Ferritin

Why It Matters

Ferritin is a protein that stores iron. It makes iron available for essential cellular processes while protecting lipids, proteins, and DNA from potential iron toxicities. (source)

Low Ferritin: Depleted Iron Reserves

Low serum ferritin levels can stem from physiological factors such as impaired iron absorption in the gastrointestinal tract and inadequate iron storage in the liver and bone marrow. From a nutritional perspective, a diet lacking in iron-rich foods and poor absorption due to low stomach acid, or certain dietary components can also contribute to decreased ferritin levels. (source, source)

Potential Performance Impact:

• Reduced oxygen-carrying capacity limits endurance and VO2max ceiling
• Depleted iron reserves impair mitochondrial energy production, accelerating fatigue under load
• Compromised red blood cell turnover slows recovery between training sessions
• Suboptimal ferritin blunts neurotransmitter synthesis, reducing cognitive sharpness and reaction time

Optimization

Prioritize iron-rich foods: Consumption of iron has been shown to increase serum ferritin concentrations. (source, source, source) Ferritin stores iron, so increased intake of iron increases ferritin levels in the body. (source, source)

Protocol: Consume at least two servings of iron-rich foods weekly.

One serving examples: Liver (3 oz), Oysters (3 oz), Lentils (1 cup), Pumpkin Seeds (1 oz)

Food Journal: Low energy availability is associated with decreased iron saturation. (source) Food journaling can ensure adequate energy consumption, especially during high-intensity training blocks.

Protocol: Write down the types and amounts of food consumed throughout the day and calculate the daily calories. This will help ensure adequate caloric intake.

Supplement with iron: Iron supplementation has been shown to increase serum ferritin concentrations. (source, source, source) Ferritin stores iron, so increased intake of iron increases ferritin levels in the body. (source)

Protocol: Supplement with at least 9 mg of elemental iron daily.

High Ferritin: Excess Iron Storage

High serum ferritin levels can often stem from physiological factors related to iron metabolism and storage, which are primarily regulated by the liver. Nutritionally, excessive intake of iron-rich foods or supplementation can contribute to elevated ferritin levels. (source, source)

Potential Performance Impact:

• Excess stored iron promotes oxidative stress, damaging cellular structures and accelerating tissue breakdown
• Iron overload triggers chronic low-grade inflammation that impairs recovery and training adaptation
• Elevated ferritin signals potential organ stress, particularly in the liver, which compromises detoxification capacity
• Surplus iron can interfere with zinc and copper absorption, disrupting enzymatic processes critical to performance

Optimization

Prioritize dark leafy green vegetables: Consumption of dark leafy green vegetables has been shown to reduce ferritin levels. These foods contain compounds called oxalates that can inhibit iron absorption, thus lowering the body's ability to store iron in ferritin molecules. (source)

Protocol: Consume at least two servings of dark leafy green vegetables daily.

One serving examples: Spinach (1 cup), Kale (1 cup), Broccoli (1 cup), Bok Choy (1 cup), Collard Greens (1 cup)

Donate blood: Blood donation has been shown to help reduce ferritin. Donating blood reduces total red blood cell and iron count, thus reducing ferritin levels, as there is less circulating iron to store. (source)

Protocol: Begin donating blood on an approved frequency guided by your local donation clinic.

Avoid iron: Iron supplementation has been shown to increase ferritin levels. (source) Ferritin stores iron, so increased intake of iron increases ferritin levels in the body. (source) Limiting the intake of iron will decrease ferritin levels.

Protocol: Monitor excess iron intake. Avoid iron-containing supplements.

Supplement with quercetin: Quercetin has been shown to inhibit iron absorption. (source, source) Quercetin binds iron within the intestines, preventing uptake into the bloodstream. It also downregulates the protein ferroportin, which plays a key role in iron export into the blood. (source) Consuming quercetin decreases ferritin by decreasing the amount of iron in the blood.

Protocol: Supplement with at least 200 mg of quercetin.