Vitamin D and attainment of peak bone mass among peripubertal Finnish girls: a 3-y prospective study

Abstract

Pubertal girls with hypovitaminosis D seem to be at risk of not reaching maximum peak bone mass, particularly at the lumbar spine. Dietary enrichment or supplementation with vitamin D should be considered to ensure an adequate vitamin D status.

Adverse interaction of low-calcium diet and low 25(OH)D levels on lumbar spine mineralization in late-pubertal girls

“…Low calcium intake is known to increase the efficiency of calcium absorption in adolescents. (46) One possible explanation would be that this adaptive mechanism, because it depends on 1,25-dihydroxyvitamin D 3 [1,25(OH) 2 The proposed threshold of 40 nmol/L for serum 25(OH)D levels to enable optimal lumbar spine mineralization during late puberty, even in low-calcium, low-dairy-product conditions, is similar to thresholds proposed earlier for optimal bone mass accrual during growth: 25 TO 30 nmol/L (9,10,13,35,36) or 40 to 50 nmol/L. (10,11) Given the small size of the subgroup with low calcium and low 25(OH)D levels, it was not possible to single out the negative impact of low 25(OH)D levels from that of other factors associated with winter-spring (eg, lower ultraviolet light energy, qualitative difference in sport activities, or diet).…”

“…(9)(10) But the consequences of low 25(OH)D levels are less clear on trabecular bone sites, such as hip, upper femur, and lumbar spine. (8,9,12,13) At the lumbar spine, one longitudinal observational study (13) and two randomized, placebo-controlled studies (42,43) suggest that low 25(OH)D levels may impair bone mass acquisition during the early phase of puberty, but not in girls with more advanced sexual maturation. In contrast, numerous reports have shown the negative impact of low intake of calcium/dairy products on girls' trabecular bone after menarche.…”

“…(1)(2)(3)(4)(5)(6) But data on a possible impact of low vitamin D status are less convincing. (7,8) Indeed, associations between low 25-hydroxyvitamin D [25(OH)D] levels, below 25 to 30 nmol/L (9) or 40 to 45 nmol/L, (10,11) and impaired bone mineralization have been observed at appendicular sites (ie, tibia and forearm) in girls during growth but not at trabecular bone sites (eg, hip, femoral neck, or lumbar spine) (9,12,13) or only during the early phase of puberty in severely vitamin D-deficient girls with 25(OH)D levels below 20 nmol/L. (13) Serum 25(OH)D levels are considered the best marker of vitamin D status and have been used commonly to assess the prevalence of vitamin D deficiency/insufficiency in healthy children and adolescents.…”

“…(7,8) Indeed, associations between low 25-hydroxyvitamin D [25(OH)D] levels, below 25 to 30 nmol/L (9) or 40 to 45 nmol/L, (10,11) and impaired bone mineralization have been observed at appendicular sites (ie, tibia and forearm) in girls during growth but not at trabecular bone sites (eg, hip, femoral neck, or lumbar spine) (9,12,13) or only during the early phase of puberty in severely vitamin D-deficient girls with 25(OH)D levels below 20 nmol/L. (13) Serum 25(OH)D levels are considered the best marker of vitamin D status and have been used commonly to assess the prevalence of vitamin D deficiency/insufficiency in healthy children and adolescents. (9,10,(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26) However, a clear understanding of the biologic significance of given concentrations of circulating 25(OH)D is still lacking, and reference ranges for vitamin D are being reassessed on the basis of what constitutes a normal concentration compared with optimal concentrations.…”

Persistent Effect of Vitamin D Supplementation on Musculoskeletal Parameters in Adolescents One Year After Trial Completion

“…(5) Therefore, an adequate intake of vitamin D during childhood and adolescence is necessary to enhance intestinal calcium absorption and ensure normal bone mineralization. (5) Several trials have investigated means to maximize peak bone mass through lifestyle measures, by increasing physical activity or emphasizing on dairy products consumption or supplementation of calcium and vitamin D. (1,(6)(7)(8)(9) Two randomized trials using calcium-fortified milk demonstrated increments in bone mass in adolescent Chinese girls and Gambian boys, but could not demonstrate residual effect after trial completion. (10,11) Our group had previously reported on the beneficial effects of vitamin D supplementation in adolescent girls, (12) but not boys, (13) on bone mineral content (BMC), bone mineral density (BMD), and lean mass, in a 1-year trial that compared two doses of vitamin D (low dose ¼ 200 IU/day; high dose ¼ 2000 IU/day) to placebo.…”