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 .
Factors affecting bone density in young adults.
A 14-y follow-up of 581 children who took part in a r and omized controlled trial of the effect of a milk supplement on growth of children was conducted to investigate the supplement 's effect on adult bone mineral content ( BMC ) and density ( BMD ) . BMC and BMD of the nondominant forearm were measured by single-photon absorptiometry in 371 subjects ( 64 % ) aged 20 - 23 y , at a proximal site ( shaft of radius and ulna ) and at a distal site near the wrist .  BMC s and BMDs tended to be higher in the intervention group ( NS ) . Cross-sectionally , BMD was positively associated with body weight ( P less than 0.01 ) in both sexes ; inversely associated with alcohol consumption ( P less than 0.05 ) , and positively with manual occupation ( NS ) in men ; positively associated with current intakes of calcium ( P less than 0.05 ) , vitamin D ( P less than 0.01 ) , and sports activity during adolescence ( P less than 0.01 ) , and inversely with parity ( NS ) in women . In multiple linear-regression analysis body weight and sports activity during adolescence were stronger determinants of female BMD than was diet
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 .