Incidence rate of vitamin D deficiency and FGF23 levels in 12- to 13-year-old adolescents in Japan

Abstract

Introduction The incidence rate of vitamin D deficiency is increasing throughout the world. We measured the incidence rate of vitamin D deficiency and fibroblast growth factor 23 (FGF23) levels in 12-to 13-year-old adolescents in Japan. Materials and methods A total of 492 adolescents (247 boys and 245 girls) from Japanese community enrolled in this study. 25 hydroxyvitamin D (25(OH)D) was measured with radioimmunoassay. In the subjects with low 25(OH)D levels (≦ 20 ng/ ml), intact parathyroid hormone (iPTH), calcium (Ca), phosphorus (P), albumin (Alb), alkaline phosphatase (ALP) and FGF23 were measured. Results 25(OH)D levels were significantly lower in girls (20.9 ± 3.1 ng/ml) than in boys (22.2 ± 3.3 ng/ml) (p < 0.0001). Fifty-five boys (22.3%) and 83 (33.9%) girls showed vitamin D deficiency (< 20 ng/ml). One-hundred eighty-six (75.3%) boys and 162 (66.1%) girls showed vitamin D insufficiency (≧ 20 ng/ml, < 30 ng/ml). In the subjects whose 25(OH)D levels were ≦ 20 ng/ml, the levels of iPTH, Ca, P, Alb, ALP and FGF23 were 22.3 ± 9.0 pg/ml, 9.5 ± 0.4 mg/dl, 4.7 ± 0.6 mg/dl, 4.6 ± 0.3 g/dl, 920.8 ± 339.3 U/l and 42.6 ± 26.0 pg/ml, respectively. There was a significant negative association between serum 25(OH)D levels and iPTH [r = − 0.290 (p < 0.0001)]. There was no significant association between serum 25(OH) D levels and FGF23. Conclusion We show that 28% of Japanese 12-to 13-year-old early adolescents suffer from vitamin D deficiency. Findings from this study indicate that vitamin D deficiency requires close oversight in public health during adolescence to ensure proper bone health.

Severe 25-Hydroxyvitamin D Deficiency May Predict Poor Renal Outcomes in Patients With Biopsy-Proven Diabetic Nephropathy

“…In consist with previous studies, we confirmed that 25(OH)D is associated with the serum level of calcium ( 29 ) and PTH ( 30 ). Low level of 25(OH)D is usually related to the clinical symptoms of vitamin D deficiency ( 31 ).…”

Mineral Metabolism in Children: Interrelation between Vitamin D and FGF23

“…There are limited data about mineral metabolism variables in healthy children due to the complexity of the sample that involves changes inherent to growth and development and the difficulties involved in studies in the pediatric population compared to the adult population (difficulties in recruiting a large number of healthy participants and issues in collecting adequate blood volumes, particularly from very young children). Table 1 provides information on calcium, phosphate, PTH, vitamin D metabolites, FGF23 and Klotho in healthy children on the basis of published findings meeting the necessary criteria to be considered as reference laboratory values [ 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 ].…”

“…Despite the metabolic connection between FGF23 and vitamin D, little is known about the status of FGF23 and Klotho in individuals with rickets induced by vitamin D deficiency. A study in 492 healthy Japanese adolescents found that 28% are vitamin D deficient and there is no significant correlation between serum concentrations of 25OHD and FGF23 [ 21 ]. In contrast, Kubota et al [ 49 ] found low serum FGF23, less than 19 pg/mL, in patients with vitamin-D-deficient rickets.…”