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 .
1,25-Dihydroxyvitamin D3 and muscle strength in the elderly: a randomized controlled trial.
An unexplained loss of muscle strength occurs with aging . Vitamin D deficiency can cause myopathy and administration of 1,25-dihydroxyvitamin D3 [ 1,25-(OH2)D3 ] to persons with low serum concentrations can improve strength . To test the hypothesis that the weakness associated with aging is in part due to inadequate serum concentrations of [ 1,25-(OH2)D3 ] , we conducted a r and omized , controlled , double blinded trial in 98 men and women volunteers over 69 yr old . Treatment consisted of 0.25 micrograms 1,25-(OH)2D3 , orally , twice per day or identical placebo for 6 months .  Leg muscle strength of the quadriceps was measured with an isokinetic dynamometer . There was no difference between the two groups at 1 week , 1 month , or 6 months of treatment in any of the measures of muscle strength . We conclude that oral administration of 0.5 micrograms 1,25-(OH)2D3/day does not improve muscle strength in older persons . Further research is needed to determine the etiology of the decline in muscle strength associated with aging
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 .