The Effects of Dairy Product Supplementation on Bone Health Indices in Children Aged 3 to 18 Years: A Meta-Analysis of Randomized Controlled Trials

Abstract

Childhood and adolescence are critical periods for optimizing skeletal growth. Dairy products are valuable sources of bone-beneficial nutrients, particularly calcium and protein. A random-effects meta-analysis of published randomized controlled trials was performed to quantitatively assess the effects of dairy supplementation on bone health indices in children and adolescents. The PubMed and Web of Science databases were searched. Dairy supplementation increased whole-body bone mineral content (BMC) (+25.37 g) and areal bone mineral density (aBMD) (+0.016 g/cm²), total hip BMC (+0.49 g) and aBMD (+0.013 g/cm²), femoral neck BMC (+0.06 g) and aBMD (+0.030 g/cm²), lumbar spine BMC (+0.85 g) and aBMD (+0.019 g/cm²), and height (0.21 cm). When expressed as a percentage difference, whole-body BMC was increased by 3.0%, total hip BMC by 3.3%, femoral neck BMC by 4.0%, lumbar spine BMC by 4.1%, whole-body aBMD by 1.8%, total hip aBMD by 1.2%, femoral neck aBMD by 1.5%, and lumbar spine aBMD by 2.6%. Dairy supplementation increased serum insulin-like growth factor I concentrations (19.89 nmol/L) and reduced concentrations of urinary deoxypyridinoline (-1.78 nmol/mmol creatinine) and serum parathyroid hormone (-10.46 pg/mL) but did not significantly affect the serum concentrations of osteocalcin, bone alkaline phosphatase, and C-terminal telopeptide of type 1 collagen. Serum 25-hydroxyvitamin D concentrations (+4.98 ng/mL) increased with vitamin D-fortified dairy supplementation. The positive effects on bone mineral mass parameters and height were generally consistent across subgroups defined by sex, geographical region, baseline calcium intake, calcium from the supplementation, trial duration, and Tanner stages. In summary, dairy supplementation during growth leads to a small but significant increase in bone mineral mass parameters, and these findings are generally supported by the changes in several biochemical parameters related to bone health.

Keywords: bone; calcium; dairy; growth; milk; pediatric.

FIGURE 1

The weighted mean difference (WMD) (95% CI) in bone mineral content between dairy product and control groups in children/adolescents. All data are expressed in g.

FIGURE 2

The weighted mean difference (WMD) (95% CI) in bone mineral density between dairy product and control groups in children/adolescents. All data are expressed in g/cm².

FIGURE 3

The weighted mean difference (WMD) (95% CI) in height between dairy product and control groups in children/adolescents. All data are expressed in cm.

FIGURE 4

The weighted mean difference (WMD) (95% CI) in the concentrations of osteocalcin, bone alkaline phosphatase (BALP), deoxypyridinoline (Dpd), C-terminal telopeptide of type 1 collagen (CTx), parathyroid hormone, 25-hydroxyvitamin D (25(OH)D), and IGF-I between dairy product and control group in children/adolescents. The data are expressed in ng/mL for osteocalcin, CTx, and 25(OH)D; μg/L for BALP; nmol/mmol creatinine for Dpd; pg/mL for parathyroid hormone; and nmol/L for IGF-I.