|
 |
Vitamin B1 (Thiamine)
Vitamin B1 is considered an "anti-stress" vitamin because it is believed to enhance the activity of the immune system and improve the body's ability to withstand stressful conditions. Thiamine is essential during exercise, when energy expenditure is high. Thiamine deficiency is rare, but tends to occur in people who get most of their calories from sugar or alcohol. Individuals with thiamine deficiency have difficulty digesting carbohydrates. As a result, a substance called pyruvic acid builds up in the bloodstream, causing a loss of mental alertness, difficulty breathing, and heart damage. In general, thiamine supplements are primarily used to counteract this deficiency known as beriberi. Some scientists have speculated that thiamine may have some benefit in relieving Alzheimer's disease. This theory is based on the effects that this nutrient has on the brain and the symptoms that people develop when deficient in thiamine. The studies on this subject to date are limited in number and inconclusive, however. Much more research would be needed before anything could be said regarding a possible use for thiamine in combating Alzheimer's disease.
Vitamin B2 (Riboflavin)
Unlike other B vitamins, Vitamin B2 (Riboflavin) is not found in many foods, so the most common cause of deficiency is lack of dietary intake, especially in the elderly. Symptoms of riboflavin deficiency include fatigue; slowed growth; digestive problems; cracks and sores around the corners of the mouth; swollen magenta tongue; eye fatigue; soreness of the lips, mouth and tongue; and sensitivity to light. Riboflavin is an important nutrient in the prevention of headache and some visual disturbances, particularly cataracts.
Vitamin B3 (Niacin)
Vitamin B3 Niacin or Niacinimide is a water-soluble vitamin that participates in more than 50 metabolic functions, all of which are important in the release of energy from carbohydrates. Because of its pivotal role in so many metabolic functions, niacin is vital in supplying energy to, and maintaining the integrity of, all body cells. Niacin also assists in antioxidant and detoxification functions, and the production of sex and adrenal hormones. Vitamin B3 (niacin, niacinamide, nicotinic acid) lowers cholesterol by preventing its buildup in the liver and arteries. Niacin moves fat from tissues for fat metabolism, burning it for energy. It promotes healthy skin, the health of the myelin sheath (the protective covering of the spinal nerves), and good digestion, where it is also vital for the production of hydrochloric (stomach) acid. It is an aid in protecting the pancreas, and is necessary for the health of all tissue cells.
Vitamin B5 (Pantothenic acid)
Vitamin B5, Pantothenic acid, and its derivatives, 4'-phosphopantothenic acid, pantothenol and pantethine, have been shown, in vitro, to protect cells against lipid peroxidation. This protective effect does not appear to be due to the scavenging of the reactive oxygen species by pantothenic acid. It is thought that the antioxidant effect of pantothenic acid is due to its stimulation of increased cellular levels of coenzyme A. Coenzyme A may facilitate removal of lipid peroxides by increasing mobilization of fatty acids, and promote repair of plasma membranes by activating phospholipid synthesis. Pantothenic acid has also been shown to increase levels of cellular reduced glutathione. The mechanism by which pantothenic acid increases glutathione levels is unknown. However, increased levels of glutathione may play a large role in the protective effect of pantothenic acid against peroxidative damage of cell membranes.
There is some evidence that pantothenic acid may be helpful in the management of some with rheumatoid arthritis. The mechanism of this putative effect is unclear. Activated granulocytes play a role in the inflammatory response by production of reactive oxygen species. Pantothenic acid, in the form of calcium D-pantothenate, was found to significantly inhibit the release of myeloperoxidase from granulocytes in vitro, as well as to inhibit the production of reactive oxygen species by these cells. This effect of pantothenic acid as well as the antioxidant effect of the vitamin discussed above, may account, in part, for the putative action of pantothenic acid in rheumatoid arthritis.
Pantothenic acid has been shown to accelerate wound healing in experimental animals. The mechanism of the putative wound healing effect of pantothenic acid is unclear. In human dermal fibroblasts in culture, calcium D-pantothenate was demonstrated to accelerate the wound healing process by increasing the number of cells migrating into a wounded area, as well as their mean migration speed. Dexpanthenol (pantothenol), the corresponding alcohol of pantothenic acid, is used topically for the relief of various minor skin disorders and to promote wound healing. Topical dexpanthenol has been found to improve stratum corneum hydration, reduce tranepidermal water loss and to stabilize the epidermal barrier function. The putative wound healing activity of pantothenic acid, may also be accounted for, in part, by its possible antiinflammatory activity.
Vitamin B6 (Pyridoxine)
Vitamin B6, also called Pyridoxine, Vitamins B12, B6, and B9 (folic acid) work closely together to control blood levels of the amino acid homocysteine. Elevated levels of this substance appear to be linked to heart disease. Plus, vitamin B6 is essential for normal brain development and function, participating in the process of making important brain chemicals called neurotransmitters. Pyridoxine is an especially important vitamin for maintaining healthy nerve and muscle cells and it aids in the production of DNA and RNA, the body's genetic material. It is necessary for proper absorption of vitamin B12 and for the production of red blood cells and cells of the immune system. Pyridoxine has also been called the "woman's vitamin" because it may help relieve symptoms of premenstrual syndrome (PMS). In addition to other B complex vitamins, pyridoxine is considered an "anti-stress" vitamin because it is believed to enhance the activity of the immune system and improve the body's ability to withstand stressful conditions.
Vitamin B9 (Folic Acid or Folate)
Vitamin B9 is required for energy production, formation of red and white blood cells (immunity), and is considered brain food. Normal red blood cell production prevents anemia. As a brain food, Vitamin B9 assists in regulating mood (antidepressant) and sleep patterns, particularly in older persons. It works as a coenzyme in DNA and RNA synthesis therefore, it is important to normal cell division/replication. This is one reason why intake of folic acid is so important during pregnancy - for embryonic and fetal nerve cell development. Inadequate folic acid levels have been linked to birth defects such as spina bifida and anencephaly. Folic acid helps to eliminate Homocysteine, a blood toxin known to affect heart muscle and influences cholesterol to deposit in heart muscle. Its use is known to help prevent stroke and heart attack. Increased homocysteine levels result in weak bones leading to osteoporosis and fractures. Additionally, folic acid may play an important role in prevention of certain cancers: lung, colon, and cervical.
Vitamin B12 (Cobalamin)
Vitamin B12 is the most chemically complex of all the vitamins. It is also one of the most biologically interesting ones. Because of the striking dark red color of its crystals, vitamin B12 has been called "nature's most beautiful cofactor." Its close relatives hemoglobin, chlorophyll and the cytochromes are also brightly colored complex organometallic substances, which, along with vitamin B12 and some others derived from the parent molecule called uroporphyrinogen III, have led to their being known as the pigments of life. Vitamin B12 works in close partnership with folate in the synthesis of the building blocks for DNA and RNA synthesis as well as the synthesis of molecules important for the maintenance of the integrity of the genome. It is also essential for the maintenance of the integrity of the nervous system and for the synthesis of molecules which are involved in fatty acid biosynthesis and the production of energy. The human body does all of this with just two to three milligrams of the vitamin, which is much less than the weight of a tenth of a drop of water. It is even speculated that B12 was mainly responsible for the origin of the DNA world from the RNA world.
Deficiency of vitamin B12 results in hematological, neurological and gastrointestinal effects. The hematological effects of the deficiency are identical to that of folate deficiency and are caused by interference with DNA synthesis. The hematologic symptoms and signs of B12 deficiency, include hypersegmentation of polymorphonuclear leukocytes, macrocytic, hyperchromic erythrocytes, elevated mean corpuscular volume (MCV), elevated mean corpuscular hemoglobin concentration (MCH, MCHC), a decreased red blood cell count, pallor of the skin, decreased energy and easy fatigability, shortness of breath and palpitations. The resulting anemia of B12 deficiency, as is the case of the anemia of folate deficiency, is a megaloblastic macrocytic anemia. However, in the context of a simultaneous iron deficiency anemia, which is a microcytic one, anemia secondary to B12 deficiency may not result in macrocytic erythrocytes.
The neurological effects of the vitamin deficiency may occur even in the absence of anemia. This is particularly true in those who are over 60 years old. Vitamin B12 deficiency principally affects the peripheral nerves, and in later stages, the spinal cord. The symptoms and signs of the neurological effects of B12 deficiency, include tingling and numbness in the extremities (particularly the lower extremities), loss of vibratory and position sensation, abnormalities of gait, spasticity, Babinski's responses, irritability, depression and cognitive changes (loss of concentration, memory loss, dementia). Visual disturbances, impaired bladder and bowel control, insomnia and impotence may also occur. Gastrointestinal effects of B12 deficiency, include intermittent diarrhea and constipation, abdominal pain, flatulence and burning of the tongue (glossitis). Anorexia and weight loss are general symptoms of B12 deficiency. Recently, age-related hearing loss has been associated with poor vitamin B12 and folate status. Poor B12 status has also been associated with Alzheimer's disease.
|