Vitamin D supplementation had no statistically significant effects on total body bone mineral content or on bone mineral density of the hip or forearm .
It is unlikely that vitamin D supplements are beneficial in children and adolescents with normal vitamin D levels .
OBJECTIVE To determine the effectiveness of vitamin D supplementation for improving  bone mineral density in children and adolescents and if effects vary with factors such as vitamin D dose and vitamin D status .
Vitamin D intake is low and hypovitaminosis D common in healthy 9− to 15-year-old Finnish girls
Objectives : To study the prevalence of hypovitaminosis D , the effect of vitamin D supplementation on serum 25-hydroxyvitamin D [ S-25(OH)D ] , and the intakes of vitamin D and calcium in Finnish 9− to 15-year-old athletic and nonathletic girls . Design : 1-year follow-up study ( February 1997-March 1998 ) with three months of vitamin D supplementation ( 10 μg/d ) from October to January . Setting : Turku University Central Hospital , Finl and .Subjects : 191 female volunteers aged 9–15 y ( 131 athletes and 60 controls ) . Methods :  Vitamin D and calcium intakes were estimated by a four-day food recording and a semi-quantitative food frequency question naire ( FFQ ) . S-25(OH)D was followed by radioimmunoassay ( RIA ) . Results : At baseline the mean S-25(OH)D concentration was 33.9 nmol/l among all girls . In winter severe hypovitaminosis D ( S-25(OH)D<20 nmol/l ) occurred in 13.4 % of the participants and in 67.7 % S-25(OH)D was below 37.5 nmol/l . By the next summer the mean S-25(OH)D concentration was 62.9 nmol/l and in 1.6 % of the subjects it was below 37.5 nmol/l . The prevalence of severe hypovitaminosis D was not significantly reduced by three months of vitamin D ( 10 μg/d ) supplementation . At baseline , the mean intake of vitamin  D was 2.9 μg/d by food recording and 4.3 μg/d by FFQ . The mean calcium intake was 1256 mg/d and 1580 mg/d , respectively . The intakes of vitamin D and calcium remained unchanged during the follow-up period . The athletes consumed more calcium than nonathletic controls , whereas the intake of vitamin D was quite similar among both groups . The vitamin D intake by FFQ correlated with the S-25(OH)D concentration in wintertime ( r=0.28 , P<0.01 ) . Conclusion : Hypovitaminosis D is fairly common in growing Finnish girls in the wintertime , and three months of vitamin D supplementation with 10 μg/d was insufficient in preventing hypovitaminosis D. The daily dietary vitamin D intake was insufficient ( < 5 μg/d ) in the majority of participants , while the calcium intake was usually sufficient . Sponsorship : Supported by the Yrjö Jahnsson Foundation , The Turku University Foundation , and the Medical Research Foundation of the Turku University Central Hospital
Vitamin D supplementation had no statistically significant effects on total body bone mineral content or on bone mineral density of the hip or forearm .
It is unlikely that vitamin D supplements are beneficial in children and adolescents with normal vitamin D levels .
OBJECTIVE To determine the effectiveness of vitamin D supplementation for improving  bone mineral density in children and adolescents and if effects vary with factors such as vitamin D dose and vitamin D status .