Higher serum 25-hydroxyvitamin D levels in school-age children are inconsistently associated with increased calcium absorption.
J Clin Endocrinol Metab
; 94(7): 2421-7, 2009 Jul.
Article
em En
| MEDLINE
| ID: mdl-19383779
ABSTRACT
CONTEXT Increasing serum 25-hydroxyvitamin D (25-OHD) in adults may enhance calcium absorption (Ca-abs). There are few similar pediatric data leading to uncertainty about the optimal target for 25-OHD to maximize Ca-abs. OBJECTIVE:
Our objective was to evaluate the relationship between 25-OHD and Ca-abs in a large cohort of school-age children and adolescents.DESIGN:
We evaluated data from 439 Ca-abs measurements performed using dual-tracer stable isotope techniques conducted at our center over a 15-yr period in 251 healthy children, 4.9-16.7 yr of age.RESULTS:
Serum 25-OHD ranged from 28 to 197 nmol/liter (mean 85 +/- 2 nmol/liter) (sem). Total Ca-abs (intake times fractional absorption) were significantly correlated to 25-OHD in the whole population (r = 0.16, P = 0.001). This relationship was closer in the 197 studies in early puberty (Tanner 2 or 3, r = 0.35, P < 0.001) and not significant in pre- or late pubertal subjects. For the whole population, fractional Ca-abs adjusted for calcium intake were slightly but significantly higher at 25-OHD of 28-50 nmol/liter (0.344 +/- 0.019) compared with 25-OHD of 50-80 nmol/liter (0.280 +/- 0.014) or 25-OHD greater than 80 nmol/liter (0.297 +/- 0.015, P < 0.01 for each), suggesting adaptation to moderately low 25-OHD values.CONCLUSION:
There is no consistent pattern of relationship between 25-OHD and either fractional or total calcium absorption in school-age children. However, there appears to be a modest calcium absorptive response to higher 25-OHD during early puberty.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Vitamina D
/
Cálcio
Idioma:
En
Ano de publicação:
2009
Tipo de documento:
Article