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 .
Differences in vitamin D3 dosing regimens in a geriatric community-dwelling population.
OBJECTIVE The adequate dose of vitamin D supplementation for community-dwelling elderly people has not been thoroughly investigated . This study aims to determine the efficacy of a low-dose and a higher dose of vitamin D3 in maintaining 25-hydroxyvitamin D [ 25(OH)D ] levels at or above 30 ng/mL. METHODS This was a single site , double-blind , r and omized exploratory clinical trial that enrolled adults 65 years of age and older . Within strata of baseline 25(OH)D levels ( < 30 versus ≥ 30 ng/mL ) subjects were r and omized in a 1:2 ratio to receive either 400 or 2,000 IU vitamin D3 daily for 6 months . The main outcome measures were changes in serum 25(OH)D levels according to baseline 25(OH)D levels and dose of vitamin D3 . RESULTS At baseline , 41 of 105 participants ( 39 % ) had low 25(OH)D levels ( < 30 ng/mL ) . After 6 months of vitamin D3 supplementation , 21 of 32 participants ( 66 % ) receiving 400 IU and 14 of 59 participants ( 24 % ) receiving 2,000 IU of vitamin D3 still had low 25(OH)D levels . The largest increases in serum 25(OH)D levels were observed in subjects with baseline levels < 30 ng/mL who received 2,000 IU of vitamin D daily . CONCLUSION Regardless of baseline 25(OH)D level , in persons 65 years of age and older , 6-month vitamin D3 supplementation with 400 IU daily result ed in low 25(OH)D in most individuals , while 2,000 IU daily maintained 25(OH)D levels within an acceptable range in most people on this regimen
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 .