Mineral Elements Inorganic nutrients © PDST Home Economics

Minerals The human body needs 20 mineral elements in small amounts to protect us from diseases The human body needs 20 mineral elements in small amounts to protect us from diseases Major mineral elements Trace mineral elements Calcium Ca Iron Fe Phosphorus P Zinc Zn Sodium Na Iodine I Potassium K Copper Cu Magnesium Mg Chloride Cl

Calcium Found in bone & teeth (99%) and rest in blood, muscles and nerves. Found in bone & teeth (99%) and rest in blood, muscles and nerves. Calcification is the word for the hardening of the bones Calcification is the word for the hardening of the bones They harden by absorbing Calcium and Phosphorus (Calcium phosphate) They harden by absorbing Calcium and Phosphorus (Calcium phosphate)

Sources Milk (103mg/100g) Milk (103mg/100g) Cheese (800mg/100g) Cheese (800mg/100g) Yoghurt. Yoghurt. Tinned Fish e.g. Sardines 550mg/100g Tinned Fish e.g. Sardines 550mg/100g Leafy green veg. e.g. Spinach 70mg/100g Leafy green veg. e.g. Spinach 70mg/100g Fortified flour Fortified flour Hard water Hard water White Bread 100mg/100g White Bread 100mg/100g

RDA Children800mg Children800mg Adolescents1200mg Adolescents1200mg Adults800mg Adults800mg Preg/Lac1200mg Preg/Lac1200mg

Functions Making strong bones and teeth Making strong bones and teeth Blood Clotting Blood Clotting Muscle contractions e.g. regular heartbeat Muscle contractions e.g. regular heartbeat Normal nerve function Normal nerve function

Calcium Deficiency Rickets in children Rickets in children Osteomalacia Osteomalacia Tooth decay Tooth decay Poor blood clotting Poor blood clotting Irregular muscular contractions Irregular muscular contractions Malfunction of nerve cells Malfunction of nerve cells

Absorption Only 20-30% of the calcium we eat is absorbed. Only 20-30% of the calcium we eat is absorbed. Certain things help or hinder absorption Certain things help or hinder absorption Assisting absorption Hindering absorption Vitamin D Vitamin D Parathormone Parathormone Phosphorus Phosphorus Acid environment e.g. eat vit.C with calcium Acid environment e.g. eat vit.C with calcium Protein –calcium has to bonds to protein to be absorbed Protein –calcium has to bonds to protein to be absorbed Phytates Phytates Oxalates Oxalates Excess fat Excess fat Excess protein Excess protein Wrong calcium / phosphorus ratio. Wrong calcium / phosphorus ratio. Too many soft drinks Too many soft drinks

IRON 50% of the iron in the human body is in the blood 50% of the iron in the human body is in the blood The rest is in the liver, spleen and bone marrow. The rest is in the liver, spleen and bone marrow. Small amount in muscle protein and cell enzymes. Small amount in muscle protein and cell enzymes.

Sources of Iron Haem iron sources Non-haem iron sources Offal e.g. liver(11mg/100g) Meat Meat products Chicken Eggs (2mg/100g) Whole cereals e.g. Wholegrain flour (4mg/100g) Dark green veg e.g. Spinach (4mg/100g) Fish

RDA for Iron Children 8mg Children 8mg Adolescents14mg Adolescents14mg Adults10mg Adults10mg Pregnancy/Lactation15mg Pregnancy/Lactation15mg

Functions of Iron Needed to make haemoglobin in the red blood cells which is needed to carry oxygen from the lungs to the body cells. Needed to make haemoglobin in the red blood cells which is needed to carry oxygen from the lungs to the body cells. Needed to make myoglobin which carries oxygen to muscle. Needed to make myoglobin which carries oxygen to muscle. Needed to make certain enzymes. Needed to make certain enzymes.

Iron deficiency Tiredness Tiredness Muscles tire easily Muscles tire easily Paleness Paleness Breathlessness Breathlessness Anaemia Anaemia

Anaemia Caused by shortage of haemoglobin due to lack of iron in diet or failure to absorb the iron Caused by shortage of haemoglobin due to lack of iron in diet or failure to absorb the iron More common in females – menstruation More common in females – menstruation Symptoms: tiredness, dizziness, headaches, paleness, breathlessness, loss of appetite Symptoms: tiredness, dizziness, headaches, paleness, breathlessness, loss of appetite

Absorption of Iron Only 15% of the iron you eat is absorbed. Only 15% of the iron you eat is absorbed. Things that help iron absorption: Source: haem iron is easier to absorb Source: haem iron is easier to absorb Vit C changes ferric iron to the ferrous state which is easier to absorb. Vit C changes ferric iron to the ferrous state which is easier to absorb. If haem and non-haem iron are eaten together If haem and non-haem iron are eaten together Things that hinder absorption: Excess Fibre Excess Fibre Tannins Tannins Source: non-haem Source: non-haem Phytates (in wholegrains), Oxalates (in dark green veg.) Phytates (in wholegrains), Oxalates (in dark green veg.)

Retaining vitamins & minerals in food Choose fresh food Choose fresh food Don’t store for too long Don’t store for too long Store in cool dry dark place Store in cool dry dark place Eat raw if possible Eat raw if possible Avoid peeling Avoid peeling Prep just before use Prep just before use Avoid steeping Avoid steeping Sharp knife reduces oxidase damage Sharp knife reduces oxidase damage Use pre boiling salted water Use pre boiling salted water Cook for shortest possible time Cook for shortest possible time Use as little liquid as possible Use as little liquid as possible Cover cooking pot Cover cooking pot Use cooking liquid in sauce or gravy Use cooking liquid in sauce or gravy Don’t add bread soda to greens Don’t add bread soda to greens Serve immediately after cooking. Serve immediately after cooking. Avoid reheating Avoid reheating

Potassium (K) SourcesFunctionsDeficiency Pulses Green leafy veg. BananaOrangesMeatMilk Fruit juice Nuts Fluid balance in body tissue Healthy nerves Normal muscle activity Rare Mental confusion Cardiac arrest Weak muscles RDA: g

Sodium (Na) SourcesFunctionDeficiency Salt Processed food Smoked food Cured food Meat products Cheese Snack foods Fluid balance in body tissues Healthy nerves Normal muscle activity Muscle weakness Muscle cramp Low blood pressure Loss of appetite RDA:1.6g

Zinc (Zn) SourcesFunctionDeficiency Meat Meat products CerealsOystersLegumesRDA7-12mg Enzyme activity Protein & carb. metabolism Hormone activity Healthy hair Healthy skin Frequent infection Reduced appetite Delayed healing Dry skin

Iodine SourcesFunctionsDeficiency Seafood Cod liver oil Iodised salt Veg. grown in iodine rich soil RDA: μg Making the thyroid hormone thyroxine Regulates growth & development Regulates metabolism Goitre Retarded mental development Lethargy