Why is childhood a critical period?
Bones are not static; they are built and broken down throughout life. But the period in which bone mass accumulates fastest is childhood and especially adolescence; most of adult bone mass is gained by the end of puberty. The higher this “peak bone mass”, the lower the risk of bone loss (osteoporosis) in later life. In other words, the foundation laid in childhood is a lifelong investment in bone health.
For this reason, viewing bone health as only an issue for the elderly is misleading. The truly decisive period is childhood and adolescence, when bones grow the most; the nutrition and movement habits of this period leave a lasting effect.
Calcium and vitamin D
Calcium is the basic building block of bone. Its main sources are dairy products such as milk, yoghurt and cheese; as well as green leafy vegetables, sesame/tahini, pulses and calcium-fortified foods. In children who do not consume dairy, importance should be given to these alternative sources and, where needed, to expert support.
Vitamin D, in turn, is needed for calcium to be absorbed from the gut and laid down in bone; even if calcium is adequate, bone health suffers if vitamin D is deficient. The main source of vitamin D is its production in the skin through sunlight; the amount obtained from food is usually limited. Deficiency is common in children who cannot benefit enough from the sun, and supplementation may be needed following a clinician’s assessment.
The role of movement
Bone strengthens by responding to the load placed on it. For this reason, weight-bearing and impact activities — running, jumping, skipping, basketball, dance — are among the strongest stimuli for bone development in childhood. Not only nutrition but also regular movement directly increases peak bone mass.
This is another reason why children’s sport should be considered together with nutrition. An active childhood full of varied movement, combined with balanced nutrition, provides both strong bones and healthy overall development. Conversely, a sedentary lifestyle also limits bone gain.
Risks and points to watch
Some situations can adversely affect bone health. In children who train intensively but do not take in enough energy — especially in female athletes with menstrual irregularity — bone gain can suffer; this is an important picture that should be assessed within the framework of relative energy deficiency (RED-S). Sugary drinks taking the place of milk, very restrictive diets and inactivity also limit bone health.
The way to support bone health is not miracle products but balanced, calcium-rich nutrition, adequate vitamin D, regular weight-bearing movement and a healthy energy balance. If there is a clear concern about nutrition or bone health, consulting a paediatrician or dietitian is the right step. It should be remembered that bone health is shaped not by a single nutrient or supplement but by the whole of nutrition, movement and general health habits. Because the foundation laid in childhood directly affects bone health in later life, the habits built today are in fact a long-term investment.