Found in: yellow / orange vegetables, especially carrots; green vegetables; tomatoes', full-fat diary produce', liver', kidney', eggs', fish-liver oils', apricots and peaches (fresh or dried). lt is absent from vegetable fats and oils but is added to margarine during manufacture. RDA: O.75mg; 1 .2mg for nursing mothers
Vision, especially in dim light; healthy skin and mucous membranes (respiratory, digestive and urinary tracts) resistance to infection. Sometimes used to treat acne. Warning - large doses can be toxic.
Night blindness; damage to cornea and eventual blindness', ear, eye and respiratory infections', dry skin', dull hair and hair loss', weight loss, and stunted growth.
* Because Vitamin A has a specific function in the retina of the eye, it is known as retinal.
* Retinol is derived from foods of animal origin.
* Beta carotene is derived from fruit and vegetables.
* Beta carotene is converted into retinal via the intestinal wall (if fat absorption is normal)
* The amount of vitamin A from carotene is less than the mount derived from the same amount of retinal. Weight for weight, six times as much beta carotene is needed to provide an equivalent amount of retinal.
* Because the vitamin is fat soluble and is not easily broken down by the body, excessive intakes of retinal are poisonous, and are associated with damage to the foetus during pregnancy.
* Unlike retinal, carotenoids pose no risk to health, although continued high intakes of beta carotene can lead to a condition called carotenaemia in which the skin takes on a yellow tinge, particularly on the palms of the hands and soles of the feet.
As well as supplying vitamin A to the body, beta carotene is also an ANTIOXIDANT.
Produced by action of sunlight on human skin. Found in: liver, fish-liver oils and oily fish such as kippers, mackerel, sardines, tuna, tinned salmon, margarine, egg yolk, evaporated milk, full-fat dairy products', malted milk drinks, sprouted seeds. RDA : 10 micrograms
Absorptions of calcium and phosphorous for healthy bones and teeth.
Bone deformities, dental caries, cramp, muscle weakness, rickets and osteomalacia (equivalent to rickets in adults). People most at risk of deficiency are those who are compelled to stay indoors, such as babies, the sick and the elderly, or women who traditionally wear clothes which almost completely cover their bodies.
* Named the 'sunshine' vitamin because it can be produced by the exposure of the skin to the sun's ultraviolet rays.
* in the West, most dietary vitamin D comes from fortified foods such as margarine - which in Britain is fortified with vitamin D by law - and breakfast cereals.
* Vitamin D is converted into an 'active' form in the kidneys. It then ants as hormone which controls the calcium absorbed from the intestine and regulates the levels of calcium and phosphorous in the blood and bones.
* In Britain rickets is quite rare, except among the Asian community, but osteomalcia - a softening of the bones which causes pain and makes fractures more likely - is relatively common in the elderly.
* There is only a small margin between safe and toxic levels of the vitamin (an excess can cause kidney damage) always observe the instructions on appropriate dosage when taking vitamin D supplements.
Found in most foods, but especially vegetable oils, egg yolks, wholegrain cereals, wheat germ, green vegetables, nuts and seeds pulses, margarine. A small packet Of peanuts or a small handful of almonds, or just over a teaspoon of sunflower oil Would each supply about 3mcg of vitamin E.
RDA: 10 micrograms or 12-15IU
Healthy cell membranes, so may retard the effects of aging; healthy blood cells; blood clotting', resistance to infection; possibly fertility.
Dull hair; muscle weakness; enlarged prostate gland', miscarriage. However, deficiency is rare, occurring only in premature babies and people who are unable to absorb fat. When it does occur, it causes hemolytic anemia and nerve damage. High doses are not toxic but may lead to a vitamin K deficiency.
* Vitamin E is the collective name given to a group of biologically active ANTIOXIDANT compounds.
* some studies suggest a link between much higher intakes of vitamin E - as much as 75-100 mcg - and a lower risk of disorders associated with free radical damage such as certain cancers, stroke, heart disease and atherosclerosis.
* Vitamin E prevents damage caused by oxidation to polyunsaturated fatty acids found in cell membranes. To ensure its protective role, people with a diet which is high in polyunsaturated fatty acids should also take plenty of vitamin E.
* vitamin E is available in three different types: - natural d-alpha tocopherol - synthetic dl-alpha tocopherol acetate - a blend of synthetic and natural a * Vitamin E works well with selenium * women taking the pill or receiving hormone treatments have an increased need for this vitamin.
Synthesized by bacteria in the large intestine. Absorption is dependent on the presence of bile salts in the small intestine. Found in: green vegetables, especially brassicas, seaweed (kelp) liver; potatoes; eggs;, wheat germ. RDA: 70-140 micrograms
Blood clotting Also used to make other proteins needed for healthy bones and tissues.
Very rare, but can occur when the body does not absorb fat properly as in gall- bladder disease or where there is an excessive intake of vitamin E. ln extreme cases it could impair blood clotting. it may also occur in adults when there is obstruction to the flow of bile, severe liver damage and in malabsorption conditions, such as coeliac disease. It may occur in newborn infants before microbes are established in the bowel.
* Because the transfer of the vitamin across the placenta during pregnancy is poor and the sterile gut of the infant is unable to produce menaquinones, newborn babies are routinely given supplements of vitamin K either with an injection or orally. However, there may be a link between new-born babies who have been injected with vitamin k and a raised incidence of leukaemia in childhood.
* Vitamin k is stored in the liver.
* There are three types of vitamin K. Vitamin K1 and km are fat soluble and vitamin K3 is synthetic and water soluble.