Minerals Metabolism and Trace Elements

Minerals Metabolism Overview

• The human body comprises macroelements (e.g., magnesium, calcium, potassium, phosphorus) and trace elements (e.g., zinc, copper, iodine, selenium).
• Deficiencies in trace elements can lead to various diseases in humans and animals.

Magnesium (Mg2+)

• Acts as a critical intracellular cation (ICF), with a total body content of approximately 25g.
• 60% of body magnesium is complexed with calcium in bones; 1/3 is exchangeable with serum magnesium.
• Functions:
  • Activates numerous enzymes that require ATP, including alkaline phosphatase and hexokinase.
  • Plays roles in carbohydrate, nucleotide, nucleic acid, and amino acid metabolism.
  • Essential for protein synthesis, muscle activation, hormone receptor binding, cardiac excitability, and neurotransmitter release.
• Regulation:
  • The kidneys are key regulators, balancing magnesium through filtration and reabsorption.
  • Normal intake ranges from 300-350 mg/day, with 100-150 mg/day excreted in urine, maintaining equilibrium.
• Hypomagnesemia (magnesium deficiency) leads to symptoms like weakness, muscle cramps, and confusion; associated with several health conditions.
• Toxicity can lead to hypermagnesemia, primarily in cases of renal failure or excess antacid intake.

Potassium (K+)

• The human body contains about 250g of potassium, primarily within cells (ICF).
• Functions:
  • Maintains plasma volume and contributes to muscle contraction.
  • Requires 14 mg of potassium to store 1g of glycogen in the liver/muscles.
• Normal serum potassium levels range from 3-5 mEq/L.
• Hypokalemia (potassium deficiency) can occur due to vomiting, diarrhea, or diuretic use; symptoms include muscular weakness and paralysis.
• Hyperkalemia occurs in renal failure and severe dehydration; symptoms can involve weakness and cardiac issues.
• Good sources include oil seeds, eggs, meat, vegetables, and fruits. RDA is 2.3g/day.

Chloride (Cl-)

• The body contains approximately 120-150g of chloride, primarily as an extracellular anion.
• Functions:
  • Essential for hydrochloric acid (HCl) secretion in gastric juice and maintaining electrical neutrality in cells.
• Normal serum chloride levels range from 95-105 mEq/L; deficiencies are rare.
• Hypochloremia can result from prolonged vomiting or diarrhea, with symptoms including muscular spasms.
• Dietary sources include pulses, milk, meat, and eggs, with a daily requirement of 1.5-3.5g.

Phosphorus (P)

• Body contains around 500-700g of phosphorus, mainly as inorganic phosphate in bones and teeth.

Zinc

• Present in the body in small amounts, stabilizing insulin and supporting immune functions.
• Functions include roles in DNA replication, transcription, and cellular activation.
• Rare deficiency but sources include seafood, meat, dairy, and grains; RDA is 15mg/day (25mg during pregnancy/lactation).

Copper (Cu)

• The body holds about 100-150mg of copper, with significant amounts in muscle, liver, and brain.
• Functions in enzyme activity related to metabolism, blood cell formation, and antioxidant defense.
• Toxicity can result in health issues like hemolysis; deficiency, although rare, may lead to anemia and skeletal fragility.
• Good sources include cereals, meat, and dairy; RDA is 2.0mg/day.

Iodine

• The body contains approximately 15-20mg, primarily in the thyroid gland.
• Essential for synthesizing thyroid hormones required for growth and development.
• Iodine deficiency can lead to goiter, decreased IQ, and thyroid dysfunctions.
• Goitrogenic foods (e.g., cabbage) may inhibit iodine uptake, mimicking deficiency symptoms.
• Iodized salt can prevent IDDs; sources include seafood, dairy, and grains. RDA is 150 micrograms/day.