Trace Minerals: Iron and Copper – Functions, Sources, Deficiency, and Toxicity

Trace Minerals: Iron and Copper

Iron (Fe)

Iron is an essential trace mineral required for various physiological functions, particularly in oxygen transport and cellular metabolism.

• Main Body Functions:

  • Component of hemoglobin (in red blood cells) and myoglobin (in muscle cells).

  • Major role in oxygen transport in the blood and muscles.

• Recommended Dietary Allowance (RDA):

  • Males (15-50): 8 mg

  • Females (15-50): 18 mg

• Upper Limit (UL): 45 mg

Food Sources

• Meat and animal products (heme iron)

• Plant products (non-heme iron)

Absorption

• Heme iron (from animal sources) is absorbed more efficiently than non-heme iron (from plant sources).

• Absorption is enhanced by Vitamin C and Factor: Vitamin C.

• Absorption is limited by factors such as phytates, polyphenols, and calcium.

Deficiency

• Iron Deficiency Anemia:

  • Low hemoglobin and red blood cell count.

  • Symptoms: Fatigue, weakness, pale skin, impaired cognitive function.

• At-Risk Groups: Vegetarians, vegans, menstruating women, and individuals with increased iron requirements.

Excess/Toxicity

• Symptoms: Nausea, vomiting, diarrhea, constipation, organ damage.

• High iron intake can be toxic, especially in children.

Table: Iron – Sources, Deficiency, and Toxicity

Food Sources	Deficiency	Excess/Toxicity
Meat, animal products, plant products	Iron deficiency anemia: fatigue, pale skin, weakness	Nausea, vomiting, diarrhea, constipation, organ damage

Example

• Vegetarian females are at greater risk for anemia due to lower intake and absorption of heme iron.

• Combining plant-based iron sources with vitamin C-rich foods enhances absorption.

Key Terms

• Heme iron: Iron from animal sources, highly bioavailable.

• Non-heme iron: Iron from plant sources, less bioavailable.

• Iron deficiency anemia: Condition caused by insufficient iron, leading to reduced oxygen transport.

Copper (Cu)

Copper is a trace mineral that acts as a cofactor for many enzymes and is essential for iron metabolism and connective tissue formation.

• Main Body Functions:

  • Cofactor for enzymes involved in energy metabolism.

  • Assists in iron transport in the blood.

  • Required for collagen and elastin synthesis.

  • Regulates gene expression and antioxidant defense.

• Recommended Dietary Allowance (RDA): 900 μg (15-50 years)

Food Sources

• Organ meats, seafood, nuts, seeds, whole grains.

Absorption

• Absorption can be limited by high intakes of zinc and iron, as well as vitamin C.

Deficiency (Rare)

• Can impair hemoglobin synthesis, leading to anemia.

Excess/Toxicity

• Not a major concern under normal dietary conditions.

Table: Copper – Sources, Deficiency, and Toxicity

Food Sources	Deficiency	Excess/Toxicity
Organ meats, seafood, nuts, seeds, whole grains	Impaired hemoglobin synthesis, anemia	Not a concern

Key Terms

• Cofactor: A non-protein chemical compound required for enzyme activity.

• Hemoglobin synthesis: The process of producing hemoglobin, dependent on both iron and copper.

Example

• High zinc supplementation can reduce copper absorption, potentially leading to deficiency.

Additional info:

• Iron and copper metabolism are interrelated; copper is necessary for iron transport and utilization.

• Both minerals are essential for healthy blood and connective tissue.