HomeEc: Minerals

How many different minerals does the body require

20

Classifications of minerals

macro minerals and trace minerals

Examples of macro minerals

calcium, phosphorus, potassium, sodium

Examples of trace minerals

iron, zinc, iodine and flourine

Sources of calcium

• milk

• cheese

• yoghurt

• leafy green vegetables

• sardines

• sesame seeds

RDA/RI of calcium

Children: 800mg
Teenagers: 1,200mg

Adults: 800mg
Pregnant and Lactating: 1,200mg

Biological Functions of Calcium

• formation of strong bones and teeth

• assists blood clotting

• normal muscle contraction

Effects of Deficiency of calcium

• increased risk of bone diseases

• slow blood clotting (haemorrhaging)

• muscles fail to relax (spams, cramps, convulsions)

Convulsion definition

condition where muscles contract and relax repeatedly, causes uncomfortable shaking of the body

How much of consumed calcium is absorbed by the body

20-30%

Factors assisting calcium absorption

• Vitamin D stimulates production of calcium-binding proteins

• Hormone parathromone from parathyroid gland controls blood calcium levels

• Hormone oestrogen from ovaries

• Phosphorus combines to make calcium phosphate (easier to absorb)

• Acid environment from vitamin C

Factors that hinder calcium absorption

• tannins

• excess fibre bind to calcium

• excess fat binds and makes fat soaps

• burning protein makes sulfates (increases excreted calcium)

• phytic acid in wholegrains binds

• oxalic acid in rhubarb and spinach binds

Forms of iron

haem and non haem iron

Haem iron

Ferrous Iron, easily absorbed

Non-haem iron

ferric iron, not easily absorbed and changed to ferrous

Sources of haem iron

• red meat

• offal

• poultry

• meat products

Sources of non-haem iron

• cereals

• pulses

• eggs

• leafy green veg

RDA/RI of iron

Children and adult males: 10mg
Teens and adult females: 14mg
pregnant and lactating: 15mg

Biological functions of iron

• makes RBCs and haemoglobin to carry oxygen

• forms part of myoglobin to carry oxygen to muscles

• works with enzymes to release energy

Effects of deficiency of iron

• anaemia due to low haemoglobin and RBCs means less oxygen (tiredness, paleness, short breath, irritability and dizziness)

• muscle fatigue

• less energy

How much of consumed iron is absorbed

15%

Factors assisting iron absorption

• haem and non-haem consumed together (increases non-haem absrobed)

• high vitamin C with non-haem

• acidity from HCl in stomach changes non-haem

Factors hindering iron absorption

• tannins bind

• excess fibre binds

• phytic acid in wholegrains binds

• oxalic acid in rhubarb and spinach binds

Sources of zinc

• meat

• seafood

• eggs

• pulses

• milk

• seeds

RDA/ RI of zinc

Children: 4-7mg
Teens and Adults: 7-10mg

Biological functions of zinc

• aids metabolism of fats, carbs and protein for energy release

• helps healing wounds and tissue repair

• healthy skin and hair

Effects of zinc deficiency

• tiredness and irritability

• impaired wound healing (infections)

• hair loss and dry skin conditions

Sources of iodine

• seafood

• meat

• cod liver oil

• milk

• seaweed

RDA/ RI for iodine

Children: 70-100 μg

Teens and adults: 120-130μg

Biological functions of iodine

• aids making thyroxine in thyroid for metabolism

• growth and development in gestation and childhood

• maintains thyroid gland

Effects of deficiency of iodine

• Reduced BMR due to lack of throxine leads to obesity

• stunted or delayed physical or mental growth of kids

• goitre (abnormal enlargement of thyroid gland in neck)

Sources of sodium

• table salt

• snack foods

• white bread

• cheese

• cured meats

RDA/RI of sodium

Children: 1.6g of sodium (4g salt)

Teens and adults: 2.4g sodium (6g salt)

Bological functions of sodium

• regulated BP

• healthy nerve activity

• normal muscle contraction

Effects of sodium deficiency

• High BP (hypotension) meaning reduced oxygen to organs

• delayed nerve impulses means cognitive impairment

• muscles fail to relax means spasms, convulsions etc

How to reduce salt intake

• avoid high salt snacks

• buy reduced salt foods

• don’t add salt

• read labels for hidden salts, eg. monosodium glutamate

Sources of potassium

• meat

• milk

• bananas

• fish

• leafy green veg

RDA/RI of potassium

Children: 0.8-2g

Teens and adults: 3.1g

Biological functions of potassium

• metabolism of carbs and proteins for energy

• healthy nerve activity

• normal muscle contraction

Effects of potassium deficiency

• tiredness and irritability

• delayed nerve impulses means cognitive impairment

• muscles fail to relax means spasms and convulsions