VITAMINS
Vitamins are vital for human life because they play integral roles in hundreds of life-sustaining biochemical reactions. Vitamins are the catalysts for all reactions using proteins, fats and carbohydrates for energy, growth and cell maintenance. Certain nutrients are required in excess of the typical amounts supplied in the diet depending on specific nutritional needs. Consuming dietary vitamin and mineral supplements may help play an important role in maintaining good health. For the most part, vitamins cannot be produced in the body and must be supplied through the diet or vitamin and mineral supplements.

Vitamin A has many important functions and is:

• Related to helping to maintain normal vision in dim light and helping to prevent night blindness.

• Essential for body growth, since it aids in the growth and formation of body cells. It is especially needed for bone growth. If vitamin A intake is not sufficient, bones will stop growing before the soft tissue is fully mature.

• Necessary to help normal tooth development. Enamel-forming cells are affected by the absence of vitamin A.

• Important for helping to maintain healthy skin and mucous membranes. Without vitamin A, the skin cells become dry and flat and gradually harden to form scales that shed.

• Necessary to help support the health of the sex glands and uterus, as well as the membranes which line the stomach, intestinal wall, bladder, and urinary passages.

Vitamin A is a fat soluble vitamin which is frequently found together in nature with vitamin D. Cod Liver Oil is an excellent source of the combination of vitamins A and D.

Vitamin D is necessary to help support the growth, development and maintenance of bones and teeth in both adults and children. It is also required for calcium and phosphorus absorption and utilization. In its active form, vitamin D works with calcium to help control bone formation. Vitamin D is unique in that it is obtained not only by eating foods that contain vitamin D, it is also formed spontaneously in the skin, the result of a photochemical reaction - caused by the sun - in the epidermis.

Foods that contain vitamin D include oily fish, egg yolk, live yoghurt. Cod Liver Oil is a good source of both Vitamin D and A.

Vitamin B
There are a large number of B vitamins - all involved in the process of the metabolism of living cells. Working with proteins, they serve as coenzymes in the various enzyme systems of the body. B vitamins must be replaced regularly because they are water-soluble and are not stored in the body to any extent. Also, because B vitamins work together synergistically, insufficient intake of one or more B vitamins can hamper the utilization of others, causing an imbalance to occur.

Vitamin B1 (thiamin) is a coenzyme involved in the metabolic pathway which converts carbohydrates such as glucose into energy. It is essential to help maintain the proper functioning of nerves, muscles, the heart and the brain.

Vitamin B2 (riboflavin) is a coenzyme that activates the breakdown and utilization of carbohydrates, fats and proteins. It is essential to help produce cellular energy. Riboflavin is closely related to the metabolism of protein and all functions requiring increases in protein such as growth. Riboflavin is also essential to help maintain healthy eyes.

Vitamin B6 (pyridoxine) serves several essential roles in the body. It is a coenzyme in protein metabolism. It is needed to help in the conversion of tryptophan to niacin. It is also needed to help in the formation of red blood cells. It facilitates the release of glycogen for energy from the liver and muscles. It also participates in the utilization of energy in brain and nervous tissue, thus being essential in helping to regulate the central nervous system.

Vitamin B12 (cobalamin) is the only vitamin that contains cobalt, a trace mineral. It is essential to help maintain the normal functioning of all body cells, especially those of the bone marrow, gastrointestinal tract, and nervous system. B12 is also necessary for forming red blood cells. The metabolism of vitamin B12 is closely correlated with folate (folic acid) metabolism.

Biotin (vitamin H) is an essential coenzyme that assists in the synthesis and oxidation of fatty acids. It also aids in the utilization of amino acids, folic acid, pantothenic acid (Vitamin B5) and vitamin B12. It is also involved in the growth of healthy cells.

Choline is usually considered part of the vitamin B complex. It is a component of lecithin, which helps facilitate the movement of fat from the liver into cells. It must be present before vitamin A can be stored. Choline is manufactured from the dietary phosphatides found in lecithin.

Folic Acid functions as a coenzyme for approximately 20 enzymes. It works with vitamins B12 and C in the utilization of proteins. It is essential to the development of heme, the protein-containing iron in haemoglobin needed to form red blood cells. Folic acid may also help prevent neural tube defects in developing foetuses and is essential during pregnancy. Some folic acid is produced by intestinal bacteria.

Inositol is usually considered part of the vitamin B complex. Scientists believe that inositol, along with choline and several B vitamins, may help in the metabolism of fat in the body.

Niacin (vitamin B3) and niacinamide are both used by the body. Niacin is needed as a coenzyme in the production of energy. Niacin is essential to help maintain the health of skin, nerves and the digestive system.

Pantothenic acid plays a pivotal role in energy production from fat, carbohydrate and protein. It is involved in the formation of certain hormones and nerve regulating substances, and is particularly supportive of the adrenal glands.

Vitamin C / Bioflavonoids
Vitamin C is also known as ascorbic acid and is a water-soluble, antioxidant vitamin that plays a role in more than 300 bodily functions. It is essential to help support health and wellness and requires daily replenishment.

Unfortunately, human beings - unlike most other animals - cannot manufacture vitamin C. Nor can they store vitamin C to any appreciable amount. Instead, the kidneys, acting as regulators, excrete vitamin C causing the need for regular replenishment. In addition, vitamin C is destroyed during food preparation.

Vitamin C's primary function is to help maintain collagen, a protein necessary for forming skin, ligaments, bones and teeth and for helping to maintain the strength of blood vessel walls. High levels of vitamin C are also essential for the metabolism of white blood cells, which are critical components of the immune system. In addition, vitamin C plays an important role in the absorption of iron, which is necessary for the formation of red blood cells and in the utilization of folic acid, one of the B-complex vitamins.

Bioflavonoids work together with vitamin C to build strong capillaries and serve as antioxidants and as anti-inflammatory agents.

Vitamin E (alpha tocopherol) was first isolated from plant oils. Tocopherols are the primary fat-soluble antioxidants that help minimize the effects of free-radicals.

Of the four compounds - designated as alpha, beta, delta and gamma tocopherols - alpha tocopherol has the greatest nutritional and biological value. Vitamin E (alpha tocopherol) may help:

• Prevent polyunsaturated fatty acids from breaking down and combining with substances that may harm the body. As a result, fats and oils containing vitamin E are less likely to turn rancid than those without vitamin E.

• Prevent oxygen from converting to toxic peroxide free radicals.

• To maintain muscle and nerve function.

• Bring nourishment to cells.

• Strengthen capillary walls.

• Protect red blood cells from being destroyed by poisons, such as hydrogen peroxide, in the blood.

• Promote healthy immune function.

• Decrease platelet aggregation (thins blood).

Vitamin K
Vitamin K is important to help support proper coagulation (blood clotting). The liver uses vitamin K to synthesize blood-clotting proteins. Without vitamin K, the level of the blood-clotting proteins drops, and clotting time is prolonged. Vitamin K has also been recognized for its role in helping to maintain the health of bones. There are three types of vitamin K:

Phylloquinone, which was discovered in Denmark and termed vitamin K for the Danish word koagulation, is the natural vitamin K found in alfalfa and other foods. It is known as K1.

Menaquinone, produced by intestinal bacteria, is K2. Menadione, a synthetic compound with the basic structure of the quinones, is K3.

Vitamin K is found in dark leafy greens, most green plants, alfalfa and kelp. Blackstrap molasses and the polyunsaturated oils, such as safflower, also contain some vitamin K. Animal sources of vitamin K include liver, milk, yoghurt, egg yolks and fish liver oils.

Absorption of vitamin K takes place primarily in the upper part of the small intestine with the help of bile or bile salts and pancreatic juices. It is then carried to the liver for the synthesis of prothrombin, a key blood-clotting factor.

Since natural vitamin K (K1) is fat soluble, it requires bile and pancreatic juice in the intestine for optimal absorption. In contrast, some of the synthetic vitamin K compounds (K3) are water soluble and more easily absorbed. So people who do not tolerate natural vitamin K, such as those with decreased bile acid secretion, may find K3 helpful.

Menaquinone (K2), which is produced by intestinal bacteria, may be the most beneficial source of vitamin K. This is why vitamin K supplementation may be particularly important for those whose normal balance of intestinal bacteria has been disrupted.

The vitamin K available on this site is a highly tolerable, water-dispersible version of vitamin K.

Important Notice Regarding Supplementation

For many people, nutritional supplementation can be an important and useful adjunct to a healthy diet. However, by no means should supplementation be a substitute for food and it should also be recognised that certain nutrients should be used within the recommended guidelines so as to reduce the possibility of toxicity or side effects.

This list is only offered as a general guide and is not to be viewed as a definitive statement on the subject of drug-nutrient interactions or toxicity.

Caution should always be used with individuals who are taking any form of drug therapy.

Ongoing research will no doubt turn up additional information on the relationship between optimum nutrient intake and overdose. If in doubt consult either an authoritative text such as Martindale, Merck Index or the Royal Pharmaceutical Society.

The following may serve as a useful guide to some of the more common contra-indications:

Vitamin A
Supplements containing above 2000i.u. (600mcg) should be avoided in pregnancy and also by women planning pregnancy unless clinically indicated and supervised by a healthcare professional.

Vitamin A may be contra-indicated in patients with kidney stones or a history of kidney stones.

Vitamin A should be avoided by individuals sensitive to vitamin A.

Vitamin B
Prolonged use of isolated B vitamins at high levels may induce a deficiency in some of the other B vitamins.

Individuals taking the drug L-Dopa should seek medical advice before taking B Complex.

High intakes of vitamin B Complex can cause stomach cramps, nausea and diarrhoea.

Vitamin B1 above 75mg daily must be supervised by a doctor in patients with diabetes and larger intakes (700-800mg) may cause drowsiness.

Vitamin B2 commonly causes a bright yellowing of the urine with larger intakes possibly affecting laboratory blood tests.

Vitamin B3 (niacinamide) intake above 100mg may aggravate stomach ulcers, glaucoma and diabetes with doses of one gram and above causing impairment of liver function in some individuals.

Niacin intake above 100mg daily may cause a temporary flushing sensation.

Vitamin B6 in large levels over 100mg daily for a long period may cause numbness in hands and feet together with headaches (peripheral neuritis)

Vitamin B6 above 20-30mg daily should be used only under supervision in pregnancy.

High intakes of folic acid may mask vitamin B12 deficiency and vice versa.

Individuals taking Methotrexate should avoid folic acid in doses of 1mg and above unless under supervision.

PABA (Para Amino Benzoic Acid) may interfere with the drug sulphonamide.

Vitamin B12 in high levels (mg doses) should be avoided in pregnancy and in children under the age of twelve unless clinically indicated.

Vitamin C
High intake can cause diarrhoea, stomach cramps and flatulence.

Avoid supplementing over 1 gram of vitamin C daily if using the contraceptive pill.

Vitamin C as ascorbic acid may aggravate stomach ulcers if used in high levels.

Long-term use of ascorbic acid at high intake levels may deplete calcium, magnesium and potassium.

Potassium ascorbate is contra-indicated in kidney disease and hyperkalemia.

High intakes of vitamin C may interfere with some cytotoxic drugs used in cancer therapy.

Medical advice should be taken if individuals are on drug therapy before taking large doses of vitamin C and before blood tests.

Vitamin E
Intakes above 100i.u. in individuals with high blood pressure should initially be used with caution.

Individuals taking anticoagulant drugs such as Warfarin, Heparin and Coumarin should avoid vitamin E above 100mg daily unless supervised by a medical practitioner.

Individuals with a recent history of heart disease should avoid excessive intakes of vitamin E unless supervised by a medical practitioner.

Women with active breast, ovarian or hormonally dependent tumours should avoid high intakes of vitamin E presented in a base of wheatgerm, soy, corn oil or other polyunsaturated oils.