Vitamins are divided into two groups, fat-soluble and water-soluble, depending on how they are absorbed. The fat-soluble vitamins, A, D, E and K, require the presence of fat carriers to be absorbed and are therefore not as easily assimilated as water-soluble vitamins. Fat-free diets interfere with these vitamins, since fatty acids are needed for their absorption. Once fat-soluble vitamins enter the bloodstream, they are stored in the tissues. Fat-soluble vitamins are measured in International Units (IU). Water-soluble vitamins, vitamin C, bioflavonoids and the B vitamins, including choline and inositol, are easier to assimilate because they dissolve in water. Since excess vitamins are eliminated through the urine, they need to be replenished more often than fat-soluble vitamins. Water-soluble vitamins are measured in milligrams, micrograms or grams.
Different Forms of Vitamins
Fat-soluble vitamins usually come as an oil in capsule form, but there are exceptions. Liquid emulsions are fat-soluble vitamins suspended in water, but still absorbed as a fat-soluble vitamin. Micellized liquids, in contrast, are fat-soluble vitamins turned into and absorbed as water-soluble vitamins, which are excellent for people who have absorption difficulties. Another type of fat-soluble vitamin is sold in dry form, usually in a capsule. Although the vitamin is still fat-soluble, most of the oils have been removed. For people who have trouble assimilating fat-soluble vitamins, the oil form is the most difficult to absorb and the micellized form the easiest.
Water-soluble vitamins tend to come in powders which are then encapsulated or compressed into tablets.
Vitamin A and Beta-carotene
Vitamin A is essential to many bodily processes, and is perhaps best known for its role in the development and renewal of the skin and mucous membranes. It is involved with the repair process of the lining of the digestive and respiratory tracts, protecting against pollutants and enabling appropriate gastric juices to be secreted for protein digestion. Vitamin A keeps the tissues lining the bladder, kidneys and genital organs healthy. Our immune and reproductive systems are dependent on vitamin A to function properly. Most of us are familiar with its essential role in vision, especially night vision, but it is also important for the bones, teeth, blood and our genetic material, ribonucleic acid (RNA).
Vitamin A comes in two basic forms, as itself and as its precursor, beta-carotene. Vitamin A, or retinol, is preformed, and is only found in animal sources. Beta-carotene is also known as pro-vitamin A and is found in plants. The carotene family is a group of red and yellow pigments found naturally in all plants that use photosynthesis for energy. Of all the carotenes, beta-carotene is the most active as a vitamin A precursor. While most people have no trouble converting beta-carotene into vitamin A, the factors vitamin C, zinc, vitamin B12 and protein must be present for the conversion. Diabetics and those with low thyroid activity often have difficulty with this conversion.
The carotenes act as powerful antioxidants. Also, since indeterminate amounts of beta-carotene can be consumed without symptoms of toxicity (maybe a little yellowing of the skin), some people prefer to supplement with beta-carotene instead of vitamin A. Carotenes are stored in fat cells, the skin and several organs, including the liver.
Most vitamin A is stored in the liver. Vitamin A is usually well absorbed, especially when adequate protein, zinc and vitamin E are available.
Retinol and retinyl-palmitate are natural forms of vitamin A. Micellized and emulsified forms are also available for those who need improved absorption.
The most common source for beta-carotene is synthetic; look for natural sources of mixed carotenes which are available from Dunaliella algae rich in alpha- and beta-carotene.
Vitamin D is known as the sunshine vitamin because it is manufactured by ultraviolet rays on the skin, as well as being provided in food and nutritional supplements. Vitamin D is crucial for bone growth and renewal as it stimulates the absorption of calcium. Vitamin D allows the body to absorb vitamin C and to metabolize phosphorus. Vitamin D is also required for nervous system function and for blood clotting.
Vitamin D is found in different forms in the body. The precursor to this vitamin is manufactured from cholesterol in the skin, and is converted to vitamin D3 (cholecalciferol) with sunlight. Even after its conversion, it requires activation first by the liver and then by the kidneys to become fully useful.
As a supplement, synthetic vitamin D2 (ergocalciferol) is the most common. The natural form, vitamin D3, is usually derived from cod liver oil, cold-water fish, butter and egg yolks. Both these forms still require conversion in the liver and kidneys. The converted form, which is used directly by the body, is calcitriol, available by prescription for those who suffer kidney diseases and are not able to break down vitamin D. Vitamins A and D work well together in the body.
Vitamin E is best known as the anti-sterility vitamin and as a powerful antioxidant. Protecting the body from the effects of pollution, other toxins and free radicals, it helps prevent premature aging, cancer and other chronic, degenerative diseases. Vitamin E even protects other nutrients from damage. The immune system is dependent upon vitamin E to function properly and the nerves and muscles require this vitamin for strength and stability. Adequate vitamin E is needed to heal injured tissues and prevent scarring. This vitamin also possesses some anticoagulant activity to prevent the formation of blood clots. Vitamin E is mainly stored in the liver, but excess amounts are eliminated through the urine.
Studies show that the natural form of vitamin E, d-alpha tocopherol, is highly superior to the synthetic form, dl-alpha tocopherol. There is also increasing evidence that tocopherols work better when taken together with other tocopherols, such as d-alpha tocopherol with beta, gamma and delta tocopherols. The form of vitamin E with acetate or succinate, natural carrier substances, lend the vitamin greater stability.
Iron and vitamin E should always be taken separately (one in the morning, the other in the evening) since they hinder each other’s absorption. In contrast, the antioxidants vitamin C and selenium enhance the action of vitamin E. Vitamin A and essential fatty acid absorption are benefited from adequate amounts of vitamin E.
As a supplement, vitamin E is also available as micellized E, making it more readily absorbed.
Vitamin K’s main role is to maintain healthy blood clotting. Newborns are routinely injected with this vitamin to prevent a disease that causes life-threatening bleeding. Aside from this role, vitamin K is seldom supplemented because our intestinal bacteria manufacture vitamin K, and deficiencies are rare. Nevertheless, vitamin K is also needed to store carbohydrates in the body and to support bone structure.
Vitamin K exists in different forms. The kind produced by our intestinal bacteria is vitamin K2. Vitamin K1 is available in the chlorophyll of plants, and vitamin K3, used for newborns, is synthetically produced. This vitamin is not otherwise available as a supplement, but it can be added to the diet through alfalfa, wheatgrass, barley grass or kelp.
This group of vitamins work as coenzymes, helping enzymes carry out their functions, especially in the metabolism of carbohydrates, fats and proteins. Many are important for cell reproduction, including healthy red and white blood cell production. They also assist digestion and stabilize the nervous system. The intestinal bacteria manufacture some B vitamins. Most of the B vitamins are used up quickly, however, and need to be replenished often. Just as the B vitamins are found together in nature and work together in the body, they should be taken together in a vitamin B supplement complex.
Look for vitamin B supplements that exist in higher dosages such as 50 mg or more.
Vitamin B1 (Thiamine)
Thiamine is known as the “morale vitamin” because of its importance in the maintenance of mental well-being. Thiamine affects learning capacity and growth in children. It promotes good muscle tone in the digestive tract, improving assimilation of nutrients and stabilizing the appetite.
Thiamine was the first B vitamin to be chemically identified. Japanese scientists early in the twentieth century suspected a link between the severe occurrence of the nervous disease beriberi in Japan and the Japanese diet of polished white rice. Thiamine deficiency is often associated with alcoholism because one needs more thiamine to metabolize alcohol. Caffeine found in coffee and soft drinks destroys thiamine. Thiamine supplementation is recommended for pregnant and breast-feeding women since their need for thiamine is increased.
Vitamin B1 as a supplement usually comes in the form thiamine hydrochloride, and magnesium is required to convert it to its active form.
Vitamin B2 (Riboflavin)
Riboflavin is needed for normal growth and energy. Stored in the muscles, it becomes vital for physical activity. It also promotes healthy vision, protecting against cataracts, dry eyes and eye fatigue. The skin, nails and hair all require riboflavin for their health and vitality. Cracks, especially in the corner of the lips, is a deficiency symptom.
As a supplement, vitamin B2 is available as riboflavin or in its active form (more readily used by the body) as riboflavin-5-phosphate. Because of its pigment, it causes the urine to glow a yellow-green color.
Vitamin B3 (Niacin)
Another coenzyme, niacin is important for energy and for the metabolism of carbohydrates, proteins and fats. Like other B vitamins, it is required for brain and nervous system function and is important for healthy digestion and skin. In addition, niacin regulates blood-sugar levels, reduces cholesterol and helps eliminate toxins. The production of adrenal and sex hormones also requires this vitamin.
Because of its strong effect on capillary circulation, niacin supplements in dosages of 50 mg can cause a flushing sensation, creating heat, reddening the skin and lasting about fifteen minutes. This is a normal reaction. The body is capable of manufacturing niacin from the amino acid, tryptophan. Alternative names for niacin are nicotinic acid and nicotinate. To obtain all the positive effects of niacin without the flush, a special form of niacin called inositol hexanicotinate is available. Niacin is stored in the liver, but excesses are eliminated in the urine.
Niacinamide, or nicotinamide, is the synthetic form of niacin, and acts somewhat differently in the body, causing neither the “niacin flush” nor the cholesterol-reducing action of niacin. In contrast, niacinamide is more useful for its effects on rheumatoid and osteo-arthritis and early-onset type-1 diabetes. It is an antioxidant, but also enhances insulin secretion and increases insulin sensitivity.
Vitamin B5 (Pantothenic acid)
Pantothenic acid derives its name from the Greek word panthos, meaning “everywhere,” because it is found in every living cell, plant and animal. It is also manufactured by our natural intestinal bacteria. The adrenal glands are dependent on this vitamin for the production of hormones. Like the other B vitamins, pantothenic acid plays a vital role in metabolism and energy production. It is also needed for the production of healthy red blood cells.
The two main supplement forms of vitamin B5 are pantothenic acid, used primarily for adrenal support, while its more active form, pantethine, is used to combat high levels of blood fats and cholesterol.
Vitamin B6 (Pyridoxine)
This B vitamin has recently gained recognition for its importance to hormonal balance. Anyone on a high-protein diet has an increased need for this nutrient, as it is crucial for protein metabolism. Vitamin B6 is also needed for the production of stomach acid and for effective absorption of B12. Required for the formation of all cells, B6 plays a role in blood cell production and immune function. It allows the essential fatty acids to function more effectively and to produce prostaglandins, hormone-like substances needed for all body functions. In regulating fluids, it acts as a diuretic. Like other B vitamins, pyridoxine plays a vital role in maintaining the health of the nervous system.
Vitamin B6 requires magnesium and B2, as well as a well-functioning liver, for conversion to its active form, pyridoxyl-5-phosphate. In turn, B6 increases the effects of magnesium and zinc in the body. As a supplement, the usual forms for B6 are pyridoxine hydrochloride and the reduced form, pyridoxyl-5-phosphate. Although vitamin B6 is water-soluble, extremely high dosages over long time periods have caused adverse effects to the nervous system. This has not been the case with the reduced form pyridoxal-5-phosphate, which has an excellent safety record even at high doses.
Vitamin B12 (Cobalamin)
Vitamin B12 is best known for its treatment of anemia and fatigue, and is the most easily depleted vitamin in those following strict vegetarian diets (no eggs, milk or fish). Required for deoxyribonucleic acid (DNA) and RNA synthesis, this vitamin is vital to the production of every cell, especially the red blood cells. Together with folic acid, vitamin B12 is vital to energy production, immune function and maintenance of healthy nerves. B12 increases the body’s supply of the melatonin hormone and is necessary for the conversion of beta-carotene into vitamin A in the body.
This vitamin is also unique because it requires a special enzyme, intrinsic factor, for proper absorption. Many elderly people are thought to be deficient in this vitamin as a result of poor assimilation. Once in the blood, this vitamin is stored in the liver and a variety of other organs.
Vitamin B12 is usually available as cyanocobalamin. The more active form methylcobalamin is less widely distributed. For people with difficulty absorbing B12, large dosages are needed. A sublingual tablet, which dissolves under the tongue, bypasses the stomach and does not require intrinsic factor, is also available. Physicians prefer the injectable form, which avoids any absorption problems.
The absorption and utilization of B12 requires adequate calcium, B6 and iron. For treatment of anemia, besides B12, folic acid and iron, adequate protein and vitamin C are also needed.
Biotin is essential for the metabolism of fats and carbohydrates, as well as for cell formation. The use of fatty acids in the body could not occur without biotin. This B vitamin assists in protein metabolism and the body’s use of other B vitamins, especially pantothenic acid, folic acid and B12. The hair, nails and skin need biotin for health and luster. As a supplement, it has proved particularly useful in the treatment of seborrhea. Available in food and supplements, biotin is also produced by healthy intestinal bacteria.
The supplement is usually available as biotin, but also as biocytin.
Folic acid and vitamin B12 work hand-in-hand creating healthy red blood cells, and are used to prevent and treat anemia. Folic acid is needed for DNA synthesis in the reproduction of all cells. For this reason, it is especially important during pregnancy for normal fetal development. Concentrated in the spinal fluids and neurotransmitters, folic acid is necessary for brain and nervous system function. Together with B12 and vitamin C, folic acid allows the body to use proteins. In digestion, it stimulates appetite and stomach acid, and supports liver function.
The supplement is available as folic acid, also known as folate, and folinic acid, the active form. In addition to its close relationship with vitamin B12, folic acid also works well in conjunction with the other B vitamins, and vitamins C and E.
Vitamin C is the most popular of all vitamins, largely because of its effectiveness in fighting infections. By maintaining the protein collagen, vitamin C strengthens tissues, prevents easy bleeding and promotes wound healing. As one of the best antioxidants, it protects the body from free-radical damage to tissues, which ultimately leads to degenerative diseases and early aging. Vitamin C helps the body absorb other nutrients better, especially iron, and it works well together with bioflavonoids.
While animals manufacture their own vitamin C, humans can only obtain it from food and supplements. Vitamin C is the least stable of vitamins, however, and once it is absorbed, it cannot be stored in the body. For this reason, this vitamin needs to be replenished often. Evidence supports the use of vitamin C supplements for health maintenance, more than any other vitamin. Vitamin C is also widely used to treat a variety of problems, from infections and allergies to degenerative illnesses, including AIDS, diabetes and cancer.
Vitamin C is a weak acid. When high doses of vitamin C are taken, most candida, bacteria, fungi and parasites are killed, releasing toxins into the system. Gas, headaches, nausea and lightheadedness sometimes result, but are just signs of a temporary cleansing or detoxification reaction.
A vitamin C flush, also known as taking vitamin C to bowel tolerance, will eliminate many illnesses. This is done by increasing the dose of vitamin C to the point of diarrhea which usually results in a purge of the majority of these toxins. The vitamin C flush is best done with buffered vitamin C powder, taking a teaspoon in juice every half hour. After this bowel tolerance level is reached, the dose can be adjusted to where the bowels feel comfortable.
In response to its popularity, vitamin C is available in a wide variety of forms. The most common is ascorbic acid. Buffered forms are used by people who have trouble with its high acidity in the stomach. Calcium ascorbate is the most common buffered form, but sodium, magnesium and potassium ascorbates also exist. Bioflavonoids taken with vitamin C improve its absorption. As an antioxidant, vitamin C works well when taken with other antioxidants, such as vitamin E, selenium and beta-carotene.