Minerals

• Micronutrients


  Vitamins and minerals required by the body for good health and the prevention of many diet related disorders
• Minerals to identify rich sources and explain functions

  • Calcium
  • Iron (haem and non-haem)
  • Iodine
  • Sodium
  • Potassium
• Iodine deficiency


  Can result in health issues
• Factors affecting bioavailability and absorption of minerals


  • Haem iron vs non-haem iron
  • Caffeine and alcohol consumption
• Vitamin C


  Promotes absorption of non-haem iron
• Calcium


  Inhibits iron absorption
• Minerals

  Inorganic compounds (do not contain carbon), water soluble, not easily destroyed
• Major minerals


  Required in larger amounts, found in the body in amounts greater than 5 grams
• Trace minerals


  Required in smaller amounts, found in the body in amounts less than 5 grams
• Common mineral imbalances in Australian diets

  • Calcium
  • Sodium
  • Iron
  • Potassium
• Calcium


  • Calcium is lost from the body every day through bodily fluids (primarily urine)
  • Bones act as a 'calcium bank'
  • Recommendations are based on the amount needed to retain as much calcium in the bones as possible. This allows bones to develop to their fullest potential in size and density
  • Individuals achieve their peak bone mass by their mid to late twenties
• Foods high in calcium

  • Milk and milk products
  • Fortified products (Cereals, dairy, juices)
  • Tofu, made from soya bean curd
  • Almonds
  • Sesame seeds
  • Most breads
  • Dark green vegetables, eg. Broccoli and bok choy and seaweed (nori)
• Functions of Calcium

  • Development of bone's structure framework (main function)
  • Bones support the body and provide attachment points for muscles, enabling movement.
  • During bone formation, calcium combines with phosphorus to create Calcium Phosphate crystals on a collagen protein matrix
  • This process, known as mineralisation, enhances bone density. strength, and rigidity
  • Bone formation is a lifelong process involving continuous remodelling, where bone is both reabsorbed and produced
• Osteoporosis


  A disorder characterised by low bone density and the structural deterioration of bone tissue which becomes more porous and fragile, leading to weakened bones, which are compressible like a sponge, increasing the chance of fractures
• Factors affecting the bioavailability of calcium

  • Excessive sodium, alcohol and caffeine intakes can reduce calcium bioavailability by promoting greater calcium urinary excretion
  • Consuming a high intake of calcium absorption inhibitors and having conditions that can impair calcium absorption and can contribute to the development of osteoporosis
  • Vitamin D promotes the absorption of calcium - without Vitamin D we cannot make use of the calcium in food, resulting in weak bones and teeth
• Iron


  • The average red blood cell has a life span of 115 days, before it is taken apart in preparation for recycling and excretion
  • The iron component of the red blood cell can be recycled and taken to the bone marrow to be reused in new red blood cells
  • Iron is not readily absorbed in the body - iron deficiency is the most common nutrient deficiency disorder in the world
  • Higher RDI to accommodate this
• Two forms of Iron

  • Haem iron: flesh of foods derived from animal sources, such as meat, chicken and fish (More readily absorbed 7-35%)
  • Non-haem iron: food derived from plant sources, such as lentils, beans, tofu, nuts, seeds, grains animal sources, such as eggs, milk and dairy (Not as readily absorbed by the body 2-20%)
  • Absorption is dependent on individuals' dietary factors and body's iron stores
• Functions of Iron

  • Producing haemoglobin in red blood cells
  • Producing myoglobin
• Factors affecting the bioavailability of iron

  • Iron is poorly absorbed in the body as exposure to oxygen makes it insoluble
  • Some dietary choices can bind with non-haem iron, inhibiting its absorption, enhancing the chances of iron-deficiency anaemia
  • Vitamin C increases the absorption rate of iron – protects iron, especially non-haem, from oxygen (antioxidant)
• Iron deficiency anaemia

  Characterised by chronic fatigue, irritability, and decreased exercise capacity
• Groups susceptible to iron deficiency

  • Vegetarians
  • Athletes (especially those in high impact sports)
  • Individuals with low food intake
• Anaemia


  A deficiency in the quantity or quality of red blood cells, which carry oxygen through haemoglobin
• Iodine


  • Trace mineral (needed in small amounts), however cannot store it
  • Iodine is naturally in many foods from uptake from soil
  • The amount of iodine in fruit and vegetables is dependent on the quality of the soil it is grown in, and the fertiliser used
  • Oceans still hold sufficient iodine - shellfish and fish are high in iodine
  • Iodised salt - fortified with iodine
• Functions of Iodine

  • Iodine is required to produce a hormone in the thyroid gland, known as thyroxine
  • This hormone is responsible for regulating the growth and development of tissues, metabolism, and thermoregulation
  • Once thyroxine is released into the blood, it communicates with the cells to increase metabolism
  • A deficiency in iodine can also cause symptoms of weight gain and fatigue as less energy is being burnt, causing it to be stored instead
  • It can also cause the enlargement of the thyroid gland, which is referred to as goitre
• Sodium


  • The Australian and New Zealand government recommends that adults consume approximately 2000mg of sodium per day - equivalent to about 5000mg (5g) or one teaspoon of salt
  • Babies and children require less
  • 1/3 Australians exceed the adequate intake
• Food sources of sodium

  • Table salt
  • Naturally found in foods but low amounts (Fruit & veg)
  • Manufactured and processed foods are high in salt: salami, ham, bacon, canned veg, sauces, salted nuts, pretzels, chips etc.
• Functions of Sodium


  • Regulating the volume of extracellular fluid
  • Assisting with the contraction of muscles and the transmission of nerve impulses
• Excess sodium


  Causes high blood pressure (Hypertension), fluid retention (Oedema), kidney and heart failure, reduced absorption of calcium
• Sodium deficiency


  • Causes muscle cramps, vomiting and apathy
  • Not common in Australia but high levels of physical activity in intense heat can result in deficiency in the short term
• Foods high in salt

  • Smoked, cured, salted or canned meat, fish or poultry including bacon, cold cuts, ham, frankfurters, sausage, sardines, caviar and anchovies
  • Frozen breaded meats and dinners, such as burritos and pizza
  • Canned entrees, such as ravioli, spam and chili
  • Salted nuts
  • Beans canned with salt added
  • Buttermilk
  • Regular and processed cheese, cheese spreads and sauces
  • Cottage cheese
  • Bread and rolls with salted tops
  • Quick breads, self-rising flour, biscuit, pancake and waffle mixes
  • Pizza, croutons and salted crackers
  • Prepackaged, processed mixes for potatoes, rice, pasta and stuffing
  • Regular canned vegetables and vegetable juices
  • Olives, pickles, sauerkraut and other pickled vegetables
  • Vegetables made with ham, bacon or salted pork
  • Packaged mixes, such as scalloped or au gratin potatoes, frozen hash browns and Tater Tots
  • Commercially prepared pasta and tomato sauces and salsa
• More salt


  More water in blood vessels = higher pressure
• Potassium


  Potassium is both an electrolyte and a mineral
• Functions of Potassium

  • Regulating the volume of extracellular fluid – regulates how much sodium enters and exits the cells
  • Assisting the contraction of muscles and the transmission of nerve impulses – sodium-potassium pump in the cell membrane
• Potassium deficiency

  • Causes weakness, muscle cramps, irregular heartbeat and increased blood pressure
  • More often caused by excessive losses than a deficiency of intake. Losses occur if a person is dehydrated, or has prolonged vomiting or diarrhoea and/or the use of diuretics or steroids
• Potassium excess


  Rare unless excessive intake of supplements as excess is excreted from the body
• The greater processing a fresh product is exposed to, the less potassium will be present and the more sodium it will contain
• It is recommended that people increase their intake of fresh produce to meet the recommended daily intake of potassium, which is 3800 mg for males and 2800 mg for females
• Functions of Calcium


  Children and adolescents experience greater bone production compared to the elderly.

  • Older individuals are more susceptible to osteoporosis, a condition characterised by fragile and porous bones
  • People who are chronically (long-term) deficient in calcium, and menopausal women, are at risk of developing osteoporosis
• Assisting in the transmission of nerve impulses, along with muscle contractions and relaxations

  • Muscles and nerves work together to use calcium
  • Nerve tissue uses calcium to stimulate nerve impulses to trigger muscle contractions
  • Calcium also assists the heart beating and contracting as the heart is also a muscle
• Producing Haemoglobin in Red Blood Cells

  • Iron is a crucial component of haemoglobin, a protein in red blood cells.
  • Haemoglobin picks up oxygen in the lungs as blood passes through them.
  • Oxygen is transported throughout the body by haemoglobin and delivered to cells for aerobic respiration.
  • Haemoglobin gives red blood cells their colour; when oxygenated, they appear red.