In this post we will be looking at the food sources and functions of major and trace elements of iron, calcium, phosphorus, potassium, sodium and iodine.


Iron is a trace element found in every cell of the body. It is needed for the formation of haemoglobin, which carries oxygen from the lungs to the body cells. Iron is also a part of many proteins in the body. It also aids in energy production and cell diffusion and helps the immune and central nervous systems.

The best sources for iron include:

  • Dried beans
  • Dried fruits
  • Eggs (yolks)
  • Iron-fortified cereals
  • Liver
  • Lean red meat
  • Oysters
  • Poultry, dark red meat
  • Salmon
  • Tuna
  • Whole grains

Iron from fruits, vegetables, grains and supplements are difficult for the body to absorb. Foods rich in Vitamin C increase iron absorption. Substances like commercial black or pekoe teas reduce iron absorption. When a person’s iron level is low, iron deficiency anaemia can develop.


Calcium is the most plentiful mineral in the human body and is needed for healthy bones, teeth, normal blood clotting and nervous system. It also helps muscles contract, relax and is important in blood pressure regulation. Proper levels of calcium throughout your lifetime can help prevent osteoporosis.

Calcium can be found in:

  • Milk
  • Dairy products: yogurt, cheese, buttermilk
  • Green leafy vegetables: broccoli, collards, kale, mustard greens, turnip greens, bok choy or Chinese cabbage.
  • Dietary supplements

For individuals on a vegan diet or who do not eat dairy products foods products such as: orange juice, soy milk, tofu, ready-to-eat cereals and breads; are a good source of calcium.


Phosphorus is found in every cell and takes up 1% of a person’s total body weight. It is needed for healthy bones, teeth, energy metabolism, and acid-base balance in the body. Is is also needed for the body to make protein for growth, maintenance, and repair for cells and tissues. This mineral is involved with the production of ATP, a molecule the body uses to store energy.

Phosphorus works with B vitamins and helps with: kidney function, muscle contraction, normal heartbeat and nerve signaling.

The main food sources are the protein food groups of meat and milk. Fruits and vegetables contain a small amount of phosphorus. A meal plan that provides adequate amounts of calcium and protein will also provide an adequate amount of phosphorus.


Potassium is essential for maintaining proper fluid balance, nerve impulse function, muscle function and cardiac function. Potassium is also in every cell of the body.

The best source for potassium is food not supplements:

  • Meats: pork tenderloin, chicken breast
  • Milk
  • Fresh fruits: cantaloupe, banana
  • Vegetables: broccoli
  • Whole grains
  • Legumes: lentils
  • Fish: Halibut, salmon


Sodium is essential for the proper function of the body. The body uses sodium to control blood pressure and blood volume, for the proper functioning of muscles and nerves and for fluid balance.

Sodium occurs naturally in most foods. The most common form of sodium is sodium chloride, which we know as table salt. Other natural sources of sodium are: beets, celery, milk and water (depending on source).

Added sodium can be found in:

  • Worcestershire sauce
  • Soy sauce
  • Onion salt
  • Garlic salt
  • Bouillon cubes
  • Processed meat: bacon, sausage, ham
  • Canned soups
  • Vegetables
  • Fast food


Iodine is a trace mineral and a nutrient naturally found in the body. It can be found in the thyroid hormone which helps regulate growth, development and metabolism.


  • Iodized table salt is the main food source of iodine
  • Seafood: cod, sea bass, haddock and perch
  • Vegetable: kelp
  • Dairy products
  • Plants grown in iodine rich soil.


This quiz tests your knowledge on the information in the post above.


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