VitaminsVitaminsBy

Komal and Hussain

Vitamins may be regarded as organic compounds required in the diet in small amounts to perform specific biological functions for normal maintainance of optimum growth and heath of an organism.

Hopkins coined the term ‘accesory factors’ to the unknown and essential nutrients present in the natural foods.

Funk in 1913 isolated an active principle (an amine) from the rice polishing and later in yeast, which could cure beri-beri in pigeons. He coined the term vitamine (in greek vita- life).

mainly classified as, 1) Fat soluble - includes Vit. A,D,E,K 2) Water soluble - further classified as, a) Non- B complex i) Vit. C b) B complex i) Energy releasing – includes B1,B2,B3,B6,B7

and Pantethonic acid ii) Hematopoietic – includes Vit. B12 and folic acid

Fat soluble vitamins include: A and carotenoids, E, K, D

Associated with fat absorption. Needed in small amounts. Stored in fatty tissues. Excess intake has toxic consequences.

Vitamin A:3 forms in the body› retinol› retinal› retinoic acid

collectively known as retinoids› found in food derived from animals

Retinol, the alcohol form Retinal, the aldehyde form Retinoic acid, the acid form

Beta-carotene, a precursor

Cleavage at this point canyield two molecules of vitamin A*

precursor: beta-carotene› derived from plant foods› can split and form retinol in intestine and liver

promote vision maintain epithelial tissue and skin› mucous membranes

support reproduction and growth› sperm development› fetal development

deficiency› infectious disease-pneumonia, measles,

diarrhea› Keratinization -dry, rough, scaly skin› night blindness

Deficiency leads to night blindness toxicity› yellow skin: too much beta-carotene

excess stored under skin in fat

› weaken bones found in› colorful vegetables› Liver, kidney,egg yolk› milk, cheese, butter› Carrot, pumpkin, mango› papaya, spinach

Deficiency: • increased morbidity in children under age 5 with no evident clinical signs of deficiency

• Signs, when present include xeropthalmia, anorexia, retarded growth, increased susceptibility to infections, enlargement of hair follicle, and keratinization of epithelial (mucous cells) of the skin.

Toxicity:• Hypervitaminosis A

• Nausea, vomiting, double vision, headache, dizziness, and desquamation of the skin

• Teratogen

Vitamin D

body can make› from sunlight› precursor made from cholesterol

not essential production occurs in liver and kidney› diseases can affect activation

target tissue› intestines, kidneys, bones

part of the bone-making/maintenance team› maintains blood concentrations of Ca & P

deficiencies› ultimately creates a calcium deficiency

toxicity› most common in vitamin D› excess vitamin D = increase in blood

calcium = stones or hardening of blood vessels

sourcessources› fortified food: milk, margarine, cereals, beef, fortified food: milk, margarine, cereals, beef,

eggseggs

antioxidant› defender against free radicals

polyunsaturated fatty acids may reduce the risk of heart disease deficiencies› rare› erythrocyte hemolysis

preemies – destruction of red blood cells toxicity› rare› may interfere with blood-clotting

mechanisms of vitamin K widespread in food› easily destroyed by heat processing

aids in blood clotting deficiency causes hemorrhagic disease toxicity› not common

sources› made by bacteria in GI tract

absorbed and stored in liver ½ of needs

liver is also high in vitamin K

Dietary sources: citrus fruits, amla , guava, green vegetables(Cabbage, spinach) , tomatoes, potatoes.

Biochemical functions:› Collagen formation› bone formation› iron and hemoglobin metabolism› tryptophan metabolism› reduces risk of cataract› increase phagocytic action of leucocyte

Scurvy: characterised by spongy and sore gums, loose teeth , anaemia, swollen joints, fragile blood vessels, decreased immunocompetency, delayed wound healing, hemorrhage, osteoporosis etc.

B VitaminsB Vitamins

Muscles and other tissues metabolize protein.

Brain and other tissues metabolize carbohydrates.

Bone tissues make new blood cells.

Liver and other tissues metabolize fat.

Digestive tract lining replaces its cells.

Coenzymes

Chief functions in the body› Part of coenzymes NAD (nicotinamide

adenine dinucleotide) and NADP (its phosphate form) used in energy metabolism

Toxicity symptoms› Painful flush, hives, and rash (“niacin

flush”)› Excessive sweating› Blurred vision› Liver damage, impaired glucose

tolerance

1998 adequate intake (AI)

› Adults: 5 mg/day Chief functions in the body

› Part of coenzyme A, used in energy metabolism

Easily destroyed by food processing Deficiency leads to burning feet

syndrome.

Widespread in foods

Organ meats Mushrooms Avacado Broccoli Whole grains egg liver, meat,

milk

1998 adequate intake (AI)

› Adults: 30 µg/day Chief functions in the body

› Part of a coenzyme used in energy metabolism, fat synthesis, amino acid metabolism, and glycogen synthesis

Significant sources

›Widespread in foods› Also produced by GI bacteria

Widespread in foods

Organ meats, fish

Egg yolks Soybeans Whole grains

Controversial other dietary compounds Still under scientific investigation May be “conditionally” essential Supplements NOT necessary Widespread in foods

Choline› Contains N2; made from methionine

› Used to make lecithin & acetylcholine

› Adequate Intake (AI) established 1998 Men=550 mg/day; Women=425 mg/day

Inositol› Part of cell membrane structure

Carnitine› Transports long-chain fatty acids

Not essential for humans; essential only for bacteria or other forms of life

PABA (para-aminobenzoic acid)

Vitamin P (hesperidin)-a bioflavonoid Ubiquinone (Coenzyme Q10)

Pyrroloquinoline quinone (methoxatin) Orotic acid Lipoic acid

Vitamin O (oxygenated salt water) Vitamin B15 (Pangamic acid)

Vitamin B17 (Laetrile)

› Alleged “cancer cure”

› Potentially dangerous

Vitamin B5

› Simply another name for Pantothenic Acid

Good friends are like stars, you don’t always see them –

but you know they are there.