Serum 25-hydroxyvitamin D levels among Mexican children ages 2 y to 12 y: a national survey.

Objective: The aim of this study was to assess the vitamin D status in preschool and school-age children in Mexico.

Methods: 25-hydroxyvitamin D (25-OH-D) serum concentrations were measured using a direct enzyme-linked immunosorbent assay commercial kit in a nationally representative sample of 1025 Mexican children ages 2 y to 12 y who participated in the 2006 Mexican National Health and Nutrition Survey.

Results: Mean serum 25-OH-D concentration was 94.6 ± 47 nmol/L. Concentrations were lower in preschool children (2-5 y; 78.3 ± 37 nmol/L) than in school-aged children (6-12 y; 105.8 ± 51 nmol/L; P < 0.001). Children living in urban areas had lower levels (89.8 ± 36 nmol/L) than children from rural areas (108.1 ± 75 nmol/L; P < 0.05). Twenty-four percent of preschool children had vitamin D deficiency (25-OH-D < 50 nmol/L) compared with 10% of school-aged children (P < 0.05). Thirty percent of preschool children had vitamin D insufficiency (25-OH-D 50-74.9 nmol/L) compared with 18% of school-aged children (P < 0.05). In urban areas, 18% of children had vitamin D deficiency and 25% had insufficiency compared with 10% and 16% of children in rural areas, respectively (P < 0.05). Prevalence of severe vitamin D deficiency (25-OH-D < 20 nmol/L) was extremely low (0.3%).

Conclusions: Vitamin D deficiency and insufficiency are important public health problems in Mexican children.