Benefits of milk powder supplementation on bone accretion in Chinese children

Low dietary calcium intake has been demonstrated to be a risk factor for hip and vertebral fractures in studies conducted among Hong Kong Chinese. Few studies have demonstrated the effect of milk supplementation in bone accretion in Chinese children. The aim was to examine the effects of milk powder supplementation in enhancing bone accretion in Chinese children. Three hundred and forty-four children, aged 9-10 years old, were randomized to receive milk powder equivalent to 1300 mg and 650 mg calcium, and to a control group, respectively. Bone mineral density (BMD) at the proximal femur, lumbar spine and total body were measured at 6 months, 12 months and 18 months. The treatment effects were modeled using linear mixed effect models and compared using linear contrast F-tests, by intention-to-treat. Subjects randomized to milk powder equivalent to 1300 mg calcium had significantly higher increase in BMD at both the total hip (7.4+/-0.4% in treatment group versus 6.3+/-0.4% in the control) and the spine (8.4+/-0.5% in the treatment group versus 7.0+/-0.5% in the control group). Subjects randomized to milk powder equivalent to 650 mg calcium had smaller increases in BMD at the total hip and spine, although the increase in BMD at the total body was significantly higher (3.1+/-0.3% in treatment group versus 2.4+/-0.2% in controls). It is concluded that supplementing the diet of Chinese children with milk powder was effective in enhancing bone accretion.