Slide 1: MINERAL METABOLISM Dr. V. SIVA PRABODH
MD. IRON : IRON Total body content of Iron is 3-5 gm.
70% in Erythrocytes (in Hb)
5% in Myoglobin
Remaining as other hemoproteins, like cytochromes, catalase, xanthine oxidase, tryptophan pyrollase, peroxidase etc.
Non hemo proteins like transferrin, ferritin & Hemosiderin Biochemical functions : Biochemical functions As imp. components of Hb & Mb helps in transport of O2
As imp. components of cytochromes & non heme substances helps in OXIDATIVE PHOSPHORYLATION
Peroxidase – required for phagocytosis Daily requirement : Daily requirement Adult - 10 mg/day
Menstruating women - 18 mg/day
Pregnant & Lactating mother – 20-40 mg/day
Rich Source – Liver, heart, kidney, spleen
Good Sources: Spinach, bananas, apples,
Poor Sources: Milk, wheat Absorption : Absorption Iron is absorbed in Ferrous state. In food stuff Iron is present in Ferric form which is converted to Fe++ by Ascorbic acid or cysteine.
Factors affecting Iron absorption
Acidity, Ascorbic acid & cysteine levels
High phosphate diet
Phytic acid & Oxalates
Cu deficiency Normal Serum Iron level is 65 – 170 mg/100ml : Normal Serum Iron level is 65 – 170 mg/100ml Iron level in blood is maintained at the level of absorption only.
It is not excreted in Urine.
In Iron levels – Iron absorption
In Iron levels – Iron absorption Disorders : Disorders Iron deficiency anemia
Defect in absorption
Chronic blood loss
Hook worm Infestation
Nephrosis Slide 8: 2. Hemosiderosis
3. Hemochromotosis Slide 9: Major Elements:
Daily requirement more than 100mg.
- calcium, Magnesium, Phosphorus, Sodium, Potassium, Chlorine, Sulphur.
Daily requirement less than 100mg.
- Iron, Iodine, Cu, Mn, Zn, Co, Mo, Se & F. Calcium : Calcium Total content of Ca in our body is around 1 – 1.5 kg
Sources:- Milk – Good source
Fish Medium source
Cereals - poor source
Adults – 500mg
Children – 1200 mg
Pregnant & Lactating women – 1500 mg Slide 11: Normal Serum levels 9 -11 mg/dl Slide 12: Absorption:
Ca absorption requires a carrier(calbindin)
Factors increase Ca absorption
Vitamin D (Calcitriol)
Amino acids ( Lysine & Arginine)
Factors decrease Ca absorption
High phosphate content
Malabsorption syndromes. Ca is mainly extracellular.Ca influx into the cell by Ca++/Na+ exchange expulsion by Ca++/H+ ATPase dependent pump. : Ca is mainly extracellular.Ca influx into the cell by Ca++/Na+ exchange expulsion by Ca++/H+ ATPase dependent pump. Functions
Activation of Enzymes
Calmodulin is a regulatory protein 4 Ca++ ions binds to calmodulin and activates it.
Ex: 1) Glycogen synthase
2) glycerol – 3- phosphate dehydrogenase
4) Pyruvate dehydrogenase etc.
Ca directly activates enzymes like Pancreatic lipase, enzymes in coagulation . Slide 14: 2) Ca mediates excitation and contraction of Muscle fibres.
Ca causes neuromuscular Irritability Tetany.
3) Ca helps in transmission of nerve impulses
4) Ca – Calmodulin complex
regulates – Degranulation of
- Cell motility Slide 15: 5) Secretion of hormones
6) Act as second Messenger in Signal
7) Decreases Vascular permeability
8) Ca is a factor in Coagulation
9) In Myocardium Ca++ prolongs systole
10) Bone & teeth Slide 16: Factors regulate Blood Ca levels
Vit – D
5) Serum Protein
6) Alkalosis & Acidosis
7) Children & Pregnancy
8) Kidney threshold. Slide 17: PTH – acts on bones
It induces osteoclasts
Osteoclasts release Lactate – Solubulize
Bone resorption Ca++ Slide 18: PTH - acts on kidney
PTH causes renal excretion of Ca
renal excretion of Ph
PTH induces formation of Calcitriol, this indirectly increases calcium absorption from Intestine Slide 19: Calcitonin Thyroid parafollicular cells.
Decreases serum Ca levels
Decreases the activity of
Decreases resorption of
Calcitonin secretion is stimulated by Serum Ca levels, gastrin, glucagon and biological amines. Slide 20: Serum Proteins :
Hypo albunemia Serum Ca levels but ionized Ca level will be normal.
Alkalosis - favor binding of Ca++ to
leading to Hypocalcemia
Acidosis - favors Ionization of Ca++
Kidney threshold – Renal threshold for Calcium is 10 mg/dl (Ionized) Slide 21: Hypercalcemia
Calcium levels more than 11mg/dl
Major cause Hyper parathyrodism
ectopic PTH Secreting
X-rays show punched out lesions on bone.
Urinary Calcium elevated
Recurrent Urinary calculi
Anorexia, muscle weakness. Slide 22: Hypocalcemia
Calcium levels less than 8.8 mg/dl.
less then 7.5 mg/dl leads to Tetany.
In tetany – Carpopedal spasm
- Laryngismus Slide 23: Renal tubular acidosis
Defect in production of H+ ions in Renal tubules.
Excess urinary loss of Ca, bicarbonate, Sodium, potassium, mg & P. Phosphorus : Phosphorus Total body content of phosphorus is 1kg
It is an intracellular ion.
Formation of bone & teeth
Production of high energy phosphates
Synthesis of coenzymes NAD, NADP.
DNA & RNA Synthesis
Involved in Phosphorylation reactions
Regulates Acid Base balance Slide 25: Daily requirement
Milk - good source
Cereals, nuts & meat - moderate source
Calcitriol Increases Phosphate absorption Slide 26: Normal levels
3 – 4 mg/dl in adults
5 – 6 mg/dl in children
Hypo phosphatemia in
Rickets. Slide 27: A reciprocal relation with Phosphorus and Calcium.
In Renal failure – Phosphorus excretion diminished
- Ca excretion Increase
leading to low Ca levels and high phosphorus level Tetany Magnesium : Magnesium Total body magnesium is 20 gm
75% in bones
25% in soft tissues & body fluids. Mainly seen in Intracellular fluid.
Men - 400 mg/day
Women- 300 mg/day
Cereals, beans, vegetables, milk & fruits
Absorption requires a specific carrier in intestinal cells. Normal Serum levels 1.8 – 2.2 mg/dl : Normal Serum levels 1.8 – 2.2 mg/dl Functions :
Magnesium is the activator of enzymes requiring ATP.
Mg++ is required for proper Neuromuscular function.
Mg++ has a role in Insulin Sentivity
Bone formation Disorders : Disorders Hypo magnesemia
Protein energy Malnutrition
Neuromuscular – hyper irritability
Carpopedal Spasm (Na+) Sodium : (Na+) Sodium Total body Sodium is 4000 meq
50% in bones, 40% in ECF & 10% in Soft tissues
It is the major Extracellular cation
In Hypertensive 1 gm/day is recommended
Table salt (Nacl) is the major source.
Other sources are vegetables, nuts, eggs and milk. Functions : Functions Sodium regulates Osmotic pressure and fluid balance
2) Regulates Acid-base balance (NaH Co3)
3) It is involved in absorption of Glucose, Galactose & Aminoacids.
4) It helps in cell permeability. Absorption : Absorption Sodium is readily absorbed in GIT
Normal Serum level is 135-145 meq/L
Kidney is the major source of excretion.
Around 800 gm/day is filtered by Glomerulus in that 99% is reabsorbed by tubules.
This reabsorbtion is controlled by Aldosterone
Sweating causes loss of sodium. Disorders : Disorders Hyponatremia Sodium levels.
- Diarrhea, Vomiting
- Chronic renal failure
- Addisons disease (adreno cortical Insufficiency)
- Renal tubular acidosis
Mild - head ache, muscle cramps
Moderate & severe - Low Blood pressure & Circulatory failure Hypernatremia Sodium levels : Hypernatremia Sodium levels Cushings syndrome
Prolonged administration of steroid hormones (Cortisone, ACTH/Sex hormones)
Severe dehydration (only water)
(Burns, Diabetes Insipidus)
Increased Blood volume, HTN Potassium : Potassium Total body potassium is 3500 meq 75% in skeletal muscle
It is the major Intracellular cation
Banana, Orange, Potato, beans, Liver etc.
Rich Source is Tender coconut water. Slide 37: Functions:
It maintains Intracellular Osmotic pressure
Involves in cardiac & skeletal muscle activities
Mainly K+ required in depolarization & contraction of Heart.
Involved proper transmission of Nerve Impulses
Pyruvate kinase needs K+
Involved in Biosynthesis of proteins Slide 38: Normal Serum Potassium
3.5 – 5 meq/L
(Cell contain 100 – 120 meq/L)
Excretion is through urine, during absorption of Na+ there is obligatory loss of K+
Aldosterone K+ excretion Disorders : Disorders Hypo kalemia
Serum K+ less than 3 meq/L
Renal tubular acidosis
Diarrhea & vomiting
In Diabetic coma treatment with Insulin & Glucose
Cardiac arrest Hyperkalemia : Hyperkalemia Addisons disease
Depression of central Nervous system
Bradycardia & Cardiac arrest Chlorine : Chlorine Intake, output & metabolism of Na+& cl- run in parallel
table salt – Nacl
grains, leafy vegetables, eggs & Milk. Excretion is through urine as sodium : Excretion is through urine as sodium Functions
Regulates Acid Base balance, Osmotic pressure, fluid balance in relation with Na+ & k+
Cl- are necessary for HCL formation
Salivary amylase is activated by chloride Slide 43: Normal serum level is 96-106 meq/L
CSF level is 125 meq/L
Renal tubular acidosis