a). Vitamin A: is derived from a pro-vitamin, β - carotene a yellow plant pigment which is cleaved to vitamin A by an enzyme in intestinal mucosa.
Structure: occurs in three forms: retinol, vitamin A aldehyde ( retinal) , vitamin A acid ( retinoic acid).
Function: retinal is combined with the protein, opsin, to form the visual pigment, rhodopsin. Rhodopsing is found in the retina and Is very important in the process of vision. Further function of vitamin A ( for which a dietary supply of any form will suffice ) are in differentiation of epithelial cells and in growth.
Sources: β - carotene in green and yellow vegetables, carrots, pumpkin, some melons. Vitamin A itself occurs only in animal products, especially butter ( but often there by fortification ) eggs, fish liver oil, liver ( polar bear liver may contain toxic amounts ).
Deficiency: Night blindness is an early warning. This may advance to keratinization of epithelial tissues, especially of the eye, causing xerophthalmia, form of blindness which is of major concern in some areas.
Requirement: 0.8 - 1.0 mg (as retinol ), or six times that amount as β - carotene, since the conversion is inefficient.
b). Cholecalciferol or Vitamin D
Function: Cholecalciferol is like a prohormone. It is helped by parathyroid hormone. The effect is to raise the level of blood calcium and to promote the mineralization of bone.
Sources: Minimal exposure to sunlight ( 10 cm² for 10 minutes a day). If there is not exposure to sun , dairy products, especially fortified milk, and fish liver oils are good sources.
Deficiency: rickets. Adult form is osteomalacia.
Requirements: 5- 10 ug ( in absence of sunlight ).
c). Vitamin E:
Vitamin E is an antioxidant, it traps free radicals.
Sources of vitamin E: Occurs widely , especially in vegetable oils.
Deficiency: in animals, sterility and muscular dystrophy. In humans, anemia and neurological disorders may occur rarely.
Requirement: 8-10 mg/day , but may be greater with increased consumption of polyunsaturated oils . These, however, are also good sources of vitamin E.
d). Vitamin K ( phylloquinone)
Structure: There are two natural sources of vitamin K , These natural forms are fat- soluble and absorbed from the intestine with the aid of bile salts.. K 1 is ingested with the food. The bacterial flora of the intestinal tract synthesize K 2
The synthetic menadione K 3 s also active . Other Synthetic vitamins K :K 4, K 2-R isolated from putrefying fish meal, K 5, K 6.
Requirement:
Dietary Sources (Micrograms per 100 g of edible portions)
Cabagge 250 Alfalfa 425-850 Cauliflower 275 Spinach 334 Soybeans 190 peas 7 Wheat Germ 37
Function: needed for the production of active blood clotting factors VII, IX, IX and prothrombin.
Sources: Ubiquitous in foods, and also synthesized by intestinal bacteria.
Deficiency: is rare but can occur in the newborn infant and in malabsorption syndromes, causing hemorrhage due to hypoprothrombinemia. Dicoumarol and related compounds are antagonists of vitamin K and are used to prevent thrombosis.
Requirement: 2 mg / day
a. Thiamine ( Vitamin B 1 )
Structure : a substituted pyrimidine joined to a substituted thiazole.
Thiamin Pyrophospfate (TPP). Tpp funtions in the descarboxylation of pyruvate to form CoA.
Sources of Vitamin B1 : meat, liver, whole grains , vegetables.
Deficiency: The classical disease is beriberi. Alcoholics may have a multiple B- deficiency known as Wenicke'disease.
Requirement: 1-2 mg/day
b. Riboflavin (Vit B2) A heterotriciclic system joined to ribitol.As part of flavoproteins, act in transfer of Hydrogen and electrons.
Sources : milk, liver, meat, green vegetables. Cooking or exposure to light tends to destroy it.
Deficiency : lesions of the lips, skin, genitalia.
Requirement : 1-2 mg/day
c. Nicotinamide , Nicotinic Acid ( Niacin):
Carriers of hydrogen and electrons in a multitude of dehydrogenase reactions. The cofactors act in catabolism or synthetic reactions, metabolism of drugs and various hydroxylations.
Source: meat, liver, peanuts, legumes, whole grains. Nicotinate can be biosynthesized from tryptophane ( 1 mg from 60 mg). Corn is a poor source of both niacin and trytophane.
Deficiency: Pellagra characterized by diarrhea, dermatitis, dementia and death ( 4 D's).
Pelagra used to occur in a broad geographic area where the population was dependent on corn as a main food.
Requirement: 15 - 20 mg / day
d. Pyridoxine (Vit B6)
Function : Act as coenzymes of amino acid transaminases, some decarboxylations.
Sources : milk, meat, liver, whole grains.
Deficiency : convulsions, oxalate kidney stones. Deficiency can cause by treatment with the drug isoniazid.
Requirement : 2 mg/day
e. Pantothenic Acid
Essential for all living organisms. Manteins a normal skin, normal growth and normal development of the central nervous system. One of the cofactors is Acetyl Coenzime A (CoA). CoA is very importan to provide energy. Involved in adrenal function. Related to utilization of other vitamins, especially riboflavin.. The utilization of pantothenic acid depends upon the availability of folic acid and biotin
Requirements : 4-7 mg of pantothenic acid per day.
Sources : Ubiquituos in food , especially liver, meat wheat germ, wheat bran, roasted peanuts, eggs.
f. Biotin
Biotin is important in the metabolism of essential fatty acids, sugar and proteins. In diabetics, biotin improves glucose tolerance and immune response.
Is a B complex vit.necesary for healthy hair,skin and nails; along with other B complex vitamins, biotin benefits hair loss, dandruff, scalp problems eczema and dermatitis.
When Biotin es present, the fungus Candida will not multiply in the intestine.
Sources: Synthesized by intestinal flora in sufficient quantities. Dietary sources : liver, cauliflower, chocolate, eggs, hazel nuts, mushrooms, roasted peanuts, dried peas and others.
Deficiency: Produced by dietary deficiency, impaired intestinal synthesis by micro-organisms, or combination with avidin of raw egg white seen in laboratory when human volunteers ate 200 g. of raw dried egg white daily, but a spontaneous biotin deficiency in humans seem unlikely
Requirements: 150- 300 mcg/ day supplied entirely by intestinal flora
Therapeutic Dosage; 1000 - 3000 mcg / day ( scalp, nails, hair), in diabetics : 9 mg /day.
a. Folic acid: It is very important in the synthesis of RNA and DNA ,necessary for the normal functioning of blood formation . Essential for the normal metabolism of tissues and growing cells, body growth, fetal development, brain neurotransmiters and proper utilization of sugars and amino acids. Help to fight infections helping to build antibodies. Functions together
Stimulates formation of red blood cells .
Analogues of folic acid are useful as anticancer agents : Aminopterin, amethopterin, metrotrexate.
Sources: Kidney, liver, dark green leafy vegetables.
Deficiency : Macrocitic anemia.
Requirements : 0.4 mg/day
b. Cobalamine: (Vitamin B12) it is very important in the functioning of all cells, especially in bone marrow, growth factor for children, gastrointestinal tract, nervous system in the formation of myelin sheath of spinal cord, reproductive cells, lungs ( helps asthma sufferers ) , immune system, hearing, metabolism of proteins, fats and carbohydrates.
Helps relieve fatigue ,depression and poor concentration.
Sources: Organ meats in high content, muscle meats and fish in medium content.
Deficiency : Strict vegetarian. Pernicious anemia the deficiency is of the intrinsic factor, a glycoprotein produced by the stomach, which is necessary for absorption of B12.
Neurological anomalies appeared before the hematologic symptoms of a pernicious anemia , these includes at the beginning numbness and weakness of extremities.
Gastrointestinal symptoms : constipation, diarrhea, abdominal pain, glositys
Requirement : 3 ug/day. B12 can be stored , the liver can hold several years supply.
The daily dose most recommended is 100-500 ug.Tablets, sublingual, liquid spray for the mouth or intranasal gel. Therapeutic dose is 1000 - 7000 for pernicious anemia given by intramuscular injection.
A continued use of high amounts may cause a overproductions of red blood cells.
Ascorbic Acid ( Vitamin C)
It is important in the absorption of iron and in the collagen and elastin synthesis.
Other intracellular substances regulated include dentine, cartilage and the matrices of bone.
Vitamin C repairs tissue, promotes healing of wounds. Helps skin and gums, growth and adrenal gland function. Antioxidant. Recycles Vit. E. Increases white blood cell activity and strengths immune system and the lens of the eyes. Protects against allergies heart diseases, arthritis, cancer. Its important in the treatment of diabetes, constipation, iron insufficiency. Used in post surgery.
Deficiency: Scurvy: Delayed healing of wounds and hematomas, fragility of bones , loosening of teeth, capillary fragility.
Sources: Guavas, citrus fruits, tomatoes, mangoes, strawberries and other berries, papaya.
Requirement: 60 mg/day. Recommendations fall between 500-2500 mg.
Ester C is a patented formula and a metabolite form of Vitamin C , more absorbed and more slowly excreted than ascorbic acid.
a. Sodium: The major element found in the extracellular fluids of the body ( about 0.2 % of the body).
Functions : Acid-base balance , osmotic pressure; ph , muscular contractility, nervous system transmition.
Sources of sodium: Foods of animal origin , olives, corn bread, sauerkraut.
Deficiency: Due to profuse perspiration, vomiting and/or diarrhea.
Requirement: 2 - 3 mg/day. A continue intake of 30 mg. or more daily can cause hypertension in susceptible individuals and/or edema due to a disturbed water balance in the body.
b. Potassium: It is found mostly within the cells, it es the major element found in the intracellular fluids of the body, especially in the muscle cells. Insulin helps potassium to enter the cell.
Functions: Acid-base balance , osmotic pressure, Muscle tone.
Sources: Variety of foods , especially of vegetable origin : banana. Oranges, raisins.
Deficiency: Due to profuse perspiration, vomiting and/or diarrhea, some diuretics, diabetes.
Excess: hyperglycemia due to lack of insulin, strenuous exercise,acute renal failure, intoxication with Cl K
Requirement: 40- 150 mEq/ day
c. Chloride: Accompanies sodium and potassium.. Deficiency is not a problem.
a. Calcium: 1.5- 2% of body mass. Forms the skeleton. Role in muscle contraction, blood clotting. Absorption is aide by Vit. C , vit. D and by the precense of lactose.
Sources : dairy products, sardines, ,eggs, almonds, broccoli, parsley, soy.
Deficiency : Secondary to vitamin D deficiencies, in women after multiple pregnancies and lactation.
Requirement: 0.8 - 1.2 g/day in a ratio 1:1.5 of calcium to phosphorus.
b. Phosphorus: Normal muscle metabolism, carbohydrate metabolism, fat metabolism, brain and nerve metabolism, blood chemistry, protein metabolism, skeletal growth, tooth development, acid- base regulation, vitamin and enzyme activity.
Absorption is favored by an acid medium and lactose.
Excess of iron , aluminum and magnesium interferes with phosphorus absorption .
Sources: wheat germ, dairy products, peaches raisins, bran flakes, Oat, wheat, brown rice,
nuts, beef, fish,, eggs. Chickpeas and other beans
Requirement: 0.8-1.2 g/ day
Deficiency : Diabetics.
c. Magnesium: 70% of magnesium absorbed is in the bones. Follow the metabolic pathways of phosphorus and the energetic metabolic pathways related to ATP.. necessary for the efficient utilization of aminoacids in the formation of protein .
Sources : Whole grains and other vegetables.
Requirement: 300 - 400 mg/day
d. Iron: Transport oxygen. Part of heme protein hemoglobin and myoglobin . Necessary for blood transport of oxygen and carbon dioxide.
The absorption of dietary iron is only 1-2 mg/day as of ferrous form.
If the body has adequate body iron stores, intestinal cells have a ferritin trap that prevents further passage of absorbed iron into de bloodstream. When there is a need for iron , ferritin is not produced by intestinal cells, and iron that is taken in is allowed to pass into the blood. Storage mostly in ferritin of liver.
Simultaneous intake of vitamin C enhances the absorption, 200 mg increases the absorption 2 - 3 times..
The absorption is affected by the composition of the food. Example: when you eat an egg the absorption of iron is 2%, when you eat bread , the absorption is 30% , but if you eat egg and bread together the absorption is 5 and 5.3% respectively.
Diets with 50- 100 mg of EDTA reduces the absorption of iron ( EDTA is added to some food to avoid oxidation of free metals in doses of 25 - 800 mg / kg )
Deficiency : iron anemia is common since dietary iron is inefficiently absorbed. It is most often seen in children , young mothers and in persons with chronic loss of blood.
Requirements: Adults: 10 mg/day in the ferrous form. Teenagers and women of childbearing age : 18 mg /day
Sources : meat, egg yolk, liver.
a .Iodine: required for thyroid function . Found in sea foods, iodized salt. Requirenment : 150µg/day . Deficiency : endemic goiter.
b. Zinc: Associated with hair growth. Associated with carbon dioxide metabolism. Essential for the normal functioning of the pancreas and carbohydrate metabolism.
Sources: Egg, oysters , wheat bran, beef, grains , carrots.
Requirenment : 15 mg/ day.
c.Fluoride: Partially prevents dental cavities. 1 ppm in the water supply will provide 1 -1.5 mg of fluoride/ lt/day. An avegare daily diet will provide 0.25 - 0.32 mg. of fluoride
Sources : codfish ,animal products, almonds, apples, canteloupes, carrots , corn, and other fruits and vegetables.
d. Copper: necessary in the formation of hemoglobin. Related to iron. A defficiency of copper result in "bleaching of the hair". Related to oxidation - reduction enzymes of the body. Defficiency may result in loss of calcium.
e. Manganese: Related to iron. Necesarry for various enzymes.. Widely available.
f. Molybdenum: Stimulates absorption of iron from the intestine
g. Selenium: Antioxidant
h. Chromium: Involved with the action of insulin.
i. Cobalt: Component of vit. B12
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