الشدي� -EBTESAM ALابتسامSHEDDI

Email: ebtesam.saad@yahoo.com Site: faculty.ksu.edu.sa/10252

413 PHG

50% by Dr.Ebtesam S. Al-Sheddi -15 marks midterm exam-20 marks final exam

50% by Dr. Areej Al-Taweel-15 marks midterm exam--20 marks final exam

-Lab :-30 marks: - Practical exam

COURSE DESCRIPTION The course will cover the following subjects:

Vitamins Minerals Allergens Biologics

BY THE END OF THE COURSE

You should be able to know: What are the Water soluble vitamins What are the Fat soluble vitamins The recommended dose, function,

deficiency and the toxicity of each vitamin.

What are the micro and macro-minerals

The recommended dose, function, deficiency and the toxicity of each mineral.

What are allergens and the different types.

What are biologics and the different types

Vitaminslecture 1

Presented By :Ebtesam Al-Sheddi

WHEN SUBSTANCE IS DEFINED AS VITAMINThree criteria:

1 -Required in small amounts2 -Must be organic chemical.

3 -There is specific set of symptoms or specific diseases associated with a deficiency of each vitamin.Could be called cofactors or catalysts or others depending on the functions.

13 VITAMINS FOR GOOD HEALTH: 2 GROUPS

Water soluble vitaminsB group:B1 thiaminB2 riboflavinB3 niacin B5 pantothenic acidB6 pyridoxineB7 bitoinB9 folic acidB 12 cyanocobalminVitamin C ascorbic acid

Fat soluble vitaminsVitamin AVitamin DVitamin EVitamin K

FAT VERSUS WATER SOLUBLEVITAMINSFat-soluble

vitamins Dissolve in fat Require bile

acids to be dissolved and then absorbed.

Can be stored in body: liver, adipose tissue.

Toxicity is possible.

Water-soluble vitamins

Dissolve in water. Easily absorbed. Not stored in

large quantities. Execrated via

urine. Generally non-

toxic.

Fat soluble vitaminsvitamin A

Generally called retinol.It is a group of compounds with the

biological activity of retinol.These compounds include: Provitamin A and Preformed vitamin A

Preformed vitamin A Provitamin A Animal source Called retinoids: Retinol (key player)

and retinyl ester.

Consist of 4 isoprene units (C20)

Plant source Called carotenoids: α-carotene, β-

carotene and β-cryptoxanthin.

Consist of 8 isoprene units (C40)

Retinoids and carotenoids are precursors for the biosynthesis of 2 essential metabolites of vitamin A:

11-cis-retinal and all-trans-retinoic acid.

Vitamin A functions11 -cis- retinal All trans-retinoic acid

Required for night and color vision.

Formed in retina. Component of visual

pigments (rhodospin rods) that present in retina.

The most bioactive form. Required for:1. regulation of embryonic

development and growth and reproduction.

2. maintenance of epithelial tissue and repair of body tissues.

3. proper function of immune systemCarotenoids

Serve as antioxidants.

Source: Preformed: liver, milk,

ready eat cereal, margarine and egg.

Provitamin: carrot, cantaloupe, sweet potato and spinach.

Recommended daily allowance (RDA) = 4000 – 5000 IU (International Units).

1 IU from 0.3 µg of retinol or 0.6 µg of β-carotene

Vitamin A deficiency More obvious deficiency

symptoms than other vitamins Night blindness

Leading cause of blindness in third world countries

Cell keratinization Dry skin (treatment and pregnancy?) Xerophthalmia (dryness of cornea &

conjunctiva) Reproductive failure Abnormal skeletal

development/maintenance Immune dysfunction Respiratory infection.

Hypervitaminosis A• Skeletal malformations, spontaneous fractures,

internal hemorrhages• Overconsumption of beta carotene from food sources

may cause skin to turn yellow but is not harmful• Birth defects and miscarriage• Decalcification, joint pain, fragility• Dry itchy skin (caution about acne treatments) • Hair loss• Liver damage

Fat soluble vitaminsvitamin D

The two major forms are vitamin D2 or ergocalciferol, plant

version vitamin D3 or cholecalciferol, animal version

(Calciferol)

Vitamin D2 (made from ergosterol) Vitamin D3 is made in the skin when 7-

dehydrocholesterol reacts with ultraviolet light.

Vitamin D3 is biologically inert, must undergo two hydroxylation reactions to be activated in the body.

Calcitriol (1,25-dihydroxycholecalciferol) is the active form of vitamin D

http://4.bp.blogspot.com/_JF6JYGEMDKs/SDOFF8yfANI/AAAAAAAAACA/bn9VI5hfYSc/s320/vitamin-D.gif

Vitamin D - Functions Regulation of bone health, calcium, and

phosphorus Regulation of muscle composition and

muscle function Prevention of cancer Regulation of immune system Regulation of insulin and blood sugar Regulation of blood pressure and

cardiovascular health

Sourses Vitamin D is naturally produced by the human body

when exposed to direct sunlight. Expose hands, face, arms 2-3 x/week for 5-10 minutes each time. Milk, yogurt, margarine, cereals, bread, pastries

fortified with vitamin D2 and/or vitamin D3.

Egg cod liver oil and salmon Adequate Intake (AI) for VitaminD• 5 ug/d (200 IU/day) for adults under age 51• 10-15 ug/day (400 - 600 IU/day) for older adults –May need combination of fortified foods

Vitamin D deficiency impaired bone mineralization and leads to

bone softening diseases, rickets in children and osteomalacia in adults, and possibly contributes to osteoporosis.

Hypervitaminosis D Hypercalcemia High blood pressure Anorexia, nausea and vomiting These symptoms are often followed by

polyuria, polydepsia, weakness, nervousness, pruritus, and eventually renal failure

Fat soluble vitaminsVitamin E

The term vitamin E refers to a family of eight related compounds, the tocopherols and the tocotrienols

The four major forms of vitamin E are designated a, b, d, g, that have varying levels of biological activity

Alpha- (or α-) tocopherol is the most active form

Termed an antioxidant

Protects cell membranes and other fat-soluble parts of the body (LDL cholesterol) from oxidation May reduce the risk of heart disease May also discourage development of some types of

cancer Promotes normal growth and development Promotes normal red blood cell formation Acts as anti-blood clotting agent Plays some role in the body’s ability to process

glucose Also been known to aid the process of wound healing

Vitamin E

Sources Plant sources Cereal grains wheat germ oil, almonds, sunflower seeds,

sunflower oil, safflower oil, hazelnuts, peanut butter, peanuts, corn oil, spinach, broccoli, soybean oil, kiwi and mango. Vegetable and seed oils

Little in animal sources Beef fed high levels of vitamin E right before

slaughter to improve shelf life can be source The RDA (recommended daily allowance) for

vitamin E is 15 mg of d-alpha-tocopherol for adult men and women (1 mg of d-alpha-tocopherol is equal to 1.5 IU, so the RDA is equal to 22.5 IU).

Vitamin E Toxicity• Wide range of safe intake compared to other

fat soluble vitamins (toxicity rare)– Extreme high doses (50- to 100-fold above

recommended intakes) may affect the blood clotting effects of vitamin K and may lead to increased risk of hemorrhage

Fat soluble vitaminsVitamin K

Vitamin K2

K1, phylloquinone Chloroplasts in plants

K2, menaquinone Bacterial synthesis

K3, menadione Synthetic, water soluble form Complexed to improve

stability

Physiological Effects of Vitamin K Vitamin K serves as an

essential cofactor for a carboxylase that catalyzes carboxylation of glutamic acid residues on vitamin K-dependent proteins. These proteins are involved in:

1) Coagulation2) Bone Mineralization3) Cell growth

Coagulation The transformation of

liquid blood into a solid gel Stops blood flow in the

damaged area Fibrin is the final protein

which produces a meshwork to trap RBC and other cells

Vitamin K Dependent Coagulation Certain clotting factors/proteins require calcium to bind for

activation

Calcium can only bind after gamma carboxylation of specific glutamic acid residues in these proteins

The reduced form of vitamin K2 (vitamin KH2) acts as a cofactor for this carboxylation reaction.

These proteins are known as “Vitamin K dependent” proteins

Vitamin K Dependent Proteins factor II (prothrombin) factor VII (proconvertin) factor IX (thromboplastin component) factor X (Stuart factor) protein C & protein S Protein Z

Clotting Cascade

Vitamin K Cycle

Glutamic Acid

Gamma Carboxy Glutamic Acid

Vitamin K

Vitamin K Epoxide

Vitamin KH2

Vitamin K DependentCarboxylase

Reductase

EpoxideReductase

Warfarin Inhibits

The best food sources of vitamin K are green leafy vegetables.

Milk and liver. Daily requirement:

Dietary Sources

Life Stage Age    Males (mcg/day)

Females (mcg/day)

Infants 0-6 months 2.0 2.0

 Infants 7-12 months 2.5 2.5

Children    1-3 years 30 30

Children 4-8 years  55 55

Children 9-13 years 60 60

Adolescents 14-18 years 75 75

Adults 19 years and older

120 90

Pregnancy 18 years and younger 

- 75

Pregnancy 19 years and older

- 90

Breast-feeding 18 years and younger 

- 75

Breast-feeding 19 years and older

- 90

Vitamin K Deficiency

Results in impaired blood clotting and, potentially, bleeding.

Vitamin K deficiency can result from:

a lack of vitamin k in the diet disorders that reduce fat absorption Taking certain drugs, including anticonvulsants and some antibiotics Use of coumarin anticoagulants Salicylates Large doses of vitamin E Hepatic insufficiency

Symptoms of Vitamin K Deficiency

• Bruising from bleeding into the skin• Nosebleeds• Bleeding gums• Bleeding in stomach• Blood in urine• Blood in stool• Tarry black stool• Extremely heavy menstrual bleeding• In infants, may result in intracranial hemorrhage

Vitamin K Deficiency in InfantsNewborns are prone to vitamin K deficiency because…

1. Vitamin K and lipids are not easily transported across the placental barrier

2. Prothrombin synthesis in the liver is an immature process in newborns, especially when premature.

3. The neonatal gut is sterile, lacking the bacteria that is necessary in menaquinone synthesis.

4. Breast milk is not a good source of vitamin K

Results in a hemorrhagic disease called vitamin K deficiency bleeding (VKDB)

This disease is associated with breastfeeding, maladsorption of lipids, or liver

disorders.

Vitamin K - Toxicity Not common except with over-

supplementation Phylloquinone and menaquinone are relatively

nontoxic Jaundice; brain damage

Menadione toxic to skin and respiratory tract in high doses