ESPE Abstracts

Back ground: The incidence rate of vitamin D deficiency is increasing throughout the world in recent years, but the rate of vitamin D deficiency in Japan is unknown.

Aims: We measured the incidence rate of vitamin D deficiency in 12-year old children in Japan.

Methods: A total of 492 children (247 boys and 245 girls) from one Japanese community enrolled in this study. At age 12, 25 hydroxyvitamin D (25OHD) were measured in all children by using radioimmunoassay. The levels of intact parathyroid hormone (iPTH), calcium (Ca), phosphorus (P), albumin (Alb), alkaline phosphatase (ALP) and fibroblast growth factor 23 (FGF23) were also measured in the subjects who shows low 25OHD level (≦20 ng/ml).

Results: 25OHD levels were significantly lower in girls (20.9±3.1 ng/ml) than in boys (22.2±3.3 ng/ml) (P<0.0001). The number of subjects who showed vitamin D deficiency (<20 mg/ml) were 74 (30.0%) in boys and 111 (45.3%) in girls and severe vitamin D deficiency (<15 ng/ml) were 3 (1.2%) in boys and 8 (3.3%) in girls. The levels of iPTH, Ca, P, Alb, ALP and FGF23 in subjects who showed vitamin D deficiency were 22.3±8.9 pg/ml (range 4–74 pg/ml), 9.5±0.4 mg/dl (8.3–10.7 mg/dl), 4.7±0.6 mg/dl (3.3–6.1 mg/dl), 4.6±0.3 g/dl (3.5–5.2 g/dl), 918.3±340.1 U/l (200–1834 U/l) and 46.5±58.2 pg/ml (12–740 pg/ml), respectively. Only one subject whose 25OHD level was 16 ng/ml showed some little higher levels of iPTH (74 pg/ml) and ALP (1484 IU/L), but normal levels of Ca and P.

Conclusion: We show that 38% of Japanese 12-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.