same meal reduce iron absorption. Spacing their intake away from iron-rich meals improves bioavailability.

Physical activity. Intense, prolonged exercise can lower iron reserves through several mechanisms: mechanical haemolysis (destruction of red blood cells from ground impact), sweat losses and transient post-exercise inflammation. Endurance athletes are particularly affected.

Menstrual cycles. Monthly blood loss is the leading cause of low reserves in women of reproductive age. Heavy cycles amplify this effect.

Inflammation. Any acute or chronic inflammation raises ferritin independently of actual iron stores. hs-CRP, measured by Singular in the same panel, helps contextualise the result.

Age and sex. Iron reserves naturally increase with age, particularly after menopause in women. Men typically have higher levels than women.

In the Singular Formula

Ferritin is one of the central parameters in Singular's personalisation engine. It determines whether iron (iron bisglycinate) is included in the formula and at what dosage. This decision relies on cross-referencing with TSAT and haemoglobin.

When both ferritin and TSAT fall in low zones, the engine activates iron at a reinforced dosage. It simultaneously increases vitamin C to enhance absorption. If ferritin is low but TSAT remains optimal, iron dosage is adjusted to an intermediate level. This cross-referenced approach avoids supplementing iron based solely on ferritin, which can be influenced by inflammation.

When ferritin, TSAT and haemoglobin all reach the optimal zone or above, iron is removed from the formula. Sufficient reserves do not require supplementation. If ferritin was not measured in the panel, iron is also excluded as a precaution.

Vitamin B9, vitamin B12 and vitamin B6 (P5P) participate in iron metabolism and red blood cell formation. They complement iron's role in supporting tissue oxygenation.

Singular measures ferritin, TSAT, haemoglobin and hs-CRP together in every panel. This cross-referenced approach distinguishes genuine iron insufficiency from inflammatory elevation and adjusts the formula with precision.

Scientific Studies

Frequently Asked Questions