There is currently no firm evidence that vitamin D supplementation decreases or increases cancer occurrence in predominantly elderly community-dwelling women .
Vitamin D₃ supplementation  decreased cancer mortality  and vitamin D supplementation  decreased all-cause mortality , but these estimates are at risk of type I errors due to the fact that too few participants were examined , and to risks of attrition bias originating from substantial dropout of participants .
Combined vitamin D₃ and calcium supplements  increased nephrolithiasis , whereas it remains unclear from the included trials whether vitamin D₃ , calcium , or both were responsible for this effect .
BACKGROUND The evidence on whether vitamin D supplementation is effective in decreasing cancers is contradictory .
OBJECTIVES To assess the beneficial and harmful effects of vitamin D supplementation for prevention of cancer in adults .
The effects of calcitriol on falls and fractures and physical performance tests
There is an increase in the incidence of falls with aging and about 10 % of falls lead to fractures . Nearly all hip fractures are due to falls and hip fractures are the most severe of the osteoporotic fractures because they lead to a 20 % mortality rate and a loss of independent living in 50 % of cases . Although there are multiple factors associated with falls , our interest is the role that vitamin D metabolism plays in the pathogenesis of falls . Recent clinical trials show that both vitamin D and the metabolite calcitriol reduce the number of falls by 30 - 40 % in elderly subjects . This should also reduce the number of fractures . In European studies , the decrease in falls could be attributed to an improvement in the muscle weakness that often accompanies vitamin D deficiency . However , in the studies using calcitriol there was no vitamin D deficiency , so the mechanism of its efficacy is less clear . It could be due to increased muscle strength , an improvement in the neurological control of balance or both . Underst and ing these mechanisms would allow us to search for analogs of vitamin D that act more selectively on muscle and on the central nervous system
There is currently no firm evidence that vitamin D supplementation decreases or increases cancer occurrence in predominantly elderly community-dwelling women .
Vitamin D₃ supplementation  decreased cancer mortality  and vitamin D supplementation  decreased all-cause mortality , but these estimates are at risk of type I errors due to the fact that too few participants were examined , and to risks of attrition bias originating from substantial dropout of participants .
Combined vitamin D₃ and calcium supplements  increased nephrolithiasis , whereas it remains unclear from the included trials whether vitamin D₃ , calcium , or both were responsible for this effect .
BACKGROUND The evidence on whether vitamin D supplementation is effective in decreasing cancers is contradictory .
OBJECTIVES To assess the beneficial and harmful effects of vitamin D supplementation for prevention of cancer in adults .