Vitamin D supplementation had no statistically significant effects on total body bone mineral content ( BMC ) , hip bone mineral density ( BMD ) or forearm BMD .
These results do not support vitamin D supplementation to improve bone density in healthy children with normal vitamin D levels , but suggest that supplementation of deficient children may be clinical ly useful .
BACKGROUND Results of r and omised controlled trials ( RCTs ) of vitamin D supplementation to improve  bone density in children are inconsistent .
OBJECTIVES To determine the effectiveness of vitamin D supplementation for improving  bone mineral density in children , whether any effect varies by sex , age or pubertal stage , the type or dose of vitamin D given or baseline vitamin D status , and if effects persist after cessation of supplementation .
Randomized study of sunshine exposure and serum 25-OHD in breast-fed infants in Beijing, China.
The hypothesis that breastfed infants in Beijing , China , have low vitamin D status and that sunshine exposure increases serum 25-hydroxyvitamin D ( 25-OHD ) concentrations was tested in a r and omized prospect i ve study involving 42 healthy infants 1 - 8 months of age . 24 controls were exposed to the usual amount of sunshine , while the 18 cases were provided with 2 hours of sunshine/day . All infants were being breastfed without vitamin D supplementation .  Serum 25-OHD concentrations at entry into the study ranged from 3 - 61 ng/ml and increased with age . 3 infants in each group were diagnosed as having rickets . Serum 25-OHD concentrations did not change significantly during the 2-month study period among controls , while serum 25-OHD values increased significantly in the experimental group . Final infant serum 25-OHD concentrations correlated with ultraviolet exposure scores ( p.001 ) . The estimate of ultraviolet score needed to maintain a serum 25-OHD of 11 ng/ml was 2.4 ( 24 minutes/day with only the face uncovered ) . Rickets has been reported in as many as 18 % of Chinese infants and seems to especially affect those 2 - 4 months of age . The fact that not all infants with rickets in this study had low 25-OHD concentrations suggests 2 possibilities : 1 ) not all rickets is necessarily related to a vitamin D deficiency , or 2 ) serum 25-OHD concentrations are not the best indicator of vitamin D status . The low serum 25-OHD concentrations in many Chinese infants may be related to low maternal milk vitamin D content result ing from the lack of vitamin D food fortification . Overall , these results suggest that the diet of breastfed Chinese infants should be supplemented with orally administered vitamin
Vitamin D supplementation had no statistically significant effects on total body bone mineral content ( BMC ) , hip bone mineral density ( BMD ) or forearm BMD .
These results do not support vitamin D supplementation to improve bone density in healthy children with normal vitamin D levels , but suggest that supplementation of deficient children may be clinical ly useful .
BACKGROUND Results of r and omised controlled trials ( RCTs ) of vitamin D supplementation to improve  bone density in children are inconsistent .
OBJECTIVES To determine the effectiveness of vitamin D supplementation for improving  bone mineral density in children , whether any effect varies by sex , age or pubertal stage , the type or dose of vitamin D given or baseline vitamin D status , and if effects persist after cessation of supplementation .