© PDST Home Economics

Major mineral Trace mineral

Calcium (Ca) Iron (Fe)

Phosphorus (P) Zinc (Zn)

Chlorine (Cl) Copper (Cu)

Sodium (Na) Manganese (Mn)

Potassium (K) Fluorine (F)

Magnesium (Mg) Cobalt (Co)

Iodine (I) Selenium (Se)

Chromium (Cr)

Iron is an important mineral Deficiency in iron is the most common

mineral deficiency in humans Iron is present in haemoglobin in the blood,

myoglobin in the muscles, enzyme systems in the body cells, and is also stored in the liver, spleen and bone marrow

Functions Effects of deficiency

Sources RDA (mg/day)

•Iron is necessary for the formation of haemoglobin, which carries oxygen around the body

•Its forms part of myoglobin which carries oxygen to the muscles

•It is an important part of enzyme systems that use oxygen to release energy from food

•Iron deficiency causes haemoglobin levels to fall, which means that there is not enough oxygen going to the body tissues

•It can lead to:1.Tiredness2.Paleness3.Breathlessness4.Anaemia

•Anaemia is a common condition in Ireland especially women

•Meat•Meat products•Chicken•Cereals•Eggs•Pulses•Green Vegetables•Fish

• Children 10•Adolescents 13-14•Adults: Males 10, f females 14•Pregnant or lactating women 15

Definition & Cause: Anaemia is a disease caused by a shortage of haemoglobin, as a result of insufficient iron in the diet, or an inability to absorb iron

It is more common in females due to menstruation

Symptoms: Tiredness, dizziness, headaches, paleness, shortness of breath & loss of appetite

Haem iron Non-haem iron

• This is ferrous iron• Its chemical symbol is Fe²+• It is soluble & easily absorbed•Sources of haem iron include meat, meat products, chicken

• This is a ferric iron•Its chemical symbol is Fe²+•It cannot be absorbed in the body & must be changed into ferrous iron to be absorbed•Sources of non-haem iron include cereals, eggs, pulses, green vegetables, fish

Factors aiding iron absorption

Eating haem iron (because it is more easily absorbed than non-haem iron)

Eating non-haem and haem iron together increases non-haem iron absorption

Vitamin C is a reducing agent, as it changes ferric iron (Fe³+) to the more easily absorbable ferrous iron (Fe²+)

Hydrochloric acid in the stomach aids absorption by changing non-haem iron to haem iron

Factors hindering iron absorption

Phytic acid, in cereals and legumes, binds to iron, decreasing its absorption

A dietary fibre intake above 35g per day has a tendency to bind iron, decreasing its absorption

Oxalic acid, which is found in some fruit and vegetables (rhubarb & spinach), combines with iron, inhibiting its absorption

Tannins in tea, coffee & cocoa decrease iron absorption.

99% of calcium in the human body is present in human bones

It is also found in the blood, muscles and nerves

Functions Effects of Deficiency

Sources RDA mg/day

•Calcium plays a major role in the formation & development of bones & teeth•Calcium is important in blood clotting•Calcium is necessary for muscle contractions, normal functioning of nerves & membrane permeability•Calcium is required to regulate metabolism in the cells

•Rickets•Osteomalacia in adults•Osteoporosis in the elderly•Tooth decay•Poor blood clotting•Failure of the muscles to relax (muscular spasms)

•Dairy products, e.g. Milk, cheese, eggs•Dark green vegetables e.g. Spinach, cabbage•Canned fish, e.g. Salmon•Fortified Flour•Hard water

•Children 800•Adolescents 1200•Adults 800•Pregnant/ lactating women 1200

10

Approx. 20% of Calcium intake is absorbed in the small intestine where it is bound to a specific carrier protein

Factors aiding calcium absorption

Vitamin D which stimulates calcium binding protein & increases absorption

Parathormone is a hormone that controls the level of calcium in the blood (It is produced by the parathyroid gland)

Amino acids combine with the calcium salts, which are absorbed easily

Phosphorus combines with calcium to form calcium phosphate

An acid environment helps calcium absorption (eating vitamin C with calcium rich foods)

Factors hindering calcium absorption

Phytic acid, present in cereals and grains binds to calcium, preventing its absorption

Oxalic acid, present in rhubarb & spinach, binds to the calcium, preventing its absorption

Fibre binds to calcium, preventing its absorption Excess saturated fat forms insoluble soaps

with calcium, preventing its absorption Overconsumption of soft drinks An incorrect calcium/phosphorus ratio Levels of oestrogen in postmenopausal women

play a major role in the absorption of calcium Tannins in tea

ZincFunction

•Reinforces the immune system•Protects against infection•Needed for:

The metabolism of carbohydrate and proteinThe production of male sperm and female ovaThe formation of bone tissue and healing wounds

Sources•Zinc from animal foods, such as meat, liver, eggs, poultry and milk, is more readily absorbed than zinc from plant foods•Seafood, wheat germs, nuts, pulses, bread

Zinc

Effects of deficiency•Deficiency is found in those whose diet is high in refined cereals, and whose intake of animal protein is low. Deficiency can cause:

Skin problemsGeneral tirednessHair lossProlonged healing of wounds

RDA•Zinc is not stored in the body so a daily intake is required

4 – 7 mg for children7 – 9 mg for adolescents7 – 10 mg for adults

IodineFunction

•Very important as it is a part of the thyroid hormone thyroxine, which is essential for normal growth and physical and mental development•Also involved in maintaining metabolic rate

Sources•Fish, meat, milk, table salt

Effects of deficiency•Deficiency is rare in the Western world but it may cause:

GoitreCretinismIncreased incidence of miscarriage and still births

RDA•150 g for adults, 90 g for children

PotassiumFunction

•Vital for the correct functioning of the heart muscles and nerves•Helps protein metabolism

Sources•Found in nearly all foods including green veg, wholemeal products, pork, fruit (especially bananas), fruit juices, dairy products and grains

Effects of deficiency•Deficiency is rare but it may cause:

Diarrhoea, excessive sweating, fatique, bloating, insomnia

RDA•As potassium is stored in the fluids of the body cells, it is excreted, therefore a daily intake is essential

3 g for children, 3.5 g for adults

SodiumFunction

•Needed to regulate body fluids•Needed for energy release•Needed for proper functioning of nerves and muscle contraction

Sources•Smoked fish, soy sauce, ham, bacon, olives, processed foods and table salt

Effects of deficiency•As sodium is found in small amounts in many foods and is particularly high in processed foods, most people have a higher sodium intake than they need. High sodium intake has been linked to high blood pressure and strokes

RDA•RDA met by a high intake of processed foods

Vitamin Relationship with Minerals

1. Vitamin D

2. Vitamin K

3. Vitamin C

4. Vitamin B6, B12, Folic Acid

•Works in the absorption of calcium & phosphorus

•Works with calcium in clotting blood

•Works in the absorption of iron & calcium

•Works with iron in the formation of red blood cells

Water (H2O)

•Water is essential for life•Two-thirds of our body is made up of water•Water is the main component of blood, lymph and digestive secretions, as well as all other liquid parts of the body•It is made up of hydrogen and oxygen molecules in the ratio 2:1

WaterProperties

•Colourless, odourless and tasteless liquid•Boils at 100°C and freezes at 0°C•Neutral PH of 7•Excellent solvent capable of dissolving a number of substances•Exists in three states: solid (ice), liquid (water), and gas (steam)•Able to absorb heat and maintain it

Sources•Tap/ bottled water•Beverages such as tea and coffee•Fruit and vegetables•All foods contain a certain amount of water

WaterFunctions

•Transporting nutrients, oxygen, enzymes and hormones around the body•Removal of waste products from the body, e.g. from the kidneys•Quenches thirst•Contains the minerals calcium and fluorine•Controls body temperature through perspiration•Significant in the hydrolysis of nutrients during digestion•Essential element of all body fluids and tissues

RDA•Between 2 and 3 litres per day