Problem with niacin: side-effect; has to be used in very high doses, in which it causes facial flushing and feeling of pins and needles. Tends to disappear in the long term. Many other B vitamins exist. Unifying factor is their mechanism of action. They are coenzymes. Enzymes are biological catalysts. They are proteins made in the body and enhance all of the chemical reactions that, together, constitute life. But for these enzymes to work properly, they have to collude with the B vitamins, which is why they are called co-vitamins or cofactors. Different B vitamins will react with different enzymes and they take part in many processes. They are involved in energy production by the body but are not “pep” pills. Energy supplements usually contain B vitamins but this is just marketing. The active ingredient is in fact caffeine. Ex. Red Bull loaded up with B vitamins, but energy you get there is from caffeine. It is true that people will lack energy if they are deficient in B vitamins, but the opposite won’t energize them. Vitamin B6 deficiency: - Weakness - Sleeplessness - Peripheral neuropathy - Personality changes - Dermatitis (classic sign) - Glossitis-sore, red tongue These signs are associated with many other conditions as well. Very high doses of B6 will in fact cause some neuropathies. Widely available in food so supplements are really not necessary. Folic Acid: Need to pay attention to it. Shown that can reduce the risk of malformation during pregnancy. It is now added to many foods as a fortifying substance (bread, cereal, etc). The evidence of benefit is very clear, steady decrease in incidence of Spina Bifida (spine malformation). It also has financial impacts because treatments of the malformation are very expensive. Available in supplements (400mcg a day for a pregnant woman). In 1947, researchers discovered that the administration of folic acid to leukemia patients made it worse. It was a diet deficient in folic acid that could provide improvement. Methotrexate:
Treatment for leukemia. Chemical similarity with folic acid. This one can inhibit nzymes that would normally use folic acid in the synthesis of DNA which is required by cancer cells. It blocks the action of folic acid. There has been some concern that high doses of folic acid may enhance cancer cell multiplication, but only in VERY high doses (practically impossible via food). Do not want to go over 400 mcg in terms of supplement. Vitamin B12: Important for the metabolism, the formation of red blood cells and the maintenance of the central nervous system (brain and spinal chord). Very complicated molecule. We are not capable of synthesizing it and neither are plants nor animals. Only BACTERIA have the enzymes required for its synthesis. Many foods are a natural source of B12 because of bacterial symbiosis; when we eat animal foods, we do get B12. The bacteria which produce it are not found in humans so we need it from an outside source. It is found only in ANIMAL products. The deficiency is linked with many symptoms. All of these can be addressed by taking a supplement or increasing the
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- Spring '11
- Vitamin , Health Science Lesson