Thyroid appearance of cells is viewed to determine whether they resemble normal or cancerous cells. There can be many nodules, which is termed a multinodular goitre, and this can sometimes be a toxic multinodular goitre. An enlarged thyroid gland is called a goitre. Goitres are present in some form in about 5% of people, and are the result of a large number of causes, including iodine deficiency, autoimmune disease (both Grave's disease and Hashimoto's thyroiditis), infection, inflammation, and infltrative disease such as sarcoidosis and amyloidosis. Sometimes no cause can be found, a state called "simple goitre". Some forms of goitre are
Vitamin B12 deficiency vitamin B. Elevated methylmalonic acid levels may also indicate a deficiency. A type of anemia known as megaloblastic anemia is often but not always present. Treatment consists of using vitamin B by mouth or by injection; initially in high daily doses, followed by less frequent lower doses as the condition improves. If a reversible cause is found, that cause should be addressed if possible. If no reversible cause is found - or when found it cannot be eliminated - lifelong vitamin B supplementation is usually recommended. Vitamin B deficiency is preventable with supplements containing the vitamin: this is recommended in