Minerals According to the body needs, minerals are divided into 2 groups: I. Macrominerals: They are required in amounts less than 100 mg/day. They include: iron, copper, fluoride, iodine, manganese, selenium and zinc. They are required in amounts greater than 100 mg/day. They include: calcium, phosphorus, magnesium, sodium, potassium and chloride II. Microminerals (trace elements):

I. Macrominerals Calcium Sources: Milk, milk products, beans and egg yolk. Absorption: By active transport system in the upper small intestine by the help of vitamin D (1,25 dihydroxy cholicalciferol). Body calcium: calcium is the most abundant mineral in the body. Most of calcium (99%) is present in the skeleton (bones and teeth), the remaining 1% are present in body fluids and other tissues Plasma calcium: Plasma calcium: normal level ranges from 9-11 mg/dl

Hormonal regulation of Plasma calcium: 1. Calcitonin: is secreted from thyroid gland in response to increased blood Ca level. It decreases Ca through: A.Mobilization of calcium from blood into bone B. Decrease Ca reabsorption by renal tubules 2. Parathyroid hormone (PTH): secreted from parathyroid gland in response to decreased calcium levels. It increase calcium by: A. Mobilization of calcium from bone to blood (bone resorption) B. Increases Ca reabsorption by renal tubules C. Increase absorption of calcium from small intestine through stimulation of vitamin D activation.

Hypercacemia : may be due to: 1.Hyperparethyrodism due to adenoma ( benign tumor of the gland) 2.Excess intake of vitamin D or calcium 3.Milk-alkali syndrome : patients who receive milk and alkalies for long time, for treatment of peptic ulcer 4.Drugs such as thiazide diuretics Hypocacemia: due to: 1.Hypoparathyrodism 2.Renal disease where activation of vitamin D is inhibited Requirments: 1.Adult: 800 mg/day 2.Children, pregnant and lactating women: mg/day

Sodium Sources: Sources: The main source is table salt Absorption: Absorption: from small intestine (ileum). It is nearly completely absorbed. Body sodium: 2/3 of sodium is present in tissues and body fluids. About 1/3 is present in skeleton (bone and teeth) Requirements: 5 g/day Alterations of plasma sodium: Hypernatremia : excess plasma sodium is caused by: 1.Cushing syndrome. 2.Conn's disease due to excessive aldosterone secretion 3.Diabetes inspidus due to rapid loss of water 4.Drugs such as cortisone

Hyponatremia: decrease plasma sodium caused by: 1.Addison's disease: due to deficiency of aldosterone 2.Renal failure where renal reabsorption of sodium is inhibited 3.Dehydration: due to loss of water and sodium 4.Thaizide diuretics which block renal reabsorption of sodium Toxicity of sodium: Hypertension in susceptible individuals. Potassium Sources: vegetables, fruits and nuts vegetables, fruits and nutsAbsorption: Readily occur from small intestine Body sodium: 2/3 of potassium is present in tissues and body fluids. About 1/3 is present in skeleton (bone and teeth) Requirements: 4 g/day

Alterations of plasma sodium: Hyperkalemia: excess plasma potassium is caused by: 1.Addison's disease: due to deficiency of aldosterone 2.Acidosis 3.Tissue necrosis e.g. major trauma and burns due to leakage of tissue potassium 4.Chronic renal failure with oliguria 5.Uncontrolled D. M. Lack of insulin prevent potassium from rntering cells 1.alkalosis 2.treatment of hyperglycemia with insulin without taking potassium, as insulin helps potassium ion to enter cells 3.Excessive vomiting and diarrhea 4.Cushing syndrome 5.Diuretics Hypokalemia: decrease plasma potassium caused by:

Microminerals (Trace elements) IRON Sources: Liver, heart, kidney, spleen, and fish Sugarcane syrup (molasses), dates and egg yolk N.B. Most of dietary iron is present in the ferric stae. Absorption: from small intestine. Usually 10-20% of dietary iron is only absorbed. Iron is absorbed in ferrous state. Reducing substances such as vitamin C and SH- of cysteine of dietary protein help the reducing of ferric ions into the absorbable form (ferrous state). Body iron: The total body iron of adult is 3-5 g distributed as follows: I -RBCs iron ( haemoglobin) is about 65% of total iron II- Tissue iron (32%): includes

Available forms (28%) i.e. can be used when there body need 1-Ferritin : is the main storage form of iron. Composed of protein (apoferritin + iron). Present in iron stores: liver, spleen, bone marrow and intestine. 2- Haemosiderin: These are granules composed of iron, protein and polysaccharides. Used as another store of iron III- Plasma iron: present in the form of: 1-plasma iron : ranges from μg/ dl 2- Transferrin : is a glycoprotein which carry iron in ferric state. 2- Transferrin : is a glycoprotein which carry iron in ferric state. Non available forms (4%): can not be used even there is body need. All these forms are hemoprotein i.e. contain heme ring. Examples are: 1. Myoglobin: present in muscle and heart 2. Cytochromes: a, b and c: act as electron carriers 3. Catalase and peroxidase: act to destroy H 2 O 2

Transport and storage of iron: 1.Absorbed iron enters in the portal blood in the ferrous state. 2.In the plama it is rapidly oxidized to ferric state by the help of protein- containing copper called: Ceruloplasmin 3.Then ferric ions are carried by transferring, which is\taken mostly by bone marrow to synthesize hemoglobin 4.Iron from iron stores (ferritin) can be released into plasma and carried by transferring to be used by B.M. and other tissues Requirements: Requirements: 1.adults: 10 mg/day 2.Pregnant and lactating female: 30 mg/day

Copper Sources: Most diet provides the amount of copper needed per day. Absorption: Mainly in the upper small intestine Body copper: 64% of copper are found in muscles and the remaining in other tissues including liver and bones. Plasma copper : 90 μg/ dl. Copper is essential component of several metaloenzymes such as: 1.Ceruloplasmin: which oxidizes ferrous into ferric in plasma 2.Superoxide desmutae: antioxidant enzyme 3.Cytochrome oxidase Requirements: 2-3 mg/day Alterations of plasma copper: Hyper cupremia (Excess copper and ceruloplasmin) occur in infections and malignancies

Hypocupremia (decreased plasma copper): occure in a disease called Wilson's disease in which copper accumulate in large amounts in: 1.Liver causing liver cirrhosis 2.cornea causing greenish- brown color of the corneal margine Kidney causing damage of renal tubules leading to increased excretion of copper and ceruloplasmin resulting in low plasma copper. Iodine The only function is formation of T3 and T4 from thyroid gland, so deficiency of iodine leading to hypothyroidism and disease called Simple Goiter. Requirements: μg/day Zinc, Selenium, fluoride and cobalt