Whether or not outcomes such as osteoporosis ( or low bone mass ) and specific types of cancer may be prevented by ' generous ' vitamin D supplementation is unclear and mostly based on indirect epidemiologic data not clearly substantiated by r and omized controlled trials SUMMARY The dose of daily vitamin D supplements needed to prevent rickets is probably much lower than that recommended by most expert committees .
PURPOSE OF REVIEW To underst and the basis for current recommendations for  vitamin D supplementation in childhood and the differences between the recommendations published by major expert committees , using the Medline engine of the US National Library of Medicine and the National Institutes of Health .
Most trials have examined the question of whether a specific daily vitamin D dose is capable or not to prevent rickets ( by study ing surrogate markers of rickets ) .
A prospective nested case-control study of vitamin D status and pancreatic cancer risk in male smokers.
Sun exposure is associated with lower death rates for pancreatic cancer in some ecological studies . Skin exposure to UVB light induces cutaneous production of precursors to 25-hydroxyvitamin D [ 25(OH)D ] . Pancreatic islet and duct cells express 25(OH)D(3)-1alpha-hydroxylase that generates the biologically active 1,25(OH)(2 ) vitamin D form . Thus , 25(OH)D concentrations could affect pancreatic function and possibly pancreatic cancer etiology . We conducted a prospect i ve nested case-control study in the Alpha-Tocopherol , Beta-Carotene Cancer Prevention cohort of male Finnish smokers , ages 50 to 69 years at baseline , to test whether more adequate vitamin D status , as determined by prediagnostic serum 25(OH)D concentrations , was associated with lower pancreatic cancer risk . Two hundred incident exocrine pancreatic cancer cases that occurred between 1985 and 2001 ( up to 16.7 years of follow-up ) were matched by age and date of blood draw to 400 controls who were alive and free of cancer at the time the case was diagnosed .  Odds ratios ( OR ) and 95 % confidence intervals ( 95 % CI ) were calculated using conditional logistic regression . Higher vitamin D concentrations were associated with a 3-fold increased risk for pancreatic cancer ( highest versus lowest quintile , > 65.5 versus < 32.0 nmol/L : OR , 2.92 ; 95 % CI , 1.56 - 5.48 , P(trend ) = 0.001 ) that remained after excluding cases diagnosed early during follow-up . Contrary to expectations , subjects with higher prediagnostic vitamin D status had an increased pancreatic cancer risk compared with those with lower status . Our findings need to be replicated in other population s and caution is warranted in their interpretation and implication . Our results are intriguing and may provide clues that further the underst and ing of the etiology of this highly fatal cancer
Whether or not outcomes such as osteoporosis ( or low bone mass ) and specific types of cancer may be prevented by ' generous ' vitamin D supplementation is unclear and mostly based on indirect epidemiologic data not clearly substantiated by r and omized controlled trials SUMMARY The dose of daily vitamin D supplements needed to prevent rickets is probably much lower than that recommended by most expert committees .
PURPOSE OF REVIEW To underst and the basis for current recommendations for  vitamin D supplementation in childhood and the differences between the recommendations published by major expert committees , using the Medline engine of the US National Library of Medicine and the National Institutes of Health .
Most trials have examined the question of whether a specific daily vitamin D dose is capable or not to prevent rickets ( by study ing surrogate markers of rickets ) .