Vitamin D plays an essential role in maintaining good health. It has several important functions, including helping to regulate the amount of calcium and phosphate in the body. These substances are needed to keep bones and teeth healthy.
Without adequate vitamin D, bones can become thin, brittle and misshapen. In extreme cases this can lead to rickets in children, a condition involving a softening of the bones that can lead to fractures and deformity. In adults softening of the bones is usually called osteomalacia, and may cause pain and muscle weakness.
Vitamin D may have other important roles in the body including regulating cell growth, neuromuscular and immune function, and reduction of inflammation. Even years after its discovery, there is still ongoing research examining the various other functions vitamin D might perform in the body.
According to the Scientific Advisory Committee on Nutrition (SACN) – a group of experts that advises the government about all aspects of nutrition – some evidence suggests that vitamin D may be important in preventing other diseases including cancer, cardiovascular disease and multiple sclerosis, although it points out further research is needed before any definite conclusions can be drawn.