<unk>  at standard conditions is a solid composed of dark red crystals.<unk>  injection USP (1000 mcg/mL) is a clear red liquid solution. Shown is 500 mcg B-12 prepared for subcutaneous injection. Vitamin B12 deficiency Standard therapy for treatment of vitamin B12 deficiency has been intramuscular (IM) or intravenous (IV) injections of<unk> <unk> , since the majority of cases are due to malabsorption by the enteral route (gut). It is used pediatric patients with intrinsic cobalamin metabolic diseases, vitamin B12-deficient patients with tobacco amblyopia due to cyanide poisoning, and patients with pernicious anemia who have optic neuropathy. In a newly diagnosed vitamin B12-deficient patient, normally defined as when serum levels are less than 200 pg/ml, daily IM injections of<unk>  up to 1,000 μg (1 mg) per day are given to replenish the body's depleted cobalamin stores. In the presence of neurological symptoms, following daily treatment, injections up to weekly or biweekly are indicated for six months before initiating monthly IM injections. Once clinical improvement is confirmed, maintenance supplementation of B12 will generally be needed for life. Cyanide poisoning<unk>  is first line therapy for people with cyanide poisoning.<unk>  converts cyanide to the much less toxic cyanocobalamin. Cyanocobalamin is renally cleared. The use of<unk>  became first line due to its low adverse risk profile, rapid onset of action, and ease of use in the prehospital setting. Injectable<unk>  Injection of<unk>  is used to rectify the following causes of vitamin B12 deficiency (list taken from the drug prescription label published by the U.S. Food and Drug Administration) * Dietary deficiency of vitamin B12 occurring in strict vegetarians and in their breastfed infants (isolated vitamin B12 deficiency is very rare) * Malabsorption of vitamin B12 resulting from damage to the stomach, where intrinsic factor is secreted, or damage to the ileum, where intrinsic factor facilitates vitamin B12 absorption. These conditions include tropical sprue and nontropical sprue (celiac disease). * Inadequate secretion of intrinsic factor, resulting from lesions that destroy the gastric mucosa (which can be caused by ingestion of corrosives, extensive tumors, and conditions associated with gastric atrophy, such as multiple sclerosis, certain endocrine disorders, iron deficiency, and subtotal gastrectomy) * Structural lesions leading to vitamin B12 deficiency, including regional ileitis, ileal reactions, and malignancies * Competition for vitamin B12 by intestinal parasites or bacteria. The tapeworm from undercooked fish (Diphyllobothrium latum) absorbs huge quantities of vitamin B12, and infested patients often have associated gastric atrophy. The blind loop syndrome may produce deficiency of vitamin B12 or folate. * Inadequate use of vitamin B12, which may occur if antimetabolites for the vitamin are employed in the treatment of neoplasia Pernicious anemia is the most common cause of vitamin B12 deficiency. While it technically refers to anemia caused specifically by autoimmune deficiency of intrinsic factor, it is commonly used to refer to B12-deficient anemia as a whole, regardless of cause.
Hydroxocobalamin
Cyanocobalamin
Sodium thiosulfate 
Dimethyl methylphosphonate
Acetylcysteine
Fomepizole
Penicillamine
Zinc pyrithione