Key words: Peak bone mass Adolescence Vitamin D Calcium Osteoporosis Saudi Arabia. INTRODUCTION . healthy diet during the adolescence will achieve optimal growth by . investigated the inverse relationship between PHT and. Home › Preventing Fractures › Nutrition for Bone Health › Peak Bone Mass and adolescents who have higher PBM reduce their risk of osteoporosis later in life. Between 18 and 25, you reach peak bone mass, the greatest amount of bone you Osteoporosis is a bone-thinning disease that causes your bones to become thin Eating a varied nutrient-rich diet that includes plenty of fruits and vegetables Freedom of Information Law (FOIL) · Forms · Related Sites · Health Topics A to.
The mechanosensation and transduction in osteocytes still involve other factors including nitric oxide NOprostaglandins and ATP. Age and optimal response to loading. Growing bones are usually more responsive to mechanical loading than adult bones. Physical activity increases bone mineral mass accumulation in both children and adolescents. However, the impact appears to be stronger before than during or after the period of pubertal maturation.
The greater gain in aBMD or BMC in young athletes compared with less active controls is preferentially localized in weight bearing bones, such as the proximal femur.
Osteoporosis | Nutrition Australia
Studies in adult elite athletes strongly indicate that increased bone mass gains resulting from intense physical activity during childhood and adolescence are maintained after training attenuates or even completely ceases. Exercise during growth and fracture prevention in adulthood. The question whether the increased PBM induced by physical exercise will be maintained into old age and confer a reduction in fracture rate remains uncertain.
A cross-sectional study of retired Australian elite soccer players suggested that this might not be the case. In the perspective of public health programs aimed at increasing bone mineral mass gain in children and adolescents, it is obvious that only physical exercise of moderate intensity, duration and frequency, but which would still be effective, can be taken into consideration.
In children, prepubertal individuals or those at an early stage of sexual maturation, several interventions implemented within the school curriculum indicate that moderate exercise can impact positively on bone development. Nevertheless, it remains uncertain to what extent the greater aBMD gain in response to moderate and readily accessible weight-bearing exercise is associated with a commensurate increase in bone strength.
Peak bone mass and osteoporosis prevention.
The magnitude of benefit in terms of bone strength will depend upon the nature of the structural change. An effect consisting primarily of an increased periosteal apposition and consecutive diameter will confer greater mechanical resistance than a response limited to the endosteal apposition rate leading essentially to a reduction in the endocortical diameter.
Recent studies suggest site-specific differences in how the pre-pubertal skeleton develops in response to repetitive loading. Role of energy intake and muscle mass development. In healthy subjects, the energy intake is adjusted to increased physical activity. Hence it is difficult to ascribe the additional gain in bone mass to mechanical loading alone.
Indeed, nutrients such as calcium and proteins, that are usually consumed in various amounts in relation to physical activity, could substantially contribute to the positive effect on bone mass acquisition.
The independent mechanical contribution can be measured by the differential effect observed according to the skeletal sites solicited. However, the best evidence of the distinct effect of mechanical loading from concomitant increase in nutritional intakes is provided by studies on the use of rackets, as determined by measuring the difference between loaded and unloaded arms. It has been suggested that the exercise-induced gain in bone mass, size and strength essentially results from an adaptation secondary to the increase in muscle mass and strength.
Impaired bone mass acquisition can occur when intensive physical activity leads to hypogonadism and low body mass. Intake of energy, protein and calcium may be inadequate as athletes go on diets to maintain an idealized physique for their sport. Intensive training during childhood may contribute to a later onset and completion of puberty. Hypogonadism, as expressed by the occurrence of oligomenorrhea or amenorrhea, can lead to bone loss in females who begin training intensively after menarche.
The differential impact of calcium The extent to which variations in the intake of certain nutrients by healthy, apparently well-nourished, children and adolescents affect bone mass accumulation, particularly at sites susceptible to osteoporotic fractures, has received increasing attention over the last 15 years.
Most studies have focused on the intake of calcium. However, other nutrients such as proteins, which are not discussed in this review, should also be considered. In most regions of the world, the supply of calcium is sufficient to avoid the occurrence of clinically manifest bone disorders during growth.
Nevertheless, by securing adequate calcium intake, provided the skin and food supply of vitamin D is adequate, it is expected that bone mass gain can be increased during infancy, childhood and adolescence and thereby optimal PBM can be achieved.
The prevention of adult osteoporotic fractures is the main reason for this widespread preoccupation. International and national agencies have adopted recommendations for calcium intake from infancy to the last decades of life.
Decisions from these recommending bodies can be based on either calcium balance, allowing estimations to be made regarding maximal retention, or on a factorial method that calculates from available data on calcium accretion and endogenous losses modified by fractional absorption.
Observational and interventional studies are also taken into consideration. The recommendations vary widely among regional agencies56 table I. Thus, for children aged years, the recommended daily calcium intakes are set at,and up to mg, in the United Kingdom, the Nordic European countries, France and the United States of America, respectively.
Variability in calcium intake recommendations can be explained partly by the discrepant results obtained in observational and interventional studies.
Retrospective epidemiological data obtained in women aged years, indicated that milk consumption during childhood and adolescence can be positively correlated to bone mineral mass. Several calcium intervention studies have been carried out in children and adolescents. Nevertheless, the response appears to vary markedly according to several factors including the skeletal sites examined, the stage of pubertal maturation, the basal nutritional conditions, i.
The benefit of supplemental calcium was usually greater in the appendicular that in the axial skeleton. In agreement with our longitudinal observation in healthy subjects aged 8 to 19 years figure 6the skeleton appears to be more responsive to calcium supplementation before the onset of pubertal maturation than during the peripubertal period.
Peak bone mass and osteoporosis prevention.
Two co-twin studies strongly suggest that increasing calcium intake after the onset of pubertal maturation above a daily spontaneous intake of about mg does not exert a significant positive effect on bone mineral mass acquisition. This contrasts to the widespread intuitive belief that the period of pubertal maturation with its acceleration of bone mineral mass accrual would be the most attractive time for enhancing calcium intake well above the prepubertal requirements.
As described above efficient adaptive mechanisms secure an adequate bone mineral economy in response to the increased demand of the peripubertal growth spurt. As intuitively expected, the benefit observed at the end of intervention is particularly substantial in children with a relatively low calcium intake. In contrast, the additional gain was minimal in those girls with a relatively high calcium intake. According to the "programming" concept, environmental stimuli during critical periods of early development can provoke long-lasting modifications in structure and function of various biological systems.
The possibility that physical activity could modulate the bone response to dietary calcium supplementation during growth has been considered in infants, children and adolescents.
Overall, the results suggest an interaction: At moderately low calcium intake, the effect may not be positive. Thus, in a longitudinal study in infants months of age, i. In young children aged years, either calcium supplement or gross motor activity increased bone mass accrual as compared to either placebo or fine motor activity.
This regional specificity suggests that the effect of physical activity alone or combined with relatively high calcium supply is not merely due to an indirect influence on the energy intake, which in turn would positively affect bone mass acquisition.
It has not been established whether the type of calcium salt used to supplement diets may modulate the nature of the bone response. The observation that calcium supplementation can increase bone size, at least transiently, has been observed using either milk extracted calcium-phosphate as well as calcium carbonate salt. Another uncertainty is the question of whether gains observed by the end of the intervention are maintained or lost after discontinuation of calcium supplementation.
A clear answer to this question requires long term follow up, since sustained gain even on bone mass and size may be transient, possibly resulting from some indirect influence of calcium supplementation on the tempo of pubertal and thereby bone maturation. The observational and interventional studies discussed above illustrate the numerous factors that can modulate the bone response to calcium intake.
This foregoing analysis may, at least in part, explain the difficulty to reach a scientifically based worldwide consensus on dietary allowance recommendation for children and adolescents. Nevertheless, taking into account both the results of all studies as well as our knowledge on the physiology of calcium and bone metabolism, particularly on the adaptive mechanisms operating during the peripubertal period,61 it appears reasonable and safe to recommend food intake that would provide about mg of calcium per day from prepuberty to the end of adolescence.
Assessment of fracture risk and its application to screening for postmenopausal osteoporosis. Report of a WHO study group. Briot K, Roux C. Best Pract Res Clin Rheumatol ;19 6: Specker BL, Schoenau E. Quantitative bone analysis in children: J Pediatr ; 6: Osteoporos Int ;4 Suppl 1: Familial resemblance for bone mineral mass is expressed before puberty.
J Clin Endocrinol Metab ;83 2: Differential effect of race on the axial and appendicular skeletons of children. J Clin Endocrinol Metab ;83 5: Pathogenesis of bone fragility in women and men.
Longitudinal monitoring of bone mass accumulation in healthy adolescents: Evidence for a marked reduction after 16 years of age at the levels of lumbar spine and femoral neck in female subjects. J Clin Endocrinol Metab ;75 4: Relative contribution of vertebral body and posterior arch in female and male lumbar spine peak bone mass.
Osteoporos Int ;4 5: Vertebral size in elderly women with osteoporosis. Mechanical implications and relationship to fractures.
J Clin Invest ;95 5: Naganathan V, Sambrook P. Gender differences in volumetric bone density: Osteoporos Int ;14 7: Asynchrony between the rates of standing height gain and bone mass accumulation during puberty. Osteoporos Int ;7 6: Fracture patterns in children.
Analysis of 8, fractures with special reference to incidence, etiology and secular changes in a Swedish urban population Acta Orthop Scand Suppl ; Epidemiology of fractures of the distal end of the radius in children as associated with growth.
J Bone Joint Surg ;71 8: Childhood fractures are associated with decreased bone mass gain during puberty: An early marker of persistent bone fragility?
J Bone Miner Res ;21 4: Bonjour JP, Chevalley T. Pubertal timing, peak bone mass and fragility fracture risk. Peak trabecular vertebral density: Calcif Tissue Int ;43 4: Relationship between bone mass and rates of bone change at appendicular measurement sites.
J Bone Miner Res ;7 7: Schweiz Med Wochenschr ;25; Evaluation of a prediction model for long-term fracture risk. J Bone Miner Res. A theoretical analysis of the relative influences of peak BMD, age-related bone loss and menopause on the development of osteoporosis. Osteoporos Int ;14 Structural and biomechanical basis of racial and sex differences in vertebral fragility in Chinese and Caucasians. Construction of the femoral neck during growth determines its strength in old age.
J Bone Miner Res ;22 7: Bone density at various sites for prediction of hip fractures. Meta-analysis of how well measures of bone mineral density predict occurrence of osteoporotic fractures. Br Med J ;18; Reduced bone mass in daughters of women with osteoporosis. N Engl J Med ;2; 9: Bone mass in middle-aged osteoporotic men and their relatives: J Bone Miner Res ;13 Endocr Rev ;20 6: Endocr Rev ;23 3: World Rev Nutr Diet ; Gene-environment interactions in the skeletal response to nutrition and exercise during growth.
Med Sport Sci ; Endocr Rev ;25 3: Reversing sex steroid deficiency and optimizing skeletal development in the adolescent with gonadal failure. The earlier gain and later loss of cortical bone: Assessment of the risk of post-menopausal osteoporosis using clinical factors.
Clin Endocrinol Oxf ;36 3: The effect of gynecological risk factors on lumbar and femoral bone mineral density in peri- and postmenopausal women. Epidemiology of spinal osteoporosis. Spine ; 15;22 24 Suppl: Risk factors for hip fracture in European women: J Bone Miner Res ;10 Relation of early menarche to high bone mineral density. Calcif Tissue Int ;57 1: Factors affecting peak bone density in Japanese women.
Calcif Tissue Int ;64 2: Pubertal timing predicts previous fractures and BMD in young adult men: J Bone Miner Res ;21 5: Interaction between calcium intake and menarcheal age on bone mass gain: An eight-year follow-up study from prepuberty to postmenarche. J Clin Endocrinol Metab ;90 1: Caverzasio J, Bonjour JP. Characteristics and regulation of Pi transport in osteogenic cells for bone metabolism.
Kidney Int ;49 4: Biomechanical and molecular regulation of bone remodeling. Annu Rev Biomed Eng ;8: Mechanical loading reduced osteocyte expression of sclerostin protein. J Bone Miner Res ;21 Suppl 1: The role of calcium in bone health has been extensively reviewed elsewhere 115 — Unfortunately, there are a significant proportion of some population groups failing to achieve the recommended calcium intakes in a number of Western countries Besides the amount of calcium in the diet, the absorption of dietary calcium in foods is also a critical factor in determining the availability of calcium for bone development and maintenance.
Calcium must be released in a soluble, and probably ionized, form before it can be absorbed. Once in a soluble form, calcium is absorbed by 2 routes, transcellular and paracellular transport, and these have been reviewed elsewhere The central feature is that calcium absorption occurs by 2 independent processes, namely transcellular and paracellular transport of calcium across the epithelium.
The paracellular route of calcium absorption involves a passive calcium transport through the tight junctions between mucosal cells see Fig. However, the large intestine may represent a site of increased importance for calcium absorption when acidic fermentation takes place This is important if one remembers that consumption of prebiotics will lead to acidic fermentation in the large intestine. When dietary calcium is abundant, the paracellular pathway is thought to be predominant.
In contrast, when dietary calcium is limited, the active, vitamin D-dependent transcellular pathway plays a major role in calcium absorption. A number of food constituents have been suggested as potential enhancers of calcium absorption. Individual milk components, such as lactose, lactulose, and casein phosphopeptides have in the past attracted considerable attention, and these have been reviewed extensively elsewhere 20 — In addition, there is a growing body of evidence to show that nondigestible oligosaccharides can improve calcium absorption in some life-stage groups.
This evidence base has been reviewed elsewhere 1923 and is the subject of 3 further articles in this Supplement Abrams et al.
Vitamin D is found naturally in very few foods; endogenous synthesis of vitamin D, therefore, which occurs when skin is exposed to UVB radiation from sunlight during summer, is a principal determinant of vitamin D status.
Thus, during the winter months there is an increased reliance on dietary supply of vitamin D. Of concern, vitamin D intakes are low in many populations 25placing many people at risk of low vitamin D status, with possible consequences for bone health.
Vitamin D deficiency is characterized by inadequate mineralization, or demineralization, of the skeleton.