Minerals

Minerals

• Macro minerals (major elements)• 1. They are required in amount greater than

100mg/day.• 2. Include six elements: Ca, P , Mg , Na, K and

Cl.• Micro minerals(traces elements)• 1. required in amount less than 100mg/day. • Cr,Co,Cu , F,I, Fe , Mn , Mo, Selenium and Zn.

Calcium

• Sources: milk, and milk products,beans,leafy vegetables and egg yolk.

• Absorption: • 1. Ca is absorbed by an active transport

mechanism in the upper small intestine.• 2. Absorption requires Ca binding proteins in

the intestinal mucosal cells.

Functions of Ca

• 1.Unionized Ca: found in the structure of bones and teeth,acts as Ca reservoir.

• 2. Ionized Ca: important for :• 1. transmission of nerve impluse .• 2. contraction of muscles with the presence of

ATPase and troponine.• 3. Blood coagulation and milk rennin clotting.• 4.Maintance of cell membrane permeability for

water and other ions.

excretion

• 1. Most of Ca excretion is eleminated with faeces

• 2. Small amount of Ca is excreted in urine (about 200 mg/day).

Requirements

• 1. adult men and women :800mg/day.• 2.children , pregnant and lactating women:

800-1200mg/day.

Phosphorus

• Sources: milk, and milk products, fish , meat,liver and kidney, leafy vegetables and egg yolk.

• Absorption:• 1. it is absorbed by an active transport

mechanism in the mid-jejunum and enters blood stream via portal circulation.

• 2. absorption is regulated by active vitamin D(calcitriol).

Functions

• 1. found in teeth and bones.• 2. helps in the formation of following cellular

compounds:• A. nucleic acids.• B. phospholipids: lecithin, cephalin• C. phophoproteins• D coenzyme: NAD,NADP+• E. high energy phosphate compounds: ATP,GTP• F. Cyclic AMP and cGMP.

Excretions

• Mostly (90%) is excreted out in urine

Requirements

• Same as for Ca

Magnesium

• Sources: leafy vegetables(containing chlorophyll)

• Absorption: • Occurs in the upper small intestine.

Functions

• 1. found in the structure of skeleton and (bone and teeth)

• 2. activates many enzyme e.g kinase, enzyme.• 3. required for the active transport of other

cations (Ca,Na,K) across the cell membrane.• 4. important for muscles contraction , nerve

impulse transmission and it decreases neuromuscular excitability.

excretion

• Mostly 75% in faeces.

Requirements

• For adult male (18 years) : 400 mg/day.

Sodium

• Sources:table salt • Absorption:occurs in small intestine (ileum). It

is nearly completely absorbed.

Functions

• Maintenance of osmotic pressure and volume of plasma and extracellular fluid.

• Transmission of nerve impulse.• Contraction of muscles.• Regulation of acid base balance.

Excretion

• For adults: 5g/day.

Potassium

• Sources: vegetables ,fruits and nuts.• Absorption: readily occurs in the small

intestine.

Functions

• 2/3 of P is present in tissues and body fluids.• About 1/3 is present in skeleton.• Maitenance of osmotic pressure and volume

of intracellular fluid.• Transmission of nerve impluse.• Contraction of muscles.• Regulation of acids base balance.

Excretion

• Mainly in urine.

Requirements

• 4g/day

Chloride

• Sources: table salt• Absorption : readily occurs in small intestine.

Functions

• Chloride is the main extracellular anion .Together with sodium , it maintains the osmotic pressure and volume of plasma and extracellular fluids.

• Chloride ions is essential for information of HCL in the stomach .

• Activation of enzyme :CL- activates salivary and pancreatic amylase.

Excretion

• Mainly in urine.

Requirements

• For adults :5g/day.

Micro minerals (trace elements)iron

• Sources : liver ,heart,kidney,,spleen,and fish• Sugar cane syrup,dates,and eggs• Absorption:• 1. it ocurrs in duodenum and the proximal

part of intestine.• 2. in normal people ,about 10-15% of dietiary

iron is absorbed.

Functions

• 1. haemoglobin:which carries oxygen.• 2. myoglobin: which stores oxygen.• 3.respiratory enzymes: which use oxygen.• 4.cytochrome P450: which detoxicates drugs

and oxygen.

Excretion

• Excreted in the faeces is mainly exogeneous iron i.e dietary iron that has not been absorbed.

• In males ,there is an average loss of endogeneous iron of about 1 mg/day.It is derived from desquamated cells from skin and the intestinal mucosa.

• In fermales ,there is addition sources of loss ,due to mensturation and pregnancy.

• Urine contain negligiblre amount of iron.

Requirements

• Adult ;10mg/day• Pregnant women and lactating women:

30mg/day.• Menstruation : 18mg/day.

Copper

• Sources: liver, kidney dried legumes and nuts• Absorption:mainly occur in the upper small

intestine.

Functions

• Haemoglobin synthyesis• Bone formation• Maintainance of mylein of the nerve.• Metalloenzyme.• Cytochrome oxidase.• Ceruloplasmin• Superoxide dismutase.

Excretion

• Mainly with bile • Urinary excretion is minimal due to large

molecular weight of ceruloplasmin.

Requirements

• Adults: 2-3 mg/day

Zinc

• Sources: meat ,liver ,egg,,sea food, milk,whole grain product are good sources.

• Absorption;zinc absorption occurs mainly in small intestine,especially from the duodenum.

Requirements

• An adult male: 10-20mg/day.

Excretion

• Mainly in faeces • Zinc deficeincy:• 1. hypogonadism• 2 poor healing of wounds• 3. poor apetite and retarded growth in

children• 4. liver crrrhosis.

Iodine

• Sources: table salt,fish,sea food,weeds,vegetables,grown near seaboard are good sources.

• Absorption:• Occurs mainly form small intestine.

Cont.

• Plasma iodine: organic iodine: 4-8mg/dl• Inorganic iodine: 1-2ug/dl• Functions: the only known function of iodine

is the formation of thyroid hormone (T3-T4)• Excretion: mainly (70%) in urine• Requirement: for adult 100 -150ug/day.• Deficeincy: it results in thyroid

hypertrophy( enlargement ) and groin.

Selenium • Selenium is an essential components of the enzyme

glutathione peroxidase(GSH-PX)which catalyzes the reaction:• 2GSH+H2O2 GSH-Px GSSG +2H2O2. • This reaction acts as protective mechanism against the

oxidative damage of hydrogen peroxide (H2O2) and fatty acids hyroperoxide by destroying them:

• 1. RBCs ,it prtoect haemoglobin for and red cell membrane.• 2. in liver , it is important for detoxifying lipid hydroperoxides

and prevents necrosis.• 3.in lens tissues of the eye prevents its oxidative damage.

Deficiency

• Defeciency of selenium (GSH-Px). • Haemolytic anaemia • Liver cirrhosis• Cataract• Cardiomyopathy• RDA-50 -200ug.keshan syndrome

Mangenese

• Normal growth structure• Reproduction(spermatogenesis and ovulation)• Normal function of the central nervous

system.• RDA: 5-6mg• Activate the arginase.

Cobalt

• Cobalt is a component of vitamin B12 which is necessary for normal blood cell formation.

• It gives vitamin B12 it red colour.• Deficiecy of vitamin B12 causes pernicious

anaemia.•

chromium

• It acts only together with insulin to promote glucose utilization .

• Its defeciency leads to impairement of glucose utilization by tissue.

• Antiatherogenic( LDL HLD) .

Molybdenum

• It is component of oxidase enzyme e.g xanthine oxidase and aldehyde oxidase.

Flouride

• It increases the hardness of bones and teeth.• Its deficiency causes dental caries and

osteoporosis.• Now- a –days it is suppied in drinking water.• Excess fluoride leads to fluorosis : mottling

and discoloration of the enamel of teeth and changes in bones.

• RDA; <2ppm