Many gaps exist in our understanding of the role of nutrition and other lifestyle variables during the growing years on lifelong bone health. The difficulty in measuring bone changes during growth is a major barrier to our understanding of environmental effects. Changes in bone size are difficult to monitor with two-dimensional images such as those obtained by bone densitometry. Apparent bone density changes may reflect changes in bone size rather than bone density. Volumetric bone density measures, if they can be made at appropriate sites with acceptable radiation exposure, will provide the next generation of outcome measures for assessing interventions. Quantitative ultrasound measures are being explored for use in children as a potential measure of bone quality, but the interpretation of the measures is as of yet unknown. It is difficult to follow the effects of adolescent nutrition into adulthood. Most work in children is observational in nature, rather than involving a rigorous intervention. Published randomized placebo-controlled trials are relatively short in duration. It is unknown whether short term increases in the rate of bone accretion due to dietary interventions such as calcium result in greater increases in peak bone mass or if the peak is merely achieved earlier. During the pubertal growth spurt, hormonal changes may overwhelm any lifestyle interventions, as seems to be the situation during menopause, a much more studied phenomenon. We know so little about interactions of nutrients with other parameters during growth. Important areas for further research include nutrient-gene interactions, nutrient-exercise interactions, and nutrient-nutrient interactions. How do genetics determine who will respond to dietary supplementation? Will exercise increase bone size without sufficient calcium? Does an active lifestyle modify nutrient requirements? When considering the role of childhood and adolescent nutrition in lifelong bone health, we may not know precise requirements, but the risks lie with insufficient nutrient intakes, with the exception of energy. Therefore, clinicians should take an active role in assessing the diets of all patients, but especially for adolescents whose skeletal demands are so great. Research on behavior modification to achieve appropriate lifestyle choices in this age group is urgent. Strategies to instill healthy habits before this age are equally important, and they may be more effective. The benefits are potentially great. Variations in calcium nutrition in early life may account for as much as 50% of the difference in hip fracture rates in postmenopausal years (31). Taking calcium-rich products with every meal goes a long way toward ensuring that requirements are met for many bone-related nutrients, including calcium, magnesium, phosphorus, and vitamin D. However, we need more alternative strategies for many individuals, including fortified foods and palatable supplements. Evidence is compelling that inadequate nutrition during puberty results in suboptimal peak bone mass, which, in turn, increases the risk of fracture in childhood and later in life.
ASJC Scopus subject areas
- Endocrinology, Diabetes and Metabolism
- Clinical Biochemistry
- Biochemistry, medical