The Earth's Crust is like the skin of an apple. It is very thin in comparison to the other three layers. The crust is only about 3-5 miles (8 kilometers) thick under the oceans(oceanic crust) and about 25 miles (32 kilometers) thick under the continents (continental crust).
The problem behind your itchy skin might be insufficient vitamin intake. There are a number of vitamins that promote the hydration and healthiness of your skin. A shortage in these could trigger itchiness, dry skin and other skin conditions. Alternatively, an overdose of such vitamins might also lead to itchy skin.
Other nutritional deficiencies may cause burning mouth syndrome, including lack of zinc, iron and other B vitamins like folate, thiamin, riboflavin and pyridoxine. B12 deficiency and folate deficiency can also cause canker sores, or pale yellow ulcers with red outer rings.itamin B12 Deficiency. Poor nutrition or inadequate intake of vitamin B12 can cause B12 deficiency. Vitamin B12 food sources include animal products such as meat, poultry, fish, clams, oysters, eggs and dairy products.