Before you buy materials, choose the location for your built-in cabinet and cut the hole. Then you can adjust the dimensions if your wall studs arenât exactly 14-1/2 in. apart. Remember, your walls are full of pipes, wires and ducts, so you need to do a little detective work to find a good spot.
Vitamin A Elmer V. McCollum and M. Davis discovered vitamin A during 19121914. In 1913, Yale researchers, Thomas Osborne and Lafayette Mendel discovered that butter contained a fat-soluble nutrient soon known as vitamin A. Vitamin A was first synthesized in 1947.
Vitamin B 12 was discovered from its relationship to disease pernicious anemia, which is an autoimmune disease in which parietal cells of the stomach responsible for secreting intrinsic factor are destroyed (these cells are also responsible for secreting acid in the stomach).ecause intrinsic factor is crucial for the normal absorption of B 12, its lack in pernicious anemia causes a vitamin B12 deficiency. Many other subtler kinds of vitamin B 12 deficiency and their biochemical effects have since been elucidated.