Nutrition as therapy

Vitamin A is required for healthy skin and mucus membranes, and for night vision. Its absence from diet leads to a loss in weight and failure of growth in young animals, to the eye diseases; xerophthalmia, and night blindness, and to a general susceptibility to infections. It is thought to help prevent the development of cancer.
Vitamin A is structurally related to carotene. Carotene is converted into vitamin A in the liver, two molecules of vitamin A are formed from on molecule of beta carotene, hence good sources of carotene, such as green vegetables are good potential sources of vitamin A. Vitamin A is manufactured by extraction from fish-liver oil and by synthesis from beta-ionone.
Good sources of Vitamin A - Butter, margarine, milk, cheese yogurt, cream, sweet potatoes, butternut squash, carrots, red peppers, chilies, leeks lettuce, broccoli, Swiss chard, spinach, tomatoes, watercress, basil, coriander, parsley, apricots, cantaloupe melons, mangoes, papayas, guavas, Sharon fruit.

Food Source

The richest natural sources are fish liver oils. It is also very concentrated in animal liver. Other sources include oily fish, egg yolk, fortified margarine, butter and full fat milk.

Description/Function

A fat-soluble vitamin, stored mainly in the liver. Vital for maintenance of good eyesight, particularly for the normal function of the retina and visual adaptation to darkness, and healthy skin. It is also important for growth in children.

Intake

Increased susceptibility to infections, scaly skin, flaking scalp, brittle, dull hair; poor eyesight and night vision, loss of appetite.

Who might Benefit from supplements

Side Effects/Precautions

Just before, or during the first three months of pregnancy, women are advised by the Department of Health that they should not eat liver, or take vitamin A supplements which contain more than the 800mcg RDA unless under medical supervision. As vitamin A (retinol) is teratogenic, it may induce developmental abnormalities in a foetus if taken in high amounts just before, or during the first three months of pregnancy. However, too little vitamin A in pregnancy can also cause problems. Some prescription medicines may reduce the absorption of vitamin A. Upper safe level: 2300mcg (long term usage); 7500mcg (short term usage)

Food Source

Fruit and vegetables such as carrots, red pepper, spinach (and other dark green leafy vegetables), mango, peaches and apricots (60 per cent of the average UK intake comes from carrots). Levels are stable during cooking, but losses occur due to exposure to light and air.

Description/Function

The precursor form of vitamin A which means that beta-carotene is converted to vitamin A in the body on an ‘as-required’ basis. This makes it safe during pregnancy when high levels of vitamin A itself (retinol) should be avoided. Beta-carotene acts as an antioxidant in the body, neutralising potentially damaging free radicals.

EU labeling RDA: Not established. There is insufficient evidence to make any specific recommendations about consumption. Five portions of fruit and vegetables per day will usually provide about 6mg of beta-carotene. However, apples, bananas and onions provide almost no beta-carotene.

Deficiency Symptoms

Side Effects/Precautions

High intakes are not recommended for smokers as two separate studies show that taking synthetic beta-carotene may increase the risk of lung cancer/death in smokers. Unlike vitamin A, beta-carotene is safe before and during pregnancy

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Vitamin B1, Thiamine, aneurine, releases energy from carbohydrate, alcohol and fat. It is an anti-neuritic factor, the absence of which from the diet of animal leads to the disease beri-beri, and from that of mammals and birds to polyneurtics, the most fundamental symptoms of which is general nervous atrophy.

Thiamine pyrophosphate. The biochemically active derivative of thiamine, the pyrophosphate ester of thiamine. It is coenzyme which is concerned in a number of important metabolic process. These include the decarboxylation of alpha-oxoglutaric acid in citric acid cycle and the conversion of alanine, via pyruvic acid to acetyl coenzyme A. The actions of thiamine pyrophosphate are all similar in that they involve the intermediacy of the active aldehyde attached (as carbinol substituents) to the thiaole ring at position 2.

Good sources of sources Vitamin B1 are yeast, eggs and germ of cereals. It is not present in polished rice and other highly purified cereal products. The minimum required daily dose is believed to be about 2 mg.

vitamin B1 -2D structure - It is isolated as the chloride, C₁₂H₁₈Cl₂H_4OS.H₂0

Food Source

Brown rice, peas, beans and other vegetables, fortified breakfast cereals, and wholemeal breads and cereals, pork, bacon and liver.

Description/Function

Thiamin aids the nervous system and is essential for the functioning of some important enzymes. These enzymes have vital roles in the processes that make energy available in the body. Thiamin is essential for the transmission of certain types of nerve signal between the brain and the spinal cord.

Intake

Depression, poor memory, muscle weakness and stiffness, nerve tingling, burning sensation and numbness, tiredness, headache, loss of appetite and nausea. A clinical condition associated with deficiency is beri-beri.

Older people (over 55), those who consume large amounts of alcohol or have busy/stressful lives, athletes. Also, people of all ages whose diets are restricted or of poor quality.

Upper safe level: 100mg (long and short term - no adverse effect has been established)

4. Vitamin B2 - Riboflavin

Vitamin B2, Riboflavin is found to releases energy from protein, fat and carbohydrate. Riboflavin is the part of the original vitamin B2 complex which stimulates growth of rats.

It is the precursor of flavoproteins, flavin-adenine dinucleotide and flavin mononucleotide.

Good sources of Vitamin B2 are in liver, milk and white of egg, though it occurs widely in nature.

Vitamin B2 -2D structure - Crystallizes in orange needles m.p. 271 ^oC. Soluble in water, C₁₇H₂₀N₄O₆

Liver, kidneys, fortified breakfast cereals, meat, milk, some green vegetables, eggs, cheese, yeast extracts. Decomposed by heat and also exposure to light. This is significant with respect to milk, which is a major source of riboflavin (ie if milk is exposed to bright sunlight/light for long periods of time).

A water soluble vitamin, essential for the formation of two substances: FAD (flavin adenine dinucleotide) and FMN (flavin mononucleotide). Both are vital for the processes that make energy available in the body. Riboflavin works effectively with iron, vitamin B6 and folic acid. It is important for skin and eye health.

Trembling, dizziness, poor concentration and memory. Also, blood-shot, red, tired or gritty eyes. Mouth ulcers or sores and cracks at the corner of the mouth. Red, inflamed tongue and lips and scaly eczema-like skin rash.

Those who consume large amounts of alcohol, dieters, those with a busy/stressful lifestyle, athletes.

Side Effects/Precautions

None known. Upper safe level: 200mg (long and short term - no adverse effect has been established)

5. Vitamin B3 - Niacin also Nicotinamide/Nicotinic Acid

Vitamin B3, nicotinic acid, niacin, or 3-pyridine carboxylic is involved in the oxidative release of energy from food, protects the skin and helps improve circulation. Nicotinic acid is an essential component of mammalian diet. It is the pellagra-preventing factor of vitamin B. The amide, nicotinamide is incorporated into nicotinamide adenine dinucleotide.

It can be prepared synthetically by oxidizing nicotine with a variety of agents or more cheaply from pyridine or quinoline.

Meat, oily fish, poultry, bread, potatoes, breakfast cereals, and can be synthesised from tryptophan (an essential amino acid).

A water soluble vitamin vital for energy release in tissues and cells. It helps form NAD (nicotinamide adenine dinucleotide) and NADP (nicotinamide adenine dinucleotide phosphate), coenzymes which are involved in the release of energy and food. They help to maintain a healthy nervous and digestive system. Essential for normal growth and for healthy skin.

Loss of appetite, headache, nausea, fatigue, mouth ulcers, dry skin, difficulty in sleeping, poor memory, irritability. A clinical symptom associated with deficiency is pellegra.

Doses of over 150mg of the nicotinic acid form may cause temporary flushing of the skin in some people. Upper safe level: nicotinamide - 450mg (long term usage); 1500 mg (short term usage). Nicotinic acid - 150mg (long term usage); 500mg (short term usage).

6. Vitamin B6 - Pyridoxine

Vitamin (B6), Pyridoxine, 2-methyl-3-hydroxy-4,5-bis(hydroxy-methyl)pyridine, is essential for protein metabolism, and for the formation of haemoglobin - the pigment in the blood that carries oxygen round the body. Pyridoxine is needed by rats to cure dermatitis developed on a Vitamin B -free diet supplemented by thiamine and riboflavin. Its absence from diet is also associated with anaemia. It is needed also by certain bacteria.

The related compounds pyridoxamine and pyridoxal, in which the CH2OH group in the 4-postion is replaced by CH2NH2 and CHO respectively, also posses vitamin B6 activity and for certain bacteria are much more active than pyridoxine.

Good sources of Vitamin B6 are rice husks, maize, wheat germ, yeast and other sources of vitamin B.

Food Source

Wholemeal bread, meat (especially liver and pork), fish, bananas, wheatbran and fortified breakfast cereals.

A water soluble vitamin which is important in protein metabolism and the function of a number of enzymes in the body. Promotes healthy skin, is essential for maintaining a healthy nervous system and also for the formation of haemoglobin in red blood cells and antibodies that help fight infection. Often used to supplement diet in the pre-menstrual part of the cycle

Deficiency Symptoms

Women taking the combined contraceptive pill, older people (over 55), vegetarians and vegans and those who consume large amounts of alcohol.

Side Effects/Precautions

It is safe to take up to 100mg per day on a long term basis, although high levels of up to 200mg have not been shown to cause problems. Upper safe level: 100mg (long term usage); 200mg (short term usage)

Folic acid, pteroyl-L-glutamic acid, or vitamin Bc is involved in the formation of new cells and therefore essential for the normal growth and development of the foetus.

Folic acid and its derivatives (mostly the tri and heptaglutamyl peptides) are widespread in nature. It is a specific growth factor for certain micro-organisms, but in animals the intestinal bacteria provide small quantities needed for growth.

The coenzyme forms are actually the reduced products of folic acid. The main function of 5,6,7,8-tetrahydrofolate (THFA) is as a carrier of a C1 (methanoate) unit in the biosynthesis of purines, serines and glycine. The nitrogen atoms at 5 and 10 positions are reactive sites of the molecule.

Good sources of Vitamin Bc are most green leaves which are especially rich in the vitamin.

Yeast extract, wholegrain cereals, liver, brussels sprouts, broccoli, leafy green vegetables, beans, fortified breakfast cereals, oranges, beer. Levels are unstable unless the foods are refrigerated and can also be destroyed by cooking.

Description/Function

A water-soluble vitamin essential for efficient neural tube development during pregnancy which forms the brain and spinal cord. ‘Neural tube defects’, such as spina bifida, in babies appear to be linked to a ‘metabolic defect’ in folate metabolism in the mother. This means that, even though the mother may have an adequate dietary intake of folic acid, her body cannot use it efficiently. Taking extra folic acid at the time when the neural tube is forming can reduce the chance of the baby having a neural tube defect. However, the neural tube is formed very early during pregnancy - about a month after conception. Women are advised to take folic acid prior to conception and to continue taking folic acid supplements until the 12th week of pregnancy. In addition, folic acid is essential for the formation of red blood cells and has been shown to reduce the levels of an amino acid (homocysteine). This reduction may have a protective effect against heart disease.

EU labelling RDA: 200mcg In the UK, women who are planning or who may become pregnant are advised to take a supplement containing 400mcg folic acid every day, twice the RDA. Women may also choose to eat a diet containing lots of fortified foods such as breakfast cereals and some breads and folate rich foods.

Women planning a pregnancy and those in the early stages of pregnancy. Also, older people (over 55) and those who consume large amounts of alcohol.

Side Effects/Precautions

Upper safe level: 400mcg (long term usage); 700mcg (short term usage). Those taking anti-epileptic drugs should seek doctor’s advice.

Vitamin B12, cyanocobalamine, helps protect nerves and is involved in the formation of red blood cells in thee bone marrow. Vitamin B12 is also concerned in the biosynthesis of methyl groups of choline and methionine. The vitamin deficiency is often due to failure to absorb B12 from the stomach and can be alleviated by giving mg doses with extracts of hog's stomach which contains the intrinsic anti-pernicious anaemia factor (a mucoprotein) which promotes absorption.

Vitamin B12 is produced by the growth of certain micro-organisms and also occurs in the liver. Vitamin B12 has been prepared synthetically.

Vitamin B12 -space-filling image - Dark red crystals, C₆₃H₉₀CoN₁₄O₁₄P

A water soluble vitamin. Essential for recycling certain important enzymes in the body to maintain health of blood, nerve and other cells.

Deficiency Symptoms

Pregnant and breast-feeding women and older people (over 55). Since vitamin B12 is not found in plant foods unless fortified (eg breakfast cereal), vegans are likely to benefit.

None known. Upper safe level: 3000mg (long and short term - no adverse effect established)

9. Biotin - Vitamin H

Food Source

Brown rice, wholemeal bread, eggs, liver, kidneys, cauliflower, nuts, peas and beans.

A water soluble vitamin which works synergistically with other B vitamins. It is involved in the metabolism of carbohydrates, proteins and fats as well as helping to maintain healthy skin and nails.

Intake

Patches of hair loss (alopecia), reversible baldness, depression, muscle pains and wasting. Also, dry, flaky skin, rash around the nose and mouth, brittle hair, tiredness and loss of appetite. Biotin is widely distributed in many foods and is also synthesised in the gut.

None known. Upper safe level: 2.5mg (long and short term - no adverse effect has been established).

Pantothenic Acid is an oil which is required by higher animals and some micro-organisms. This is considered a member of the Vitamin B group and is present in many natural products and is a constituent of coenzyme A

Coenzyme A is involved in many acyl group transfer reaction pathways in the body. Importantly it is involved in the formation of fatty acids, polyketides and the synthesis of terpeniods and steroids. Structurally coenzyme A is composed of adenosine-3',5'-diphosphate and pantetheine phosphate. Pantetheine itself is made from pantothenic and mercaptoethylamine.

Food Source

A water soluble vitamin which forms part of two substances, co-enzyme A and the acyl carrier protein. These have key roles in the release of energy from foods. It is also needed for healthy growth and the production of antibodies to help fight infection

Deficiency Symptoms

Poor muscle co-ordination, muscle cramps, numbness and tingling, painful burning feet, depression, fatigue, weakness, headache and loss of appetite.

Those who consume large amounts of alcohol plus people under stress or who have undergone surgery.

Side Effects/Precautions

Upper safe level: 1000mg (long and short term - excessively large doses of around 10,000mg have been known to cause diarrhoea and gastrointestinal disturbances).

Vitamin C or Ascorbic acid, is the enolic form of 3-oxo-L-gulofuranolactone. It can be prepared by synthesis from glucose, or extracted from plant sources such as rose hips, blackcurrants or citrus fruits. It is easily oxidised in air. It is essential for the formation of collagen and intercellular material, bone and teeth and for the healing of wounds. It helps maintain elasticity of the skin, aids the absorption of iron and improves resistance to infection. It is used in the treatment of scurvy. May prevent the occurrence and development of cancer.

Good sources of Vitamin C are Broccoli, Brussels sprouts, cauliflower, cabbage, mangetout, green leafy vegetables, red peppers, chilies, watercress, parsley, blackcurrants, strawberries, kiwi fruit, guavas, citrus fruit.

Most fresh fruit (especially citrus fruits), vegetables and fruit juices. Vitamin C is easily destroyed by cooking and is reduced during storage. In fruits, vitamin C accumulates during the period up to the point at which they are ripe. Once ripe, the longer they are left on the tree, the less vitamin C they contain.

A water soluble vitamin. An antioxidant, able to neutralise potentially damaging free radicals. Helps the white blood cells to fight infection and is essential for wound healing. Also needed for the formation of collagen, for healthy skin, and for the formation of other structural materials in bones, teeth and capillaries. Helps the absorption of iron from plant (non-animal) sources.

Poor wound healing, dry skin, broken thread veins, scalp dryness, irritability, weakness.

Older people (over 55), convalescents, those who consume large amounts of alcohol, those with active, busy lives, people with colds, smokers (each cigarette destroys some vitamin C), those exposed to excessive pollution, athletes and routine aspirin users.

Some medicines can be affected by vitamin C. Women on the contraceptive mini-pill should not take excessively large doses of vitamin C at the same time of day as this may reduce the pill’s effectiveness. Upper safe level: 2000mg (long term usage); 3000mg (short term usage).

Vitamin D is needed for the absorption of calcium and the regulation of calcium levels in the blood. Both vitamins, which have almost identical actions, are used for the prevention and cure of infantile rickets The absence of vitamin D in the food of young animals leads to the development of rickets unless the animal is exposed to sunlight or u.v. irradiation.; they are essential for the normal development of teeth, and are used for treating osteomalacia and dental caries. They are necessary for the absorption of Ca and P from the gut. Sunlight activates the metabolism of vitamin D in the body.

The first vitamin D to be discovered was a crude mixture called vitamin D1. Irradiation of erggoterol with u.v. light gives calciferol or vitamin D2. Irradiation of 7-dehydrocholesterol gives the natural vitamin D or vitamin D2, which differs in the structure only in the side chain.

Good sources of vitamin D are butter, margarine, cheese cream, yogurt, milk eggs and sunlight. It is soluble in fats, milk, butter and eggs. The richest sources of vitamin D are fish-liver oils, particularly those of the halibut and the cod

All dairy products (apart from low fat), oily fish, eggs and fortified margarine. Food alone is unlikely to provide sufficient vitamin D and it is also formed by the action of sunlight on the skin.

A fat-soluble vitamin which helps the body to absorb and use calcium and phosphorus. It is therefore essential for maintaining strong and healthy bones.

Intake

Poor growth, bone pain and deformities (ie rickets in children and osteomalacia in adults), constipation and muscle weakness.

Anyone with low exposure to sunlight, some vegetarians and vegans, older people (over 55), pregnant and breastfeeding women, young children, those concerned about osteoporosis. The Department of Health recommends that pregnant and breastfeeding women take a supplement to achieve an intake of 10mcg per day. It also recommends that Asian women and children take vitamin D supplements if they have a vegetarian diet, low calcium intakes and limited exposure to sunshine.

Side Effects/Precautions

None known. Upper safe level: 10mcg (long term usage); 50mcg (short term usage). Allows for contribution from sunlight.

Essential for fertility and reproduction. Deficiency in rats leads to absorption in the female and loss of fertility on the male. The vitamin is supposed to work as an antioxidant that protects the cells from attack by reactive form of oxygen and free radicals. It is also nvolved in red blood cell formation.

The structure is that of the tocopherols. These are methylated derivatives of tocol.

They are widely distributed in vegetable lipids and in the body fat of animals, though animals cannot synthesize them. They have vitamin E activity and can protect unsaturated lipids against oxidation. Four are found naturally:

· alpha - tocopherol, C29H50 O2 is 5,7,8,-trimethyltocol - strongest vitamin E activity.

Good sources of Vitamin E are vegetable oils, nuts and nut oils seeds, egg yolk, margarine, Parmesan, Cheddar, chickpeas, soya beans, wheat germ, oatmeal, avocados, olives, carrots, parsnips, red peppers, green leafy vegetables, sweet potatoes, tomatoes, sweet corn, watercress.

Seed oils, and the outer germ of cereals are the richest sources as well as olive oil, avocado pear, muesli, nuts, leafy green vegetables, wholemeal bread, cereals and egg yolks.

Description/Function

A fat-soluble antioxidant vitamin which helps to neutralise potentially damaging free radicals in the body. Vitamin E is particularly important for the protection of cell membranes as well as maintaining healthy skin, heart and circulation, nerves, muscles and red blood cells.

Intake

Deficiency Symptoms

Those on high polyunsaturated fat diets and those with fat malabsorption problems.

Side Effects/Precautions

None known. Upper safe level: 800mg (long and short term - no adverse effects have been established).

Vitamin K is needed for effective blood clotting. A deficiency is rare due to bacteria synthesis within the body. Vitamin K is an accessory factor needed chickens, ducks, and geese, the absence of which is characterized by hemorrhages due to a failure of the blood to clot properly. The factor is associated in some way with prothrombin, and may be part of the prothrombin molecule.

Vitamin K1 is from alfalfa oil, it is 2-mehtl-3-phytyl-1,4-naphthoquinone. The term vitamin K2 was applied to 2-methyl-3-difarnesyl-1,4-naphthoquinone, isolated from putrefied fish meal. It now includes a group of related natural compounds - menaquinones, differing in the number of isoprene units in the side chain and in their degree of unsaturation. These quinones also appear to be involved in electron transport mechanism and oxdative phosphorylation.

Good sources of Vitamin K are most vegetables. It is fat-soluble and found in the liver fats, vegetables and to a lesser extent cereals. It is stable to heat and light and destroyed by alkalis.

Food Source

Description/Function

A fat soluble vitamin required for the formation of several of the proteins, called ‘clotting factors’, that regulate blood clotting. Vitamin K is also required for the formation of some proteins which are important for the maintenance of healthy bones and teeth and in vivo biosynthesis by gut bacteria/flora.

Intake

EU Labelling RDA: Not established. However, most adults require 60 - 80mg per day.

Deficiency Symptoms

Side Effects/Precautions

Those taking anti-coagulants should not take supplements, containing over 100mg except on the advice of a doctor. Upper safe level: none known.

1. Vitamin A - Retinol

Importance of MINERALS, Other supplements

1. Vitamin A - Retinol

Food Source

Description/Function

Intake

Who might Benefit from supplements

Side Effects/Precautions

Food Source

Description/Function

Deficiency Symptoms

Side Effects/Precautions

Food Source

Description/Function

Intake

4. Vitamin B2 - Riboflavin

Side Effects/Precautions

5. Vitamin B3 - Niacin also Nicotinamide/Nicotinic Acid

6. Vitamin B6 - Pyridoxine

Food Source

Deficiency Symptoms

Side Effects/Precautions

Description/Function

Side Effects/Precautions

Deficiency Symptoms

9. Biotin - Vitamin H

Food Source

Intake

Food Source

Deficiency Symptoms

Side Effects/Precautions

Intake

Side Effects/Precautions

Description/Function

Intake

Deficiency Symptoms

Side Effects/Precautions

Food Source

Description/Function

Intake

Deficiency Symptoms

Side Effects/Precautions

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