Current guidelines provide a universal recommendation on vitamin D intake to prevent insufficiency. However, the relative influence of food, UVB and other factors on serum 25-hydroxyvitamin D (25(OH)D) insufficiency has been poorly investigated in preschool children. We assessed serum 25(OH)D quantities and their association with vitamin D intake using a brief-type self-administered diet history questionnaire for children aged 3-6 years (BDHQ3y), outdoor playing time and background UVB radiation level among 574 36-month-old Japanese children living at latitude 35∞N. The average serum 25(OH)D concentration was 23∑5 (sd 6∑1) ng/ml, and 170 (29∑6 %) children had vitamin D insufficiency (<20 ng>
Serum 25-hydroxyVitamin D levels showed strong seasonality but lacked association with Vitamin D intake in 3-year-old Japanese children
