At each stage of life our nutrient needs change, depending on our gender and whether we need to build and grow, or repair and maintain our bodies. A varied diet rich in whole foods is the best way to meet our requirements for most nutrients, although in some cases nutrition supplements are beneficial, and at times necessary.
Iron
- Why you need it: The formation of healthy red blood cells, which carry oxygen around the body, as well as healthy functioning of the immune system and energy production
- Best food sources: Haem iron is found in animal products including organ meats and eggs, and is the form most efficiently absorbed by our bodies. Non-haem iron is found in plant foods and iron supplements, and it’s absorption is boosted by vitamin C containing food or drinks.
- Signs you might not be getting enough: Tiredness and fatigue, shortness of breath, pale skin, poor memory, and decreased resistance to infection are the most common signs of iron deficiency anaemia.
Vitamin B12
- Why you need it: Healthy blood formation, psychological and neurological function, energy and homocysteine metabolism, immunity.
- Best food sources: Organ meats, meat, poultry, fish, eggs, dairy foods, fortified breakfast cereals.
- Signs you might not be getting enough: Pernicious anaemia, tiredness and fatigue, shortness of breath, depression, memory loss, poor nerve functioning, a smooth, sore tongue.
Folate
- Why you need it: Healthy red blood cells and immune system, cell division, protein synthesis, homocysteine metabolism.
- Best food sources: Dried yeast/yeast extract, liver, dark green leafy vegetables, legumes, nuts, oat bran
- Signs you might not be getting enough: Tiredness and fatigue, problems with nerve functioning, poor growth, weight loss, folate-deficiency anaemia
Iodine
- Why you need it: The production of thyroid hormones which regulate metabolic rate, essential for cognitive and neurological function, and healthy skin
- Best food sources: Seafood, seaweed (kelp), eggs, bread, dairy products, some vegetables and iodised salt.
- Signs you might not be getting enough: The thyroid gland becomes enlarged (called goitre) and in the long term, hypothyroidism develops with symptoms including weight gain, hair loss, dry skin, fatigue and slowed reflexes.
Calcium
- Why you need it: Strong bones and teeth, regulates nerve and muscle function, energy metabolism, blood clotting and the function of digestive enzymes.
- Best food sources: Dairy foods, leafy green vegetables, soy and tofu, salmon and sardines with bones, nuts and seeds, calcium fortified plant milks.
- Signs you might not be getting enough: Osteoporosis (brittle bones) osteomalacia (soft bones), muscle spasms and cramping, rickets (a preventable bone disease in childhood)
Magnesium
- Why you need it: Normal nerve and muscle functioning, normal psychological function, is also a part of hundreds of enzymes used for normal cell division and protein synthesis. It works together with calcium and phosphorus to build strong bones and teeth.
- Best food sources: Nuts, wholegrains including bran, dairy foods, dark green vegetables (spinach), fish and meat, pumpkin and sunflower seeds, soybeans, tofu, potatoes, and legumes
- Signs you might not be getting enough: Tiredness and fatigue, muscle spasm and weakness, sleep disorders, irritability, agitation and anxiety
Sodium
- Why you need it: Regulating fluid balance and blood pressure, nerve and muscle function
- Best food sources: Sodium is a mineral found in salt (salt = sodium chloride) and around 75 per cent of the salt in our diet comes from processed foods including processed meats, takeaway foods, shops, stocks and snack foods.
- Signs you might not be getting enough: The issue with sodium is that we have too much! High intakes of salt are associated with high blood pressure, which is a risk factor for kidney disease and cardiovascular disease (such as heart disease and stroke). While an adequate intake is 920mg/day, the National Health and Medical Research Council (NHMRC) suggest Australian adults reduce their sodium intake to less than 2,300mg (1 ½ teaspoons or 6 grams of salt) a day. We need to aim even lower to help reduce our risk of chronic disease - ideally limiting sodium intake to 1,600 mg of sodium (4 grams of salt) a day.
Potassium
- Why you need it: Nerve impulses, and works with sodium to regulate the body’s fluid balance and blood pressure.
- Best food sources: Fresh and fruit and vegetables, dried fruit, wheat bran, fish meat poultry, milk and yoghurt.
- Signs you might not be getting enough: It’s rare to be deficient in potassium as it is present in so many foods.
Zinc
- Why you need it: Immunity, healthy hair, nails and skin, wound healing, carbohydrate, protein and fat metabolism, fertility and reproduction, testosterone levels, vision, and cognitive function.
- Best food sources: Oysters, shellfish, meat, wheat germ, bran, legumes, milk, yogurt, cheese.
- Signs you might not be getting enough: Loss of taste, poor growth and wound healing, dry skin, increased susceptibility to infection.
Vitamin C
- Why you need it: Collagen formation for healthy skin, teeth, gums, cartilage and bones, and blood vessels, protecting cells from free radical damage, immunity, neurological and psychological function, energy metabolism and Iron absorption from food,
- Best food sources: Strawberries, kiwi fruit, citrus fruits, cauliflower, green leafy vegetables (broccoli, brussels sprouts), red and green capsicum.
- Signs you might not be getting enough: Dry skin, poor wound healing, bleeding gums, bruising, increased risk of infection.
Vitamin A
Vitamin A comes in a number of forms (retinol, retinal, retinoic acid or retinyl ester), so the recommended intake is expresses as retinol equivalents.
- Why you need it: Normal vision, immunity, reproduction, iron metabolism, skin and mucous membrane structure and function
- Best food sources: Liver (pate), fish, eggs, yellow, orange, red and dark green vegetables (apricots, mango, sweet potato, carrots, pumpkin, tomato) milk, yoghurt and cheese.
- Signs you might not be getting enough: Poor vision, increased susceptibility to infection.
Thiamin (Vitamin B1)
- Why you need it: Energy production and carbohydrate metabolism, healthy heart and neurological function, and psychological function.
- Best food sources: Wholemeal grains, yeast extract, wheat germ, legumes, nuts, seeds (especially sesame seeds), organ meats, fortified breakfast cereal. White and wholemeal flour used to make bread in Australia must be fortified with thiamin.
- Signs you might not be getting enough: Muscle fatigue and weakness, lethargy, confusion, heart problems.
Riboflavin (Vitamin B2)
- Why you need it: Healthy skin, releasing energy from food, nervous system functioning, iron transport, metabolism and maintaining red blood cells.
- Best food sources: Yeast extract, dairy foods, eggs, meat, green leafy vegetables, fortified breakfast cereals, wholegrain breads.
- Signs you might not be getting enough: Swollen tongue, cracked lips and in corners of mouth. flaking skin, rashes, hair loss.
Niacin (Vitamin B3)
Niacin is the term used to describe two similar compounds, nicotinic acid and nicotinamide, so requirements are measured in niacin equivalents.
- Why you need it: Energy release from food, is a part of the structure and function of skin and mucous membranes, supports the nervous and digestive systems and plays a part in normal psychological function.
- Best food sources: Meat, fish, poultry, milk, eggs, wholegrain breads and cereals, nuts, bran, wholemeal grains.
- Signs you might not be getting enough: Deficiency is rare, and symptoms include diarrhoea, dementia, dermatitis, dizziness, confusion, swollen tongue, irritability, loss of appetite, weakness.
Vitamin B6 (Pyridoxine)
- Why you need it: Metabolism of protein, glucose and cysteine, forming red blood cells, iron transport and metabolism, normal functioning of the nervous and immune system, regulation of hormonal activity and psychological function.
- Best food sources are: Fish and shellfish, meat and poultry, liver, grains and legumes, green and leafy vegetables, nuts, fruit.
- Signs you might not be getting enough: Smooth tongue, cracks in corners of the mouth, muscle twitching, convulsions, irritability, confusion and dermatitis.
Protein
- Why you need it: Energy, tissue building and repair, growth and maintenance of bones and muscles, hormones, enzymes and blood transport/carriers.
- Best food sources: All animal foods such as meat, poultry, fish, eggs, dairy foods, as well as soy, legumes, nuts and small amounts in grains/cereals such as rice, wholemeal bread, quinoa
- Signs you might not be getting enough: Protein deficiency is not commonly seen in Australia, but low protein intakes can result in muscle wasting, fluid retention, anaemia and slow growth in children.
Fibre
There are three types of fibre: soluble, insoluble and resistant starch
- Why you need it: A healthy digestive system, keeping your bowels regular, regulating blood glucose and cholesterol levels.
- Best food sources (soluble fibre): Fruits, vegetables, oat bran, barley, seed husks, flaxseed, psyllium, dried beans, lentils, peas, soy milk and soy products.
- Best food sources (insoluble fibre): Wheat bran, corn bran, rice bran, the skins of fruits and vegetables, nuts, seeds, dried beans and wholegrain foods
- Best food sources (resistant starch): Unripe bananas, potatoes and lentils, unprocessed cereals/grains
- Signs you might not be getting enough: Constipation, diverticulitis, haemorrhoids, colon cancer.
Water
- Why you need it: Most body processes including digestion, absorption, and transporting nutrients, disposing of waste products and keeping our body temperature stable.
- Best food sources: Although ‘water’ is the best choice for hydrating our bodies, all drinks, including milk, tea, coffee and flavoured drinks are counted as fluids. Excess kilojoules from juices and soft drinks can contribute to unwanted weight gain, and be a factor in tooth decay.
- Signs you might not be getting enough: Dehydration, which reduces our physical and mental performance and increases risk of kidney stones and urinary tract infections (in women). Headaches, tiredness and reduced saliva (dry mouth) can also be caused not getting enough fluids throughout the day.
References/more information
Nutrient Reference Values for Australia and New Zealand
The Australian Dietary Guidelines
