OBJECTIVESTo investigate the effects of calcium and vitamin D supplementation in fortified milk on physical development in Chinese school girls aged 10 - 12 years.

METHODSA non-randomized, double-blind intervention trial was carried out at nine primary schools of Beijing for two years. Seven hundred and fifty-seven girls (with an average age of 10.1 years) were recruited from nine primary schools in Beijing, China. They were divided into three trial groups, a control group (n = 259) having regular diet without milk supplementation, Group 1 (n = 238) having regular diet supplemented with 144 ml/d of calcium-fortified milk, and Group 2 (n = 260) having regular diet supplemented with 144 ml/d of calcium and vitamin D-fortified milk. Data of dietary intake and physical activities were collected by questionnaire, and height, weight, sitting height and knee height were measured before, during and after intervention.

RESULTSTwo years after intervention, the percentage increases in height and weight were significantly greater in Groups 1 and 2 than those in control group (9.52%, 9.26% and 8.59% in height, and 34.53%, 35.38% and 30.91% in weight, respectively). The percentage increase of sitting height was greater in Group 1 than those in Group 2, and then than that in control group (9.21%, 8.58% and 7.87%, respectively). The percentage increase of knee height was significantly greater in Group 1 than that in Group 2 and control group (9.00%, 8.37% and 8.44%, respectively).

CONCLUSIONCalcium and vitamin D-fortified milk supplementation could promote their physical development in girls aged 10 - 12 years.