Vitamin B6 is one of the B vitamins, and thus an essential nutrient. The term refers to a group of six chemically similar compounds, i.e., "vitamers", which can be interconverted in biological systems. Its active form, pyridoxal 5′-phosphate, serves as a coenzyme in more than 140 enzyme reactions in amino acid, glucose, and lipid metabolism.Plants synthesize pyridoxine as a means of protection from the ultraviolet-B radiation of sunlight and to participate in synthesis of chlorophyll. Animals cannot synthesize any of the various forms of the vitamin, and hence must obtain it via diet, either of plants, or of other animals. There is some absorption of the vitamin produced by intestinal bacteria, but this is not sufficient to meet needs. For adult humans, recommendations from various countries food regulatory agencies are in the range of 1.0 to 2.0 milligrams (mg) per day. These same agencies also recognize ill effects from intakes that are too high, and so set safe upper limits, ranging from as low as 25 mg/day to as high as 100 mg/day depending on the country. Beef, pork, fowl and fish are generally good sources; dairy, eggs, mollusks and crustaceans also contain vitamin B6, but at lower levels. There is enough in a wide variety of plant foods so that a vegetarian or vegan diet does not put consumers at risk for deficiency.Dietary deficiency is rare.
Cavernous lymphangiomas
Composed of dilated lymphatic channels, cavernous lymphangiomas characteristically invade surrounding tissues. Cystic hygromas
Cystic hygromas are large, macrocystic lymphangiomas filled with straw-colored, protein-rich fluid. Hemangiolymphangioma
As suggested by their name, hemangiolymphangiomas are lymphangiomas with a vascular component.Lymphangiomas may also be classified into microcystic, macrocystic, and mixed subtypes, according to the size of their cysts. Microcystic lymphangiomas
Microcystic lymphangiomas are composed of cysts, each of which measures less than 2 cm3 in volume. Macrocystic lymphangiomas
Macrocystic lymphangiomas contain cysts measuring more than 2 cm3 in volume. Mixed lymphangiomas
Lymphangiomas of the mixed type contain both microcystic and macrocystic components.Finally, lymphangiomas may be described in stages, which vary by location and extent of disease. In particular, stage depends on whether lymphangiomas are present above or superior to the hyoid bone (suprahyoid), below or inferior to the hyoid bone (infrahyoid), and whether the lymphangiomas are on one side of the body (unilateral) or both (bilateral). Stage I
Unilateral infrahyoid. Stage II
Unilateral suprahyoid. Stage III
Unilateral suprahyoid and infrahyoid. Stage IV
Bilateral suprahyoid. Stage V
Bilateral suprahyoid and infrahyoid. Treatment
Treatment for cystic hygroma involves the removal of the abnormal tissue; however complete removal may be impossible without removing other normal areas. Surgical removal of the tumor is the typical treatment provided, with the understanding that additional removal procedures will most likely be required as the lymphangioma grows. Most patients need at least two procedures done for the removal process to be achieved. Recurrence is possible but unlikely for those lesions able to be removed completely via excisional surgery.