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 ) .
Vitamin D supplementation during infancy is associated with higher bone mineral mass in prepubertal girls.
The objective of this study was to determine whether vitamin D supplementation of breast-fed infants during the first year of life is associated with greater bone mineral content and /or areal bone mineral density ( aBMD ) in later childhood . The design was a retrospective cohort study . One hundred and six healthy prepubertal Caucasian girls ( median age , 8 yr ; range , 7 - 9 yr ) were classified as vitamin D supplemented or unsupplemented during the first year of life on the basis of a question naire sent to participating families and their pediatricians . Bone area ( square centimeters ) and bone mineral content ( grams ) were determined by dual energy x-ray absorptiometry at six skeletal sites . Vitamin D receptor ( VDR ) 3'-gene polymorphisms ( BsmI ) were also determined . The supplemented ( n = 91 ) and unsupplemented ( n = 15 ) groups were similar in terms of season of birth , growth in the first year of life , age , anthropometric parameters , and calcium intake at time of dual energy x-ray absorptiometry . The supplemented group had higher aBMD at the level of radial metaphysis ( mean + /- SEM , 0.301+/-0.003 vs. 0.283+/-0.008 ; P = 0.03 ) , femoral neck ( 0.638+/-0.007 vs. 0.584+/-0.021 ; P = 0.01 ) , and femoral trochanter ( 0.508+/-0.006 vs. 0.474+/-0.016 ; P = 0.04 ) . At the lumbar spine level aBMD values were similar ( 0.626+/-0.006 vs. 0.598+/-0.019 ; P = 0.1 ) . In a multiple regression model taking into account the effects of vitamin D supplementation , height , and VDR genotype on aBMD ( dependent variable ) , femoral neck aBMD remained higher by 0.045 g/cm2 in the supplemented group ( P = 0.02 ) . Vitamin D supplementation in infancy was found to be associated with increased aBMD at specific skeletal sites later in childhood in prepubertal Caucasian girls
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 ) .