Disease Risk Reduction of Vitamin D

Bone disorders
Adequate amounts of vitamin D throughout one's life - in combination with exercise, proper nutrition, calcium, and magnesium - are necessary for building up and maintaining bones and preventing bone loss. Vitamin D is needed to properly absorb calcium. Studies have shown that low levels of vitamin D and insufficient sunlight exposure (fewer than 20 minutes per day) are associated with osteoporosis.  Calcium, together with vitamin D, has been shown to help heal bone fractures from osteoporosis and decrease the risk of future bone breaks. In addition, vitamin D has demonstrated a beneficial effect on muscle function and strength and thereby reduces the risk of falling. Moreover, vitamin D is well known to protect against ‘rickets’ and ‘osteomalacia’, diseases of severe vitamin
deficiency.

Cancer
Studies in test tubes have indicated that vitamin D may have anti-cancer effects, while clinical study findings on vitamin D and specific cancers such as colorectal cancer have been inconsistent. However, some studies have shown strong evidence that high doses of vitamin D supplements may reduce the risk of colorectal cancer.  In addition, some population studies have suggested that supplementation with vitamin D may improve survival rates in those with a history of breast cancer. Other studies indicated that vitamin D3 supplementation might be effective in treating skin cancer. However, this research is still in the experimental stages.

Autoimmune diseases
Research suggests that vitamin D deficiency or a low vitamin D status may be linked to an increased risk of developing autoimmune diseases, overactive immune responses of the body attacking its own cells and organs. Clinical studies evaluating the use of vitamin D for some forms of arthritis (e.g. rheumatoid arthritis and osteoarthritis) have found vitamin D to have preventive effects. Observational data has suggested that vitamin D from foods and sunlight may help protect against multiple sclerosis (MS), a disease in which the body's immune response attacks a person's brain and spinal cord. Research has shown that supplementing infants and children with high doses of vitamin D may protect against the development of type 1 diabetes, a disease in which the body’s immune system destroys the insulin-producing cells.

Cardiovascular disease and High blood pressure 
Data from clinical studies have suggested a link between low levels of vitamin D and high blood pressure. Moreover, low vitamin D status (as measured by the 25(OH)-vitamin D plasma level) is thought to be independently associated with all-cause and cardiovascular mortality or a higher risk of a heart attack.

Other disorders 
Although the information is limited, studies have suggested that vitamin D supplementation may also be helpful to prevent Seasonal Affective Disorder (SAD), a form of depression that occurs during the winter months because of lack of sunlight, and tuberculosis, an infectious disease.