On Vitamin B12
Vitamin B12, also called cobamide, cobalamin, cyanocobalamin, etc., is a vital nutrient intimately involved in many biological processes. Vitamin B12 plays an important role in DNA synthesis. Lack of B12 leaves red blood cells particularly vulnerable. Vitamin B12 also plays a role in the formation of the myelin sheaths coating the brain’s neurons. Vitamin B12’s most diverse role seems to be its general contribution to protein function. Deficiencies invitamin B12 can decrease the availability of amino acids, and interfere with the body’s use of carbohydrates and fats.
Vitamin B12 Deficiency
There have been no identified symptoms of vitamin B12 toxicity, or any documented toxic dose. As with all water-soluble vitamins, excess quantities of vitamin B12 will most likely be flushed out of the body. Vitamin B12 deficiency is a far more common and far more pernicious problem.
The symptoms of moderate vitamin B12 deficiency include nervousness, numbness and tingling in the extremities, pallid complexion problems, weakness, memory problems, heart palpitations, fatigue, difficulty swallowing, redness in the tongue, problems with blood clotting, problems with reflexes, amenorrhea, dry skin, and dandruff. Anyone who suspects they have vitamin B12 deficiency should consult their physicians or dieticians.
Pregnant women, people with certain genetic disorders, and people with stomach problems are at an increased risk ofvitamin B12 deficiency. Since vitamin B12 is found primarily in animal foods, vegans are particularly prone to vitamin B12 deficiency. Vegetarians who eat eggs and dairy products should be fine, although they may need to eat larger quantities than people who eat meat. People on other special diets, particularly low fat diets that emphasize plant foods and stigmatize meat, may face similar risks.
The best natural food sources of vitamin B12 include sardines, salmon, venison, lamb, beef liver and other cuts of beef, turkey and chicken giblets, pork liver sausage, oysters, shrimp, crabmeat, scallops, clams, whole eggs, yogurt, whole milk, chicken breast, and cheese. Manufacturers are not required to label their products for vitamin B12 content or lack thereof, which is one reason they are unlikely to show up on food labels. Consumers must bring in outside knowledge of which foods contain or do not contain vitamin B12.
There are natural plant sources of vitamin B12, including kelp and other sea vegetables, algae, brewer’s yeast, tempeh, tofu, and other fermented plant foods. It is difficult to get adequate levels of vitamin B12 by eating only plant foods, however, unless patients eat massive quantities of them. Vegans are best advised to take supplements to ensure that they receive adequate levels of vitamin B12.
People fourteen years of age or older need 2.4 micrograms of vitamin B12 daily. Pregnant women need 2.6 micrograms, and lactating women need 2.8 to ensure enough for themselves and the baby. Young teenagers typically require 1.8 micrograms, and children need between 400 nanograms and 1.2 micrograms depending on their exact age ranges. Anyone who eats an adequate amount of animal products should be able to get enough vitamin B12