Core Topic 1: Fundamentals of Human Nutrition

1. Core Topic 1: Fundamentals of Human Nutrition Micronutrients: vitamins & minerals

2. Micronutrients • Comprise of Vitamins and Minerals • Do not provide energy, but are required to fulfil functions in the body and promote good health • The body can only synthesise vitamin D • Required in much smaller amounts than macronutrients • RDI is measured in milligrams (mg) or micrograms (ug) • 1000 milligrams (mg) = 1 gram (g) • 1000000 micrograms (μg) = 1 gram (g) • Deficiency diseases occur if there is a lack in the diet.

3. Vitamins • Identified in the 20th century • Originally named alphabetically, but now identified as chemical names. For example, Vitamin C is Ascorbic Acid. • Organic compounds (made by plants or animals). • Vitamins fall into two categories: • Fat soluble • Water soluble

4. Fat soluble Vitamins (A, D, E and K) • Fat soluble vitamins dissolve in fat • A deficiency takes a long time to develop, because the body is able to store significant amounts in the liver and adipose tissue. Activity 1: Pairs who researched fat soluble vitamins will present their findings to two large groups. You must discuss: - The role of fat soluble vitamins, common food sources, effects of deficiency and excess and RDI

5. Water Soluble Vitamins (B group and C) • Water soluble vitamins dissolve in water and in turn they are easily transported away (urine, faeces and perspiration) • Not stored in the body; thus, must be replenished regularly. • Easily destroyed by light, oxygen, poor storage, food preparation and cooking. Activity 2: Pairs who researched water soluble vitamins will present their findings to two large groups. You must discuss: - The role of fat soluble vitamins, common food sources, effects of deficiency and excess and RDI

6. Minerals • Inorganic elements derive from the soil and water. • Minerals play a role in many chemical reactions within the body and form the structure of hormones, enzymes, vitamins and bones. • Some minerals are required in large amounts: • Calcium, Phosphorus, Iron, Sodium, Potassium, Magnesium and Sulfur. • Other minerals are required in smaller amounts and are referred to as trace minerals: • Iodine, Zinc, Copper, Cobalt, Manganese, Fluoride and Selenium.

7. Calcium • The body requires calcium for: • Strong bones and teeth with help from phosphorus, vitamin C and Vitamin D • Normal blood clotting • The transmission of impulses along nerves • Contractions and relaxation of muscles

8. Calcium • Common Food Sources include: • Milk and milk products • Tofu • Almonds • Sesame seeds • Most breads • Dark green vegetables including broccoli and bok choyseaweed

9. Calcium Our bodies do not absorb calcium well if large amounts of protein, sodium or caffeine are consumed The calcium absorbed into the intestine from food must be the same as the amount lost in urine, faeces and perspiration. If sufficient calcium is not obtained from the diet, skeletal calcium will be reabsorbed causing bone loss and in the long term osteoporosis. Only about 20% of the dietary calcium consumed is absorbed by the body.

10. Iron • Iron is required by the body to: • Form a part of haemoglobin, which carries oxygen around the body. • Form a part of the myoglobin in the muscles, which makes the oxygen available for muscle contraction. • Essential part of some enzymes involved in the oxidation and utilisation of energy in cells.

11. Iron • Haem Iron • Found in animal foods such as beef, chicken, fish and offal meats including liver, brain and kidney. • Non-Haem Iron • Derives from plant foods including beans and lentils. • The body absorbs between 2%-8% of the iron from plant sources. • Good vegetarian sources of non-haemiron include iron-fortified breakfast cereals, flours and grains.

12. Iron When foods high in Vitamin C (citrus fruits, broccoli, pumpkin, cabbage) are consumed, the absorption rate of iron increases. Meat will increase the absorption of Iron Soy proteins, Calcium and Phosphorus reduce the absorption of Non-Haem Iron. Tea, coffee and wine reduce iron absorption by binding the iron and carrying out of the body. Vitamin A helps release iron; thus, insufficient Vitamin A may lead to an iron deficiency.

13. Iron • The most common deficiency across the world. • Deficiency will lead to decreased production of red blood cells; thus, leading to anaemia, chronic tiredness, irritability and decreased capacity to exercise. Q1: Who is at risk of an iron deficiency? Vegetarians Athletes People who eat small amounts of food

14. Sodium • Sodium controls fluids that enter and leave the body cells and help to control muscle contraction and relaxation. • Common food sources include: • Salt • Processed foods • Snack foods

15. Sodium • Excess sodium intake may cause: • High blood pressure (Hypertension) • Fluid retention (Oedema) • Kidney and heart failure • Reduced absorption of calcium • 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 • RDI • Less than 2300mg per day for teenagers and adults (2.3g)

16. Water • Water is essential to health • Water is required by the body to: • Transports nutrients to all of the cells • Excretes waste • Maintain the sodium and potassium balance • Water acts as a shock absorber for your joints • Lubricate parts in the body • Saliva allows food to slip easily through the gut • Saliva also keeps your mouth moist and rinses your teeth; thus, reducing tooth decay. • Control your body temperature • Perspiration, or sweat can evaporate when it absorbs enough body heat; thus, keeping the body cool.

17. Water • Sources of water include: • Meat contains 50%-60% • Vegetables and fruit contain 95% • How much water? • 6-8 glasses of water per day • Hot weather or physical activities increases the fluid requirements by the body. • Water is lost through: • Sweating • Breathing • Faeces • Urine