Science Daily — Calcium supplements have very little benefit for preventing fractures in childhood and later adulthood, concludes a study in the British Medical Journal
Children taking such supplements are have only small improvements in bone density, which are unlikely to reduce fracture risk, says the study carried out by researchers at the Menzies Research Institute in Australia and other approaches could be more beneficial such as increasing vitamin D concentrations and eating more fruit and vegetables.
Osteoporosis is a major public health problem, particularly in women, and low bone mineral density is an important risk factor for osteoporotic fractures. Bone density worsens for women after the menopause, so intervention in childhood to maximise peak bone mass by improving factors such as diet and physical activity can minimise the impact of bone loss related to age.
The researchers analysed the findings of 19 different studies involving 2,859 children collectively aged between three and 18. They included randomised trials of calcium supplementation in healthy children that lasted at least three months and which measured bone outcomes after at least six months of follow-up.
They found there was a small effect on total body bone mineral content and upper limb bone mineral density -- children taking the supplements only had 1.7% better bone density in their upper limbs than children not taking the supplements.
However, there was no effect at important sites in the body for fracture in later life -- namely the hip and lumbar spine. After children stopped taking calcium supplements, the effect persisted at the upper limb, but disappeared for total body bone mineral content.
The authors conclude: "The small effect of calcium supplementation on bone mineral density in the upper limb is unlikely to reduce the risk of fracture, either in childhood or later life, to a degree of major public health importance. It may be appropriate to explore alternative nutritional interventions, such as increasing vitamin D concentrations and intake of fruit and vegetables.