Vitamins
Vitamins can be defined as organic substance that must be provided in small quantities in the diet because they are not synthesized in the body of their rate of synthesis is inadequate for the maintenance of the health.
Classification of vitamins
Fat soluble vitamins
➢ Vitamin A (A1 and A2)
➢ Vitamin D (D1 and D2 )
➢ Vitamin E
➢ Vitamin K (K1, K2, and K3)
Water soluble vitamins
1. Vitamin B complex
➢ Thiamine (vit-B1)
➢ Riboflavin (vit-B2)
➢ Nicotinic acid: nicotinamide (vit-
pp)
➢ Pyridoxine (vit-B6)
➢ Pantothenic acid (vit-B5 )
➢ Biotin (vit-H)
➢ Cyanocobalamin (vit-B12 )
➢ Folic acid (vit-B9)
2.Vitamin C (ascorbic acid)
Vitamin A
It is essential for formation of light sensitive pigments in photoreceptor of retina. Beta carotene (provitamin of vitamin A, that naturally grow in vegetables) act as an antioxidant.
Vitamin A exits in two forms:
➢ Animal food: As retinol
➢ Vegetables: As β carotene
Types:
➢ Vit-A1: retinol
➢ Vit-A2: dehydro-retinol
Functions of vitamin A:
➢ Maintain normal epithelia
➢ Form retinal photochemical (rhodopsin)
➢ Anti-infective; enhance immune function
➢ Anti-carcinogenic
Indications:
➢ Acne ( retin A cream)
➢ Psoriasis
➢ Darier’s disease
Vitamin D
➢Vitamin D is pro-hormone.
➢It is a member of steroid derivatives.
➢The main precursor substance of vitamin D is cholesterol.
Vitamin D exists in two forms:
➢ Vit-D2 (ergocalciferol): plant origin.
➢ Vit-D3 (cholecalciferol): animal origin
Generated in the skin by photo-activation (u-v irradiation) of 7-dehydrocholestrol
Function of vitamin D
➢Calcitriol {1, 25-(OH)² D³} is the main active
metabolites of vitamin D.
➢There are three principle sites of action of vitamin D
(1) intestine
(2) kidney
(3) bone
It maintains the calcium homeostasis in the body.
➢Intestine increased→Ca++& PO4 absorption by calcitriol.
➢Kidney decreased→calcium and phosphate excretion by 25 (OH) D3 and 1, 25(OH)2D3.
➢Bone increased→ calcium and phosphate excretion resorption by 1, 25-(OH)2D3.
➢Bone Formation→may be increased by 24, 25-(OH)2D3.
Indications:
➢ Prevention and treatment of rickets
➢ Osteomalacia and osteoporosis
➢ Psoriasis
➢ Treatment of hypocalcaemia
➢ Muscle weakness and bone pain
Vitamin E
Vitamin E is a term used to refer to eight molecules, which are divided into two categories: tocopherols and tocotrienols. Vitamin E supplements almost always contain α-tocopherol.
Indications:
➢ Sterility
➢ Recent abortion
➢ Progressive muscular dystrophy
➢ Cardiovascular disease
➢ Habitual abortion
➢ Pregnancy and lactation
➢ Antioxidant
➢ Enzymatic activity regulator
➢ Inhibit platelet coagulation
➢ Plays important role in eye and neurological function
Vitamin K
➢ Acts as coenzymes that are essential for synthesis of several clotting factor by
liver including prothrombin.
➢ Vitamin K is a fat soluble vitamin.
Types of vitamin-K
➢ Vitamin-K1: phytomenadione (found in food)
➢ Vitamin- K2: menaquinones (synthesized by intestinal flora)
➢ Vitamin-K3: menadione
Indications:
➢ Warfarin overdose
➢ Chronic liver disease
➢ Obstructive jaundice
➢ Premature infants
Deficiency:
➢ Liver disease
➢ Hypo-prothrombinemia
➢ Hematuria and clotting factor deficiency
Vitamin B complex
Vit- B1 (thiamine)
➢ Infantile beriberi
➢ Alcoholic neuritis
➢ Polyneuritis after infections disease
➢ Wenicke-korsakoff syndrome
➢ Anorexia nervosa
➢ Neuritis of pregnancy
➢ Chronic diarrhea
➢ Gastrointestinal hypotonia
Vit-B2 (riboflavin)
➢ Glossitis
➢ Cheilosis
➢ Angular stomatitis
➢ Sore throat
➢ Seborrheic dermatitis
➢ Photophobia
➢ Anemia
➢ Neuropathy
Vit-B3 (niacin)
➢ For prophylaxis and treatment of pellagra
➢ Hyper-cholesterolemia
➢ Hyper-triglyceridemia
➢ Vincent’s infections
Vit-B6 (pyridoxine)
➢ INH induces peripheral neuritis
➢ Pregnancy radiation sickness
➢ Idiopathic sideroblastic anemia
➢ Convulsion in infants
Vit-B12 (cyanocobalamin)
➢ Pernicious anemia
➢ Trigeminal neuralgia
➢ Neuropathy
➢ Macrocytic anemia
➢ Tropical sprue
➢ Alcoholism
➢ Chronic impairment of liver
parenchyma Folic acid
➢ Megaloblastic anemia
➢ Malabsorption syndrome
➢ Tropical sprue
Vitamin-C
Promotes protein synthesis including laying down of collagen in formation of connective tissue. It works with antibodies and promotes wound healing.
Sources of vitamin C:
➢ Amlaki
➢ Guavas
➢ Cabbage
➢ Tomato
➢ Cauliflower
Indications:
➢ Prevention and treatment of scurvy
➢ Treatment of wound and infections
➢ Urinary acidification
➢ Coryza
Side effects:
➢ Anemia
➢ Retardation of growth
