Nursing lecture 1 by Rãjêh Hãsãsñëh

Nutrition and Diet Therapy 2014-2015 Dr. Hazem Agha Ph.D Public Health Nutrition

Key Terms:  Nutrition:  The study of food, including:  How food nourishes our bodies  How food influences our health. 

includes all the processes involved with : ingestion, digestion, absorption, metabolism, and excretion of food. N= I+ D+ A+ M+ E 2



Nutrients:

The chemicals in foods that are critical to human growth and function. 



Six classes of nutrients:      

carbohydrates fats and oils proteins vitamins minerals water

 Essential

Nutrient:

 Body

can’t make or can’t make enough  Must meet 3 characteristics:  It has a specific biological function.  Removing it from the diet leads to a decline in human biological function.  Adding the omitted nutrient back to the diet before permanent damage occurs restores those biological functions impaired by its absence. 4

Essential Nutrients

 

Dietetics : The practical application of the principles of nutrition; it includes the planning of meals for the well and the sick.



Diet:



Typical pattern of food choices.



Balanced nutrition :

Ensuring we get a daily supply of the adequate amount of nutrients from our diet to stay healthy. 6

There are no bad foods, just bad diets“ “Absence of healthy diet and regular exercise together are one of the 3 key causes of death in Palestine.” 7

Why is Nutrition Important? 1. Nutrition contributes to wellness. Wellness: the absence of disease. “Physical, emotional, and spiritual health” 

It helps in: • Growth & development • Improves immunity • Detoxification • Anti-aging • Increasing energy levels & vitality 

Result : Overall Wellness!

2. Nutrition can prevent disease. a. Nutrient deficiency diseases: scurvy, goiter, rickets b. Diseases influenced by nutrition: chronic diseases such as heart disease c. Diseases in which nutrition plays a role: osteoarthritis, osteoporosis 10

Examples of Diseases related to Nutrition:

World Health Organization (W.H.O.) says… 70 – 70 - 50 

70% of all doctor visits are due to

diet related conditions.  70% of major killing diseases… strokes, cancer, cardio vascular diseases and diabetes, are directly related to our diet and lifestyle. 

50% of these can be prevented

with good nutrition & lifestyle improvement.

Classification of nutrients:  Inorganic nutrients: (do not contain Carbon)

▪ minerals. ▪ water.  Organic nutrients

: (contain Carbon)

▪ Carbohydrates. ▪ Lipids. ▪ Proteins. ▪ Vitamins.

 Macronutrients:

nutrients required in large amounts (gm).  provide energy.  Carbohydrates, fats and oils, proteins.  Micronutrients:  nutrients required in small amounts (mg,ug).  Do not provide energy.  Necessary for : • growth and maintenance of tissues. • regulation of body processes 



Vitamins and minerals.

acc to Energy:



 Energy Yielding: Carbohydrate, Fat, Protein  Non-energy Yielding: Vitamins, Minerals, Water

acc to Origin:



 

Foods of animal origin. Foods of vegetable origin.

acc to Function:

   

Body building foods: protein Energy giving foods: fat, CHO, protein Protective foods: vitamins, minerals.



percentages of nutrients in young male and female bodies:

Insert Figure 1.2

Vitamins are not included, because they are in very small amounts. 16

PROTEINS: Proteins are complex organic nitrogenous compounds.  They also contain Sulfur and in some cases Phosphorous and iron.  Proteins are made of monomers called Amino Acids.  There are about 20 different AA which are found in human body.  Of these, 8 AA are termed “Essential AA” as they are not synthesized in human body and must be obtained from dietary proteins. 

Essential Amino Acids: 1. 2. 3. 4.

Tryptophan Methionine Valine Threonine

5. 6. 7. 8.

Phenylalanine Leucine Isoleucine Lysine

9. Histidine (infants) 18

Proteins can supply 4 kcal of energy per gram.  They are not a primary energy source.  Proteins are an important source of nitrogen.  Sources : meats, dairy products, seeds, nuts, legumes 

Functions of Protein: 1. 2.

3. 4. 5. 6.

Body building. Repair and maintenance of body tissues ( nucleoproteins as DNA, RNA). Maintenance of osmotic pressure. Synthesis of bioactive substances and other vital molecules. All enzymes are proteins. Some hormones are proteins or peptides. " insulin, thyroxin, adrenaline” 20

7. 8.

ď&#x192;ź

Antibodies are proteins. Some proteins are important in transport and storage in the body. Transport protein: as hemoglobin; Globin is colorless protein carries O2 to cells and heme is dark red chemical compound contains iron. Storage in the body of some minerals (iron, copper) is achieved by combination with a protein. 21

10. 11.

Mechanical support to skin and bone is given by collagen. Some AA are needed as neurotransmitters. Act as PH puffer against extreme acidity or alkalinity.

 Assessment 

  

of Protein nutrition status:

Protein nutrition status is measured by Serum Albumin Concentration. It should be more than 3.5 g/dl. Less than 3.5 g/dl shows mild malnutrition. Less than 3.0 g/dl shows severe malnutrition.

Protein requirements According to current recommendations, a healthy adult requires 0.8 grams of protein per kilogram of healthy body weight.  To obtain this quantity of protein, human benefits when dietary protein makes up approximately 10% to 15% of total energy intake.  Protein requirements increased during times of stress and disease. 

FAT:  Most

of the body fat (99 %) in the adipose tissue is in the form of triglycerides.  in normal human, adipose tissue constitutes 1015 % of body weight.  Provide 9 kcal per gram.  An important energy source during rest or low intensity exercise.  Sources: butter, margarine, vegetable oils. 25

Fats 

Saturated:

Found in animal  Increase Blood Cholesterol  Unsaturated: 

Monounsaturated (has 1 point of unsaturation).  Polyunsaturated (many points of unsaturation).  Trans Fatty acids: during food processing; hydrogenation does not lead to complete saturation of polyunsat FA resulting in Trans-FA. 



Saturated Fats and Trans Fatty Acids:  Increase cholesterol level the most.



Unsaturated fats: decrease LDL cholesterol Animal fats are high in saturated fatty acids. Vegetable fats are high in unsaturated and polyunsaturated fatty acids.

 



Cholesterol : Not a true fat, classified as a sterol.  Does not provide energy ( no kcal)  Synthesized in liver (1000 mg/day). ”endogenous cholesterol”  Found in foods of animal origin: animal organs, eggs, milk. “exogenous cholesterol”  ↑↑ blood levels is a major risk factor for CAD . 



1. 2.

 o o o

Cholesterol is transported in the blood in 2 forms: LDL: bad form;↑ risk for atherosclerosis. HDL: good form ; carries cholesterol to the liver to be destroyed – Function of cholesterol: component of cell membrane. precursor of other sterols (vit D). necessary for production of several hormones. (cortisone, estrogen , adrenaline, testosterone).

 Essential

fatty acids:

Those that cannot be synthesized by humans  Dietary sources of EFA:  Linoleic acid: Sunflower oil ,Corn oil, Soya bean oil ,Sesame oil ,Groundnut oil, Mustard oil,Palm oil ,Coconut oil.  Arachidonic acid: Meat, eggs, milk.  Linolenic acid: Soya bean oil, Leafy greens. 

Functions of Fats: 1.

They are high energy foods, providing as much as 9 kcal for every gram. Fats serve as vehicles for fat-soluble vitamins. Fats in the body support viscera such as heart, kidney and intestine. Fat beneath the skin provides insulation against cold. 32

Vegetable fats are rich sources of essential fatty acids which are needed by the body for growth, structural integrity of the cell membrane and decreased platelet adhesiveness. Diets rich in EFA have been reported to reduce serum cholesterol and low-density lipoproteins. Polyunsaturated fatty acids are precursors of prostaglandins. 33

ď ° Fat

requirements:

Dietary guidelines recommended that total fat intake should not exceed 30 % of total daily energy intake. ď&#x192;ź Saturated fats should contribute less than 10%, polyunsaturated fats should not exceed 10%, monounsaturated fats should provide the remaining 10%. ď&#x192;ź

N.B : Fat Warning!  Since

fats have 9 kcal/g, while proteins and carbohydrates have only 4 kcal/g, there is more than twice as much energy in a gram of fat as in a gram of proteins and/or carbohydrates, So if one is trying to

reduce energy intake, watch the fat!

Carbohydrates: Primary source of energy for the body, especially for the brain.  Provide 4 kcal per gram.  Sources: grains (wheat, rice), vegetables, fruits, and legumes. 

Simple Carbohydrates:  Classified

according to saccharides.  Monosaccharide:  building blocks of all other CHO.  glucose (dextrose), fructose, galactose.  Disaccharide:  sucrose, lactose, maltose,  Artificial sweeteners. 37

Complex Carbohydrates:  Polysaccharides are

complex carbohydrates  Starches, glycogen, & fiber are polysaccharides.  Starches are the major source of CHO in diet. (grains, cereals, breads, pasta, starchy vegetables and legumes).  Glycogen: animal starch (found in liver & muscle tissue, provides immediate fuel for muscle action. 38

 The

carbohydrate reserve (glycogen) of a human adult is about 500g.  This reserve is rapidly exhausted when a man is fasting.  If the dietary carbohydrates do not meet the energy needs of the body, protein and glycerol from dietary and endogenous sources are used by the body to maintain glucose homeostasis. 39

 Dietary

fibers :  non-starch polysaccharide.  divided broadly into cellulose and non-cellulose polysaccharides .  cannot be broken down by body to digest.  Characterized by increased water-holding capacity so adds volume.  no fuel or energy producing.  all degraded by micro flora in the human colon.  found in: vegetables, fruits and grains.

 Functions 

of fibers: promote regularity of bowel movements

(absorb H2O → ↑ volume→ propulsion of colon content).  helps in regulating blood sugar.  reducing cholesterol.  promote weight loss.  reduce risk of colon cancer and diverticular disease. 41

Carbohydrates recommendations 

Carbohydrates has no RDA, but there is a recommendation that 55-60% of total kilocalories should come from carbohydrates.

Vitamins: 



 1. 2.

Vitamins are a class of organic compounds categorized as essential nutrients. They are required by the body in a very small amounts ( micronutrients) that do not supply energy to our bodies. Vitamins are divided in to two groups: fat soluble vitamins: A, D, E and K water soluble vitamins: B and C. 44



Fat-soluble vitamins: A, D, E and K  Dissolve

easily in fats and oils.  Stored in the body.  Toxicity can occur from consuming excess amounts because they accumulate in body.  Water-soluble vitamins: C , B vitamins.  Remain dissolved in water.  Excess are excreted by the kidneys and cannot be stored in our bodies.  Toxicity occur only as a result of vitamin supplementations. 45

Fat Soluble Vitamins : 

Vitamin A



Vitamin D



Vitamin E



Vitamin K 47

Vitamin A:  Vit

A covers both a pre-formed vitamin, retinol, and a pro-vitamin, beta carotene, some of which is converted to retinol in the intestinal mucosa.  Sources:  as Retinol: breast milk, colostrums “very rich”, animal milk and products, liver from animals and birds, kidney, eggs, butter and other animals fat.  as Carotene: dark and medium-green leafy vegetables (spinach, molokhia), orange vegetables (carrots, sweet potatoes), orange-red-yellow fruits (apricot, mango, melon sweet, peaches). 48

Functions :  It

is indispensable for normal vision. It contributes to the production of retinal pigments which are needed for normal vision in dim light.  It is necessary for growth, differentiation and integrity of epithelial cells which lines intestinal , respiratory and urinary tracts as well as the skin and eyes.  Strengthens immune system.  It supports growth, especially skeletal growth  may protect against some epithelial cancers as bronchial cancers. 49

Deficiency : 

Signs of vit A deficiency are mainly ocular.  Night blindness  Conjunctival xerosis  Bitot's spots  Corneal xerosis  Keratomalacia.

  

Follicular hyperkeratosis: dry, scaly, rough skin” goose skin”. Impaired growth. Impaired immune competence. 50

Vitamin D:  The

nutritionally important forms of Vitamin D in man are Calciferol (Vitamin D2) and Cholecalciferol (Vitamin D3).  Toxic in large amounts.  Sources:

sunlight is the principle source (UV)  cod and liver oil, egg yolk, salmon, tuna, sardines, milk fat.  Milk is poor source unless fortified. 

Functions :  Intestine:

Promotes intestinal absorption of calcium and phosphorus.  Bone: Stimulates normal mineralization, Enhances bone reabsorption, affects collagen maturation.  Kidney: ↑ tubular reabsorption of phosphate.

Deficiency:  Rickets

bone”.

(kids), osteomalacia (adult) “softening of 52

 Rickets

Vit E (tocopherols, tocotrienols): 

Sources:

• •

plant products, richest are oils, bran. animal tissues contain low amounts.



Function: 1- antioxidant “main function”. 2- normal metabolism of all cells.



Deficiency: Uncommon



occurs only in cases of lipid malabsorption Premature infants are at risk because of the limited transplacental movement.



Vitamin K: 

Synthesized in intestine.



Sources: liver, soybean oil, wheat bran, green leafy vegetables.



Function:

aids in production of prothrombin, required for normal clotting of blood. Involved in bone metabolism.

 Deficiency:

Associated with: lipid malabsorption, destruction of intestinal flora as with chronic antibiotic therapy and in liver disease.  Newborn especially premature are susceptible during first few days due to failure to establish vit k- producing intestinal flora.  Predominant sign is hemorrhage (due to hypoprothrombinemia). 

Water Soluble Vitamin : Water Soluble Vitamins  Vitamin C  B Vitamins:  Thiamin (B1)  Riboflavin (B2)  Niacin (B3)  Vitamin B6  Folic Acid  Vitamin B12  Pantothenic Acid  Biotin

Skin, bones, infections

Release energy from Macronutrients:

Thiamine (Vit B1):  Sources:   

Richest are liver and yeast. Cereals : most important but most is removed in milling Synthesized in small intestine.

 Function:  It

has essential role in CHO metabolism and neural function. this involves the metabolic activation of the vitamin to thiamin triphosphate (TTP)= cocarboxylase, which serves as enzyme in energy metabolism.

 Deficiency:

Beriberi (rare).

Beriberi: There are two major types of beriberi: 1-Wet beriberi affects CVS. 2-Dry beriberi (WernickeKorsakoff syndrome): affect the CNS.  Symptoms of dry beriberi: Difficulty walking ,Loss of sensation in hands and feet ,Loss of muscle function or paralysis of the lower legs ,Mental confusion, speech difficulties ,Strange eye movements .  Symptoms of wet beriberi: Awakening at night ,short of breath , Increased heart rate, Swelling of the legs (edema). 



Rx : Thiamine injection



N.B: wet= edema. dry= no edema. 60

 DRI

Men: 1.2 mg/day.  Women: 1.1 mg/day. Higher if pregnant or lactating 

Riboflavin (Vit B2):  Sources: 

Milk and dairy products, organ meat, eggs, green leafy vegetables.

 Function:

Essential for metabolism of CHO, amino acids and lipids (act as coenzymes).  Antioxidant.  Essential for growth.  Enzymatic role in tissue respiration. 

 Deficiency:

Deficiency is first manifest in tissues with rapid cellular turnover as skin and epithelia.  Deficiency of B2 usually occur in combination with deficiency of other water-soluble vitamins.  Occurs in children who lacks milk or meat products in their diet. 

Cheliosis, angular stomatitis, glossitis, seborrhic dermatitis of nasolabial fold.  Magenta red tongue.  Vascularization of cornea, corneal ulceration.  Photophobia and lacrimation.  Neuropathy.  Anemia. 



DRI:

 Men:

1.3 mg/day  Women:1.1 mg/day

Definition of

CHEILOSIS : an abnormal condition of the lips characterized by scaling of the surface and by the formation of fissures in the corners of the mouth

Riboflavin

deficiency – angular stomatitis of the mouth and lips, evident as irritation and fissuring in the corners of the mouth

.

. ď&#x192;źGlossitis

is a condition in which the tongue is swollen and changes color, often making the surface of the tongue appear smooth.

seborrhic dermatitis of nasolabial fold.

Niacin (Vit B3): :  

Sources:

Meats, poultry, fish, peanuts, yeast, soybeans, wheat germ.



Function:

 coenzymes in metabolism of CHO, FA, and AA.

Deficiency: Pellagra



 Characterized by 3 D : dermatitis, diarrhea,

dementia. 69

 Pellagra:

3D 

  

Dermatitis of exposed areas: face, v shaper area of chest, lower limbs Dementia Diarrhea. The 4th D: death 70

PELLAGRA

 At

risk of Pellagra:  Poorly nourished people living in urban slums •

Particularly those with alcohol addiction.



Still common in areas of Africa and Asia.

 DRI • •

of Niacin:

Men: 16 mg/day Women: 14 mg/day

 Tolerable

upper limit: 35 mg/day. 72

Pyridoxine (Vit B6):  

Its metabolic active form is pyridoxal phosphate. Functions:

Serves as coenzyme in numerous enzymes involved in all reactions in metabolism of AA, neurotransmitters, glycogen, sphingolipids, heme, and steroids. Involved in synthesis of unsaturated FA from essential ones. Essential for conversion of tryptophan to niacin. Essential for normal growth.



Deficiency:



Rare, anemia, CNS abnormalities, skin lesions, vomiting

2. 3.

 •



DRI: Adult (19-50 y): 1-3 mg/day

Tolerable upper limit: 100 mg/day.

Cobolamin (Vit B12)  Vitamin B12

is a complex organo-metallic compound with a cobalt atom.  The preparation which is therapeutically used is cyanocobalamine.  It is made by microorganism in small intestine.  B12 must bind with intrinsic factor (IF) which is protein secreted by stomach lining.  Sources: animal products (main sources), oysters, clams, organ meat, eggs, shrimps, chicken 75

Functions :  Important

for the normal metabolism of all cells especially those of GIT, bone marrow and nervous system.  Aids in proper formation of RBCs.  Cooperates with folate in the synthesis of DNA.  Has a separate biochemical role, unrelated to folate, in synthesis of fatty acids in myelin 76

Deficiency:  The

most common cause : malabsorption of vitamin due to inadequate production and secretion of IF which is common in aging and hereditary deficiency.  Dietary deficiency of B12 may occur in strict vegetarians who eat no animal products.  B12 deficiency is associated with megaloblastic anemia. 77

If IF is also missing → (pernicious anemia).  demyelinating neurological lesions in the spinal cord and infertility (in animal species).  N.B: vegan and after gastrectomy, supplementation is 

needed.  DRI: •

Adult: 2-4 µg/day. 78

Folate (Folic acid, folacin):  Sources:

Leafy green vegetables. (folate derived from” foliage” Fresh uncooked vegetables and fruits: heat of

• •

cooking and oxidation that occur during storage destroy most of folate.

liver, kidney, yeast. Orange juice and legumes. Eggs, Milk: may enhance folate absorption. Can be synthesized in intestinal tract.

• • • • •

 Of

all the vitamins, folate is most likely to interact with medications:

• • • • •

Antacids. Aspirin and its relatives.  Oral contraceptives. Anticonvulsants. Smoke

Interfere with body use of folate

 Occasional

use of these drugs is ok.  Frequent users need to pay attention to their folate intake.

Folate (Folic acid, folacin):  •



DRI: Adult: 400 µg/day

Tolerable upper intake: 1000 µg/day.



Function:

Essential for formation of RBCs and WBCs in bone marrow and for their maturation. Essential for biosynthesis of nucleic acids, especially important in early fetal development. Essential for normal maturation of RBCs. Function as coenzyme tetrahydrofolic acid.

3. 4.

 Deficiency:  Because

immature red and white blood cells and cells of GIT divide rapidly, they are most vulnerable to deficiency.  Anemia: • •

related to anemia of vit B12 malabsorption. The 2 vitamins work together in producing RBCs.

 Diminished immunity.  Abnormal

digestive function. 83

 Nural

tube birth defect:  Ranges from slight problem in the spinal cord to mental retardation.  Severely diminished brain size.  Death shortly after birth.  Arise in first few days or weeks of pregnancy.

 All

enriched grain products are fortified with folic acid.  Since fortification began, folate intakes have increased and there has been an almost 25% drop in the national incidence of neural tube defects.

Pantothenic acid:  Source: •

all plant and animal food, yeast is best source.



Function:

Energy metabolism. As part of coenzyme A, which functions in the synthesis and breakdown of many vital body compounds. Plays a role in 100 steps concerned with synthesis of lipid, hemoglobin,and neurotransmitters.



Deficiency: uncommon.

Biotin:  Source: •

Widspread in food.

 Function: 1. Energy

metabolism. 2. coenzyme in metabolism of fat and CHO.  Deficiency: uncommon.  Occur in those consuming raw eggs in great amounts or in tube feeding (when raw eggs is used).  “ raw eggs contain protein that binds to biotin” 87

Role of B Vitamins :  Metabolism of

CHO, lipids, AA. (B1, B2, B3+ Biotin+ Pantothenic).  Energy metabolism; directly or indirectly. (All B vitamins).  Protein synthesis: B6.  Cell replication: B12, folate.

How Are B Vitamins Related to Heart Diseases ?  Homocysteine:  Inherited

high level correlates with a severe early form of CVD.  Some CVD patients without the inherited disorder also accumulate homocysteine in the blood.  Elevated homocysteine may be an indicator of CVD risk. 89

 Deficiencies

of Vit B12, folate, or Vit B6 cause excess homocysteine.  Supplements of these vitamins lead to significant drop of homocysteine level.  It is unknown how this affects person’s CVD risk.  High dietary intakes of folate and Vit B6 correlate with lower blood values of other substances associated with CVD. 90

Vitamin C (Ascorbic acid):  The

most sensitive of all vitamins to heat.  Destroyed by exposure to air, processing, refrigeration, adding of alkali  Man, monkey and guinea pig are perhaps the only species known to require vitamin C in their diet 

Sources:  only

present in plant sources.  The only animal source is liver  Best sources: fruits and vegetables.

Functions :  Enhances iron

absorption (reduce ferric to ferrous)  Involved in synthesis of collagen.  Reduces liability to infection, through immunologic activity of leukocytes.  Acts as antioxidants.  Role in cancer prevention.  the role in curing and preventing common cold is controversial, it is not great to recommend routine large intakes, if benefits, are in reducing severity of symptoms. 92

Deficiency :  Deficiency

of vit C results in Scurvy.  swollen and bleeding gums.  subcutaneous bruising or bleeding into the skin or joints.  delayed wound healing.  anemia and weakness.  Scurvy which was once an important deficiency disease, now is no longer a disease of world importance. 93

Vitamins Supplementation

YES √ Or

No Χ ?? 94

 Some

Experts conclude that healthy people might benefit from vitamin supplements taken every day or two.

 Others

conclude that the potential risks of supplementation outweigh the unproven benefits.  Supplements should only be taken only when there is a risk of deficiency. 95

Minerals: Minerals: inorganic substances required for body processes. 

Minerals include sodium, calcium, iron, potassium, and magnesium. 

Minerals have many different functions such as fluid regulation, bone structure, muscle movement, and nerve functioning. 

Our bodies require at least 100 mg per day of the major minerals such as calcium, phosphorus, magnesium, sodium, potassium, and chloride. ď °

We require less than 100 mg per day of the trace minerals such as iron, zinc, copper, iodine, and fluoride. ď °

Minerals Overview:

Major Minerals: calcium, phosphorus, magnesium, potassium, sulfur, sodium, and chlorine

Calcium keeps the nervous system working well and is needed for blood clotting. Osteoporosis is disease caused by calcium deficiency.  Sodium and potassium help regulate the passage of fluids in and out of cells. Too much sodium in the diet may aggravate high blood pressure or hypertension, increasing the risk of heart attack, stroke or kidney disease. Table salt is one source of sodium in the diet. Most sodium comes in food.  Deficiency of potassium can lead to muscle weakness and abnormal heart beat. 

Trace Minerals: iron, iodine, manganese, zinc, copper, and fluorine  Iron:

is a vital part of hemoglobin .  Insufficient iron may cause anemia, As result too little oxygen is carried to cells of the body.  Iodine:  needed for the thyroid gland to function properly.  Too little iodine → thyroid enlarged (goiter).  The primary sources are seafood and iodized table salt. 

100

Calcium: Overview  It

is the most abundant mineral in the body.  It makes up about 1.5-2% of BW; and 39% of total body minerals.  99% of Ca is in bones and teeth; 1% is in blood, extracellular fluids and within cells of soft tissues.  Ca in teeth is not mobilizable. 101

Skeletal Ca: Skeleton is a dynamic tissue.  Bone is constantly synthesized and resorbed.  Bone mass results from complex interactions between osteoclast (resorbing) and osteoblasts (forming).  Peak bone mass occurs during third decade of life, adult bone loss begins during fifth decade in both sex, but progresses more rapidly in females.  Inadequate Ca intake during growth results in failure to achieve peak bone mass.  Genetic, nongenetic factors( nutrition, smoking, consumption of caffeine) and hypogonadism determine peak bone mass. 

102

Serum Ca: 

Total serum Ca consists of 3 distinct fractions: 1. 2. 3.



Ionized Ca (free) 47.6% Anion-complex Ca 6.4% Protein-bound Ca 46.0%

The free ionized Ca= functional, is controlled by parathyroid hormone, calcitonin, and vit D. Total serum Ca is maintained within narrow range of 8.8-10.8% mg. 103

Functions: 1.

Building and maintaining bones and teeth. •

Development of peak bone mass requires adequate amounts of Ca, Ph, vit D, and other nutrients.

Affects transport function of cell membranes, acting as membrane-stabilizer.

Influences transmission of ions across membranes. 104

6. 7.

Influences release of neurotransmitters at synaptic junctions. Influences function of protein hormones, and activation of intracellular and extracellular enzymes. Nerve transmission, regulation of heart beat. Balance between Na and Mg necessary for maintaining muscle tone. Initiates formation of blood clot. 105

Absorption:  Ca

is absorbed only when it is in ionic form.  Usually only 20-30% of ingested Ca and sometimes as little as 10% is absorbed.  Can be absorbed in all parts of small intestine, but the most rapid absorption occurs in the duodenum.  Ca is absorbed by 2 mechanisms:  active

transport : occur at low Ca conc.  Passive transport or paracellular movement: occurs at high ca conc. 106

Factors enhancing absorption: 1) 2)

3) 4)

Best absorbed in acid medium. (PH<7). Increased needs as in growth, pregnancy, lactation, ↓ Ca, and ↑exercise resulting in ↑bone density. Vit D through complex series of steps. Lactose in human infants, and in adults it plays a role. Taking Ca with a meal, especially in elderly. 107

Factors decreasing absorption: 1) 2)

3) 4)

5) 6)

Lack of vit D. Oxalic acid (spinach, chard,….) forming insoluble Ca oxalate.” most potent Ca inhibitor” Coca is also high in oxalate. Phytic acid, in our layers of cereals, form insoluble Ca phytate. Fiber intake, may be a problem in vegetarians. Aging (↓ efficiency of absorption) due to achlorohydria. 108

7) 8) 9) 10)

Some medications. Individuals with fat malabsorption because of formation of Ca-fatty acid soaps. Ca/Ph ratio has little effects unless Ph is very high. Hormones: A. B. C.

Glucocorticoids ↓ Ca absorption. Thyroid stimulates bone resorption. Estrogen; fall in its level in its level at menopause results in or is a major factor in bone resorption. 109

Ca - minerals interactions:  High

intake of Ca can interfere with iron absorption (be taken at different times).

 Same

with Zinc, and manganese so, iron preferred to be taken on empty stomach if possible and Ca to be taken with meal.

110

Excretion:  Over

50% of ingested Ca is excreted in urine, and rest is excreted in faces.  High urinary Ca excretion has been reported to accompany a high protein-diet especially animal protein.

111

Sources:  Milk

and its products. “richest source”  Egg yolk, dark green leafy vegetables.  Sardines, oysters, canned fish.  Soybeans, some legumes. N.B: Cup of milk contains 300 mg Ca.

112

Dietary reference intake: Adult male, Female

1000 mg/d

Post menopausal women

1200-2500mg/d

Adolescents

1300 mg/d

Pregnant and lactating

1000 mg/d

≤18 y

1300 mg/d 113

Deficiency: 1.

Bone deformities:   

Osteoporosis, osteopenia. Osteomalacia. Rickets.

Tetany: 

Extremely low levels of Ca → irritability of nerve fibers and nerve centers → muscle spasm.

N.B: Prolonged bed rest→ increase Ca loss. 114

Calcium toxicity: 

a very high intake of Ca (≥2 g/ d) resulting from taking much supplements may lead to: 1. Excessive calcification in soft tissue especially kidneys. “life threatening” 2. Formation of renal stones. 3. Constipation.

115

Clinical applications:  Protective

effect in hypertension (DASH diet) and in cancer colon.  Useful diagnostic tool in assessing parathyroid gland function, and monitoring kidney disease.

116

Phosphorus: Function 1. Phosphorus is a component of every cell and important metabolites as DNA, RNA, ATP, phospholipids. 2. 80% of the inorganic portion is in bones and teeth, and aids in their formation. 3. Maintains metabolism of fat and CHO. 4. Acts as buffer to control PH of blood. 117

Sources: group: “best source” (cheese, eggs, milk, meat, fish, poultry).  Whole grain cereals, pulses, nuts, carbonated drinks.  Meat

RDA: 700 mg/ day for adults.  Tendency

of deficiency and dietary inadequacy is not likely to occur if protein and calcium intakes are adequate. 118



Salt (sodium and chlorine)



Major/Macro Minerals



Functions



a. Maintain osmotic pressure in body cells b. Maintain neutral pH level in body tissues c. Muscle and nerve activity Formation of hydrochloric acid in digestive juices



Deficiency symptoms



a. Lack of appetite b. Reduced growth c. Lowered reproduction

 

119

 Potassium 

Major/Macro Minerals



Functions



a. Osmotic pressure b. Maintain acid-base balance of body fluids c. Muscle activity Carbohydrate digestion



Deficiency symptoms



a. b. c. d.

 

  

Slow growth rate Reduced feed consumption Muscle weakness Diarrhea

120

 Magnesium  

Major Minerals Functions

a. Activate enzyme systems in body b. Proper maintenance of nervous system c. Carbohydrate digestion d. Utilization of zinc, phosphorus and nitrates Normal skeletal development



Deficiency symptoms



a. Muscle spasms and convulsions b. Hyperirritability

   



121

Magnesium Sources Can If

be mixed with salt or supplement diet is low, magnesium will be pulled from bones

122

 Sulfur 

Major/Macro Minerals



Functions



a. Amino acids make-up b. Lipid metabolism c. Carbohydrate metabolism Energy metabolism



Deficiency symptoms



Slow growth



Sources

 



legumes, Water 123

Iron:  1.

Adult human body contains iron in 2 pools: Functional: Hemoglobin. Myoglobin. Enzymes.

Storage: Ferritin. Transferrin. Hemosiderine in liver, spleen, and bone marrow.

124

Main iron compounds in the body: 1. Haem proteins: A. Hemoglobin: (respiratory transport of O2 and CO2). B. Myoglobin: (transports and stores O2 in muscles). 2. Heam enzymes: A. Cytochromes: (electron transport). 3. Transport and Storage proteins: A. Transferrin: (transport of iron). B. Ferritin: (storage iron). C. Hemosiderin: (storage iron). 125

Why do we need iron in the diet? 1. 2. 3. 4. 5. ď ° ď ś

ď ś

Has a role in cellular respiration. Essential for forming red blood cells. Vital for immune system. Vital for cognitive performance. Critical for normal brain functioning. N.B: Function of iron results from its ability to participate in oxidation and reduction reactions. Iron is highly reactive that interact with oxygen to form intermediates that damage cell membranes or degrade DNA, iron must be tightly bound to protein to prevent this destructive 126 oxidative effect.

Sources: 1. Haem iron (in animal foods):  Constituent of haemoglobin and myoglobin therefore present in meat, fish, poultry, and blood products.  Spleen, liver and kidney are richest sources.  Heart, lean red meat, poultry and fish are 2nd choices.  Forms about 10-15% of total iron intake. 127

2. Non-haem iron:  Found in all foods of plant origin.  Some animal foods as in non-haem enzymes.  Molasses (black honey) is the richest source.  Legumes, dark green leafy vegetables and whole grain cereals are rich sources.  Dried fruits is the major source of dietary iron. 128

N.B: Iron in egg yolk is poorly absorbed due to presence of inhibiting compounds (phosvition).  Milk and its products are practically devoid of iron.  Quantity of iron in human milk is small, but is highly bioavailable.  There is a wrong held belief that foods which darken in colour on cutting are rich in iron, however, this is not true as this dark colour is due to chemical oxidation and does not indicate richness in iron content. 

129

Iron requirements: RDA (mg/d) 6-11 months

1-3 years

4-6 years

7-10 years

Male ≥ 18 years

Female 15-50 years

Female ≥ 51 years

Pregnant

lactating

130

Absorption:  Only

5-15% of dietary iron is absorbed by adult with normal Hb values.  Iron absorption can be increased to 50% in iron deficiency.  From 2-10% of iron in plant foods is absorbed.  From 10-30% of iron in animal foods protein can be absorbed.

131

Factors affecting iron absorption: “Bioavailability” 1. Iron status of the individual:  The lower the iron stores, the greater will be the rate of iron absorption. 2. Form of iron in the diet:  Haem iron is much better absorbed than nonhaem iron.  Absorption rate of non-haem iron depends on the presence of dietary enhancing or inhibiting factors consumed in the same meal. 132

3. Degree of gastric acidity:  Enhances solubility and thus the availability of iron in food.  Lack of HCl in the stomach and intake of antacids interfere with iron absorption.  Also gastric secretions include intrinsic factor which increases iron absorption.

133

4. Physiological State:  Pregnancy and growth which demand increased blood formation, stimulate iron absorption. 5. Increased intestinal motility:  Decreases iron absorption by decreasing contact time.

134



Dietary enhancing factors:

1. 2.

Vitamin C: the single most important enhancer in our community. Meat, fish, poultry by forming absorbable complex.



Dietary inhibiting factors:



Carbonates, phosphates, oxalates in vegetables, phytates in whole grains, Tannins in tea and coffee, some forms of dietary fibers, presence of calcium, EDTA (food preservative). This inhibitory effect can be counteracted by adding Vit c.



135

Iron Deficiency: Causes 1. Deficient intake of iron in diet. 2. Insufficient absorption of iron in intestine. 3. Increased need for iron:    

Growth. Pregnancy. Blood loss. Infections( parasites)

136

Iron Deficiency: Consequences 1. Cognitive performance:   

Delay in psychomotor development. Impairment of cognitive performance. Poor school achievement, less attention and shortterm memory.

2. Resistance to infection:  

Increased morbidity from infectious diseases. Diarrhea is more severe and longer lasting. 137

3. Work capacity and productivity:  

Reduced ability to work. Reduced earning capacity.

4. Outcome of pregnancy:     

Increased maternal mortality. Increased prenatal and perinatal infant loss. Increased risk of premature delivery and low birth weight infants. Precipitates early delivery. Increased maternal deaths. 138

5. Growth of children: 

Mild growth retardation.

6. Decreased social responsiveness 7. Increased risk of lead poisoning in highly polluted environments.

139

Iron overload (Toxicity): Causes Hereditary Hemochromatosis “major cause” 2) Transfusion overload. “ rare” 3) Long term ingestion of large amounts of iron. N.B: Hemosiderosis: an iron storage condition that occurs from consumption of abnormally large amounts of iron in those with a genetic defect resulting in excessive iron absorption. Hemochromatosis= Hemosiderosis+ tissue damage. 1)

140

Iodine: Why do we need iodine:  Growth,

development, and reproduction.  Development and function of brain and CNS.  Maintenance of body temperature.  Basic component of thyroxin hormone(T3,T4).

141

Sources: Iodine occurs in extremely variable amounts in food and drinking water.  Iodine comes from the soil, if soil contains enough iodine; plant foods grown on it contain enough iodine.  Sea food and all salt water fish are rich sources, fresh water fish contains lower amounts but could be considered as potent source.  Amount of iodine in other animal foods depends on the iodine in the foods that they eat.  The best way to obtain adequate intake is to use iodized salt. 

142

RDA:  Adults

and adolescents  Pregnant  Lactating  Children

150µg/d. 175 µg/d. 200 µg/d. 70-120 µg/d.

143

Iodine deficiency: life stage

Major disorders

Fetus

Abortion, stillbirth, congenital anomalies, infant mortality, psychomotor defects, cretinism. Neonatal goiter, hypothyroidism.

Neonate Child and adolescent Adult

Goiter, retarded physical development, impaired mental function and intellectual performance. Goiter, impaired mental function, hypothyroidism.

144

Cretinism: severely stunted physical and mental growth due to untreated congenital deficiency of thyroid hormones (congenital hypothyroidism) due to maternal nutritional deficiency of iodine.  coarse, dry skin, a slightly swollen face and tongue, umbilical hernia, an open mouth that drools. The baby is slow-moving, constipated, a slow feeder . 

145

Hypothyroidism: Fatigue , Weakness  Weight gain .  Coarse, dry hair  Dry, rough pale skin  Hair loss  Cold intolerance .  Muscle cramps .  Constipation  Depression , Irritability  Memory loss  Abnormal menstrual cycles  Decreased libido 

146



Manganese



Micro Minerals



Functions



a. b. c. d.



  

Utilization of phosphorus Reduction of nitrates Amino acid and cholesterol metabolism Synthesis of fatty acids

147



Manganese



Deficiency symptoms

•

Swollen and stiff joints Abnormal bone development Sterility Reduced ovulation Abortion Deformed, weak or dead offspring Appetite loss

• • • • • •   

Sources a. Trace-mineralized salt b. Most rations are sufficient

148

Zinc: Function Formation of enzymes needed in metabolism(>200 enz).  Affects normal sensitivity to taste and smell.  Aids protein synthesis and degradation, also fat and CHO.  Aids normal growth and sexual maturation.  Promotes wound healing.  May help in treatment of acne.  Involved in immune function and expression of genetic information.  Is abundant in the nucleus, where it stabilizes RNA and DNA structure.  Needed for adequate osteoblastic activity, formation of bone enzymes (alkaline phosphatase) and calcification. 

149

Sources:  Oysters,

liver, meat, poultry, milk and its products.  legumes, nuts, whole grain cereals.  Availability from animal sources is greater than that of plant sources (because of phytates which binds it causing its excretion).

RDA:  Adult male:

15 mg  Adult female: 12 mg

150

Deficiency:  Dwarfism

and impaired sexual development in

children.  Impaired appetite.  Hypogeusia.  Delayed wound healing.  Alopecia and diverse form of skin lesions.  Immunological defects. 151



Copper



Micro Minerals



Functions



a. b. c. e. f.



Deficiency symptoms



a. c. e. g. h.

  

   

Hemoglobin formation Activate some enzyme systems Hair development and pigmentation Bone development Reproduction Severe diarrhea b. Slow growth (caused by anemia) Swelling of jointsd. Bone abnormalities Weakness at birthf. Breathing difficulty Lack of muscle coordination Sudden death 152

Fluoride:  Present

in bone and teeth, it reduces dental caries and may minimize bone loss.  Present in optimal amounts in water and diet.  In areas where fluoride content of water is low, its fluoridation is important.  Sources:

Tea, coffee, rice, soybean, spinach, onions, lettuce.

 AI:

4mg (♂)

 Excess:

3 mg (♀)

causes fluorosis and dense bones.

153

Selenium: Function  Involved

in fat metabolism.  Antioxidant function.  Found in all body cells as part of an enzyme system.  Role in cancer prevention???  Role in heart diseases prevention?? Sources: grains, onions, meats, milk.  Excess

is toxic. 154

Water: “Functions”  Water

is essential for life.  The body is approximately 60% water.  Muscle tissue is ~75% water.  It is the major component of plasma and the major transportation mechanism in the body.  Body temperature regulation (sweating).  Water is essential for digestion and absorption.  involved in many body processes: fluid balance, nutrient transport , removal of wastes ,muscle contractions,…….

155

Recommendation:  Obligatory:

500 ml/day.

 AI:

♂ : 3.7 L/day. ♀ : 2.7 L/day.

156

Body Water Balance:  Body’s

water content varies at time:  Especially in women who retain water during menstruation.  High-salt meal leads to water retention: water is lost over a period of 1-2 days as sodium is excreted.  Fluctuation in water weight does not reflect gain or loss in body fat. 157

Water input: 

Total: 1.450- 2.800 ml: 1) Liquids : 550-1.500 ml 2) Foods: 700-1000 ml. 3) Water created by metabolism: 200-300 ml

158

Water output: 

Total: 1.450- 2.800 ml: 1) Kidney as urine : 500-1.400 ml. 2) Lung as vapor: 350 ml. 3) Skin as sweat: 450-900 ml. 4) Feces: 150 ml.

159

Dietary Guidelines for Palestinians: Eat a variety of foods.  Balance the food you eat with physical activity– maintain or improve your weight.  Choose a diet with plenty of grain products, vegetables, and fruits.  Choose a diet moderate in sugars.  Choose a diet moderate in salt and sodium.  If you drink alcohol, do so sensibly and in moderation. 

160

161