Supplements, B12, vitamins, health, diet, natural foods, anemia
B12 Fact or Fiction?
Fri/Jun/07 10:27 PM
Vitamin B12 is a unique molecule as it contains a carbon bonded to a metal, cobalt which gives it its red color. . It is the largest known biomolecule. Vitamin B12 is involved in many of our body functions (often in conjunction with folic acid) like development of red blood cells, insulation of nerve cells, and nerve conduction. When depleted anemia (known as pernicious anemia) and neurological complaints like numbness, burning, muscle fatigue, irritability and memory loss may occur. Absorption of B12 is quite complex and involves pepsin, hydrochloric acid, intrinsic factor and a protein known as R-protein. Deficiency of any of these substances can result in suboptimal absorption and deficiency. Recent studies in England have shown larger than expected numbers of elderly women lacking substances that aid in B12 absorption. Chronic use of antacids or other mediations used for gastric reflux may also contribute to lower than needed absorption.
Since B12 is mostly found in animal tissues. Foods especially dense in B12 include bivalves (clams, muscles and oysters),liver, kidney, eggs and milk products. Unfortunately pasteurized milk while containing B12 has much less and has fewer intact proteins to aid in its absorption). Because of these facts, vegetarians must be extra careful to get adequate B12 from their diet by using eggs and milk products. Children are especially at risk when on diets low in B12 so parents encouraging children to vegan or vegetarian diets must be careful to supplement B12.
B12 can be measured in the blood but most laboratory assays have wide ranges of normal. Deficiency generally is said to occur with blood levels lover than 200 pg/mL but most experts would encourage keeping a blood level higher than 500 pg/mL. Although traditionally supplemented with injections for pernicious anemia, there is a solid body of literature that supports the use of oral supplementation for people at risk of deficiency. Doses ranging from 100 mcg per day or higher have been touted. Levels can be checked to assess efficacy.
Since B12 deficiency due to poor diet, medications and aging is more common that previously appreciated, you should ask you doctor to assay your level and, if appropriate supplement. You can avoid B12 deficiency by eating more liver, shellfish (one serving per week), avoiding over intake of spirulina and soy, antacids or acid blocking medications. Medications like metformin may interfere with absorption. Remember that excessive folic acid intake may block B12 absorption as can artificial Vitamin C products. Smoking will deplete B12 as can oral contraceptives.
Finally, if you exhibit fatigue, weakness, infertility, tinnitus, numbness/tingling of the hands, anemia, irritability ask your doctor if B12 could be the cause.
Since B12 is mostly found in animal tissues. Foods especially dense in B12 include bivalves (clams, muscles and oysters),liver, kidney, eggs and milk products. Unfortunately pasteurized milk while containing B12 has much less and has fewer intact proteins to aid in its absorption). Because of these facts, vegetarians must be extra careful to get adequate B12 from their diet by using eggs and milk products. Children are especially at risk when on diets low in B12 so parents encouraging children to vegan or vegetarian diets must be careful to supplement B12.
B12 can be measured in the blood but most laboratory assays have wide ranges of normal. Deficiency generally is said to occur with blood levels lover than 200 pg/mL but most experts would encourage keeping a blood level higher than 500 pg/mL. Although traditionally supplemented with injections for pernicious anemia, there is a solid body of literature that supports the use of oral supplementation for people at risk of deficiency. Doses ranging from 100 mcg per day or higher have been touted. Levels can be checked to assess efficacy.
Since B12 deficiency due to poor diet, medications and aging is more common that previously appreciated, you should ask you doctor to assay your level and, if appropriate supplement. You can avoid B12 deficiency by eating more liver, shellfish (one serving per week), avoiding over intake of spirulina and soy, antacids or acid blocking medications. Medications like metformin may interfere with absorption. Remember that excessive folic acid intake may block B12 absorption as can artificial Vitamin C products. Smoking will deplete B12 as can oral contraceptives.
Finally, if you exhibit fatigue, weakness, infertility, tinnitus, numbness/tingling of the hands, anemia, irritability ask your doctor if B12 could be the cause.
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