Cobalamin C Deficiency

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Cobalamin is also called vitamin B-12, one of the B complex vitamins. It is an essential nutrient you normally obtain from food that has an important role in protein metabolism. Once you consume it, your stomach acid removes the vitamin from dietary protein and a compound called intrinsic factor helps your body absorb it. Finally, enzymes alter cobalamin into a form your cells can use. Cobalamin C deficiency is an inherited disorder that impairs the body's ability to use cobalaminin to break down protein and causes potentially serious health problems. When diagnosed in infancy or childhood, cobalamin C deficiency can usually be managed with diet and medication.


Cobalamin C deficiency is called an organic acid oxidation disorder. It is inherited in an autosomal recessive manner, meaning that a person must inherit two abnormal genes to develop the condition. The disorder develops when one of the enzymes needed for utilization of cobalamin is either missing or functioning abnormally. As a result, cobalamin or vitamin B-12 cannot be utilized properly and protein metabolism is abnormal, leading to poor utilization of protein-derived energy sources. The disorder also produces a buildup of certain compounds in the blood, including methylmalonic acid and homocysteine, that may cause problems in several organ systems.


Symptoms of cobalamin C deficiency vary depending on how soon after birth the problem is identified. In affected newborns, symptoms usually include poor appetite and slow growth, lack of energy, a weakness in muscles and skin rashes. More serious symptoms may include heart and kidney problems, seizures or slow mental development. Occasionally, symptoms only appear later in childhood and may include confusion, behavior or memory problems, slurred speech and other neurological problems.

Dietary Treatment

Because cobalamin C deficiency results from problems utilizing vitamin B-12 to metabolize proteins, a low-protein diet may be helpful in preventing symptoms. For babies, a low-protein formula will be substituted for regular formula. For children, a doctor will prescribe a dietary plan low in certain amino acids, such as valine, leucine, methionine and threonine. Foods to avoid include dairy products, meat and poultry, eggs, legumes and nuts. Instead, the diet should focus on carbohydrates, which provide good sources of energy that do not involve protein. Vegetables and fruits are also good choices since they are generally low in protein and very healthy. Consult your doctor or a registered dietitian for help in developing an acceptable dietary plan.

Other Treatment

Often, supplementing with vitamin B-12 shots improves symptoms of the disorder, although this is not always helpful. Other supplements that may be useful include L-carnitine, a natural compound that helps with energy production, and betaine, which is extracted from carbohydrate-rich foods and may lower some of the harmful compounds that accumulate in the blood of children with the disorder. Eating frequent, small meals is also a good strategy to minimize problems from cobalamin C deficiency. Consult a doctor who specializes in metabolic disorders to develop a food plan for your situation.