Humans need vitamin D in order to promote calcium absorption in the digestive system, to help cells grow and develop, and to help reduce inflammation. Without adequate vitamin D, humans may be at risk for serious diseases.
Vitamin D promotes calcium absorption throughout the digestive system and, in turn, helps to maintain the right levels of serum and phosphate concentrations in the body. This enables normal mineralization of bone to occur and promotes bone health, bone development and bone regrowth. Without sufficient amounts of the mineral, bones may become thin, brittle and mishapen. In children, vitamin D deficiency may lead to a condition known as rickets, in which their long bones bend. In adults, vitamin D deficiency may lead to osteomalacia.
Along with calcium, vitamin D may also help older adults protect themselves from osteoporosis. Vitamin D also plays a role in modulating cell growth by modulating the genes that encode proteins that regulate cell proliferation, cell differentiation and cell apoptosis. The mineral also helps control neuromuscular and immune function and helps to reduce inflammation throughout the entire body. In order to stay healthy, it is recommended that adults over the age of 19 obtain 600 IU of vitamin D per day.